Nonvolatile Memory Thin-Film Transistors Using Biodegradable

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Nonvolatile Memory Thin-Film Transistors Using Biodegradable Chicken Albumen Gate Insulator and Oxide Semiconductor Channel on Eco-Friendly Paper Substrate So-Jung Kim, Da-Bin Jeon, Jung-Ho Park, Min Ki Ryu, JongHeon Yang, Chi-Sun Hwang, Gi-Heon Kim, and Sung Min Yoon ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/am508834y • Publication Date (Web): 13 Feb 2015 Downloaded from http://pubs.acs.org on February 16, 2015

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ACS Applied Materials & Interfaces

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Nonvolatile Memory Thin-Film Transistors Using 8

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Biodegradable Chicken Albumen Gate Insulator and 12

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Oxide Semiconductor Channel on Eco-Friendly 17

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Paper Substrate 21

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So-Jung Kim1, Da-Bin Jeon1, Jung-Ho Park1, Min-Ki Ryu2, Jong-Heon Yang1, Chi-Sun Hwang2, 26 27

Gi-Heon Kim2, and Sung-Min Yoon1* 28 29 30 1

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Department of Advanced Materials Engineering for Information and Electronics,

Kyung Hee University, Yongin, Gyeonggi-do 446-701, Republic of Korea 35

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Information & Communication Core Technology Research Laboratory,

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Electronics & Telecommunications Research Institute, Daejeon 305-730, Republic of Korea 39

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KEYWORDS: eco-friendly device, nonvolatile memory, paper substrate, chicken albumen 43

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dielectric, oxide semiconductor 4 45 46 47 48 50

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Abstract: Nonvolatile memory thin-film transistors (TFTs) fabricated on paper substrates were 52

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proposed as one of the eco-friendly electronic devices. The gate stack was composed of chicken 54

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albumen gate insulator and In-Ga-Zn-O semiconducting channel layers. All the fabrication 5 57

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processes were performed below 120 oC. To improve the process compatibility of the synthethic 58 59 60 ACS Paragon Plus Environment

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paper substrate, an Al2O3 thin film was introduced as adhesion and barrier layers by atomic layer 5

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deposition. The dielectric properties of biomaterial albumen gate insulator were also enhanced by 6 7

the preparation of Al2O3 capping layer. The nonvolatile bi-stabilities were realized by the 10

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switching phenomena of residual polarization within the albumen thin film. The fabricated device 12

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exhibited a counterclockwise hysteresis with a memory window of 11.8 V, high on/off ratio of 13 14

approximately 1.1×106, and high saturation mobility (μsat) of 11.5 cm2/Vs. Furthermore, these 17

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device characteristics were not markedly degraded even after the delamination and under the 19

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bending situration. When the curvature radius was set as 5.3 cm, the ION/IOFF ratio and μsat were 20 21

obtained to be 5.9×106 and 7.9 cm2/Vs, respectively. 23

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1. Introduction 31

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The environmental sustainability is one of the most critical demands for the next-generation 32 3

electronic industries.1,2 Therefore, high-performance electronic devices prepared on paper 36

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substrates have attracted huge interests as a promising technology to replace currently-used plastic37 38

based electronic devices. The mechanical features of the paper substrate also provide a higher 39 41

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degree of freedom in folding as well as in bending capability for flexible electronic systems. 3-5 43

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Furthermore, the cost-effective and eco-friendly natures of the paper substrates secure the 4 45

additional benefits. In recent days, various devices fabricated on paper substrates have been 46 48

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reported for their promising features such as low-voltage operation, low-power consumption, and 50

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data storage function.6-10 However, the paper device performances were typically poor compared 51 53

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with those for the devices on glass or plastic substrate. Most biodegradable paper substrates suffer 5

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from several critical problems for electronic device applications, such as water absorption, low 56 57 58 59 60 ACS Paragon Plus Environment

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heat resistance, and rough surface morphology. These limitations make it difficult to fabricate 5

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high-resolution thin-film transistor (TFT) arrays by using conventional photolithography and 6 7

etching processes.11 From these backgrounds, in this work, a synthetic paper, YUPO® (synthesized 10

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by YUPO Corp.), made of polypropylene as a main ingredient, was chosen as a eco-friendly 1 12

flexible substrate due to its high thermal durability and hydrophobic nature required for the wet13 15

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chemical-based full-patterning process using photolithography techniques. The choice of YUPO 17

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substrate is the first strategy of this work to solve the problems of conventional papers for the 18 19

device fabrication and to improve the device characteristics through optimized fabrication 20 2

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procedures. 24

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On the other hand, the TFTs have been major workhorses for large-area electronics implemented 25 27

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on various substrates and they can be played as switching and memory devices. It would be 29

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interesting to introduce eco-friendly biodegradable materials to device components such as gate 31

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insulator (GI). Chicken albumen is one of the promising candidates. It can be easily and cheaply 32 34

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obtained from eggs without any additional process. The albumen layer can be comfortably formed 36

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by spin coating. The basic device characteristics for the oxide TFTs using chicken albumen gate 38

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dielectric was previously demonstrated.11-12 In this work, we proposed the nonvolatile memory 39 41

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TFTs using chicken albumen as a GI on the eco-friendly YUPO paper substrate. The memory TFT 43

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can also be an important element to realize highly-functional future electronic systems composed 4 45

of eco-friendly biodegradable devices. The nonvolatile bi-stability of the proposed memory TFT 46 48

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originated from the residual polarization effect of the albumen GI, which is analogous to the 50

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ferroelectric field-effect-driven memory transistor. This is the second strategy of this work to 51 53

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provide memory functions to the eco devices fabricated on the paper substrates. Thus, the main 5

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object of this work is to fabricate the reliable memory TFTs with the gate-stack structure of 56 57 58 59 60 ACS Paragon Plus Environment

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biodegradable albumen GI and oxide semiconductor channel on the eco-friendly YUPO paper 5

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substrate and demonstrate their nonvolatile memory performances. This is the first eco-paper 6 8

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memory TFT. 9 1

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2. Experimental Section 13

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A 300-μm-thick polypropylene-based synthetic paper YUPO® (synthesized by YUPO® ) was 14 16

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chosen as a paper substrate. Comparing with the conventional cellulose-based paper, it was 18

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featured to have a hydrophobic property and a better thermal stability. Thanks to these beneficial 19 20

features, all the patterning processes for device fabrications could be carried out by conventional 21 23

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photolithography and wet etching processes. As the first step, the YUPO substrate was laminated 25

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onto the glass substrate to facilitate the substrate handling. Then, a 3.6-μm-thick barrier layer (TR26 28

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8857-SA7, synthesized by Dongjin Semichem. Co. Ltd) was spin-coated to reduce the surface 30

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roughness. A 30-nm-thick Al2O3 was deposited as an adhesion layer by atomic layer deposition 32

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(ALD), which was introduced to improve the adhesion between the organic barrier layer and S/D 3 35

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electrodes. A 150-nm-thick ITO was deposited by RF magnetron sputtering and patterned into the 37

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S/D electrodes. An In-Ga-Zn-O (IGZO, 50 nm) was deposited as an active channel layer. Then, a 38 39

200-nm-thick diluted chicken albumen was spun with 4000 rpm for 30 s. Thermal treatment for 40 42

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curing and cross-linking was carried out at 120 °C for 10 min. Here, it was proposed to prepare an 4

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Al2O3 capping layer onto the albumen GI, which has important roles in protecting the albumen 45 46

from the following patterning processes and in enhancing the adhesion between the gate electrodes. 47 49

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Finally, an Al film was deposited by thermal evaporation and patterned as gate electrodes and S/D 51

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pads. The electrical characteristics of the fabricated devices were evaluated by using a 52 54

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semiconductor parameter analyzer (Keithley 4200SCS) in a dark box at room temperature. 56

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Channel width and length of measured TFTs were 40 and 20 μm, respectively. 57 58 59 60 ACS Paragon Plus Environment

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3. Results and discussions 6 7 8 10

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3.1. Optimization of fabrication process for the eco-paper memory TFTs 1 12 13 15

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The fabrication process of diluted albumen solution was shown in Figure 1a. The chicken white 17

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was separated and diluted by deionized water with a mixing ratio of 1:1. The precursor solution of 18 19

albumen was finally prepared by stirring for 1 hour at room temperature on a hot plate to obtain 20 2

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its homogeneity. Figure 1b shows the polarization-electric field (P-E) characteristics of the 24

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fabricated Al/Al2O3/albumen/ITO capacitor. The top electrode diameter was 100 μm and the signal 25 26

frequency was 100 Hz. The remnant polarization (Pr) and the coercive field (Ec) were 0.97 μC/cm2 27 29

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and 1.2 MV/cm, respectively. It was suggested that residual polarization could be induced within 31

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the albumen film as if ferroelectric dipoles existed, and that the nonvolatile bi-stability could be 32 34

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generated by remnant values of induced polarization for our proposed eco-paper memory TFT. In 36

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order to evaluate the effct of temperature on the protein denaturation of albumen and the 37 38

corresponding P-E characteristics of the capacitors, the annealing temperature for the albumen was 39 41

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increased to 150 and 180 o C. As a result, the residual polarization dramatically disappered when the albumen film was annealed above the temparture of 150 o C. Thus, the temperature of 120 o C, 4 45

employed in this work, was concluded to be an optimum point for device fabrication and memory 46 48

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operations. The relative dielectric constant of the albumen layer was estimated from capacitance50

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frequency measurements to be approximately 15 at 1 MHz. Futhermore, we estimated the 51 53

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wettability of the albumen solution on YUPO (Figure 1c) and Al 2O3-coated YUPO substrates 5

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(Figure 1d) by measuring the contact angles. As can be seen in figures, the contact angle was 56 57 58 59 60 ACS Paragon Plus Environment

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reduced from 92.4 to 63.1o on the Al2O3-coated YUPO substrate. This result suggests that the 5

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wettability of the YUPO substrate to the albumen solution was significantly improved by 6 8

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suitability introducing the Al2O3 barrier layer. 10

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In order to fabricate the devices on YUPO substrate, the surface roughness should be carefully 1 12

controlled. Figure 2a shows the AFM images of the bare surface of YUPO substrate, in which the 13 15

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arithmetic average of absolute roughness (Ra) value was approximately 22.3 nm and surface 17

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morphology was rather inhomogeneous. Thus, the barrier layer was introduced to reduce the 18 19

surface roughness. The Ra value for the barrier-coated substrate was markedly improved to 0.34 20 2

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nm, as shown in Figure 2b. The introduction of adhesion layer was also one of the most important 24

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features of the device fabrication process proposed in this work. Figures 2c-d show the microscopic 25 27

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images for the situations of source/drain (S/D) patterning before and after the 30-nm-thick Al2O3 29

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layer was prepared on the barrier layer, respectively. Sound patterns were obtained only on the 31

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adhesion layer. Figures 2e-g show a schematic cross-section, cross-sectional SEM image, and 32 34

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optical microscope image of the fabricated albumen-paper memory TFT, respectively. The device 36

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was confirmed to be well fabricated, in which every layer composing the device configuration was 37 38

obviously defined. 39 40 41 43

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3.2. Device characterizations for the eco-paper memory TFTs 4 45 46 48

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The capping layer (CL) of Al2O3 (10 nm) was prepared to protect the albumen GI during the 50

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fabrication process. The leakage current density of albumen layer was examined to be not so 52

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appropriate (3.2×10-5 A/cm2 at 0.23 MV/cm) for the GI application and it was additionally 53 5

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degraded after the wet process using a resist stripper, as shown in Figure 3a. On the contrary, the 56 57 58 59 60 ACS Paragon Plus Environment

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CL-treated albumen layer exhibited excellent insulating characteristics, in which the leakage 5

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current densities were effectively suppressed to 9.0×10-9 and 5.5×10-8 A/cm2 before and after the 6 7

resist strip process, respectively. The introduction of the CL was clearly found to have beneficial 10

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impact in enhancing the dielectric insulation property and protecting from the chemical damages 12

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for the albumen layer. Figure 3b shows the drain current-gate voltage (IDS-VGS) characteristics and 13 14

gate leakage currents of the fabricated albumen-paper memory TFT with the gate width and length 17

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of 40 and 20 μm. Transfer characteristics were measured in the double sweep mode of V GS from 19

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20 to 20 V at VDS of 0.5 V and 5.5 V. We calculated the device parameters by using accumulation 20 2

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capacitance values measured at 10 kHz, as shown in Figure 3c. Although off-current levels were 24

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relatively high, the on/off switching behavior could be clearly obtained. The Ion/Ioff ratio was 26

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approximately 1.1×106. The saturation mobility (μsat) and threshold voltage (VTH) were evaluated 27 29

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to be 11.5 cm2/Vs and 2.5 V, respectively, which were calculated from the derivative and x-axis 31

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intercept of (IDS)0.5-VGS plot using the standard saturation current equation. The subthreshold 32 3

swing (S.S) value was also estimated to be 1.03 V/dec. It was interesting to note that wide counter36

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clockwise hysteresis in IDS was observed due to the remnant polarization of albumen GI. The 38

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memory window (MW), which was determined as the voltage width between turn-on and turn-off 39 40

points, was estimated to be approximately 11.8 V. These results demonstrated a feasibility that the 43

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fabricated device could exhib4it nonvolatile memory characteristics by exploiting the effect of 45

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residual polarization within the albumen GI, as expected in P-E characteristics (Figure 1a). 46 48

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The capacitance – voltage (C-V) characteristics were also examined, as shown in Figure 3c. 50

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Grounding the S/D terminals, VGS was swept from -30 to 15 V in forward and reverse directions. 52

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The measurement frequency was varied to 1 MHz, 100 kHz, and 10 kHz. Although the 53 5

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accumulation capacitance values decreased with the increase in frequency due to the frequency 56 57 58 59 60 ACS Paragon Plus Environment

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dispersion, the MW was almost maintained even at 1 MHz. The nonvolatile memory 5

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characteristics were also verified in C-V measurements for the fabricated albumen-paper memory 6 7

TFT. Figure 3d shows the typical output characteristics (VDS-IDS) at different gate voltages (VGS) 10

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from 0 to 4 V in steps of 1 V. As can be seen in figure, the paper memory TFT exhibited good gate 12

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modulation and hard saturation behaviors for the saturation region, although a current crowding 13 14

behavior was observed in the linear region, indicating a moderately high contact resistance 17

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between the S/D and active layers, which probably originated from the thermal deformation of 19

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YUPO substrate during the processes. It happens that the trap or defect sites exist at IGZO 20 2

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interfaces and/or within bulk films of IGZO and albumen layers. However, for n-type device, 24

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counter-clockwise and clockwise directions of hysteresis in transfer curves represent the residual 25 26

polarization and charge injection mechanisms, respectively, as a dominant effect causing the 27 29

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hysteretic behaviors. For our fabricated paper memory TFTs, the direction of hysteresis was 31

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observed to be counter-clockwise, as shown in Figure 3b. Therefore, we can exclude the possibility 32 3

of charge-trap mechanism. It would be very important to check the origin of the obtained counter36

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clockwise hysteresis shown in Figures 3b-c, because they might also be caused by mobile ions, 38

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with which the nonvolatile memory switching cannot be guaranteed for practical applications. To 39 40

analyze these behaviors, the memory programming characteristics were verified by voltage pulse 43

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signals with given duration. Figure 3e shows the variations in the programmed IDS of the fabricated 45

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albumen-paper memory TFT when the pulse widths of program voltages applied for on and off 46 48

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programming were varied from 1 ms to 1 s at voltage amplitude of 20 and -20 V, respectively. 50

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While the program operations could not be achieved for the cases using pulses shorter than 100 52

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ms, the memory on/off ratio significantly increased with increasing the pulse width from 100 ms 53 5

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to 1 s. The albumen-paper memory TFT exhibited the maximum memory on/off ratio of 56 57 58 59 60 ACS Paragon Plus Environment

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approximately 1.0×106. Consequently, it was clearly suggested that the polarization effects within 5

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the chicken-albumen GI induced the hysteretic bi-stability observed in the fabricated device. These 6 7

results demonstrated that our proposed albumen-paper TFT could be operated as promising 10

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nonvolatile memory TFT. In most practical memory applications, the stored data should be 12

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retained with the lapse of time. Thus, in order to examine the data retention characteristics, a ±2013 14

V-high and 1-s-wide programming pulses were applied and the programmed IDS was measured at 17

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a read-out VGS of 0 V. Figure 3f shows the variations in the programmed on and off IDS with the 19

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lapse of retention time for 4×103 s. The on/off ratio was initially obtained to be approximately 20 21

1.4×106 and decreased to 4.8 after 1000 s. It was found that the memory off-state was more 24

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markedly varied with the retention time than the memory on-state. This asymmetric increase of 25 27

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off-programmed current can be interpreted by the depolarization field asymmetrically determined 29

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between the on and off states. Because the n-ch IGZO TFT operates in a depletion mode for the 31

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memory off-state, the depolarization field applied for the off-state during the retention period is 32 34

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subject to be larger than that for the on-state. Thus, a larger degradation may occur for the off36

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programmed state.13 This problem could be improved by appropriate device designs including the 37 38

film thicknesses of active channel, gate insulator, and capping layers. Even though the retention 39 41

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time for this device was not so long at this stage, the presented nonvolatile memory behaviors of 43

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the albumen-paper memory TFT could be sufficiently encouraging for future biodegradable4 45

flexible memory applications. Concerning the yield and uniformity in device behaviors, the number 46 48

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of working devices amounted to ten when the test patterns were designed to have twenty TFTs with the 50

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same size in a single device substrate. The yield would be enhanced by further improvements in 51 53

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fabrication process. When examined with ten working devices as the average performances, the memory 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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window and the ION/IOFF were estimated to be approximately 12.7 ± 1.3 V and 4.0×106 ± 2.6×106, 5

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respectively. 6 8

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In practical applications, the YUPO substrate attached on the glass substrate for easy handling 10

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during the process should be delaminated and the device characteristics of the delaminated paper 1 12

memory TFT should be evaluated again. Figure 4a shows the photo images of the fabricated 13 15

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devices on the YUPO substrate delaminated from the glass substrate. The delamination was easily 17

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performed by using tweezers wetted with acetone, as shown in inset of Figure 4a. As shown in 18 19

Figure 4b, the detached device did not experience marked mechanical deformation and/or peel-off 20 2

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of given layers composing the device. Figure 4c shows the transfer characteristics of the albumen24

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paper memory TFT after the delamination. The ION/IOFF ratio was obtained as 0.4 × 106 at VDS of 25 26

0.5 V. The μsat, VTH, and S.S values were estimated to be 6.3 cm2/Vs, 4.7 V, and 0.70 V/dec, 27 29

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respectively. Although the μsat was degraded owing to the mechanical damage during the 31

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delamination process, the obtained device behaviors were quite inspiring, considering that the 32 34

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devices were fabricated on a flexible paper substrate. The memory programming properties were 36

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also examined, as shown in Figure 4d. 37 38

The variations in the memory on/off ratio as a function of program pulse width were not so 39 41

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different from those for the laminated device and the maximum memory on/off ratio of 1.0×105 was obtained. These results suggested that the proposed memory TFT fabricated on the paper 4 45

substrate can be operated in a stand-alone manner without any supporting substrate. 46 48

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For the flexible memory applications, the variations in device behaviors against mechanical 50

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bending deformation need to be estimated for the fabricated memory TFT. The probing 51 52

configuration for the bending durability test can be shown in Figure 5a. Figure 5b shows the 53 5

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bending characteristics of the paper memory TFT by measuring the transfer characteristics and 56 57 58 59 60 ACS Paragon Plus Environment

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gate leakage currents when the substrate was bent with a curvature radius of 5.3 cm. The I ON/IOFF 5

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ratio was obtained as 5.9×106 at VDS of 0.5 V. The μsat, VTH, and S.S values were examined to be 6 7

7.9 cm2/Vs, 9.1 V, and 0.77 V/dec, respectively. Although the device operation behaviors under 10

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the bending situations was slightly changed compare with those of the delaminated device, the 12

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obtained device parameters including the μsat did not show any marked degradation. Memory 13 14

programming operation and retention characteristics were also examined, as shown in Figures 5c17

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d, respectively. The maximum memory on/off ratio was obtained as 6.3×10 3 at 1-s-width 19

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programming signals. The programmed initial on/off ratio of 3.4×103 decreased to 2.2 after the 20 21

lapse of 4×103 s. The nonvolatile memory behaviors examined under the bending situations were 24

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sufficiently encouraging. The reproducibility and stability in electrical performance of the 25 26

proposed eco-paper memory TFTs could be guaranteed by the fabrication process optimizations, 27 29

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as discussed above, and are sufficiently reliable at a present stage. 30 32

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4. Conclusion 3 34

We proposed and fabricated the nonvolatile memory TFTs using biomaterial, chicken albumen, as 37

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GI on eco-friendly paper substrate for the first time. All components were elaborately patterned 39

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with photolithography techniques and all fabrication processes were performed at low temperature 40 42

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below 120 °C. For the use of albumen as GI, the dielectric properties were enhanced by the 4

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introduction of Al2O3 capping layer. The nonvolatile bi-stability for memory operations were 46

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realized by the switching phenomenon of residual polarization in the albumen GI. The fabricated 47 49

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eco-paper memory TFT exhibited high mobility (~11.5 cm2/Vs) and high on/off ratio (>106) thanks 51

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to the optimization of fabrication procedures. Good programming operations and memory 52 53

retention performances were also successfully confirmed, in which the maximum ION/OFF ratio of 54 56

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1.0×106 was obtained with 1-µs-wide program pulses of ±20 V. Furthermore, these device 57 58 59 60 ACS Paragon Plus Environment

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characteristics were not markedly degraded even after the delamination and under the bending 5

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situation. When the curvature radius was set as 5.3 cm, the ION/IOFF ratio, μsat, VTH, and S.S values 6 7

were examined to be 5.9×106, 7.9 cm2/Vs, 9.1 V, and 0.77 V/dec, respectively. These inspiring 10

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and encouraging results obtained from the proposed eco-paper memory TFTs are expected to find 12

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new possibility in the fields of future sustainable electronics. 13 14 15 16 17 19

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FIGURES 20 21 2 23 24 25 26 27 28 29 30 31 32 3 34 35 36 37 38 39 40 41 42 43

Figure 1. (a) Preparation procedures for diluted chicken albumen solution. (b) The polarization4 46

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electric field (P-E) characteristics of the fabricated Al/Al 2O3/Albumen/ITO capacitor. The 48

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wettability of the albumen solution was examined on (c) YUPO substrate and (d) Al2O3-coated 49 50

YUPO substrate by measuring the contact angle. 51 52 53 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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Figure 2. AFM images of the (a) bare and (b) barrier-coated surfaces of YUPO substrate. 27 28

Microscopic images for the situations of S/D patterning (c) before and (d) after deposition of 3029 31

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nm-thick Al2O3 layer. (e) Schematic cross-section, (f) cross-sectional SEM image, and (e) optical 3

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microscope image of the fabricated eco-paper memory TFT. 34 35 36 37 38 39 40 41 42 43 4 45 46 47 48 49 50 51 52 53 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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Figure 3. (a) Leakage current densities of albumen and CL-treated albumen layers with and 4 45

without treatments in resist stripper. (b) IDS-VGS characteristics and gate leakage currents of the 46 48

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fabricated device with the W/L of 40/20 μm. Transfer curves were measured in the double sweep 50

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mode of VGS from -15 to 15 V at VDS of 0.5 and 5.5 V. (c) C-V measurements for the fabricated 51 53

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device. Grounding S/D terminals, VGS was swept from -30 to 15 V. The measurement frequency 5

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was varied to 1 MHz, 100 kHz, and 10 kHz, respectively. (d) IDS-VDS output characteristics at 56 57 58 59 60 ACS Paragon Plus Environment

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different VGS from 0 to 4 V in steps of 1 V. (e) Variations in the programmed IDS of the fabricated 5

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eco-paper memory TFT when the pulse widths of program voltages for on and off were varied 6 8

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from 1 ms to 1 s with the voltage amplitude of 20 and -20 V, respectively. (f) The variations in the 10

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programmed IDS with the lapse of retention time for 4×103 s. 1 12 13 14 15 16 17 18 19 20 21 2 23 24 25 26 27 28 29 30 31 32 3 34 35 36 37 38 39 40 41 42 43 4 45 46 47 48 49 50 51 52 53 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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Figure 4. (a) Photo and (b) microscopic images of the devices fabricated on the YUPO substrate 31 32

delaminated from the glass substrate. (c) Transfer characteristics of the eco-paper memory TFT 3 35

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after the delamination. (d) Memory programming properties of the delaminated memory transistor 37

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when the pulse widths of program voltages were varied from 1 ms to 1 s. The program voltages 38 39

for the memory on and off states were ±20 V. 40 41 42 43 4 45 46 47 48 49 50 51 52 53 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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Figure 5. (a) Photo image of an electrical evaluation and (b) transfer characteristics for the 32 34

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fabricated device under the bending situation. (c) Memory programming and (d) retention 36

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properties were also evaluated under the bending situation. 37 38 39 40 41 42 43 4 45 46 47 48 49 50 51 52 53 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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ASSOCIATED CONTENT 4 6

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Supporting Information 7 8 9

Associated content, including (i) the output characteristics (V DS-IDS) and C-V characteristics 12

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after the delamination (Figure S1) and under the bending situation (Figure S2), (ii) the process 14

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compatibility and effects of capping layer on the insulating properties of albumen (Figure S3), 15 17

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(iii) the annealing temperature dependence of the residual polarization effect of chicken albumen 19

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thin films (Figure S4), (iv) the adhesion improvement by the introduction of barrier layer (Figure 21

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S5), and (v) the suitability to the environmental needs evaluated in burning state (movie clip). 2 24

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This information is available free of charge via the Internet at http://pubs.acs.org/. 25 27

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AUTHOR INFORMATION 28 29 30

Corresponding Author 3

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Sung-Min Yoon 34 35 36

Dep. of Advanced Materials Engineering for Information and Electronics, 38

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Kyung Hee University 41 43

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1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, KOREA 4 45 47

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TEL: 82-31-201-3617, FAX: 82-31-204-8114 48 50

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E-mail: [email protected] 51 52 53 54 5 57

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ACKNOWLEDGMENT 58 59 60 ACS Paragon Plus Environment

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This research was supported by the National Research Foundation of Korea (NRF) grant funded 5

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by the Korean government (MEST) (2014023501). This research was also funded by the MSIP 6 8

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(Ministry of Science, ICT & Future Planning), Korea in the ICT R&D Program (The core 10

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technology development of light and space adaptable energy-saving I/O platform for future 1 12

advertising service). 13 14 15 17

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REFERENCES 19

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(1) Martins, R.; Barquinha, P.; Pereira, L.; Correia, N.; Gonçalves, G.; Ferreira, I. Fortunato, E. 20 2

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Write-Erase and Read Paper Memory Transistor. Appl. Phys. Lett. 2008, 93, 203501. 23 25

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(2) Siegel, A. C.; Phillips, S. T.; Wiley, B. J. Whitesides, G. M.; Thin, Lightweight, Foldable 26 27

Thermochromic Displays on Paper. Lab Chip 2009, 9, 2775-2781. 28 29 31

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(3) Lim, W.; Douglas, E. A.; Kim, S. H.; Norton, D. P.; Pearton, S. J.; Ren, F.; Shen, H.; Chang, 3

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W. H. High Mobility InGaZnO4 Thin-Film Transistors on Paper. Appl. Phys. Lett. 2009, 94, 34 35

072103. 38

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(4) Lu, A.; Dai, M.; Sun, J.; Jiang, J.; Wan, Q. Flexible Low-Voltage Electric-Double-Layer 40

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TFTs Self-Assembled on Paper Substrates. IEEE Electron Device Lett. 2011, 32, 518-520. 41 43

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(5) Russo, A., Ahn, B. Y.; Adams, J. J.; Duoss, E. B.; Bernhard, J. T.; Lewis, J. A. Pen-on-Paper 45

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Flexible Electronics. Adv. Mater. 2011, 23, 3426-3430. 46 48

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(6) Li, Y.; Li, C.; Xu, Y.; Minari, T.; Darmawan, P.; Tsukagoshi, K. Solution-Processed Organic 50

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Crystals for Field-Effect Transistor Arrays with Smooth Semiconductor/Dielectric Interface on 52

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Paper Substrates. Org. Electron. 2012, 13, 815-819. 53 5

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(7) Lien, D. H.; Kao, Z. K.; Huang, T. H.; Liao, Y. C.; Lee, S. C.; He, J. H. All-Printed Paper 57

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Memory. ACS Nano 2014, 8, 7613-7619. 58 59 60 ACS Paragon Plus Environment

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(8) Lim, W.; Douglas, E. A.; Norton, D. P.; Pearton, S. J.; Ren, F.; Heo, Y. W.; Son, S. Y.; Yuh, 5

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J.H. Low-Voltage Indium Gallium Zinc Oxide Thin Film Transistors on Paper Substrates. Appl. 6 8

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Phys. Lett. 2010, 96, 3510. 10

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(9) Khanna, R., Douglas, E. A., Norton, D. P.; Pearton, S. J.; Ren, F. Ti/Au Ohmic Contacts to 1 12

Indium Zinc Oxide Thin Films on Paper Substrates. J. Vac. Sci. Technol. B 2010, 28, L43-L46. 13 15

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(10) Mazzeo, A. D.; Kalb, W. B.; Chan, L.; Killian, M. G.; Bloch, J. F.; Mazzeo, B. A.; 17

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Whitesides, G. M. Paper-Based, Capacitive Touch Pads. Adv. Mater. 2012, 24, 2850–2856. 18 19

(11) Jeon, D. B.; Bak, J. Y.; Yoon, S. M. Oxide Thin-Film Transistors Fabricated Using 20 2

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Biodegradable Gate Dielectric Layer of Chicken Albumen. Jpn. J. Appl. Phys. 2013, 52, 128002. 24

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(12) Chang, J. W.; Wang, C. G.; Huang, C. Y.; Tsai, T. D.; Guo, T. F.; Wen, T. C.hicken 25 27

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Albumen Dielectrics in Organic Field-Effect Transistors. Adv. Mater. 2011, 23, 4077-4081. 29

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(13) Yoon, S.; Yang, S.; Park, S.; Jung, S.; Cho, D.; Byun, C.; Kang, S.; Hwang, C.; Yu, B. 31

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Effect of ZnO Channel Thickness on the Device Behaviour of Nonvolatile Memory Thin Film 32 34

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Transistors with Double-Layered Gate Insulators of Al2O3 and Ferroelectric Polymer. J. Phys. D: 36

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Appl. Phys. 2009, 42, 245101. 37 38 39 40 41 42 43 4 45 46 47 48 49 50 51 52 53 54 5 56 57 58 59 60 ACS Paragon Plus Environment

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For Table of Contents Only 4 5 6 7 8 9 10 1 13

12 (Left) Photo images of the devices fabricated on the YUPO substrate delaminated from the glass substrate.

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(Right) The transfer characteristics of fabricated eco-paper memory transistor.

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Nonvolatile Memory Thin-Film Transistors Using Biodegradable

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