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【Domestic Papers】Researchers Led by Prof. Xutang Tao from the Shandong University——2-inch diameter (010) principal-face β-Ga₂O₃ single crystals grown by EFG method
日期：2025-03-04阅读：84
Researchers from the Shandong University have published a dissertation titled "2-inch diameter (010) principal-face β-Ga2O3 single crystals grown by EFG method " in Journal of Semiconductors.
Program Support
The authors gratefully acknowledge the support by the fund of the National Natural Science Foundation of China (NSFC) (Grant Number: U23A20358, 51932004), Key-Area Research and Development Program of Guangdong Province (Grant Number: 2020B010174002), Natural Science Foundation of Shandong Province (ZR2023ZD05, 2022TSGC2120), the Shenzhen Fundamental Research Program (Grant No. GJHZ20220913142605011), and the 111 Project 2.0 (Grant No. BP2018013). Laboratory Construction and Management Research Project of Shandong University (Project No. sy20233203)
Abstract
The (010)-oriented substrates of β-Ga2O3 are endowed with the maximum thermal conductivity and fastest homoepitaxial rate, which is the preferred substrate direction for high-power devices. However, the size of (010) plane wafer is critically limited by die in the commercial edge-defined film-fed growth (EFG) method. It is difficult to grow the β-Ga2O3 crystal with (010) principal face due to the (100) and (001) are cleavage planes. Here, the 2-inch diameter (010) principal-face β-Ga2O3 single crystal is successfully designed and grown by improved EFG method. Unlike previous reported techniques, the single crystals are pulled with [001] direction, and in this way the (010) wafers can be obtained from the principal face. In our experiments, tree-like defects (TLDs) in (010) principal-face bulk crystals are easy to generate. The relationship between stability of growth interface and origin of TLDs are thoroughly discussed. The TLDs are successfully eliminated by optimizing growth conditions. The high crystalline quality of (010)-oriented substrates are comprehensive demonstrated by full width at half maximum (FWHM) with 50.4 arcsec, consistent orientation arrangement of (010) plane, respectively. This work shows that the (010)-oriented substrates can be obtained by EFG method, predicting the commercial prospects of large-scale (010)-oriented β-Ga2O3 substrates.
Fig. 1. (a) Schematic diagram of (010) principal-face β-Ga2O3 bulk crystals grown by EFG method. (b) (010) principal-face macro-morphology image of TLDs, showing obvious branching tendency of evolution process with (001) pulling direction from right to left. (c) Enlarged-morphology image of red rectangular block from (b). (d) Micro-morphology image of TLDs of yellow rectangular block in (b). (e) 2-inch diameter (010) principal-face non-TLDs β-Ga2O3 single crystal.
Fig. 2. (a) SEM image of (010) principal-face β-Ga2O3 bulk crystals growth cross section at early pulling stage, the bright region with branches is cross-sectional TLDs, enlarged images of (b) − (f) are different location in (a) marked by yellow rectangular block, and the location of (b) is termination point of TLDs, exhibiting destructive effect for crystalline structure of β-Ga2O3 bulk crystals. (g) SEM image of growth cross section at later growth stage of the same bulk crystal, the bright region is cross-sectional TLDs, showing the worse surface morphology than early stage in (a), enlarged images of (h) and (i) are also marked in (g), indicating severe deteriorating scene of TLDs.
LINK：
https://www.jos.ac.cn/en/article/doi/10.1088/1674-4926/24110029
