Fig. 1. (Color online) Cross-sectional schematic of the fabricated GaN E-Mode PMOS.

Fig. 2. (Color online) (a) I−V curves, (b) SBHs calculated by thermionic emission theory at various pad spacing, (c) R_c and (d) ρ_c extracted from TLM at various voltage of different wet treatments.

Fig. 3. (Color online) (a) I−V curves of three samples with 3 μm spacing, (b) the R_c and (c) R_sh extracted from TLM at various voltage for three samples, (d) SBHs calculated by thermionic emission theory at various pad spacing. The inset of (b) shows the fitted curves for the three samples extracted at 10 V.

Fig. 4. (Color online) Surface morphologies for samples without treatment, treated by POA in N₂ atmosphere and BOE (sample B), treated by POA in O₂ atmosphere and BOE (sample C), and treated only by BOE (sample A).

Fig. 5. (Color online) (a) XPS spectra of Ga 2p and (b) N 1s, (c) VBM spectra and (d) surface band barrier schematic of three samples.

Fig. 6. (Color online) (a) Ga 3d spectra for samples with different treatments and O 1s spectra for samples (b) without etching and (c) with etching. (d) Treatment schematic of samples with different treatments.

Fig. 7. (Color online) Transfer characteristics on (a) linear scale and (b) semi-logarithmic scale and (c)−(e) output characteristics of samples A−C, respectively.