A Novel Gate-to-Source ESD Protection Clamp for GaN HEMT

In this work, a novel GaN electrostatic discharge (ESD) protection clamp is proposed for enhancing the gate structure’s ESD reliability of the conventional (Con.) p-GaN high-electron-mobility transistor (HEMT). The proposed clamp features a floating p-GaN structure and a pF-grade capacitor, which is in parallel connection between the anode electrode and the floating p-GaN structure ( ${C}_{\text {GA}}$ ). It is demonstrated that the proposed clamp not only possesses a low triggering voltage ( ${V}_{t} < {10}$ V) but also can withstand a relatively high second breakdown current ( ${I}_{s} \sim 6$ A) in the transient ESD event. Hence, the proposed clamp can usefully discharge the transient electrostatic charges accumulated at the gate structure of the Con. ${E}$ -mode p-GaN HEMT and clamp its potential at a low value, thereby enhancing its ESD reliability and avoiding the gate-to-source ESD damage. It is also found that the clamp’s ${V}_{t}$ and ${I}_{s}$ have a strong correlation with ${C}_{\text {GA}}$ . Thus, through changing ${C}_{\text {GA}}$ , the clamp will possess the desired ${V}_{t}$ and ${I}_{s}$ ’s. In addition, the proposed clamp can be fabricated on the Con. ${E}$ -mode p-GaN HEMT platform, making the HEMT’s ESD design more convenient.