Preparation method of trench type metal oxide semiconductor Schottky barrier transistor

Abstract

The invention relates to a TMBS preparation method, and the method comprises the steps: providing a semiconductor structure which comprises a silicon substrate and a silicon oxide layer formed on thesurface of the silicon substrate, and defining an etching window on the silicon oxide layer; etching the silicon oxide layer to form a process hole, wherein the etching step comprises the following steps: A, the semiconductor structure is placed in a reaction cavity; B, first etching gas is introduced, the radio frequency power is adjusted to be first power, and the silicon oxide layer is etched,wherein the first power is larger than 400 W; C, before the silicon oxide layer is completely etched, the radio frequency power is adjusted to be second power, the silicon oxide layer is continuouslyetched until the silicon oxide layer is completely etched to form a process hole, and the second power is smaller than the first power; and etching the silicon substrate below the process hole and forming the TMBS. According to the preparation method, the etching of the silicon oxide layer is divided into two stages, and the radio frequency power is reduced in the second stage, so that the damageto the silicon surface is reduced, and the obtained TMBS is relatively good in performance.

Description

technical field [0001] The invention relates to the field of semiconductor technology, in particular to a method for preparing a trench type metal oxide semiconductor Schottky barrier transistor. Background technique [0002] Compared with traditional Schottky rectifier devices, Trench MOS Barrier Schottky barrier transistor (Trench MOS Barrier Schottky, TMBS) has lower reverse leakage current and higher reverse breakdown voltage, That is, TMBS has better forward conduction and reverse blocking characteristics. Such as figure 1 As shown, the TMBS die includes a semiconductor structure, the semiconductor structure is based on a silicon substrate 110, an oxide layer 120 is formed on the silicon substrate, and then the middle oxide layer is etched away by an etching process to form a process hole 121 To expose the silicon substrate, then etch the silicon below the process hole to form a trench, deposit a gate oxide layer 111 on the inner wall of the trench and fill the trench...

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Problems solved by technology

[0003] Based on this, it is necessary to provide a trenched metal oxide semiconductor Schottky barrier transistor for the problem that the oxide layer etching process in the preparation process of the trenched metal oxide semiconductor Schottky barrier transistor will damage the underlying silicon substrate. Fabrication method of barrier transistor

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