Method for producing single-layer polysilicon gate non-volatile memory

Abstract

The invention relates to a method for improving the performance of a single-layer polysilicon gate nonvolatile memory. By changing the materials of an SAB (Salicide-Block) layer, the number of positive movable ions entering the floating gate of a single-layer polysilicon gate nonvolatile memory unit can be decreased, so the charge retention of a storage unit is enhanced.

Description

technical field [0001] The invention relates to a method for preparing a single-layer polysilicon gate non-volatile memory. Background technique [0002] A key feature of non-volatile memory technology is the widespread use of floating-gate cells, such as EEPROM. According to different gate structures, floating gate units can be divided into two types, one is the so-called stacked gate (ie double-layer polysilicon gate) structure, such as figure 1 As shown, it includes: P-type silicon substrate 11, P-well 12, shallow trench isolation 13, gate oxide layer 14, floating gate 15, inner layer isolation layer 16, and control gate 17 stacked above the floating gate 15; Single-layer polysilicon gate structure, such as figure 2 As shown, it includes: P-type silicon substrate 21 , P-well 22 , N-well 23 , shallow trench isolation 24 , gate oxide layer 25 , floating gate 26 and highly doped contact region 27 . In a single polysilicon gate memory cell, the N-well 23 functions as a co...

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Problems solved by technology

[0005] The disadvantage of the single-layer polysilicon gate memory relative to the double-layer polysilicon gate memory is that the charge storage performance of the single-layer polysilicon gate memory is relatively poor, that is, the concentration of positive mobile ions in the silicon gate is relatively high. How to solve this problem Critical to the application of the single polysilicon gate non-volatile memory

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