High uniformity enhancement- and depletion-mode InGaP/InGaAs pHEMTs using a selective succinic acid gate recess process

Abstract

High uniformity enhancement-mode (E-mode) and depletion-mode (D-mode) InGaP/InGaAs pseudomorphic high electron mobility transistors (pHEMTs) have been developed on 6 inch GaAs substrate using a selective succinic acid gate recess process. The 0.5 µm long gate fingers of E-mode and D-mode pHEMTs are deposited simultaneously in this process simplification. The InGaP/InGaAs E-mode pHEMT exhibits a maximum drain-to-source current (I ds ) of 460 mA mm −1 , and a maximum transconductance (g m ) of 430 mS mm −1 . At 5.2 GHz operation, 216 mW mm −1 power density, 40% power-added efficiency and a 0.81 dB minimum noise figure (NF min ) are also achieved for the E-mode device. In this study, D-mode pHEMTs are applied for a switch monolithic microwave integrated circuit which provides an insertion loss of −1.8 dB and isolation of −9.2 dB under 28 dBm input power (P in ) and 5.5 GHz operation. From these measured results, this uniform E/D-mode InGaP/InGaAs pHEMT technology exhibits a high potential for WLAN applications.

Characteristics of Two-Stage Γ-Gate on AlGaAs/InGaAs/AlGaAs DH-HEMTs by Using AlGaAs/InGaP Etching-Stop Layers

“…For its feature development, the current driving capability, output gain and high operation frequencies of active device are strongly required. Hence, the structure design of double heterojunction HEMTs (DH-HEMTs) where another more electron supply layer is employed on bottom side of the channel is proposed to overcome it [6][7][8][9]. Accompanying with the promotion of current density, the threshold-voltage (V TH ) controllability of FET-related devices becomes more critical to handle its application such as active-region operation and the enhancement-depletion control mode in integrated circuit application.…”

“…Accompanying with the promotion of current density, the threshold-voltage (V TH ) controllability of FET-related devices becomes more critical to handle its application such as active-region operation and the enhancement-depletion control mode in integrated circuit application. Generally, gate-metal sinking and gate-recess controlling are the most popular approaches to dominate device V TH [7][8][9]. For gate-recess process of GaAs-based HEMTs, the employee of In 0.49 Ga 0.51 P material instead of Al x Ga 1-x As in device structure has been reported to provide a higher etching selectivity than Al x Ga 1-x As/In x Ga 1-x As material series.…”