Compound semiconductor device and method of manufacturing same

Abstract

The present invention relates to a compound semiconductor device and a method of manufacturing the same. The compound semiconductor device includes: an electron transport layer formed over a substrate; an electron supply layer formed over the electron transport layer; and a cap layer formed over the electron supply layer; the cap layer includes a first compound semiconductor layer containing GaN; a second compound semiconductor layer containing AlN, which is formed over the first compound semiconductor layer; a third compound semiconductor layer containing GaN, which is formed over the second compound semiconductor layer; and at least one of a first AlGaN-containing layer and a second AlGaN-containing layer, with the first AlGaN-containing layer formed between the first compound semiconductor layer and the second compound semiconductor layer and the Al content increases toward the second compound semiconductor layer, and the second AlGaN-containing layer formed between the second compound semiconductor layer and the third compound semiconductor layer and the Al content increases toward the second compound semiconductor layer. The compound semiconductor device and the method can prevent the gate electrode current and the voltage from decreasing and / or inhibit current collapse.

Description

[0001] Related Application Cross Reference [0002] This application is based on and claims priority from a prior Japanese Patent Application No. 2010-269673 filed on December 2, 2010, the entire contents of which are hereby incorporated by reference. technical field [0003] The invention relates to a compound semiconductor device and a manufacturing method of the compound semiconductor device. Background technique [0004] A compound semiconductor device having a GaN layer and an AlGaN layer formed over a substrate, where the GaN layer is used as an electron transport layer, has been actively developed. An example of such a compound semiconductor device is a GaN-based high electron mobility transistor (HEMT). GaN-based HEMTs use a two-dimensional electron gas (2DEG) at a high concentration formed at the AlGaN / GaN heterojunction interface. [0005] GaN has a band gap (3.4eV) larger than Si (1.1eV) or GaAs (1.4eV). That is, GaN exhibits a higher breakdown field strength. ...

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Problems solved by technology

[0010] However, Figure 1A The GaN-based HEMTs shown often have gate leakage or reduced withstand voltage

In addition, current collapse often occurs

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