A method for depositing polysilicon by lpcvd

Abstract

The invention discloses an LPCVD (Low Pressure Chemical Vapor Deposition) method of polycrystalline silicon. According to the method, deposited particulate matters on a tube wall can fall off during temperature change through carrying out staged heating before deposition and staged cooling after deposition; then, the particulate matters cannot pollute the surfaces of wafers by using synchronous nitrogen gas purging, so that the quality of polycrystalline silicon film deposition is improved; meanwhile, accumulated deposited particulate matters of an inner tube during single deposition are reduced, the maintenance cycle for the inner tube is prolonged, so that the production efficiency is increased.

Description

technical field [0001] The invention discloses a method for producing polysilicon, which belongs to the field of semiconductor manufacturing, in particular to a method for producing polysilicon by using a low-pressure chemical vapor deposition process. Background technique [0002] In the early 1960s, the aluminum gate MOSFET was produced in the early stage. Its speed, integration, power supply voltage, and compatibility with bipolar circuits could no longer meet the needs of applications. Therefore, polysilicon films were used as self-aligned insulated gate field effect Gate and interconnect materials for transistors. With the development of integrated circuits, the application of polysilicon is becoming wider and wider, such as for differential oxidation to simplify the process flow; for load resistors to shrink circuit units, and so on. [0003] Among various methods of making polysilicon, Low Pressure Chemical Vapor Deposition (LPCVD for short) has become the most commo...

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Problems solved by technology

[0002] In the early 1960s, the aluminum gate MOSFET was produced in the early stage. Its speed, integration, power supply voltage, and compatibility with bipolar circuits could no longer meet the needs of applications. Therefore, polysilicon films were used as self-aligned insulated gate field effect Gate and interconnect materials for transistors

[0006] However, the cleaning and maintenance of the inner tube cannot prevent the adverse effects of the particles on the tube wall on the deposition process.

At the same time, frequent maintenance cycles also slow down the production capacity of the entire semiconductor process

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