Si (100

Subscriber access provided by Kaohsiung Medical University

Article

Reduction of Threading Dislocation Density in Sputtered Ge/Si (100) Epitaxial Films by Continuous-Wave Diode Laser Induced Recrystallization Ziheng Liu, Xiaojing Hao, Jialiang Huang, Anita W. Y. Ho-Baillie, and Martin A. Green ACS Appl. Energy Mater., Just Accepted Manuscript • DOI: 10.1021/acsaem.7b00130 • Publication Date (Web): 27 Apr 2018 Downloaded from http://pubs.acs.org on April 30, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

Reduction of Threading Dislocation Density in Sputtered Ge/Si (100) Epitaxial Films by ContinuousWave Diode Laser Induced Recrystallization Ziheng Liu*, Xiaojing Hao, Jialiang Huang, Anita Ho-Baillie, and Martin A. Green School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, NSW 2052, Australia Keywords: Epitaxial Ge films; defect reduction; continuous-wave diode laser; recrystallization; magnetron sputtering Abstract We have developed a cost-effective, up-scalable and high-throughput method combining continuouswave (CW) diode laser and magnetron sputtering for fabricating low-defect single-crystalline Ge films for high efficiency III-V solar cells application. CW diode laser induced recrystallization is demonstrated to dramatically reduce the threading dislocation density (TDD) of sputter-deposited single-crystalline Ge/Si epitaxial films by more than three orders of magnitude. This might be due to the change of growth mechanism from initial Ge/Si hetero-epitaxy in sputtering process to Ge/Ge homo-epitaxy by the laser induced lateral recrystallization process, overcoming the typical issue of Ge/Si lattice mismatch to achieve low TDD.

1 Environment ACS Paragon Plus

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1. Introduction

Epitaxy of Ge on Si substrate has received intensive attention for its compatibility with Si process flow and the superior properties of Ge. The driving force for the integration of Ge with Si are its applications in metal-oxide-semiconductor field-effect transistors as high mobility channel 1, in Sibased optical devices as photodetector 2, and in high efficiency III-V solar cells as the growing substrates 3. Epitaxial Ge films on Si might be used as virtual Ge substrates for fabricating III-V high efficiency solar cells owing to its small lattice mismatch with GaAs. Compared with the bulk Ge substrates, virtual Ge substrates are much cheaper and have better electrical and mechanical properties. However, the large lattice mismatch (4.2%) between Ge and Si can generate high threading dislocation density (TDD) in Ge films 2, 4. Multiple approaches have been studied to reduce TDD of the epitaxial Ge films. Graded SiGe buffer is one way to gradually reduce the lattice mismatch and therefore the TDD. However, 10 µm thick buffer layer and chemical mechanical polishing are required 5. Defects blocking through substrate patterning is another method to reduce TDD which involves expensive and low-throughout nanometer level patterning 6. Thermal annealing approaches including two-step Ge deposition followed by furnace annealing 7, cycled Ge epitaxial growth and thermal annealing 8, and cyclic thermal annealing 9 have also been investigated to reduce TDD of Ge. These conventional thermal treatments require annealing at high temperature for long duration and can only obtain limited TDD reduction. In contrast to the aforementioned approaches, continuous-wave (CW) diode laser induced recrystallization offers a low-cost and fast alternative to effectively reduce the TDD of Ge films.

CW diode laser annealing has been used to achieve electrical activation and good lattice reordering in ion-implanted Si

10

and as a replacement of rapid thermal annealing for defect reduction in

polycrystalline Si solar cells

11-12

. The CW diode laser was first time employed to reduce TDD in

sputter-deposited single-crystalline Ge epitaxial films on Si in our previous work through annealing 2 ACS Paragon Plus Environment

Page 2 of 15

Page 3 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


at a temperature below the Ge melting point 13. However, even after multiple cycles of laser scans, the TDD reduction is limited by two orders of magnitude due to the reemission of dislocations

14

.

Melting the defects away and getting the film recrystallized might be feasible to further reduce TDD. With a similar reasoning, high quality polycrystalline Si thin films with low defect density and high mobility have been obtained by laser-induced liquid-phase crystallization

15

. In this work, we

increase the laser intensity to melt the Ge films and significant TDD reduction of more than three orders of magnitude is achieved after only one laser scan.

The significant TDD reduction can be attributed to the lateral recrystallization process induced by CW diode laser scanning. The process in this work is different from the recrystallization in pulsed laser annealing

16

where the whole layer is melted and recrystallized perpendicularly from Si. By

scanning the sample with CW diode laser, the illuminated region is melted and recrystallized laterally at a high speed which follows the laser beam motion. Owing to the lateral regrowth, the Ge film itself may act as the recrystallization seed instead of Si which changes the mechanism from Ge/Si hetero-epitaxy to Ge/Ge homo-epitaxy and therefore overcomes the typical issue of Ge/Si lattice mismatch. As a result, the TDD of Ge film can be dramatically reduced by the CW diode laser induced recrystallization. Our process makes good use of not only the fast and selectively heating characteristics of the CW diode laser, but also its unique scanning scheme.

Magnetron sputtering was used to deposit the Ge films in this work. Compared with chemical vapour deposition (CVD) and molecular beam epitaxy (MBE) systems which require high vacuum and may involve toxic gases

7, 17

, magnetron sputtering is a lower cost and safer alternative in fabricating

epitaxial Ge films on Si. The combination of magnetron sputtering and CW diode laser explored in this work is compatible with large scale production of templates to fabricate III-V solar cells.

3 ACS Paragon Plus Environment


2. Experimental

The Ge films were deposited by using a radio frequency magnetron sputtering system (AJA ATC2200) in this work. The substrates used were N-type Si (100) wafers which went through the RCA cleaning

18

and HF dip before loading into the deposition chamber. 3 inch intrinsic Ge target

(99.999% purity) was used to sputter-deposit the Ge films. The process pressure was 1.5×10-3 millibar and the deposition rate was 4 nm/min. Ge films with thicknesses between 100 and 200 nm were deposited on Si at a substrate temperature of 400 oC. 150 nm thick SiO2 were deposited following Ge depositions as the capping layer. The laser tool used in this work was Lissotschenko Mikrooptick GmbH (LIMO) continuous-wave diode laser with line-focus optics. The schematic diagram of the CW diode laser scanning process is shown in Figure S1 (supplementary data). Details of the laser process can be found in our previous report 13. The processing time for a 4 inch wafer is around 3 min at a scan velocity of 400 mm/min. Laser scans with energy densities of 67-95 J/cm2 were applied on the Ge samples. The crystallinity of the Ge samples before and after laser treatments was analyzed by Raman spectroscopy (Renishaw Ramascope) and transmission electron microscopy (TEM Phillips CM200 microscope) measurements.

3. Results and discussions

To identify the laser conditions for melting Ge thin film, the laser power has been varied to produce energy dose from 67 to 95 J/cm2 with a fixed exposure time of 40 milliseconds. Figure 1 shows the peak temperatures of the 200 nm Ge samples treated at different laser doses. The peak temperature rises sharply from 830 oC to 937 oC when the laser dose is increased from 67 J/cm2 to 78 J/cm2. After the raise, the peak temperature plateaus suggesting partial melting of the Ge sample and the absorption of latent heat

11

. As the laser dose is further increased above 92 J/cm2, the peak

temperature increases with the laser dose again. Three laser doses of 73 J/cm2, 78 J/cm2, and 92


Page 4 of 15

Page 5 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


J/cm2 were chosen to investigate the effects of laser treatments at temperatures i) below, ii) at, and iii) above Ge melting point, respectively.

Figure 1 Peak temperatures of the 200 nm Ge samples as a function of the laser doses.

TEM measurements were employed to study the effects of CW diode laser treatments at different doses on TDD of the epitaxial Ge samples. The evaluation of TDD was conducted through counting the dislocations along the planes parallel to the substrate in different areas of the samples and then estimating the TDD range

19

. Figure 2 shows the cross-sectional TEM images of Ge samples (a)

before and after laser treatments at laser doses of (b) 73 J/cm2, (c) 78 J/cm2, and (d) 92 J/cm2. As shown in Figure 2(a), the epitaxial Ge film before laser annealing has a high TDD above 1010 cm-2. After laser annealing at 73 J/cm2 below the Ge melting point, the TDD of Ge is reduced to 108-109 cm-2 which is in the similar range to that obtained by conventional thermal annealing 9. In this case, the dislocations within the Ge film are thermally activated to glide and can annihilate when having opposite Burger vector and are within an annihilation radius 20. When the laser dose is increased to 78 J/cm2 that is able to melt the Ge film, the TDD is dramatically reduced by more than three orders of magnitude to 106-107 cm-2. The CW diode laser induced melting and recrystallization process 5 ACS Paragon Plus Environment


breaks the limit of two orders of magnitude TDD reduction by conventional thermal annealing. Interestingly, it is found that the significant TDD reduction might be attributed to the lateral recrystallization of Ge which uses the Ge film as the recrystallization seed (laterally in a homoepitaxial growth mode) instead of Si (vertically in a hetero-epitaxial growth mode) and the high recrystallization speed induced vacancies supersaturation which will cause the climbing of dislocations to the lateral surface 21-22. In this way, TDD owing to the 4.2% lattice mismatch between Si and Ge can be significantly reduced. Once the laser dose is further increased to 92 J/cm2 above the Ge melting point, pronounced Ge penetration into Si and high TDD of 109-1010 cm-2 are observed in Figure 2(d). The high TDD likely originates from the Si/Ge mixture at the interface region owing to the lattice mismatch

23

. According to these observations, laser treatment at the Ge melting point

inducing recrystallization offers the most effective TDD reduction.

Figure 2 (a)-(d) Cross-sectional TEM images and (e) Raman spectra of 200 nm Ge samples before and after laser treatment: (a) no laser treatment, (b) 73 J/cm2, (c) 78 J/cm2, and (d) 92 J/cm2.

The Si/Ge inter-diffusion after laser treatment was examined by Raman spectra as shown in Figure 2(e). 514 nm Ar+ laser was used as the excitation source which penetrates the top 20 nm of the Ge 6 ACS Paragon Plus Environment

Page 6 of 15

Page 7 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


film 24-25. The laser beam power was limited to 6 mW to prevent the locally annealing effect during measurements. As shown in Figure 2(e), all the epitaxial Ge samples exhibit peaks centered around 300 cm-1 corresponding to the Ge-Ge optical vibration modes

26

. The reduced full width at half

maximum (FWHM) and increased intensity of the Ge-Ge peak after laser treatment indicates improved crystallinity which agrees well with the TEM results. In addition, after laser treatment at 78 J/cm2 at the Ge melting point, a tiny Si-Ge peak emerges suggesting small Si diffusion into the Ge film. When the laser dose is further increased to 92 J/cm2 above the Ge melting point, a strong Si-Ge peak is detected revealing that high Si content Si1-xGex alloy is formed, which agrees with the TEM observation of Ge penetration into Si.

Figure 3 (a)-(c) Cross-sectional TEM images and (d) Raman spectra of Ge samples with different thicknesses after laser treatments at Ge melting point: (a) 200 nm, (b) 150 nm, and (c) 100 nm.

Since thin Ge layer is preferred in the application of virtual Ge substrates, the CW diode laser treatment at the Ge melting point has also been applied to Ge films of 100 nm and 150 nm to demonstrate its effective TDD reduction at different Ge thicknesses. Figure 3 shows the (a)-(c) crosssectional TEM images and (d) Raman spectra of Ge samples with thicknesses of 200 nm, 150 nm, and 100 nm after laser treatments at the Ge melting point. As shown in the TEM images, the Ge films exhibit similar TDD which lies within the range of 106 cm-2-107 cm-2. Effective TDD reduction 7 ACS Paragon Plus Environment


Page 8 of 15

has been successfully achieved for all the Ge thicknesses by the laser induced recrystallization. The Raman spectra in Figure 3(d) reveal that all the Ge samples have a strong Ge-Ge peak and a very weak Si-Ge peak. The Si-Ge peak intensity increases slightly with the reducing Ge thickness suggesting more Si diffusion in the thinner Ge sample. The penetration depth of 808 nm laser in the Ge layer is more than 200 nm

24-25

. The thinner Ge allows more absorption for the Si substrate and

therefore elevates the Si temperature which induces more Si diffusion into the Ge film.

The CW diode laser induced recrystallization is much more effective in TDD reduction than solid phase thermal annealing owing to the different mechanisms. In solid phase thermal annealing, the dislocations are thermally activated to move for annihilation and coalescence

20

. However, the

reemission accompanied with the coalescence of dislocations and generation of dislocations during the thermal process limit the extent of TDD reduction 14. In the CW diode laser treatment at the Ge melting point, Ge films are melted and recrystallized laterally following the motion of scanning laser. The lateral regrowth may allow the use of Ge film itself as the epitaxial recrystallization seed. This could change the growth mechanism from Ge/Si hetero-epitaxy to Ge/Ge homo-epitaxy and therefore overcome the typical issue of 4.2% Ge/Si lattice mismatch. In addition, the high scanning speed and selective heating of the CW diode laser lead to high thermal gradient and fast regrowth rate which are the two major factors to produce vacancy supersaturation

21-22

. The possibly induced

vacancy supersaturation might in turn cause the climb of dislocations to the lateral crystal surface. Thanks to the lateral regrowth and possibly vacancy supersaturation, the TDD of Ge can be significantly reduced by more than three orders of magnitude by the fast scanning CW diode laser induced recrystallization. The obtained Ge films with TDD of 106 cm-2-107 cm-2 may be suitable for fabrication of III–V solar cells 27-28. Future optimization of the sputter-deposition and laser processes might be able to further reduce the TDD and therefore improve the cell efficiency.


Page 9 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


4. Conclusions

CW diode laser treatments have been employed to reduce the TDD of epitaxial Ge films on Si grown by magnetron sputtering. The effects of laser treatments at temperatures below, at, and above Ge melting point have been investigated. For laser treatment below Ge melting point, the TDD of Ge can be reduced by only one order of magnitude which is similar to that in thermal annealing. When the laser dose is raised too high above the Ge melting point, high Si content Si1-xGex alloy with high TDD is formed. Laser treatment at the Ge melting point offers the most effective TDD reduction by more than three orders of magnitude through recrystallization. The effective TDD reduction by the laser treatment has been demonstrated on Ge films with different thicknesses. The CW diode laser induced recrystallization may change the growth mechanism from Ge/Si hetero-epitaxy to Ge/Ge homo-epitaxy and therefore overcomes the Ge/Si lattice mismatch to achieve low TDD. The method reported in this work employing magnetron sputtering and CW diode laser is compatible with large scale production of templates to fabricate III-V solar cells.

Author information

Corresponding Author

*E-mail: [email protected]

Acknowledgements

This work has been supported by the Australian Government through the Australian Research Council (ARC, grant number DP160103433) and the Australian Renewable Energy Agency



(ARENA) and by Epistar Corporation and Shin Shin Natural Gas Co., Ltd., Taiwan. Responsibility for the views, information or advice expressed herein is not accepted by the Australian Government.

Supporting Information Available: Schematic diagram of the diode laser annealing process.

References 1. Hussain, A. M.; Fahad, H. M.; Sevilla, G. A. T.; Hussain, M. M., Thermal Recrystallization of Physical Vapor Deposition Based Germanium Thin Films on Bulk Silicon (100). physica status solidi (RRL) – Rapid Research Letters 2013, 7, 966-970. 2. Michel, J.; Liu, J.; Kimerling, L. C., High-Performance Ge-on-Si Photodetectors. Nature Photonics 2010, 4, 527. 3. Beeler, R.; Mathews, J.; Weng, C.; Tolle, J.; Roucka, R.; Chizmeshya, A. V. G.; Juday, R.; Bagchi, S.; Menéndez, J.; Kouvetakis, J., Comparative Study of Ingaas Integration on Bulk Ge and Virtual Ge/Si Substrates for Low-Cost Photovoltaic Applications. Solar Energy Materials and Solar Cells 2010, 94, 2362-2370. 4. Hui, Y.; Jinzhong, Y., Germanium Epitaxy on Silicon. Science and Technology of Advanced Materials 2014, 15, 024601. 5. Currie, M. T.; Samavedam, S. B.; Langdo, T. A.; Leitz, C. W.; Fitzgerald, E. A., Controlling Threading Dislocation Densities in Ge on Si Using Graded Sige Layers and Chemical-Mechanical Polishing. Applied Physics Letters 1998, 72, 1718-1720. 6. Yourui, H.; Wenbo, Z.; Xia, H.; Xu, F.; Guqiao, D.; Hui, Y., Heteroepitaxy of Ge on Si(001) with Pits and Windows Transferred from Free-Standing Porous Alumina Mask. Nanotechnology 2013, 24, 185302. 7. Yamamoto, Y.; Zaumseil, P.; Arguirov, T.; Kittler, M.; Tillack, B., Low Threading Dislocation Density Ge Deposited on Si (100) Using Rpcvd. Solid-State Electronics 2011, 60, 2-6. 8. Choi, D.; Ge, Y.; Harris, J. S.; Cagnon, J.; Stemmer, S., Low Surface Roughness and Threading Dislocation Density Ge Growth on Si (0 0 1). Journal of Crystal Growth 2008, 310, 42734279. 9. Liu, Z.; Hao, X.; Ho-Baillie, A.; Tsao, C.-y.; Green, M. A., Cyclic Thermal Annealing on Ge/Si(100) Epitaxial Films Grown by Magnetron Sputtering. Thin Solid Films 2015, 574, 99-102. 10.

Williams, J. S.; Brown, W. L.; Leamy, H. J.; Poate, J. M.; Rodgers, J. W.; Rousseau, D.; ‐ Phase Epitaxy of Implanted Silicon by Cw Ar Rozgonyi, G. A.; Shelnutt, J. A.; Sheng, T. T., Solid Ion Laser Irradiation. Applied Physics Letters 1978, 33, 542-544. 11. Eggleston, B.; Varlamov, S.; Green, M., Large-Area Diode Laser Defect Annealing of Polycrystalline Silicon Solar Cells. Electron Devices, IEEE Transactions on 2012, 59, 2838-2841.


Page 10 of 15

Page 11 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


12. Chowdhury, A.; Schneider, J.; Dore, J.; Mermet, F.; Slaoui, A., High-Temperature Laser Annealing for Thin Film Polycrystalline Silicon Solar Cell on Glass Substrate. Appl. Phys. A 2012, 107, 653-659. 13. Liu, Z.; Hao, X.; Huang, J.; Li, W.; Ho-Baillie, A.; Green, M. A., Diode Laser Annealing on Ge/Si (100) Epitaxial Films Grown by Magnetron Sputtering. Thin Solid Films 2016, 609, 49-52. 14. Yamaguchi, M.; Yamamoto, A.; Tachikawa, M.; Itoh, Y.; Sugo, M., Defect Reduction Effects in Gaas on Si Substrates by Thermal Annealing. Applied Physics Letters 1988, 53, 22932295. 15. Huang, J.; Varlamov, S.; Dore, J.; Yun, J. S.; Green, M. A., Micro-Structural Defects in Polycrystalline Silicon Thin-Film Solar Cells on Glass by Solid-Phase Crystallisation and LaserInduced Liquid-Phase Crystallisation. Solar Energy Materials and Solar Cells 2015, 132, 282-288. 16. Cristiano, F.; Shayesteh, M.; Duffy, R.; Huet, K.; Mazzamuto, F.; Qiu, Y.; Quillec, M.; Henrichsen, H. H.; Nielsen, P. F.; Petersen, D. H.; La Magna, A.; Caruso, G.; Boninelli, S., Defect Evolution and Dopant Activation in Laser Annealed Si and Ge. Materials Science in Semiconductor Processing 2016, 42, 188-195. 17. Guoqiang, L.; Wenliang, W.; Weijia, Y.; Yunhao, L.; Haiyan, W.; Zhiting, L.; Shizhong, Z., Gan-Based Light-Emitting Diodes on Various Substrates: A Critical Review. Reports on Progress in Physics 2016, 79, 056501. 18. Kern, W., The Evolution of Silicon Wafer Cleaning Technology. Journal of the Electrochemical Society 1990, 137, 1887-1892. 19.

Lester, S. D.; Ponce, F. A.; Craford, M. G.; Steigerwald, D. A., High Dislocation Densities in ‐ Based Light ‐ Emitting Diodes. Applied Physics Letters 1995, 66, 1249-1251. High Efficiency Gan 20. Beltz, G. E.; Chang, M.; Eardley, M. A.; Pompe, W.; Romanov, A. E.; Speck, J. S., A Theoretical Model for Threading Dislocation Reduction During Selective Area Growth. Materials Science and Engineering: A 1997, 234–236, 794-797. 21. Sinno, T.; Dornberger, E.; von Ammon, W.; Brown, R. A.; Dupret, F., Defect Engineering of Czochralski Single-Crystal Silicon. Materials Science and Engineering: R: Reports 2000, 28, 149198. 22. Dash, W. C., Growth of Silicon Crystals Free from Dislocations. Journal of Applied Physics 1959, 30, 459-474. 23. Liu, Y.; Deal, M. D.; Plummer, J. D., High-Quality Single-Crystal Ge on Insulator by LiquidPhase Epitaxy on Si Substrates. Applied Physics Letters 2004, 84, 2563-2565. 24. Wolf, I. D., Micro-Raman Spectroscopy to Study Local Mechanical Stress in Silicon Integrated Circuits. Semiconductor Science and Technology 1996, 11, 139. 25. Masini, G.; Colace, L.; Galluzzi, F.; Assanto, G., Advances in the Field of Poly-Ge on Si near Infrared Photodetectors. Materials Science and Engineering: B 2000, 69, 257-260.



26. Loh, T. H.; Nguyen, H. S.; Tung, C. H.; Trigg, A. D.; Lo, G. Q.; Balasubramanian, N.; Kwong, D. L.; Tripathy, S., Ultrathin Low Temperature Sige Buffer for the Growth of High Quality Ge Epilayer on Si(100) by Ultrahigh Vacuum Chemical Vapor Deposition. Applied Physics Letters 2007, 90, 092108. 27. Yamaguchi, M., Dislocation Density Reduction in Heteroepitaxial Iii-V Compound Films on Si Substrates for Optical Devices. Journal of Materials Research 1991, 6, 376-384. 28. Andre, C. L.; Boeckl, J. J.; Wilt, D. M.; Pitera, A. J.; Lee, M. L.; Fitzgerald, E. A.; Keyes, B. M.; Ringel, S. A., Impact of Dislocations on Minority Carrier Electron and Hole Lifetimes in Gaas Grown on Metamorphic Sige Substrates. Applied Physics Letters 2004, 84, 3447-3449.

Table of contents graphic


Page 12 of 15

Page 13 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure1 74x74mm (300 x 300 DPI)

ACS Paragon Plus Environment


155x75mm (150 x 150 DPI)


Page 14 of 15

Page 15 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


154x56mm (150 x 150 DPI)


Si (100

Recommend Documents