Effective Suppression of Current Collapse in AlGaN/GaN HEMT With N₂O Plasma Treatment Followed by High Temperature Annealing in N₂ Ambience

Abstract

We propose a high temperature annealing process in N2 ambience after N2O plasma treatment for AlGaN/GaN HEMT. The annealing process effectively improves the plasma treated surface condition and decreases the current collapse from 41.7% to 10.6%. The N2O plasma treatment is performed in a PECVD chamber and the followed high temperature annealing process is carried out at 800°C for 20min in rapid temperature annealing (RTA) system. Compared to the devices with only N2O plasma treatment, the devices with an extra high temperature annealing process perform lower surface state density (2.51E+12 cm−2eV−1, $\boldsymbol{\Delta }\text{E}$ from 0.353 eV to 0.413 eV; 5.38E+11 cm−2, $\boldsymbol{\Delta }\text{E}$ > 0.519 eV) and better dynamic characteristics.

Keywords

• AlGaN/GaN HEMT
• N₂O plasma treatment
• current collapse
• high temperature annealing