Method for embedding high-voltage device in silicon oxide-nitride-oxide semiconductor (SONOS) nonvolatile memory process

Abstract

The invention discloses a method for embedding a high-voltage device in a silicon oxide-nitride-oxide semiconductor (SONOS) nonvolatile memory process. The method comprises the following steps of: 1) preparing a field oxide region on a substrate, and performing a processing step before a grid oxide layer of a high-voltage device region is grown; 2) growing the grid oxide layer of the high-voltage device region; 3) performing a processing step before a grid oxide layer of a low-voltage device region is grown; 4) implanting and etching for a tunnel window of an SONOS nonvolatile memory region; 5) growing an oxide-nitride-oxide (ONO) dielectric layer on the whole substrate; 6) removing the ONO dielectric layer on the high-voltage device region; 7) protecting the ONO dielectric layer of the nonvolatile memory region and the grid oxide layer of the high-voltage device region by adopting photoresist, removing the ONO dielectric layer and a gasket oxide layer on the substrate, and removing the photoresist; and 8) finally growing the grid oxide layer of the low-voltage device region. By adopting the method, the reliability of the high-voltage device is improved.

Description

technical field [0001] The invention relates to a method for embedding a high-voltage device in a SONOS non-volatile memory technology. Background technique [0002] With the development of integrated circuits, single-chip system integration has become a trend. This requires the intelligent control circuit of the MCU, the non-volatile memory circuit and the analog or high-voltage circuit on one chip. [0003] In the SONOS non-volatile memory manufacturing process, by adding high-voltage metal oxide semiconductor devices (high-voltage MOS devices) and analog devices can be provided in the same process: logic, non-volatile memory, high-voltage and analog devices, as a single chip System integrated circuit design provides the necessary conditions. [0004] However, in the actual process, the thick gate oxide layer growth of high-voltage devices will introduce additional thermal processes and silicon surface consumption. If it is prepared according to conventional steps, it wi...

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Problems solved by technology

[0004] However, in the actual process, the thick gate oxide layer growth of high-voltage devices will introduce additional thermal processes and silicon surface consumption. If it is prepared according to conventional steps, it will cause serious low-voltage and SONOS non-volatile memory electrical characteristics and Variation in reliability performance

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