Study on the difference between ID(VG) and C(VG) pBTI shifts in GaN-on-Si E-mode MOSc-HEMT

In this study, we investigate the difference between I D (V G ) and C(V G ) pBTI shifts on GaN-on-Si E-mode MOS-channel HEMTs, under various gate voltage stresses (V GStress ) and temperatures (T). A new experimental setup using ultra-fast and simultaneous I D (V G ) and C(V G ) measurements enables to monitor the threshold voltage V TH drift through two metrics, $\mathrm{\Delta}\mathrm{V}_{\text{THI}}$ and $\mathrm{\Delta}\mathrm{V}_{\text{THC}}$ . Experimental pBTI results depict a difference between $\mathrm{\Delta}\mathrm{V}_{\text{THI}}$ and $\mathrm{\Delta}\mathrm{V}_{\text{THC}}$ , such as $\mathrm{\Delta}\mathrm{V}_{\text{THI}} . TCAD simulations support that ID(V G ) shift ( $\mathrm{\Delta}\mathrm{V}_{\text{THI}}$ ) is related to charge trapping in Al 2 O 3 gate oxide defects at the gate corners regions while C(V G ) shift ( $\mathrm{\Delta}\mathrm{V}_{\text{THC}}$ ) is mainly ascribed to the gate bottom, due to the presence of a back-barrier layer in the epitaxy. These previous results enable to deduce that the Al 2 O 3 defects density is more important at the gate corners than at the gate bottom.