Fabrication method of submicron gate using anisotropic etching

Abstract

Disclosed is a method for fabricating a self-aligned submicron gate electrode using an anisotropic etching process. The method involves the steps of laminating a dummy emitter defining a dummy emitter region over a heterojunction bipolar transistor structure including layers sequentially formed over a semiconductor substrate to define a base region, an emitter region, and an emitter cap region, respectively, defining a line having a width of about 1 micron on the dummy emitter by use of a photoresist while using a contact aligner, selectively anisotropic etching the dummy emitter at a region where the line is defined, to allow the dummy emitter to have an etched portion having a bottom surface with a width less than the width of the line defined by the photoresist, and depositing a contact metal on the etched portion of the dummy emitter, thereby forming a gate. In accordance with the present invention, a reliable submicron gate can be fabricated using a simple anisotropic wet etch process and an inexpensive contact aligner. Accordingly, the manufacturing costs can be reduced. In the formation of a base electrode involved in the fabrication of an HBT device, the present invention also provides an effect of reducing the distance between a base and an emitter, thereby achieving a reduction in base resistance, by virtue of a self-alignment using a V-shaped submicron gate.

Description

BACKGROUND OF THE INVENTION[0001] 1. Field of the Invention[0002] The present invention relates to a submicron gate electrode of a semiconductor device, and more particularly to a method for fabricating a self-aligned submicron gate electrode using an anisotropic etching process.[0003] 2. Description of the Related Art[0004] Remarkable development recently made in radio communication fields has resulted in an increased demand for ultrahigh broadband communication networks. An exemplary one of such networks is a network for local multipoint distribution services in which audio, video conference, and digital signals are simultaneously transmitted at a bandwidth of 1.3 GHz within a service area of 2 to 7 Km in radius, using a 28 GHz "Ka-band". In order to construct such an ultrahigh broadband communication network, it is very important to develop ultrahigh-frequency devices operating the above mentioned frequency band while achieving a miniature and high performance of devices. To this...

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Benefits of technology

[0011] Therefore, the present invention has been made in view of the above mentioned problems, and an object of the present invention is to provide a submicron gate fabrication method capable of fabricating a reliably self-aligned submicron gate using a simplified process.

[0014] In the formation of a base electrode involved in the fabrication of an HBT device, the present invention also provides an effect of reducing the distance between a base and an emitter as much as possible, thereby achieving a reduction in base resistance, in that it enables a self alignment using a V-shaped submicron gate.

Problems solved by technology

However, these techniques require an expensive exposure process, such as an electron beam writing process or a stepped exposure process, to form a submicron gate.

However, this technique requires an expensive exposure process, such as an electron beam writing process or a stepped exposure process, or a complex process involving a formation of sidewalls, to form a self-aligned submicron gate.

As a result, there is a drawback of an increase in the manufacturing costs.

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