Insight into the Near-Conduction Band States at the Crystallized Interface between GaN and SiN x Grown by Low-Pressure Chemical Vapor Deposition

Xinyu Liu; Xinhua Wang; Yange Zhang; Ke Wei; Yingkui Zheng; Xuanwu Kang; Haojie Jiang; Junfeng Li; Wenwu Wang; Xuebang Wu; Xianping Wang; Sen Huang

doi:10.1021/acsami.8b04694

Insight into the Near-Conduction Band States at the Crystallized Interface between GaN and SiN _x Grown by Low-Pressure Chemical Vapor Deposition

ACS Appl Mater Interfaces. 2018 Jun 27;10(25):21721-21729. doi: 10.1021/acsami.8b04694. Epub 2018 Jun 12.

Authors

Xinyu Liu¹, Xinhua Wang^{1

2}, Yange Zhang³, Ke Wei¹, Yingkui Zheng¹, Xuanwu Kang¹, Haojie Jiang⁴, Junfeng Li⁴, Wenwu Wang⁴, Xuebang Wu³, Xianping Wang³, Sen Huang^{1

2}

Affiliations

¹ High-Frequency High-Voltage Device and Integrated Circuits R&D Center , Institute of Microelectronics, Chinese Academy of Sciences , Beijing 100029 , China.
² Key Laboratory of Microelectronic Devices & Integrated Technology , Institute of Microelectronics, Chinese Academy of Sciences , Beijing 100029 , China.
³ Institute of Solid State Physics , Chinese Academy of Sciences , Hefei 230031 , China.
⁴ Integrated Circuit Advanced Process Center , Institute of Microelectronics, Chinese Academy of Sciences , Beijing 100029 , China.

PMID: 29863840
DOI: 10.1021/acsami.8b04694

Abstract

Constant-capacitance deep-level transient Fourier spectroscopy is utilized to characterize the interface between a GaN epitaxial layer and a SiN _x passivation layer grown by low-pressure chemical vapor deposition (LPCVD). A near-conduction band (NCB) state E_LP ( E_C - E_T = 60 meV) featuring a very small capture cross section of 1.5 × 10^-20 cm^-2 was detected at 70 K at the LPCVD-SiN _x/GaN interface. A partially crystallized Si₂N₂O thin layer was detected at the interface by high-resolution transmission electron microscopy. Based on first-principles calculations of crystallized Si₂N₂O/GaN slabs, it was confirmed that the NCB state E_LP mainly originates from the strong interactions between the dangling bonds of gallium and its vicinal atoms near the interface. The partially crystallized Si₂N₂O interfacial layer might also give rise to the very small capture cross section of the E_LP owing to the smaller lattice mismatch between the Si₂N₂O and GaN epitaxial layer and a larger mean free path of the electron in the crystallized portion compared with an amorphous interfacial layer.

Keywords: GaN; LPCVD-SiNx; Si2N2O; capture cross section; constant-capacitance deep-level transient Fourier spectroscopy; first principles; interface states; near-conduction band states.