Preparation method of gate oxide

Abstract

A preparation method of gate oxide includes the steps of providing a silicon substrate, conducting thermal oxidation treatment, implementing a technology for heating processing to form silicon dioxide gate oxide, conducting nitrogen injection on the silicon dioxide gate oxide by using a plasma nitriding technology to form SiON gate oxide, conducting laser treatment on the surface of the SiON gate oxide by using a laser rapid annealing technology, and conducting high temperature annealing on the SiON gate oxide with the surface being treated in a laser mode. According to the preparation method of the gate oxide, before high temperature annealing is conducted on the SiON gate oxide, the laser rapid annealing technology is introduced for conducting the laser treatment on the surface of the SiON gate oxide, an intrinsic oxide layer is removed, the bad influence of organic matter absorption on nitrogen doping is prevented, moreover, the formed non-crystallizing surface can prevent surface nitrogen atoms from volatilizing, and meanwhile the nitrogen atoms can be stopped from diffusing towards an SiO2 / Si interface. Therefore, high and stable nitrogen content can be guaranteed, accurate clipping of the dielectric coefficient of SiON gate media is achieved, and the electrical properties of devices can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for preparing a gate oxide layer. Background technique [0002] The rapid development of Very Large Scale Integration (VLSI) and Ultra Large Scale Integration (ULSI) puts forward more special requirements for device processing technology. Among them, the requirement for the gate oxide layer when the feature size of MOS devices enters the nanometer era is an obvious challenge. The preparation process of the gate oxide layer is a key technology in the semiconductor manufacturing process, which directly affects and determines the electrical characteristics and reliability of the device. [0003] The key performance indicator of MOSFET devices is the drive current, and the magnitude of the drive current depends on the gate capacitance. Gate capacitance is proportional to the surface area of ​​the gate and inversely proportional to the thickness of the g...

AI Technical Summary

Problems solved by technology

[0017] The present invention aims at the difficulty in process control of the traditional gate oxide layer preparation method in the prior art, and it is easy to cause the volatilization of nitrogen atoms on the surface, and it can also make the nitrogen atoms gain energy and continue to diffuse, causing some nitrogen atoms to accumulate on SiO 2 / Si interface, which can negatively affect the carrier migration speed in the channel and other defects provide a method for the preparation of the gate oxide layer

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