Manufacturing method of gate oxide layer

Abstract

The invention discloses a method for manufacturing a gate oxide layer. The method comprises the following steps of: 1, forming a first oxide layer on the surface of a semiconductor substrate through a deposition process; and 2, carrying out nitriding treatment on the first oxide layer. And 3, performing a thermal oxidation process to form a second oxide layer formed by oxidizing the semiconductor substrate at the bottom of the first oxide layer, and overlapping the first oxide layer and the second oxide layer to form a gate oxide layer. The method can reduce the loss of the semiconductor substrate under the condition of ensuring the electrical thickness and quality of the gate oxide layer, is especially suitable for reducing the loss of the fin body in the manufacturing of an input / output device of a fin-type transistor, and enables the critical size of the fin body to be maintained.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor integrated circuit, in particular to a method for manufacturing a gate oxide layer. Background technique [0002] The gate dielectric layer in the fin transistor (FinFET) covers the top surface and side surfaces of the fin body (Fin). The fin body is usually formed by patterning a semiconductor substrate, and the semiconductor substrate is usually a silicon substrate, so the fin body is also usually a silicon fin body. [0003] A core (Core) device (device) and an input-output (IO) device are usually integrated on the same semiconductor substrate at the same time. The IO device withstands a higher voltage, and the size of the device will also be larger, and the gate dielectric layer usually uses a gate oxide layer. In the existing method, the gate oxide layer is formed by performing thermal oxidation on the fin body, and the thermal oxidation process can adopt an in-situ stream gener...

AI Technical Summary

Problems solved by technology

However, to meet the withstand voltage requirements, the thickness of the gate oxide layer will not be reduced in the same proportion, so the thickness of the gate oxide layer will be relatively thick

When the gate oxide layer is formed by thermal oxidation of a smaller-sized fin body, the size consumption of the fin body by the gate oxide layer increases in proportion to the critical dimension of the entire fin body. After the gate oxide layer is formed, the critical dimension of the fin body will increase. produce large changes, which can affect the performance of the device

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