Method for manufacturing groove-type metal-oxide-semiconductor field-effect transistor

Abstract

The invention discloses a method for manufacturing a groove-type metal-oxide-semiconductor field-effect transistor, comprising the following steps: providing a substrate with a groove-type structure; forming a sacrificial oxide layer which is covered on the surface of the groove-type structure and the surface of the substrate in compliance; forming an oxide layer in the vertical direction; thickening parts, positioned on the surface of the substrate and the bottom of the groove, of the sacrificial oxide layer; removing the oxide layer and parts of the sacrificial oxide layer; reserving parts, positioned on the surface of the substrate and the bottom of the groove, of the oxide layer; growing an extra oxide layer which is covered on the substrate structure in compliance; and depositing a conducting layer on the substrate structure so as to fill the groove and serve as the grid of the groove-type transistor. By utilizing the manufacturing method provided by the embodiment of the invention, parasitic capacitance (Qgd) effect of an element can be effectively lowered, the electricity efficiency of a high-voltage semiconductor device can be enhanced, and the manufacturing cost is lowered.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor device, in particular to a method for manufacturing a trench metal oxide semiconductor field effect transistor (trench MOSFET). Background technique [0002] High-voltage component technology is suitable for the field of high-voltage and high-power integrated circuits. Traditional power transistors are designed for high withstand voltage and high current. The current flow of components is designed from a planar structure to a vertical structure. With the breakthrough of chip technology, power transistors also have different methods. At present, in the development of extremely low-voltage power transistor technology, there is a trench gate with a variety of process structure power transistors (Trench MOSFET). [0003] Because the trench field effect transistor can effectively reduce the on-resistance of the product and has a large current handling capacity, the trench type metal oxide s...

AI Technical Summary

Problems solved by technology

However, the trenched gate structure power transistor has its own difficulties in process, and the depth of the trenched gate of the transistor must be considered

In particular, the thickness of the oxide layer at the bottom of the trench of the traditional trench MOSFET is the same as the thickness of the oxide layer at other positions, which is easy to cause parasitic capacitance (Qgd) effect

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