Low-frequency gate current noise of InP based HEMTs

The low-frequency 1/f noise in the gate current I-G Of InP based HEMTs is s tudied for a broad range of operation conditions. When the Schottky barrier is in reverse operation, the corresponding gate current noise spectral den sity S-IG shows an I-G(n) law, with n approximate to 2 for not too large dr ain bias. For sufficiently large gate bias, the Schottky barrier becomes fo rward biased and the corresponding noise intensity tends to be proportional to the gate current. These results will be compared with existing theories in order to assess the responsible mechanisms. From the gate current depen dence of the corresponding noise spectral density, it is derived that gener ation-recombination noise by traps in the Schottky barrier layer is respons ible for the 1/f noise. (C) 1999 Elsevier Science Ltd. All rights reserved.