Influence of passivation induced stress on the performance of AlGaN/GaN HEMTs

Abstract

PACS 81.65.Rv, 85.30.De, 85.30.Tv This paper reports on properties of intentionally undoped AlGaN/GaN/sapphire-based high electron mobility transistors (HEMTs) before and after passivation with SiO 2 and Si 3 N 4 . Our results indicate that the DC performance of the AlGaN/GaN HEMTs improved significantly as the stress in the passivation layer increased from compressive to tensile. It corresponded to changes in the sheet carrier concentration. Unlike the DC properties, RF properties of the HEMTs were less sensitive to the stress.

GaN-based FETs using Cat-CVD SiN passivation for millimeter-wave applications

“…There were some reports that SiN passivation by plasmaenhanced CVD (PECVD) also increased the N s of AlGaN/GaN HFETs [10][11][12][13]. However, in these reports, the increase was only 10-30%, which was much smaller than the increases we got with Cat-CVD.…”

Effects of SiN passivation by catalytic chemical vapor deposition on electrical properties of AlGaN∕GaN heterostructure field-effect transistors

“…in N s because of the increase in P PE . 24,25 However, our experimental results would indicate that the increase of N s is basically governed by covering an AlGaN surface with SiN, and that the stress induced by SiN cannot be the origin because of the very small SiN thickness dependence ͑Fig. 5͒.…”

Normally-off AlGaN/GaN-on-Si MOSHFETs with TaN floating gates and ALD SiO<inf>2</inf> tunnel dielectrics

“…As shown, the HfO 2 /TaN/HfO 2 stack has a larger n s value leading to a considerably larger negative V T . The larger n s for HfO 2 could also be related to film stress (5). On the other hand, SiO 2 /TaN/HAH stack has n s value that is similar to Schottky gate FET and lower than that of HfO 2 /TaN/HfO 2 stack.…”