Analysis of Low Voltage RF Power Capability on AlGaN/GaN and InAlN/GaN HEMTs for Terminal Applications

Abstract

In this work, low voltage RF power capability on AlGaN/GaN and InAlN/GaN HEMTs is analysed from the perspective of DC and pulse characteristics, for terminal applications whose operating voltage is usually in the range of 3 to 15 V. Device fabrication is performed on mature AlGaN/GaN heterojunction as well as strongly polarized InAlN/GaN heterojunction, to make a comparison of low voltage RF power capability between two devices. Although it suffers from relatively severe RF dispersion, InAlN/GaN HEMT delivers higher output power density (Pout) than its opponent, benefiting from the lower parasitic resistance and knee voltage as well as higher output current density. At 8 GHz, Pout of 1.62 W/mm and 1.10 W/mm are achieved for InAlN/GaN and AlGaN/GaN HEMT, respectively, both of which are biased at class AB operation and Vds of 9 V. However, the tremendous degradation of power added efficiency (PAE) occurs as the higher drain voltage is applied on InAlN/GaN HEMT, as the result of the severe gate leakage. What is more, a higher PAE is more necessary than Pout for terminal applications. Either InAlN/GaN HEMT or AlGaN/GaN HEMT has its own specific voltage range to deliver higher PAE. Concretely, InAlN/GaN HEMT is more suitable to applications with operating voltage not exceeding 6 V, and AlGaN/GaN HEMT is preferred for ones with relatively higher voltage, accompanied by the decent PAE as high as 62% to 66% and moderate Pout to meet the demand of various low voltage terminal applications.

Strain-induced enhancement of 2D electron gas density in AlGaN/GaN heterojunction: a first-principles study

“…These charges near the material interface can promote the formation of a high-density and high-mobility two-dimensional electron gas (2DEG). AlGaN/GaN heterojunction semiconductors, with their wide bandgap and high-density and high-mobility 2DEG, are suitable for various high-frequency and high-power device applications [2,3,[16][17][18][19][20], such as high electron mobility transistors (HEMTs). HEMTs are semiconductor devices primarily used for high-frequency and high-speed applications.…”

InAlN/GaN HEMT With n+GaN Contact Ledge Structure for Millimeter-Wave Low Voltage Applications

“…In order to achieve high PAE and large Pout for low voltage RF devices, it is important to increase the maximum output current density (ID.max) and reduce the knee voltage (Vknee) [4][5] [6] . Therefore, reducing the parasitic resistance, including access resistance and ohmic contact resistance, is a key technology.…”

Power Performance of AlGaN/GaN High‐Electron‐Mobility Transistors with AlN Buffer on SiC Substrate at 3.5 GHz

“…Their use in applications like radars, satellites, backhaul, and 5G handsets has increased rapidly over the past two decades. [1][2][3][4][5] A typical high-electron-mobility transistor (HEMT) structure is composed of an AlGaN barrier, GaN channel layer, and GaN buffer, which has semi-insulating properties for suppressing the carrier leakage. The semi-insulating properties of the buffer layer uses dopants such as C, Fe, and Mg. [6][7][8] However, these dopants act as deep acceptors, causing trapping effects and undesirable current distribution in the buffer layer.…”