Strain Analysis of GaN HEMTs on (111) Silicon with Two Transitional AlxGa1−xN Layers

Materials

Tao Wang¹  Jie Bai¹  Yuefei Cai¹  Chenqi Zhu¹  Xiang Yu¹  Ling Jiu¹  Yipin Gong¹  Volkan Esendag¹ 

[1] Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield S1 3JD, UK;

关键词: HEMTs;    strain;    AlxGa1−xN;    crack-free;    silicon;   

DOI  :  10.3390/ma11101968

来源: DOAJ

【 摘 要 】

We have designed and then grown a simple structure for high electron mobility transistors (HEMTs) on silicon, where as usual two transitional layers of AlxGa1−xN (x = 0.35, x = 0.17) have been used in order to engineer the induced strain as a result of the large lattice mismatch and large thermal expansion coefficient difference between GaN and silicon. Detailed x-ray reciprocal space mapping (RSM) measurements have been taken in order to study the strain, along with cross-section scanning electron microscope (SEM) images and x-ray diffraction (XRD) curve measurements. It has been found that it is critical to achieve a crack-free GaN HEMT epi-wafer with high crystal quality by obtaining a high quality AlN buffer, and then tuning the proper thickness and aluminium composition of the two transitional AlxGa1−xN layers. Finally, HEMTs with high performance that are fabricated on the epi-wafer have been demonstrated to confirm the success of our strain engineering and above analysis.

【 授权许可】

Unknown