Method for forming semiconductor integrated device

Abstract

A method for forming a semiconductor integrated device, comprising: providing a semiconductor substrate, the semiconductor substrate has a first region and a second region opposite to the first region, the surface of the semiconductor substrate in the first region is sequentially formed with first A silicon oxide layer, a first polysilicon layer, and a second silicon oxide layer, and an isolation layer is formed on the surface of the semiconductor substrate in the second region; using the same formation process, the second silicon oxide layer and the isolation layer Form the second polysilicon layer on the surface of the layer; remove the second polysilicon layer, the second layer of silicon oxide layer, the first polysilicon layer, and the first layer of silicon oxide layer in the first region to form a sub-gate flash memory; removing part of the second polysilicon layer in the second region to form a polysilicon resistor. The polysilicon layer in the polysilicon resistor is formed in the same formation process as the control gate of the split-gate flash memory, which saves etching and deposition steps and improves process integration.

Description

technical field [0001] The invention relates to semiconductor manufacturing technology, in particular to a method for forming a semiconductor integrated device. Background technique [0002] As the feature size (CD, Critical Dimension) of semiconductor devices becomes smaller and smaller, the integration of semiconductor chips becomes higher and higher, and the number and types of units that need to be formed per unit area are also increasing, so the semiconductor The requirements for craftsmanship are also getting higher and higher. How to rationally arrange the positions of various units and how to save semiconductor process steps and materials by using the common points of each unit manufacturing has become a hot research topic. [0003] In the manufacture of semiconductor devices, polysilicon is a very commonly used conductive material, which can usually be used to make gate electrodes of MOS transistors, high resistance polysilicon resistors, floating gates of flash me...

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Problems solved by technology

However, due to the need to deposit a layer of polysilicon layer to form the first polysilicon control gate, the polysilicon layer in other regions is etched away and then another layer of polysilicon layer is formed to make the polysilicon resistor. , resulting in a waste of materials and an increase in process steps, and the process integration is low

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