Conversion Behavior of Threading Screw Dislocations on C Face

Subscriber access provided by CORNELL UNIVERSITY LIBRARY

Article

Conversion behavior of threading screw dislocations on C face with different surface morphology during 4H-SiC solution growth Shiyu Xiao, Shunta Harada, Kenta Murayama, Miho Tagawa, and Toru Ujihara Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.6b01107 • Publication Date (Web): 11 Oct 2016 Downloaded from http://pubs.acs.org on October 14, 2016

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 free 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 accessible to all readers and 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.

Crystal Growth & Design 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 17

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

Crystal Growth & Design

Conversion behavior of threading screw dislocations on C face with different surface morphology during 4H-SiC solution growth Shiyu Xiao,*, † Shunta Harada,†, ‡ Kenta Murayama, ‡ Miho Tagawa, †, ‡ and Toru Ujihara†, ‡ †

Department of Materials Science and Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan ‡

Center for Integrated Research of Future Electronics (CIRFE), Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan

ABSTRACT: The conversion of threading screw dislocations (TSDs) to defects on basal plane during SiC solution growth caused by macrostep advancing is a key factor to improve crystal quality. We realized on the TSD conversion in 4H-SiC C face solution growth by modification of the surface morphology including macrosteps by addition of 5at%Ti into pure Si solvent. Synchrotron X-ray topography revealed that the possibility of TSD conversion increased to about 10% by the addition of 5at%Ti. In addition, the TSD conversion ratio depends on the shape of macrostep edge. The gentle slope hardly made TSD conversion. The elastic energy of dislocations in anisotropy crystals was postulated for the explanation for the influence of step shape on TSD conversion behavior. _________________________ *Corresponding Authors Name: Shiyu Xiao; Affiliation: †Department of Materials Science and Engineering, Nagoya University; Address: Department of Materials Science and Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan; Email: [email protected]; Tel: +81-52-789-3249; Fax: +81-52-789-3248

ACS Paragon Plus Environment

1


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

Page 2 of 17

Conversion behavior of threading screw dislocations on C face with different surface morphology during 4H-SiC solution growth Shiyu Xiao,*, † Shunta Harada,†, ‡ Kenta Murayama, ‡ Miho Tagawa, †, ‡ and Toru Ujihara†, ‡ †

Department of Materials Science and Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan ‡

Center for Integrated Research of Future Electronics (CIRFE), Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan

Corresponding author footnote: Department of Materials Science and Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan TEL: +81-52-789-3249, FAX: +81-52-789-3248 Email: [email protected]


2

Page 3 of 17

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


ABSTRACT: The conversion of threading screw dislocations (TSDs) to defects on basal plane during SiC solution growth caused by macrostep advancing is a key factor to improve crystal quality. We realized on the TSD conversion in 4H-SiC C face solution growth by modification of the surface morphology including macrosteps by addition of 5at%Ti into pure Si solvent. Synchrotron X-ray topography revealed that the possibility of TSD conversion increased to about 10% by the addition of 5at%Ti. In addition, the TSD conversion ratio depends on the shape of macrostep edge. The gentle slope hardly made TSD conversion. The elastic energy of dislocations in anisotropy crystals was postulated for the explanation for the influence of step shape on TSD conversion behavior.


3


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

Page 4 of 17

1. Introduction Sillicon carbide (SiC) is expected to be a promising material for the next-generation high-breakdown and low-loss power devices due to its remarkable physical properties like wide band gap, high breakdown electric field, etc.1 In order to realize the theoretical predicted potential of SiC for power devices, the reduction of defects in crystal wafers such as threading screw dislocation (TSD), threading edge dislocation (TED) and basal plane dislocation (BPD) is extremely crucial. Today, commercially available wafers are grown by physical vapor transport (PVT) method.2 Remarkable progress has been made in reducing defect density of SiC crystal wafers. However, the density of TSD and TED are still on the orders of 102-103 and 103-104 cm-2 respectively.3-9 Solution growth is reported as a potential method to produce high quality crystals because the growth proceeds under the condition close to thermal equilibrium.10 A few groups have been developed SiC growth technique based on the top-seeded solution growth (TSSG) setup.11-13 We have reported a marked reduction of TSD density in 4H-SiC Si face grown crystals by utilizing high TSD conversion phenomenon during solution growth.14 During SiC solution growth, TSDs in seed crystals would convert to defects on basal plane. Those defects on basal plane convert from TSDs in seed crystals are excluded from grown crystals due to extending along in plane direction as the growth proceeds. As a consequence, the ultrahigh quality SiC grown crystals can be obtained. Dudley et al. pointed out that the interaction of macrostep and threading dislocation was responsible for the conversion of threading dislocation during PVT growth.15-18 Yamamoto et al. reported that the conversion phenomenon depended on the polarity of growth surface, Si face and C face. On Si face, the TSD conversion frequently happened, but no TSD conversion was observed on C face solution growth due to the absence of macrosteps.19 Contrary to this,


4

Page 5 of 17

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


4H-SiC C face bulk growth has attracted many attentions due to the difference to the Si face in many aspects such as good polytype stability for crystal growth, high channel mobility for power devices and so on.20-22 Nowadays, C-face seed crystals are often used for stabling polytype and maintaining smooth surface during 4H-SiC bulk growth. However, the TSD conversion cannot be utilized to decrease TSD density like Si face during C-face solution growth since rare TSDs conversion occurs on C-face growth. Thus the reduction of TSD density on C face growth is still a challenge. It is well known that the addition of Ti has been proved to increase step bunching process.23 Si-Ti solvent is often used for TSSG solution growth.11 In our previous study, we reported the effect of the Si-Ti composition on C-face growth morphologies. Macrosteps could be observed on the crystal surface grown with Si-5at%Ti solvent.24 In this study we realized TSD conversion on 4H-SiC C face by changing the morphology with Ti addition to solvent in TSSG. In addition, The effect of step shape at the step edge on TSD conversion behavior was investigated. 2. Experimental details 4H-SiC crystals were grown in an induction-heating furnace (NEV-SC35 Nisshin-Giken) with TSSG method. Off-axis 4H-SiC (000-1) C-face and (0001) Si-face (10 mm ×10 mm) crystals were used as seeds. The off angle was 2° and 4° and the off direction was [11-20]. Pure Si melt and alloy melt with chemical compositions of Si-5at%Ti were used as solvents respectively. 2° off substrates were used to obtain C-face grown crystals while 4° off substrates were used for Si-face growth. A graphite crucible was used to contain the solvent and was used as carbon source, too. The inner diameter of crucible is 45 mm. In order to keep the height of solvent as 20 mm in the crucible, 77.4064 g Si and 6.9435 g Ti was used. The Si for the solvents in experiments possesses a purity of 11N and Ti has a purity of 99.95%. Prior to growth, the


5


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

Page 6 of 17

4H-SiC seed crystals and the polycrystalline silicon were cleaned by sonication in methanol, acetone, and purified water (18 MΩ cm). The temperature at the seed crystal and the bottom of the crucible was measured by thermal couples. The growth temperature gradient was controlled by the relative position of crucible and the heat coil. The seed crystal mounted on the lower end of a graphite rod was dipped in solvent in a graphite crucible. Growth experiments were performed by keeping the seed crystal at 2 mm below the solvent surface under a high-purity (>99.9999 vol%) helium gas flow, where the temperature was at 2023 K and the temperature gradient was about 20 K/cm. The measurement of the temperature and temperature gradient was conducted in another paper.25 The growth time was 1 hour. The growth procedure was described in reference elsewhere.26 The thickness of Si- and C-face grown crystal using pure Si solvent was 11 µm and 10 µm respectively. The thickness of C-face grown crystal using Si-5at%Ti solvent was 10 µm. Dislocations in crystals were characterized by Synchrotron X-ray topography. In order to calculate TSD conversion ratio, topographic images were taken before and after growth over the whole area. Synchrotron X-ray topography was carried out at the high-resolution X-ray diffraction station BL3C in the Photon Factory at the High-Energy Accelerator Research Organization and BL8S2 in Aichi Synchrotron Radiation Center, Japan. The monochromatic X-ray wavelength was 1.50 Å and the applied g vectors were 11-28. The topography images were recorded on Ilford L4 nuclear emulsion plates. Specimens for cross-sectional transmission electron spectroscopy (TEM) were prepared by ion milling focus ion beam (FIB) fabrication. In order to protect the surface from tungsten deposition during FIB fabrication, carbon coating was conducted before FIB fabrication. The cross-sectional TEM observation was conducted by JEOL EM-10000BU along the [1-100] direction. High-angle annular dark field scanning (HAADF)


6

Page 7 of 17

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


images were taken for TEM samples fabricated by ion-milling. Surface morphologies were observed with a differential interference contrast (DIC) microscope Leica DM4000M using a Nomarski-type prism. 3. Results and discussion Fig. 1 shows the C-face morphologies of grown crystal using (a) pure Si solvent and (b) Si-5at%Ti solvent. The grown morphology on the C face from pure Si solvent is different from that grown with Si-5at%Ti. The growth surface by pure Si solvent is covered by smooth ordered step trains and the terrace width is about several micro-meters as shown in Fig. 1(a). On the other hand, two giant macrosteps indicated by white arrows can be observed in Fig. 1(b). No obvious small step is observed distributing on regions between macrosteps by cross-sectional TEM. The step height is about 1-2 µm as we reported before with the addition of 5at%Ti into solvent.24 In addition, the width of terrace increases to 50 µm.

Figure 1. Nomarski images of surface morphologies of grown crystal on C face using (a) pure Si solvent and (b) Si-5at%Ti solvent.


7


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

Page 8 of 17

Figure 2. The change of X-ray topography images of the 4H-SiC (000-1) C-face before and after growth with (a) pure Si solvent and (b) Si-5at%Ti solvent. Fig. 2 shows the change of the defects during 4H-SiC (000-1) C-face growth with (a) pure Si solvent and (b) Si-5at%Ti solvent which were evaluated with X-ray topography. The topographic images were taken at the identical position before and after growth. The large circular bright contrasts in topographic images correspond to TSDs. In the case of pure Si solvent, the TSDs were still observed which indicated that the TSDs propagated from substrate after growth. In the case of Si-Ti solvent knife-shaped contrasts (A') corresponding to defects on basal plane in Fig. 2 (b) extended from the positions of TSDs (A) in the seed crystal, which indicated that TSDs converted to defects on basal plane after growth. The defects on basal plane contrasts aligned on the edge of the advancing steps which appeared as the black horizontal line contrasts. This indicated that the defects on basal plane contrasts were extended by steps advancing. This result concludes again that the TSD conversion phenomenon is strongly related with the advance of macrosteps. We also noticed that TSDs indicated by B' in Fig. 2 (b) propagated from the substrate instead of conversion to defects on basal plane. So, the numbers of TSD before and


8

Page 9 of 17

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


after growth was counted respectively and TSD conversion ratio was calculated for each sample. Comparing to pure Si solvent C-face growth crystal whose TSD conversion ratio is 0, the TSD conversion ratio of C-face crystal increased to about 10% by the addition of 5at%Ti into pure Si solvent. Harada et al. reported that nearly 100% TSDs in off-axis Si face substrate convert to defects on basal plane when the growth thickness achieves 10 µm during solution growth.27 However, the conversion ratio of the present case was limited to be 10 % after about 10 µm growth. In order to clarify the difference of conversion ratio, TEM observation of the detailed step shape was conducted from [1-100] direction.

Figure 3. Cross-sectional TEM images of step shapes on C-face grown crystal using (a) pure Si solvent and (b) Si-5at%Ti solvent and (c) on Si-face grown crystal using pure Si solvent28 ((a) and (c) are dark-field images and (b) is bright-field image.) Insets show the magnification of


9


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

Page 10 of 17

corresponding step facet in (a) and (b) respectively. In order to characterize the step shape, the derivation of step height profile, dy(x)/dx where y(x) is the coordinate of step profile measured from each TEM image are plotted as shown in (d)-(f). Fig. 3 shows the cross-section TEM images of step shapes on (a) C-face grown crystal using pure Si solvent and (b) Si-5at%Ti solvent and (c) on Si-face grown crystal using pure Si solvent (It should be noted that the scale bar of (c) is different from the others.) The step height "H" was evaluated from cross-sectional TEM images of the macrosteps. The step height of C face grown crystal using pure Si solvent was 0.25 µm, but this step was composed of a few small steps as shown in the magnified TEM images. The step height of C face grown crystal using Si-5at%Ti solvent was 1.50 µm which was larger than the height of Si-face crystal, 0.15 µm. The step bunching was promoted with addition of 5at%Ti. The edge of the macrostep was composed of the smooth facet and no obvious small steps were observed. The brighter oblique line in the inset as indicated by the arrow was C coating layer. It is noted that the TSD conversion ratio of C-face grown crystal using Si-5at%Ti solvent is lower than that of Si-face grown crystal from pure Si solvent as mentioned above even though the step height in Fig. 3 (b) is ten times higher than that in Fig. 3 (c). Here we focused on the shape of macrostep. We evaluated the shape by calculating the derivation of shape profile, dy(x)/dx, where y(x) was determined by tracing the shape of steps from TEM image as shown in Fig. 3(d)-(f). The slope of step edge of C-face crystal grown using Si-Ti solvent was clearly gentler than that of Si-face crystal. The angle θ (indicated as in Fig.4) on C face crystal grown from pure Si solvent was 5° and from Si-5at%Ti solvent was 20°. On Si face crystal grown from pure Si solvent the θ increased to 30°. We assumed that the gentler slope on C-face crystal may result in the low conversion ratio.


10

Page 11 of 17

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


Figure 4. Illustration of the influence of θ on the TSD conversion behavior. The θ is identified as the angle between basal plane and facet. (a) TSD propagates (b) converts to defect on basal plane with the newly grown layer with thickness of x. The θ is identified as the angle between basal plane and facet. The discussion has been made from elastic energy aspect for the influence of step shape, which is defined as angle θ between the facet at macrostep edge and terrace as shown in Fig. 4. Here, we consider the elastic energy change of dislocation due to increase in thickness. A dislocation will proceed into a newly grown layer in the direction that the elastic energy of dislocation per unit growth length is minimum.29 If the TSD propagates into a newly grown layer with thickness of x, the energy of the newly elongated dislocation line is written as:

(1)

where is the energy per unit length of TSD and θ is the angle between facet and basal plane. If TSD convert to the defects on the basal plane the energy of the elongate dislocation line is given as


11


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

Page 12 of 17

(2)

where the is the energy per unit length of the defects on basal plane. By comparing the value of Eqs. (1) and (2), the TSD conversion behavior could be determined. When > and there is: tan >

(3)

the dislocation conversion can happen. In other words, the value of

could be seen as a

threshold for TSD conversion. When inequality (3) is satisfied by θ the TSDs would convert to defects on basal plane. Taking into account the elastic anisotropy of crystals, the value of

could be calculated. 29

Then, the value of θ as threshold for TSD conversion could be obtained according to (3). We name this threshold value for TSD conversion as θcritical. When θ is greater than θcritical TSD conversion happens and vice versa. In 4H-SiC crystals, the value of

is about 1.6 and the

θcritical is calculated as 58°. However, the calculation threshold θcritical (58°) is larger than our experiment result. The inconsistency of the calculation and experiment results indicates that the dissociation of defects on basal plane should be considered. The dissociation of defects on basal plane would decrease the value of Es. The reduction of Es of defects on basal plane results in the decrease of θcritical. The dissociation of defects on basal plane could explain our experiment result that TSD conversion happens even though θ is smaller than 58°.


12

Page 13 of 17

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


5. Conclusion We realized TSD conversion on 4H-SiC C-face growth by modification of surface morphology composed of macrosteps using Si-5at%Ti solvent during solution growth. Synchrotron X-ray topography revealed the TSD conversion ratio increased from 0 to nearly 10% after 5at%Ti addition into the solvent. The possibility of conversion depends on the step shapes, that is, the slope of macorostep edge. The steep slope of macrostep is attributed to the high TSD conversion ratio. This result means that not only step height but the step shape could affect TSD conversion behavior. The realization of TSDs conversion on C face is supposed to be beneficial to the reduction of TSD density on 4H-SiC C face growth.

Acknowledgement This study is supported in part by Super Cluster Program from Japan Society and Technology Agency (JST). The authors are grateful to Dr. H. Yamaguchi, Dr. K. Hirano and Dr. Sugiyama for the X-ray topography measurements. The X-ray topography was performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2015G114).


13


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

Page 14 of 17

References (1)

Matsunami, H.; Kimoto, T. Mater. Sci. Eng. R. 1997, 20, 125-166.

(2)

Semmelroth, K.; Schulze, N.; Pensl, G. J. Phys.: Condens. Matter 2004, 16, S1597.

(3)

Nakamura, D.; Gunjishima, I.; Yamaguchi, S.; Ito, T; Okamoto, A.; Kondo, H.; Onda,

S.; Takatori, K. Nature 2004, 430, 1009-1012. (4)

Miyazawa, T.; Tsuchida, H. ECS J. Solid State Sci. Technol. 2013, 2, N3036-N3040.

(5)

Shenai, K.; Dudley, M.; Davis, R. F. ECS J. Solid State Sci. Technol. 2013, 2,

N3055-N3063. (6)

Tsuge, H.; Ushio, S.; Sato, S.; Katsuno, M.; Fujimoto, T.; Yano, T. Mater. Sci. Forum

2013,740, 7-10. (7)

Urakami, Y.; Gunjishima, I.; Yamaguchi, S.; Kondo, H.; Hirose, F.; Adachi, A.; Onda,

S. Mater. Sci. Forum 2012,717, 9-12. (8)

Müller, St. G.; Sanchez, E. K.; Hansen, D. M.; Drachev, R. D.; Chung, G.; Thomas, B.;

Zhang, J.; Loboda, M. J.; Dudley, M.; Wang, H.; Wu, F.; Byrappa, S.; Raghothamachar, B.; Choi, G. J. Cryst. Growth 2012, 352, 39-42. (9)

Quast, J.; Hansen, D.; Loboda, M.; Manning, I.; Moeggenborg, K.; Mueller, S.;

Parfeniuk, C.; Sanchez, E.; Whitely, C. Mater. Sci. Forum 2015, 821, 56-59. (10) Dost, S.; Lent, B. Single Crystal Growth of Semiconductors from Metallic Solutions; Elsevier: Amsterdam, 2007; pp 15-18. (11) Kusunoki, K.; Okada, N.; Kamei, K.; Moriguchi, K.; Daikoku, H; Kado, M.; Sakamoto, H.; Bessho, T.; Ujihara, T. J. Cryst. Growth 2014, 395, 68-73. (12) Chaussende, D.; Jacquier, C.; Ferro, G.; Viala, J.C.; Cauwet, F.; Monteil, Y. Mater. Sci. Forum 2001, 353-356, 85-90.


14

Page 15 of 17

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


(13) Mitani, T.; Komatsu, N.; Takahashi, T.; Kato, T.; Fujii, K.; Ujihara, T.; Matsumoto, Y.; Kurashige, K.; Okumura, H. J. Cryst. Growth 2014, 401, 681-685. (14) Yamamoto, Y.; Harada, S.; Seki, K.; Horio, A.; Mitsuhashi, T.; Koike, D.; Tagawa, M.; Ujihara, T. Appl. Phys. Express 2014, 7, 065501. (15) Dudley, M.; Wu, F.; Wang, H.; Byrappa, S.; Raghothamachar, B.; Choi, G.; Sun, S.; Sanchez, E. K.; Hansen, D.; Drachev, R.; Mueller, S. G.; Lobada, M. J. Appl. Phys. Lett. 2011, 98, 232110. (16) Dudley, M.; Wang, H.; Wu, F.; Byrappa, S.; Raghothamachar, B.; Choi, G.; Sanchez, E. K.; Hansen, D.; Drachev, R.; Mueller, S. G.; Lobada, M. J. Mater. Sci. Forum 2011, 679, 269-272. (17) Wang, H.; Byrappa, S.; Wu, F.; Raghothamachar, B.; Dudley, M.; Sanchez, E. K.; Hansen, D.; Drachev, R.; Mueller, S. G.; Lobada, M. J. Mater. Sci. Forum 2012, 717, 327-330. (18) Byrappa, S.; Wu, F.; Wang, H.; Raghothamachar, B.; Choi, G.; Sun, S.; Dudley, M.; Sanchez, E. K.; Hansen, D.; Drachev, R.; Mueller, S. G.; Lobada, M. J. Mater. Sci. Forum 2012, 717, 347-350. (19) Yamamoto, Y.; Harada, S.; Seki, K.; Horio, A.; Mitsuhashi, T.; Ujihara, T. Appl. Phys. Express 2012, 5, 115501. (20) Kojima, K.; Okumura, H.;Kuroda, S.; Arai, K.; Ohi, A.; Akinaga, H. Mater. Sci. Forum 2005, 483, 93-96. (21) Tanaka, Y.; Fukuda, K.; Arai, K.; Kojima, K.; Suzuki, T.; Yatsuo, T. Appl. Phys. Lett. 2004, 84, 1774-1776. (22) Fukuda, K.; Senzaki, J.; Kojima, K.; Suzuki, T. Mater. Sci. Forum 2002, 433, 567-570.


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

Page 16 of 17

(23) Komatsu, N.; Mitani, T.; Okamura, M. Takahashi, T.; Kato, T.; Ujihara, T.; Matsunomto, U.; Kurashige, K. Research on solvent composition for supression of macroscopic surface defects in 4H-SiC solution growth. Presented at the 22nd Meeting on SiC and Related Semiconductors, Saitama Japan, December 9-10, 2013. (24) Xiao, S.; Hara, N.; Harada, S.; Murayama, K.; Aoyagi, K.; Sakai, T.; Ujihara, T. Mater. Sci. Forum 2015, 821, 39-42. (25) Seki, K.; Alexander; Kozawa, S.; Ujihara, T.; Chaudouët, P.; Chaussende, D.; Takeda, Y. J. Cryst. Growth 2011, 335, 94-99. (26) Zhu, C.; Harada, S.; Seki, K.; Zhang, H.; Niinomi, H.; Tagawa, M.; T.; Ujihara, T. Cryst. Growth Des. 2013, 13, 3691-3696. (27) Harada, S.; Yamamoto, Y.; Seki, K.; Horio, A.; Mitsuhashi, T.; Tagawa, M.; Ujihara, T. APL Mater. 2013, 1, 022109. (28) Harada, S.; Yamamoto, Y.; Xiao, SY.; Tagawa, M.; Ujihara, T. Mater. Sci. Forum 2014, 778, 67-70. (29) Klapper H.; Küppers, H. Acta Cryst. 1973, A 29, 495-503.


16

Page 17 of 17

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


Table of Contents Conversion behavior of threading screw dislocations on C face with different surface morphology during 4H-SiC solution growth Shiyu Xiao,* Shunta Harada, Kenta Murayama, Miho Tagawa and Toru Ujihara

The conversion of threading screw dislocations (TSDs) to stacking faults (Defects on basal plane) were realized on 4H-SiC C face solution growth by the addition of 5at%Ti into solvent. This result is supposed to be beneficial to the reduction of TSD density on 4H-SiC C face growth.


17

Conversion Behavior of Threading Screw Dislocations on C Face

Recommend Documents