报告题目：Defect Engineering of Wide Band Gap Semiconductors

报告人：Prof. Ling, Francis Chi Chung 凌志聰，香港大学

时 间：2025.10.27（周一）下午2:30

地 点：粤海校区南校区致原楼1206

邀请人：曾昱嘉 教授

报告简介：

Atomic-scale intrinsic defects and the corresponding defect complexes play crucial role in determining the material’s electrical, optical, magnetic and dielectric properties. Defect engineering, which includes defect characterization as well as creating and removing defects, can introduce new functionality to old materials, tailor materials properties, improve semiconductor device performance and realize selective phase control on material growth [1].

In the current seminar, I will discuss some of our results namely in defect engineering of high-k oxides and silicon carbide devices. Permittivity of ZnO, Al2O3 and HfO2 were enhanced by respectively 20 times, 40 % and 60 % via acceptor-donor co-doping [2-4]. With experimental and model simulation evidence, acceptor-donor defect complex is formed. The electronic correlated barrier hopping between the adjacent defect complexes enhances the polarization and thus the permittivity [2, 5]. With the guidance of density functional calculation, we have also achieved selective growth of phase Sb2O3 van de Waals film by controlling the oxygen vacancy abundance. The permittivity of the pure -phase film exhibits a high permittivity of ~100 [6].

Fundamental atomic scale defect study in SiC were carried out using deep level transient spectroscopy and positron annihilation spectroscopy [7-9]. I will show how these fundamental physics results benefit the SiC device industry. Collaborating with Mainland SiC industry, we worked to suppress the leakage current of commercial SiC diode. The leakage was found to be dominated by Poole-Frenkel emission from the carbon vacancy to the conduction band [10, 11]. We have developed a new p-type doping procedure for suppressing the creation of carbon vacancy, resulting in the reduction of leakage current by 30 times. The company adopted the process in their mass production line and over 30M units of devices have been produced.

[1] Francis Chi-Chung Ling S Z, Andrej Kuznetsov ed 2021 Defects in Functional Materials (Singapore: World Scientific)

[2] Huang D, Shi, Y., Younas, M., Khan, R. T. A., Nadeem, M., Shati, K., Harfouche, M., Kentsch, U., Liu, Z., Li, Y., Zhou, S., Kuznestov, A., Ling, F. C-C 2022 Small 18 2107168

[3] Yu J G, Guoyun; Han, Wei; Wei, Changting; Wang, Yueyang; Lin, Tianxiang; Zhang, Tianyu; Zheng, Zhi; Ki, Dong‐Keun; Zhang, Hongyuan; Ng, Man Ho; Liu, Hang; Wang, Shuangpeng, Wang; Hao; Ling, Francis Chi‐Chung 2022 Advanced Electronic Materials 8 2200580

[4] Shi Y-L, Huang D, Kentsch U, Zhou S-Q, Ling F C-C 2022 Journal of Alloys and Compounds 911 165057

[5] Huang D L, Wen-Long; Liu, Zhi-Fu; Li, Yong-Xiang; Ton-That, Cuong; Cheng, Jiaqi; Choy, Wallace C. H., Ling, Francis Chi-Chung 2020 Journal of Materials Chemistry A 8 4764

[6] Jing Yu R J O, Wei Han, Atta Ur Rehman, Jiuren Zhou, Genquan Han, Jing-Wen Shi, Chris Tang, Kailang Liu, Wendi Li, 　Hao Wang and  Francis Chi-Chung Ling 2025 Journal of Materials Chemistry C to be published

[7] Chen X D, Yang C L, Gong M, Ge W K, Fung S, Beling C D, Wang J N, Lui M K, Ling C C 2004 Physical Review Letters 92 125504

[8] Zhu C Y, Ling C C, Brauer G, Anwand W, Skorupa W 2008 Journal of Physics D-Applied Physics 41

[9] Ling C C, Beling C D, Fung S 2000 Physical Review B 62 8016

[10] Lin T L, Sihua; Ho, Lok-Ping; Kuznetsov, Andrej; Lee, Ho Nam; Chau, Tony; Ling, Francis Chi-Chung 2023 IEEE Electron Device Letters 44 578

[11] Ho L P, Li S, Lin T, Cheung J, Chau T, Ling F C C 2023 Semiconductor Science and Technology 38 115007

报告人简介：

Prof. Ling is a tenured associate professor of The University of Hong Kong since 2006. He graduated from The University of Hong Kong with BSc (Hon), MPh and PhD in 1990, 1993 and 1996 respectively. He was awarded the Fellow of Institute of Physics (F. Inst. Phys.), UK in 2006. He has served as the Associate Dean of Faculty of Science and the member of the Senate of The University of Hong Kong. Ling is leading a research group studying functional materials and the corresponding defect engineering, currently focusing on the 3rd generation semiconductor both in the aspects of academic fundamental research and industrial collaboration. As the principal investigator (PI), he obtained 10 General Research Funds (GRF), 1 Germany-HK Collaborative Grant from the RGC, Hong Kong; 1 GRF from the Guangdong NSF; 2 grants from the Hong Kong Innovation and Technology Fund; and participated in 1 Guangdong Province Key R&D Project. He is also the Oversea-PI of an on-going National Key R&D Program (科学技术部 国家重点研发计划). Ling has published over 206 ISI articles, with citations >4600, h-index of 35 and highest single citation >890 (Google Scholar). Prof. Ling has been invited to give 22 keynote and invited talks; and served as Co-Chair/Member of Program Committee and Organizing Committee in international conferences.