Hybrid-driven modeling using a BiLSTM–AdaBoost algorithm for diameter prediction in the constant diameter stage of Czochralski silicon single crystals

During the preparation of electronic-grade silicon single crystals (SSC), accurately predicting the crystal diameter is crucial for obtaining high-quality crystals. In this paper, a hybrid-driven modeling method integrating Bidirectional Long Short-Term Memory network (BiLSTM) and Adaptive Boosting (AdaBoost) algorithm is proposed, aiming to improve the accuracy and stability of crystal diameter prediction in the medium diameter stage of the SSC growth by the Czochralski (CZ) method. First, the initial prediction of SSC diameter is performed using a mechanistic model and the prediction error is calculated; then, the time series data are processed using a BiLSTM network to generate the predicted values at each time point. Subsequently, the prediction results of the BiLSTM network are weighted and fused by the AdaBoost algorithm to obtain the final time series prediction output, and the prediction performance is further enhanced by iterative optimization. Compared with the traditional mechanistic model or a single data-driven model, this hybrid model retains the explanatory nature of the mechanistic model while also ensuring the accuracy of the data-driven model, which effectively overcomes the challenges posed by complex coupling and nonlinear problems.