A method for controlling the diameter of a silicon single crystal based on a constant pulling rate control structure

Abstract

The invention aims to provide a silicon single crystal diameter control method based on a constant-pull-speed control structure. The method comprises steps as follows: firstly, a non-linear large lagprediction model of the thermal field temperature-crystal diameter process is recognized according to thermal field temperature and crystal diameter data in a conventional silicon single crystal control structure, wherein delay parameters, input-output orders and model parameters in the prediction model are acquired through an output correlation delay determination algorithm, a Lipschitz factor and training of a stack sparsity automatic encoder, the stack sparsity automatic encoder is taken as the prediction model to be introduced into a non-linear general predictive control algorithm, and crystal diameter control is realized through the prediction model in a prediction control algorithm, feedback correction, rolling optimization and other strategies. The problems that the control effect becomes poor and control fails due to drastic fluctuation of the crystal pulling speed in the existing silicon single crystal diameter control process are solved.

Description

technical field [0001] The invention belongs to the technical field of silicon single crystal growth control, and in particular relates to a silicon single crystal diameter control method based on a constant pulling speed control structure. Background technique [0002] With the development of integrated circuits, the quality requirements for silicon wafers are increasing day by day, and the preparation of high-quality, large-size silicon single crystals has become an inevitable trend. However, as the size of silicon single crystal increases, its growth conditions become more complicated, which puts forward higher requirements for the control of silicon single crystal. Therefore, it is very important to adopt effective control methods to prepare high-quality, large-sized silicon single crystal materials that meet the requirements of integrated circuit chips. [0003] The Czochralski method is the most important method for preparing high-quality silicon single crystals, and ...

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Problems solved by technology

[0004] The object of the present invention is to provide a silicon single crystal diameter control method based on a constant pulling speed control structure, which solves the problem that the control effect of the existing silicon single crystal diameter control process is deteriorated due to the sharp fluctuation of the crystal pulling speed, and even leads to failure of control

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