Transistor devices with localized p-type capping layer

Abstract

A transistor device with a local P-type cap layer. The transistor device comprises a substrate (121), a transition layer (122), a channel layer (123), a barrier layer (124), and a source electrode (11), a gate electrode (12), a drain electrode (13) and a P-type cap layer, which are located above the barrier layer, wherein the P-type cap layer comprises at least one first P-type region (14) and at least one second P-type region (15); the first P-type region and the second P-type region are adjacent to each other and are both located between the gate electrode and the drain electrode; the first of the first P-type regions, from the gate electrode to the drain electrode, is electrically connected to the source electrode; the doping surface concentration of a P-type impurity in the first P-type region is greater than the doping surface concentration of the P-type impurity in the second P-type region, and is also greater than the two-dimensional electron gas surface concentration below the first P-type region; and the doping surface concentration of the P-type impurity in the second P-type region is less than the two-dimensional electron gas surface concentration below the second P-type region.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a transistor device with a partial P-type cap layer. Background technique [0002] Power devices typically require high breakdown voltage, low on-resistance, and fast switching capabilities. In the past, the power semiconductor market was dominated by silicon power devices. In the past 20 years, the performance of silicon power devices has approached the theoretical limit, and it is extremely difficult to further improve their performance. [0003] Compared with silicon or gallium arsenide, gallium nitride (GaN) semiconductor has a wide bandgap (Eg=3.4eV), excellent thermal stability, high breakdown voltage, high electron saturation drift velocity and excellent radiation resistance. In addition, compared with silicon power semiconductors, GaN power semiconductors have low temperature resistance characteristics, which can reduce power conversion losses caused by power semicon...

AI Technical Summary

Problems solved by technology

The high electric field at the edge of the gate 102 leads to increased leakage current of the device, reduced breakdown voltage, and severe dynamic resistance degradation, as well as reliability issues

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