Impact of N− plasma treatment on the Current collapse of ALGAN/GAN HEMTs

The impact of N^- plasma treatment before SiNx deposition on current collapse of AlGaN/GaN HEMTs was studied. N^- plasma treatment of 1, 2 and 5 minutes was performed before SiNx deposition with plasma enhanced chemical vapor deposition (PECVD). It is found current collapse changed with three kinds of schemes. Apparent differences occurred with treatment time. The Current lags of the sample with treatment of 1 minute degenerated to 65.45%, compared with the current lag without any N^- plasma treatment and passivation. While the value of the samples with treatment of 2 and 5 minutes changed to 58.11% and 30.44%, indicating N^- plasma treatment before SiNx passivation is benefit to depress current collapse. The reason is suggested to be the N^- plasma treatment caused reduction of interface states, which is probably originate from some kind of defects related nitrogen.