A method of fabricating an embedded flash gate

Abstract

The invention discloses a method of manufacturing an embedded flash gate. According to the method of the invention, one-step etching technology is adopted for patterning a polysilicon layer of the embedded flash, only one polysilicon layer is formed in a logic circuit region, the polysilicon layer has the same key sizes and the same cross section as polysilicon of a logic gate manufactured by the prior logic circuit technology. Due to the single polysilicon layer, problems of reliability and the like caused by a multi-layer polysilicon gate adopted by the prior embedded flash technology can be avoided, a good device can be formed in the logic circuit region, and the device has good performance. In addition, due to a hard mask layer above the logic circuit region, the problems of different thicknesses of the polysilicon layers in the logic circuit region, the flash unit region and a high-voltage circuit region can be avoided, the overall performance and the yield of the embedded flash can be improved.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for manufacturing an embedded flash gate. Background technique [0002] Memory is used to store a large amount of digital information. According to recent surveys, memory chips account for about 30% of semiconductor transactions worldwide. Over the years, technological progress and market demand have led to more and more high-density various Types of memory, such as RAM (random access memory), SRAM (static random access memory), DRAM (dynamic random access memory) and FRAM (ferroelectric memory), etc. Among them, flash memory is FLASH, which has become the mainstream of non-volatile semiconductor storage technology, and can still maintain on-chip information even after the power supply is turned off; the memory is electrically erasable and reprogrammable without special high voltage ; The flash memory has the characteristics of low cost and high density. Its uni...

AI Technical Summary

Problems solved by technology

In the embedded flash memory process, the thickness of the polysilicon layer in the logic circuit area and the flash memory cell area is different, which will cause defective cross-sections in the embedded flash memory device, further affecting the performance and yield of the device

Meanwhile, a control gate with two layers of polysilicon is often used to meet the requirements of circuit design, however, there is a contact surface between the two layers of polysilicon in the logic circuit area, which can affect the performance of logic devices in the logic circuit area, Therefore, two polysilicon layers will cause reliability problems in semiconductor devices

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