Field-effect transistor and method for manufacturing same

Abstract

This field-effect transistor includes: a columnar portion (131) formed on a substrate (101) by stacking, in the following order, a first electron supply layer (102), a channel layer (104), a second electron supply layer (106), a barrier layer (107), and a cap layer (108). A first contact layer (111) and a second contact layer (112) made of a compound semiconductor are formed on the substrate (101) on both sides of the columnar portion (131). A source electrode (113) is connected to the first contact layer (111), and a drain electrode (114) is connected to the second contact layer (112).

Claims

1. A field-effect transistor comprising: a columnar portion formed on a substrate by stacking a first electron supply layer, a channel layer, a second electron supply layer, a barrier layer, and a cap layer, each composed of an InP-based compound semiconductor, in that order; a gate electrode formed on the columnar portion; a first contact layer and a second contact layer, both composed of compound semiconductors, formed on the substrate on both sides of the columnar portion and in contact with the channel layer exposed on the side walls of the columnar portion; a source electrode connected to the first contact layer; and a drain electrode connected to the second contact layer, wherein the channel layer is composed of InGaAs or InGaAs and InAs, and the barrier layer is composed of InAlAs.

2. A field-effect transistor according to claim 1, comprising: a first spacer layer formed between the first electron supply layer and the channel layer and made of a compound semiconductor having a band gap larger than that of the channel layer; and a second spacer layer formed between the channel layer and the second electron supply layer and made of a compound semiconductor having a band gap larger than that of the channel layer.

3. A field-effect transistor according to claim 1 or 2, wherein the columnar portion is formed via an etching stop layer formed on the substrate.

4. A method for manufacturing a field-effect transistor, comprising: a first step of forming an etching stop layer on a substrate; a second step of stacking a first electron supply layer, a channel layer, a second electron supply layer, a barrier layer, and a cap layer, each composed of a compound semiconductor, in that order on the etching stop layer; a third step of forming a columnar portion of a columnar structure by a patterning process that etches the first electron supply layer, the channel layer, the second electron supply layer, the barrier layer, and the cap layer down to the etching stop layer; a fourth step of forming a first contact layer and a second contact layer on the substrate on both sides of the columnar portion, connected to the channel layer exposed on the side walls of the columnar portion; a fifth step of forming a gate electrode on the columnar portion; and a sixth step of forming a source electrode connected to the first contact layer and a drain electrode connected to the second contact layer.

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