Compatibility of AlN/SiN_xPassivation With LPCVD-SiN_xGate Dielectric in GaN-Based MIS-HEMT

Abstract

In this letter, we demonstrate an integrated process that illustrates the compatibility of AlN/SiN x passivation with high-performance (i.e. low leakage and high breakdown) low-pressure chemical vapor deposition (LPCVD) SiN x gate dielectric for GaN-based MIS-HEMT. It is shown that the AlN/SiN x passivation structure maintains its superior capability of suppressing the current collapse after enduring high temperature of 780°C during the LPCVD-SiN x deposition. The AlN/SiN x passivation is shown to be significantly better than the LPCVD-SiN x passivation by delivering small dynamic R ON degradation, especially under high drain bias switching with V DS > 100 V.Index Terms-Gallium nitride, MIS-HEMT, aluminum nitride, silicon nitride, passivation.

Device physics towards high performance GaN-based power electronics

“…高温LPCVD技术不仅可以用来制备高质量的钝 化介质, 也是制备高绝缘氮化物栅介质(如SiNx)的良好 方法 [33,[44][45][46][47] . 如图22所示, LPCVD-SiNx与GaN间的导带 带阶为2.75 eV, 而且自身的击穿场强达到13 MV/cm [47] , 显著高于PECVD-SiNx栅介质, 因此LPCVD-SiNx栅介 质适合制备高压GaN基MIS-HEMT器件, 可进一步扩 展栅极的安全阈值范围.…”

Investigation of SiN x and AlN Passivation for AlGaN/GaN High-Electron-Mobility Transistors: Role of Interface Traps and Polarization Charges

“…The "virtual gate" caused by surface/interface trapping is suppressed, and the GaN HEMTs with SiN x passivation layer can deliver mitigated current collapse [6]. However, the SiN x passivated devices typically exhibit a significant increase in dynamic R ON after high voltage stress (off-state drain bias > 100 V) [12]− [14].…”

Pulse-Mode DynamicRonMeasurement of Large-Scale High-Power AlGaN/GaN HFET

“…It is well known that the problem of current collapse is due to electron trapping in the interface between AlGaN and surfaces [11]- [13]. The interface problem has been discussed before, and many groups have tried to solve it using various passivation materials (SiN X , AlN, and polyimide), surface treatments (post-gate annealing and various types of plasma), and edge termination (gate-and source-field plates) [14]- [18]. In addition, it was recently reported that GaN buffer traps play a role in off-state leakage and dynamic on-resistance.…”