High-Frequency High-Voltage Device and Integrated Circuits R&D Center , Institute of Microelectronics, Chinese Academy of Sciences , Beijing 100029 , China.
Key Laboratory of Microelectronic Devices & Integrated Technology , Institute of Microelectronics, Chinese Academy of Sciences , Beijing 100029 , China.
ACS Appl Mater Interfaces. 2018 Jun 27;10(25):21721-21729. doi: 10.1021/acsami.8b04694. Epub 2018 Jun 12.
Constant-capacitance deep-level transient Fourier spectroscopy is utilized to characterize the interface between a GaN epitaxial layer and a SiN passivation layer grown by low-pressure chemical vapor deposition (LPCVD). A near-conduction band (NCB) state E ( E - E = 60 meV) featuring a very small capture cross section of 1.5 × 10 cm was detected at 70 K at the LPCVD-SiN /GaN interface. A partially crystallized SiNO thin layer was detected at the interface by high-resolution transmission electron microscopy. Based on first-principles calculations of crystallized SiNO/GaN slabs, it was confirmed that the NCB state E mainly originates from the strong interactions between the dangling bonds of gallium and its vicinal atoms near the interface. The partially crystallized SiNO interfacial layer might also give rise to the very small capture cross section of the E owing to the smaller lattice mismatch between the SiNO and GaN epitaxial layer and a larger mean free path of the electron in the crystallized portion compared with an amorphous interfacial layer.
采用恒电容深能级瞬态傅里叶光谱技术研究了低压化学气相沉积（LPCVD）生长的氮化硅（SiN）钝化层与 GaN 外延层之间的界面。在 LPCVD-SiN / GaN 界面处，于 70 K 下检测到具有非常小的俘获截面（1.5×10 cm）的近导带（NCB）态 E （ E - E = 60 meV）。高分辨率透射电子显微镜检测到界面处存在部分结晶的 SiNO 薄膜。基于结晶 SiNO / GaN 薄片的第一性原理计算，证实 NCB 态 E 主要源于界面附近悬空键的强相互作用及其相邻原子。由于 SiNO 和 GaN 外延层之间的晶格失配较小，以及结晶部分中电子的平均自由程大于非晶界面层，部分结晶的 SiNO 界面层也可能导致 E 的俘获截面非常小。
