Method for manufacturing silicon oxynitride gate oxide layer

Abstract

The invention provides a method for manufacturing a silicon oxynitride gate oxide layer of an MOS (metal oxide semiconductor) device, and the method comprises the following steps: firstly nitridizing on a provided silicon substrate for forming silicon oxynitride, then performing thermal oxidization for forming a first silicon oxide layer between the silicon oxynitride and the silicon substrate and a second silicon oxide layer on the silicon oxynitride, and then depositing polysilicon on the second silicon oxide layer after secondly annealing the silicon substrate; and etching for forming a gate and the silicon oxynitride gate oxide layer. The silicon oxide layer is introduced between the silicon substrate and the silicon oxynitride, thereby reducing dangling bonds between the silicon oxynitride gate oxide layer and the silicon substrate, further reducing the interface state charge density between the silicon oxynitride gate oxide layer and the substrate and improving certain properties of the MOS device, such as improving the stability of threshold voltage of the device, reducing the hot-carrier effect and the flicker noise of the device and the like.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for manufacturing a silicon oxynitride gate oxide layer. Background technique [0002] A Metal-Oxide Semiconductor Field Effect Transistor (MOS) device structure includes an active region, a source, a drain and a gate, wherein the active region is located in a semiconductor silicon substrate, and the gate The electrode is located above the active region, and the active regions on both sides of the gate are respectively implanted with ions to form a source and a drain. There is a conductive channel under the gate, and there is a gate oxide between the gate and the conductive channel. layer. According to different types of ion implantation, MOS devices are divided into PMOS devices and NMOS devices. In the manufacturing process of the MOS device, the gate oxide layer and the gate are first grown on the semiconductor silicon substrate, and then other structures ...

AI Technical Summary

Problems solved by technology

With the increase of the charge and discharge times of the gate capacitance, the threshold voltage of the device will eventually become unstable, which will affect the reliability of the device.

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