Method for growing thick gate oxide layer for high-voltage metal oxide semiconductor (MOS) device

Abstract

The invention discloses a method for growing a thick gate oxide layer for a high-voltage MOS device. The growth of the thick gate oxide layer for the high-voltage device happens before shallow channel isolation, and a silicon nitride layer serves as a hard mask. According to the method, changes of electrical characteristics and reliability of low-voltage devices in a high-voltage gate oxidation process are avoided, risks are reduced; and simultaneously, the process is simple, and the number of photoetching plates remains unchanged.

Description

technical field [0001] The present invention relates to integrated circuit manufacturing technology. Background technique [0002] With the development of integrated circuits, single-chip system integration has become a trend. This requires both the intelligent control circuit of the MCU and the analog or high-voltage circuit on one chip. [0003] However, in the actual process, the growth of a thick gate oxide layer for high-voltage devices will introduce additional high-temperature and long-term thermal processes and wet etching processes, resulting in changes in related particle injection conditions and lattice defects induced by stress changes in the silicon substrate. And surface silicon consumption, which causes serious changes in the electrical characteristics and reliability performance of low-voltage devices. Existing solutions have focused on growing thick gate oxides for high-voltage devices after shallow trench isolation (STI) and before gate oxide growth for l...

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In this way, there are disadvantages of complex process and high risk

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