On an InGaP/InGaAs Double Channel Pseudomorphic High Electron Mobility Transistor With Graded Triple $\delta$ -Doped Sheets

An interesting InGaP/InGaAs double channel pseudomorphic high electron mobility transistor is fabricated and demonstrated. Due to the employed InGaP Schottky and buffer layers, InGaAs double channel structure, and graded triple delta-doped sheets, both DC and RF performances are improved. From experimental results, the studied device, with a gate dimension of 0.8 x 100 mum² , shows a drain saturation current of 176 mA/mm, a maximum extrinsic transconductance of 176 mS/mm, a unity current gain cutoff frequency of 16 GHz, and a maximum oscillation frequency of 33.2 GHz at room temperature. Moreover, a theoretical analysis based on a 2-D semiconductor simulation package is used to study the device properties and compare the experimental results. Good agreement between the theoretical analyses and experimental results is found.