Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

Guang Yang; Hao Luo; Jiajun Li; Qinqin Shao; Yazhe Wang; Ruzhong Zhu; Xi Zhang; Lihui Song; Yiqiang Zhang; Lingbo Xu; Can Cui; Xiaodong Pi; Deren Yang; Rong Wang

doi:10.1088/1674-4926/43/12/122801

J. Semicond. > 2022, Volume 43 > Issue 12 > 122801, doi: 10.1088/1674-4926/43/12/122801

ARTICLES

Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

Guang Yang^{1, 2, 3}, Hao Luo^{2, 3}, Jiajun Li^{2, 3}, Qinqin Shao^{2, 3}, Yazhe Wang^{2, 3}, Ruzhong Zhu^{2, 3}, Xi Zhang^{2, 3}, Lihui Song^{2, 3}, Yiqiang Zhang⁴, Lingbo Xu¹, Can Cui^1,, Xiaodong Pi^{2, 3,}, Deren Yang^{2, 3} and Rong Wang^{2, 3,}

+ Author Affiliations

Corresponding author: Can Cui, cancui@zstu.edu.cn; Xiaodong Pi, xdpi@zju.edu.cn; Rong Wang, rong_wang@zju.edu.cn

Abstract: Discrimination of dislocations is critical to the statistics of dislocation densities in 4H silicon carbide (4H-SiC), which are routinely used to evaluate the quality of 4H-SiC single crystals and homoepitaxial layers. In this work, we show that the inclination angles of the etch pits of molten-alkali etched 4H-SiC can be adopted to discriminate threading screw dislocations (TSDs), threading edge dislocations (TEDs) and basal plane dislocations (BPDs) in 4H-SiC. In n-type 4H-SiC, the inclination angles of the etch pits of TSDs, TEDs and BPDs in molten-alkali etched 4H-SiC are in the ranges of 27°−35°, 8°−15° and 2°−4°, respectively. In semi-insulating 4H-SiC, the inclination angles of the etch pits of TSDs and TEDs are in the ranges of 31°−34° and 21°−24°, respectively. The inclination angles of dislocation-related etch pits are independent of the etching duration, which facilitates the discrimination and statistic of dislocations in 4H-SiC. More significantly, the inclination angle of a threading mixed dislocations (TMDs) is found to consist of characteristic angles of both TEDs and TSDs. This enables to distinguish TMDs from TSDs in 4H-SiC.

Key words: 4H-SiC single crystals, dislocations, molten-alkali etching

References

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[3]	Yoon J, Kim K. A 3.3 kV 4H-SiC split gate MOSFET with a central implant region for superior trade-off between static and switching performance. J Semicond, 2021, 42, 062803 doi: 10.1088/1674-4926/42/6/062803
[4]	Yeo I G, Yang W S, Park J H, et al. Two-inch a-plane (11-20) 6H-SiC crystal grown by using the PVT method from a small rectangular substrate. J Korean Phy Soc, 2011, 58, 1541 doi: 10.3938/jkps.58.1541
[5]	She X, Huang A Q, Lucía Ó, et al. Review of silicon carbide power devices and their applications. IEEE Trans Ind Electron, 2017, 64, 8193 doi: 10.1109/TIE.2017.2652401
[6]	Wang X, Zhong Y W, Pu H B, et al. Investigation of lateral spreading current in the 4H-SiC Schottky barrier diode chip. J Semicond, 2021, 42, 112802 doi: 10.1088/1674-4926/42/11/112802
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[10]	Wang J F, Yan F F, Li Q, et al. Coherent control of nitrogen-vacancy center spins in silicon carbide at room temperature. Phys Rev Lett, 2020, 124, 223601 doi: 10.1103/PhysRevLett.124.223601
[11]	Wang J F, Yan F F, Li Q, et al. Robust coherent control of solid-state spin qubits using anti-Stokes excitation. Nat Commun, 2021, 12, 3223 doi: 10.1038/s41467-021-23471-8
[12]	Ha S, Benamara M, Skowronski M, et al. Core structure and properties of partial dislocations in silicon carbide p-i-n diodes. Appl Phys Lett, 2003, 83, 4957 doi: 10.1063/1.1633969
[13]	Abadier M, Myers-Ward R L, Mahadik N A, et al. Nucleation of in-grown stacking faults and dislocation half-loops in 4H-SiC epitaxy. J Appl Phys, 2013, 114, 123502 doi: 10.1063/1.4821242
[14]	Wahab Q, Ellison A, Henry A, et al. Influence of epitaxial growth and substrate-induced defects on the breakdown of 4H-SiC Schottky diodes. Appl Phys Lett, 2000, 76, 2725 doi: 10.1063/1.126456
[15]	Neudeck P G, Powell J A. Performance limiting micropipe defects in silicon carbide wafers. IEEE Electron Device Lett, 1994, 15, 63 doi: 10.1109/55.285372
[16]	Grekov A, Zhang Q C, Fatima H, et al. Effect of crystallographic defects on the reverse performance of 4H-SiC JBS diodes. Microelectron Reliab, 2008, 48, 1664 doi: 10.1016/j.microrel.2008.05.001
[17]	Neudeck P G, Huang W, Dudley M. Study of bulk and elementary screw dislocation assisted reverse breakdown in low-voltage (<250 V) 4H-SiC p+n junction diodes. I. DC properties. IEEE Trans Electron Devices, 1999, 46, 478 doi: 10.1109/16.748865
[18]	Stahlbush R E, Twigg M E, Sumakeris J J, et al. Mechanisms of stacking fault growth in SiC PiN diodes. MRS Online Proc Libr, 2004, 815, 241 doi: 10.1557/PROC-815-J6.4
[19]	Ha S, Chung H J, Nuhfer N T, et al. Dislocation nucleation in 4H silicon carbide epitaxy. J Cryst Growth, 2004, 262, 130 doi: 10.1016/j.jcrysgro.2003.09.054
[20]	Zhuang D, Edgar J H. Wet etching of GaN, AlN, and SiC: a review. Mater Sci Eng R, 2005, 48, 1 doi: 10.1016/j.mser.2004.11.002
[21]	Christiansen K, Helbig R. Anisotropic oxidation of 6H-SiC. J Appl Phys, 1996, 79, 3276 doi: 10.1063/1.361225
[22]	Geng W, Yang G, Zhang X, et al. Identification of subsurface damages of 4H-SiC wafers by combining photo-chemical etching and molten-alkali etching. J Semicond, 2022, 43, 102801 doi: 10.1088/1674-4926/43/10/102801
[23]	Brander R W, Boughey A L. The etching of-silicon carbide. Br J Appl Phys, 1967, 18, 905 doi: 10.1088/0508-3443/18/7/304
[24]	Dong L, Zheng L, Liu X F, et al. Defect revelation and evaluation of 4H silicon carbide by optimized molten KOH etching method. Mater Sci Forum, 2013, 740, 243 doi: 10.4028/www.scientific.net/MSF.740-742.243
[25]	Li J J, Luo H, Yang G, et al. Nitrogen decoration of basal-plane dislocations in 4H-SiC. Phys Rev Appl, 2022, 17, 054011 doi: 10.1103/PhysRevApplied.17.054011
[26]	Katsuno M, Ohtani N, Takahashi J, et al. Mechanism of molten KOH etching of SiC single crystals: Comparative study with thermal oxidation. Jpn J Appl Phys, 1999, 38, 4661 doi: 10.1143/JJAP.38.4661
[27]	Sakwe S A, Müller R, Wellmann P J. Optimization of KOH etching parameters for quantitative defect recognition in n- and p-type doped SiC. J Cryst Growth, 2006, 289, 520 doi: 10.1016/j.jcrysgro.2005.11.096
[28]	Yao Y Z, Ishikawa Y, Sugawara Y, et al. Molten KOH etching with Na₂O₂additive for dislocation revelation in 4H-SiC epilayers and substrates. Jpn J Appl Phys, 2011, 50, 075502 doi: 10.1143/JJAP.50.075502
[29]	Siche D, Klimm D, Hölzel T, et al. Reproducible defect etching of SiC single crystals. J Cryst Growth, 2004, 270, 1 doi: doi.org/10.1016/j.jcrysgro.2004.05.098
[30]	Yang Y, Chen Z Z. Defect characterization of SiC by wet etching process. J Synth Cryst, 2008, 37, 634 doi: 10.16553/j.cnki.issn1000-985x.2008.03.051
[31]	Song H Z, Sudarshan T S. Basal plane dislocation mitigation in SiC epitaxial growth by nondestructive substrate treatment. Cryst Growth Des, 2012, 12, 1703 doi: 10.1021/cg300077g
[32]	Luo H, Li J J, Yang G, et al. Electronic and optical properties of threading dislocations in n-type 4H-SiC. ACS Appl Electron Mater, 2022, 4, 1678 doi: 10.1021/acsaelm.1c01330
[33]	Takahashi J, Kanaya M, Fujiwara Y. Sublimation growth of SiC single crystalline ingots on faces perpendicular to the (0001) basal plane. J Cryst Growth, 1994, 135, 61 doi: 10.1016/0022-0248(94)90726-9
[34]	Gao Y, Zhang Z H, Bondokov R, et al. The effect of doping concentration and conductivity type on preferential etching of 4H-SiC by molten KOH. MRS Online Proc Libr, 2004, 815, 6 doi: https://doi.org/10.1557/PROC-815-J5.20
[35]	Zhang Y, Chen H, Liu D Z, et al. High efficient polishing of sliced 4H-SiC (0001) by molten KOH etching. Appl Surf Sci, 2020, 525, 146532 doi: 10.1016/j.apsusc.2020.146532
[36]	Cui Y X, Hu X B, Xie X J, et al. Threading dislocation classification for 4H-SiC substrates using the KOH etching method. CrystEngComm, 2018, 20, 978 doi: 10.1039/C7CE01855J
[37]	Nakamura D, Yamaguchi S, Gunjishima I, et al. Topographic study of dislocation structure in hexagonal SiC single crystals with low dislocation density. J Cryst Growth, 2007, 304, 57 doi: 10.1016/j.jcrysgro.2007.02.002
[38]	Konishi K, Nakamura Y, Nagae A, et al. Direct observation and three dimensional structural analysis for threading mixed dislocation inducing current leakage in 4H-SiC IGBT. Jpn J Appl Phys, 2020, 59, 011001 doi: 10.7567/1347-4065/ab5ee8
[39]	Yao Y Z, Ishikawa Y, Sugawara Y, et al. Correlation between etch pits formed by molten KOH+Na₂O₂ etching and dislocation types in heavily doped n⁺-4H-SiC studied by X-ray topography. J Cryst Growth, 2013, 364, 7 doi: 10.1016/j.jcrysgro.2012.12.011
[40]	Fukunaga K, Jun S D, Kimoto T. Anisotropic etching of single crystalline SiC using molten KOH for SiC bulk micromachining. Micromachining and Microfabrication Process Technology XI, 2006 doi: https://doi.org/10.1117/12.647116
[41]	Katsuno T, Watanabe Y, Hirokazu F, et al. New separation method of threading dislocations in 4H-SiC epitaxial layer by molten KOH etching. Mater Sci Forum, 2011, 679/680, 298 doi: 10.4028/www.scientific.net/MSF.679-680.298

Fig. 1. (Color online) Representative OM images of etched 4H-SiC samples. The doping profiles and etching durations are labelled in etch figure.

DownLoad: Full-Size Img PowerPoint

Fig. 2. (Color online) Representative OM images of molten-KOH etched 4H-SiC with the etching duration of 30 min. The doping of 4H-SiC and molten additives are labelled in the figure.

DownLoad: Full-Size Img PowerPoint

Fig. 3. (Color online) The LSCM images and depth profiles of (a) TSD, (b) TED, and (c) BPD.

DownLoad: Full-Size Img PowerPoint

Fig. 4. (Color online) The relationship between the sizes and inclination angles of the etch pits in (a) n-type SiC and (b) SI SiC.

DownLoad: Full-Size Img PowerPoint

Fig. 5. (Color online) The average (a) size and (b) inclination angle of etch pits of different dislocations as functions of the etching duration in both n-type and SI 4H-SiC.

DownLoad: Full-Size Img PowerPoint

Fig. 6. (Color online) (a) OM, (b) AFM, and (c) LSCM images of a representative TMD. (d) Depth profile of the TMD.

DownLoad: Full-Size Img PowerPoint

Fig. 7. (Color online) TEM images at (a) g = 0004 and (b) g = $1\bar{2}10$ of the etch pit of TMD.

DownLoad: Full-Size Img PowerPoint

[1]	Casady J B, Johnson R W. Status of silicon carbide (SiC) as a wide-bandgap semiconductor for high-temperature applications: A review. Solid State Electron, 1996, 39, 1409 doi: 10.1016/0038-1101(96)00045-7
[2]	Wright N G, Horsfall A B, Vassilevski K. Prospects for SiC electronics and sensors. Mater Today, 2008, 11, 16 doi: 10.1016/S1369-7021(07)70348-6
[3]	Yoon J, Kim K. A 3.3 kV 4H-SiC split gate MOSFET with a central implant region for superior trade-off between static and switching performance. J Semicond, 2021, 42, 062803 doi: 10.1088/1674-4926/42/6/062803
[4]	Yeo I G, Yang W S, Park J H, et al. Two-inch a-plane (11-20) 6H-SiC crystal grown by using the PVT method from a small rectangular substrate. J Korean Phy Soc, 2011, 58, 1541 doi: 10.3938/jkps.58.1541
[5]	She X, Huang A Q, Lucía Ó, et al. Review of silicon carbide power devices and their applications. IEEE Trans Ind Electron, 2017, 64, 8193 doi: 10.1109/TIE.2017.2652401
[6]	Wang X, Zhong Y W, Pu H B, et al. Investigation of lateral spreading current in the 4H-SiC Schottky barrier diode chip. J Semicond, 2021, 42, 112802 doi: 10.1088/1674-4926/42/11/112802
[7]	Lukin D M, Dory C, Guidry M A, et al. 4H-silicon-carbide-on-insulator for integrated quantum and nonlinear photonics. Nat Photonics, 2020, 14, 330 doi: 10.1038/s41566-019-0556-6
[8]	von Bardeleben H J, Cantin J L, Csóré A, et al. NV centers in 3C, 4H, and 6H silicon carbide: A variable platform for solid-state qubits and nanosensors. Phys Rev B, 2016, 94, 121202 doi: 10.1103/PhysRevB.94.121202
[9]	Banks H B, Soykal Ö O, Myers-Ward R L, et al. Resonant optical spin initialization and readout of single silicon vacancies in 4H-SiC. Phys Rev Appl, 2019, 11, 024013 doi: 10.1103/PhysRevApplied.11.024013
[10]	Wang J F, Yan F F, Li Q, et al. Coherent control of nitrogen-vacancy center spins in silicon carbide at room temperature. Phys Rev Lett, 2020, 124, 223601 doi: 10.1103/PhysRevLett.124.223601
[11]	Wang J F, Yan F F, Li Q, et al. Robust coherent control of solid-state spin qubits using anti-Stokes excitation. Nat Commun, 2021, 12, 3223 doi: 10.1038/s41467-021-23471-8
[12]	Ha S, Benamara M, Skowronski M, et al. Core structure and properties of partial dislocations in silicon carbide p-i-n diodes. Appl Phys Lett, 2003, 83, 4957 doi: 10.1063/1.1633969
[13]	Abadier M, Myers-Ward R L, Mahadik N A, et al. Nucleation of in-grown stacking faults and dislocation half-loops in 4H-SiC epitaxy. J Appl Phys, 2013, 114, 123502 doi: 10.1063/1.4821242
[14]	Wahab Q, Ellison A, Henry A, et al. Influence of epitaxial growth and substrate-induced defects on the breakdown of 4H-SiC Schottky diodes. Appl Phys Lett, 2000, 76, 2725 doi: 10.1063/1.126456
[15]	Neudeck P G, Powell J A. Performance limiting micropipe defects in silicon carbide wafers. IEEE Electron Device Lett, 1994, 15, 63 doi: 10.1109/55.285372
[16]	Grekov A, Zhang Q C, Fatima H, et al. Effect of crystallographic defects on the reverse performance of 4H-SiC JBS diodes. Microelectron Reliab, 2008, 48, 1664 doi: 10.1016/j.microrel.2008.05.001
[17]	Neudeck P G, Huang W, Dudley M. Study of bulk and elementary screw dislocation assisted reverse breakdown in low-voltage (<250 V) 4H-SiC p+n junction diodes. I. DC properties. IEEE Trans Electron Devices, 1999, 46, 478 doi: 10.1109/16.748865
[18]	Stahlbush R E, Twigg M E, Sumakeris J J, et al. Mechanisms of stacking fault growth in SiC PiN diodes. MRS Online Proc Libr, 2004, 815, 241 doi: 10.1557/PROC-815-J6.4
[19]	Ha S, Chung H J, Nuhfer N T, et al. Dislocation nucleation in 4H silicon carbide epitaxy. J Cryst Growth, 2004, 262, 130 doi: 10.1016/j.jcrysgro.2003.09.054
[20]	Zhuang D, Edgar J H. Wet etching of GaN, AlN, and SiC: a review. Mater Sci Eng R, 2005, 48, 1 doi: 10.1016/j.mser.2004.11.002
[21]	Christiansen K, Helbig R. Anisotropic oxidation of 6H-SiC. J Appl Phys, 1996, 79, 3276 doi: 10.1063/1.361225
[22]	Geng W, Yang G, Zhang X, et al. Identification of subsurface damages of 4H-SiC wafers by combining photo-chemical etching and molten-alkali etching. J Semicond, 2022, 43, 102801 doi: 10.1088/1674-4926/43/10/102801
[23]	Brander R W, Boughey A L. The etching of-silicon carbide. Br J Appl Phys, 1967, 18, 905 doi: 10.1088/0508-3443/18/7/304
[24]	Dong L, Zheng L, Liu X F, et al. Defect revelation and evaluation of 4H silicon carbide by optimized molten KOH etching method. Mater Sci Forum, 2013, 740, 243 doi: 10.4028/www.scientific.net/MSF.740-742.243
[25]	Li J J, Luo H, Yang G, et al. Nitrogen decoration of basal-plane dislocations in 4H-SiC. Phys Rev Appl, 2022, 17, 054011 doi: 10.1103/PhysRevApplied.17.054011
[26]	Katsuno M, Ohtani N, Takahashi J, et al. Mechanism of molten KOH etching of SiC single crystals: Comparative study with thermal oxidation. Jpn J Appl Phys, 1999, 38, 4661 doi: 10.1143/JJAP.38.4661
[27]	Sakwe S A, Müller R, Wellmann P J. Optimization of KOH etching parameters for quantitative defect recognition in n- and p-type doped SiC. J Cryst Growth, 2006, 289, 520 doi: 10.1016/j.jcrysgro.2005.11.096
[28]	Yao Y Z, Ishikawa Y, Sugawara Y, et al. Molten KOH etching with Na₂O₂additive for dislocation revelation in 4H-SiC epilayers and substrates. Jpn J Appl Phys, 2011, 50, 075502 doi: 10.1143/JJAP.50.075502
[29]	Siche D, Klimm D, Hölzel T, et al. Reproducible defect etching of SiC single crystals. J Cryst Growth, 2004, 270, 1 doi: doi.org/10.1016/j.jcrysgro.2004.05.098
[30]	Yang Y, Chen Z Z. Defect characterization of SiC by wet etching process. J Synth Cryst, 2008, 37, 634 doi: 10.16553/j.cnki.issn1000-985x.2008.03.051
[31]	Song H Z, Sudarshan T S. Basal plane dislocation mitigation in SiC epitaxial growth by nondestructive substrate treatment. Cryst Growth Des, 2012, 12, 1703 doi: 10.1021/cg300077g
[32]	Luo H, Li J J, Yang G, et al. Electronic and optical properties of threading dislocations in n-type 4H-SiC. ACS Appl Electron Mater, 2022, 4, 1678 doi: 10.1021/acsaelm.1c01330
[33]	Takahashi J, Kanaya M, Fujiwara Y. Sublimation growth of SiC single crystalline ingots on faces perpendicular to the (0001) basal plane. J Cryst Growth, 1994, 135, 61 doi: 10.1016/0022-0248(94)90726-9
[34]	Gao Y, Zhang Z H, Bondokov R, et al. The effect of doping concentration and conductivity type on preferential etching of 4H-SiC by molten KOH. MRS Online Proc Libr, 2004, 815, 6 doi: https://doi.org/10.1557/PROC-815-J5.20
[35]	Zhang Y, Chen H, Liu D Z, et al. High efficient polishing of sliced 4H-SiC (0001) by molten KOH etching. Appl Surf Sci, 2020, 525, 146532 doi: 10.1016/j.apsusc.2020.146532
[36]	Cui Y X, Hu X B, Xie X J, et al. Threading dislocation classification for 4H-SiC substrates using the KOH etching method. CrystEngComm, 2018, 20, 978 doi: 10.1039/C7CE01855J
[37]	Nakamura D, Yamaguchi S, Gunjishima I, et al. Topographic study of dislocation structure in hexagonal SiC single crystals with low dislocation density. J Cryst Growth, 2007, 304, 57 doi: 10.1016/j.jcrysgro.2007.02.002
[38]	Konishi K, Nakamura Y, Nagae A, et al. Direct observation and three dimensional structural analysis for threading mixed dislocation inducing current leakage in 4H-SiC IGBT. Jpn J Appl Phys, 2020, 59, 011001 doi: 10.7567/1347-4065/ab5ee8
[39]	Yao Y Z, Ishikawa Y, Sugawara Y, et al. Correlation between etch pits formed by molten KOH+Na₂O₂ etching and dislocation types in heavily doped n⁺-4H-SiC studied by X-ray topography. J Cryst Growth, 2013, 364, 7 doi: 10.1016/j.jcrysgro.2012.12.011
[40]	Fukunaga K, Jun S D, Kimoto T. Anisotropic etching of single crystalline SiC using molten KOH for SiC bulk micromachining. Micromachining and Microfabrication Process Technology XI, 2006 doi: https://doi.org/10.1117/12.647116
[41]	Katsuno T, Watanabe Y, Hirokazu F, et al. New separation method of threading dislocations in 4H-SiC epitaxial layer by molten KOH etching. Mater Sci Forum, 2011, 679/680, 298 doi: 10.4028/www.scientific.net/MSF.679-680.298

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Received: 24 May 2022 Revised: 30 July 2022 Online: Accepted Manuscript: 01 September 2022Uncorrected proof: 02 September 2022Published: 02 December 2022

Article Navigation > Journal of Semiconductors > 2022 > 43(12): 122801

Guang Yang, Hao Luo, Jiajun Li, Qinqin Shao, Yazhe Wang, Ruzhong Zhu, Xi Zhang, Lihui Song, Yiqiang Zhang, Lingbo Xu, Can Cui, Xiaodong Pi, Deren Yang, Rong Wang. Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits[J]. Journal of Semiconductors, 2022, 43(12): 122801. doi: 10.1088/1674-4926/43/12/122801 G Yang, H Luo, J J Li, Q Q Shao, Y Z Wang, R Z Zhu, X Zhang, L H Song, Y Q Zhang, L B Xu, C Cui, X D Pi, D R Yang, R Wang. Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits[J]. J. Semicond, 2022, 43(12): 122801. doi: 10.1088/1674-4926/43/12/122801Export: BibTex EndNote

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G Yang, H Luo, J J Li, Q Q Shao, Y Z Wang, R Z Zhu, X Zhang, L H Song, Y Q Zhang, L B Xu, C Cui, X D Pi, D R Yang, R Wang. Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits[J]. J. Semicond, 2022, 43(12): 122801. doi: 10.1088/1674-4926/43/12/122801

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Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

doi: 10.1088/1674-4926/43/12/122801

Guang Yang^{1, 2, 3},
Hao Luo^{2, 3},
Jiajun Li^{2, 3},
Qinqin Shao^{2, 3},
Yazhe Wang^{2, 3},
Ruzhong Zhu^{2, 3},
Xi Zhang^{2, 3},
Lihui Song^{2, 3},
Yiqiang Zhang⁴,
Lingbo Xu¹,
Can Cui^1,,
Xiaodong Pi^{2, 3,},
Deren Yang^{2, 3},
Rong Wang^{2, 3,}

1.
Key Laboratory of Optical Field Manipulation of Zhejiang Province, Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China
2.
State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
3.
Hangzhou Innovation Center, Zhejiang University, Hangzhou 311200, China
4.
School of Materials Science and Engineering & Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450001, China

More Information

Author Bio:
Guang Yang is a master’s degree student of school of science, Zhejiang Sci-Tech University, class of 2020. His research focuses on dislocations in 4H-SiC

Can Cui received his Ph.D. degree at Zhejiang University in 2006. He then carried out research at Tohoku University and National Institute for Materials Science. He is now a professor in Zhejiang Sci-Tech University. His research mainly focuses on crystal growth and optoelectronic devices

Xiaodong Pi received his Ph.D. degree at the University of Bath in 2004. He then carried out research at McMaster University and the University of Minnesota at Twin Cities. He joined Zhejiang University as an associate professor in 2008. He is now a professor in the State Key Laboratory of Silicon Materials, the School of Materials Science and Engineering and Hangzhou Innovation Center at Zhejiang University. His research mainly concerns group IV semiconductor materials and devices

Deren Yang is an academician of Chinese Academy of Science, present of NingboTech University, director of Faculty of Engineering at Zhejiang University and chief scientist of Hangzhou Innovation Center of Zhejiang University. He received his Ph.D. in 1991, at Zhejiang University. In 1990s, he worked in Japan, Germany, and Sweden for several years as a visiting researcher. He has been engaged in research on silicon materials for microelectronic devices, solar cells, and nanodevices

Rong Wang received her Ph.D. degree at Zhejiang University in 2014. She then carried out research at Taiyuan University of Technology and China Academy of Engineering Physics. She joined Hangzhou Innovation Center of Zhejiang University in 2020. Her research mainly focuses on wide-bandgap semiconductor physics
Corresponding author: cancui@zstu.edu.cn; xdpi@zju.edu.cn; rong_wang@zju.edu.cn
Received Date: 2022-05-24
Revised Date: 2022-07-30

Available Online: 2022-09-01

Abstract

Abstract

Discrimination of dislocations is critical to the statistics of dislocation densities in 4H silicon carbide (4H-SiC), which are routinely used to evaluate the quality of 4H-SiC single crystals and homoepitaxial layers. In this work, we show that the inclination angles of the etch pits of molten-alkali etched 4H-SiC can be adopted to discriminate threading screw dislocations (TSDs), threading edge dislocations (TEDs) and basal plane dislocations (BPDs) in 4H-SiC. In n-type 4H-SiC, the inclination angles of the etch pits of TSDs, TEDs and BPDs in molten-alkali etched 4H-SiC are in the ranges of 27°−35°, 8°−15° and 2°−4°, respectively. In semi-insulating 4H-SiC, the inclination angles of the etch pits of TSDs and TEDs are in the ranges of 31°−34° and 21°−24°, respectively. The inclination angles of dislocation-related etch pits are independent of the etching duration, which facilitates the discrimination and statistic of dislocations in 4H-SiC. More significantly, the inclination angle of a threading mixed dislocations (TMDs) is found to consist of characteristic angles of both TEDs and TSDs. This enables to distinguish TMDs from TSDs in 4H-SiC.
- 4H-SiC single crystals,
- dislocations,
- molten-alkali etching

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References

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Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

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Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

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Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

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Discrimination of dislocations in 4H-SiC by inclination angles of molten-alkali etched pits

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