Low-Frequency-Noise Characteristic of Quasi-Enhancement-Mode HEMT Using a Selectively Hydrogen-Pretreatment

The DC, RF, and low-frequency noise characteristics were investigated for a quasi-enhancement-mode (QE) HEMT using a selective hydrogen pretreatment (SHP). The QE-HEMT with SHP showed a large shift in threshold voltage without severe degradation of RF performances including cut-off frequency and maximum oscillation frequency, compared with those of HEMT without SHP. Moreover, the QE HEMT exhibited a reduction of low-frequency noise bulges compared with those of depletion-mode HEMT without an SHP, leading to an one-order smaller input noise spectral density at 100Hz, and offered a potential for application to a low phase noise oscillator