Enhanced Power and Breakdown in III-N RF Switches With a Slow Gate

We show that III-nitride radio-frequency switches with a composite slow/fast gate have higher maximum switching power and breakdown voltage compared with conventional switches of the same type. The composite gate design includes an additional “slow gate” electrode formed under the metal gate using a low-conducting InGaN layer. The “slow gate” covers the entire source-drain spacing. The addition of the “slow gate” layer not only offers a lower insertion loss and higher isolation but, as shown in this letter, also increases the power handling capability by “delaying” switch self-modulation under high-power stress. We also show that, the “slow gate” design increases breakdown voltage.