Method for manufacturing VDMOS

Abstract

The embodiment of the invention provides a method for manufacturing a VDMOS. The method comprises the following steps: providing an N type substrate and forming an N type epitaxial layer at a first surface of the substrate; growing field oxide at the N type epitaxial layer to form a field oxidation layer; etching an active zone at the field oxidation layer and injecting N type ions and carrying out driving; etching at least one ring zone at the field oxidation layer and injecting P type ions into the ring zone; growing gate oxide at the active zone and the ring zone to form a gate oxidation layer; forming a threshold injection layer below the upper surface of the N type epitaxial layer; depositing polycrystalline silicon at the gate oxidation layer to form a polycrystalline layer used as a grid electrode of a VDMOS; injecting P type ions into the active zone and the two sides of the polycrystalline silicon layer and carrying out driving; forming a source electrode of the VDMOS at the zone with driven P type ions; carrying out reduction on a second surface of the substrate and growing a metal layer at the reduced second surface to form a drain electrode of the VDMOS. With the method, the voltage can be adjusted at any time; and the method can be implemented conveniently.

Description

technical field [0001] The invention relates to the technical field of semiconductor chip manufacturing technology, in particular to a method for manufacturing a VDMOS device. Background technique [0002] At present, the existing process for fabricating a vertical double-diffused metal-oxide semiconductor field-effect transistor (VDMOS) usually includes the following fabrication process: [0003] Step one, such as Figure 1A As shown, an N-type substrate 101 is provided, and an N-type epitaxial layer 102 is formed on the first surface of the substrate. [0004] Step two, such as Figure 1B As shown, oxygen is field-grown on the N-type epitaxial layer 102 to form a field oxide layer 103 . [0005] In this step 2, it is preferable to perform field oxygen growth in the range of 1100-1200 degrees, and the thickness of the field oxide layer 103 can be formed between 0.8-1.4 microns. The reason why this layer is formed is mainly for isolation use; [0006] Step three, such as...

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Problems solved by technology

[0026] The embodiment of the present invention provides a method for manufacturing VDMOS, which is used to solve the problem of inconvenient use of the VDMOS manufactured by the existing method for manufacturing VDMOS

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