FCVD Anneal Process for Fin CD Loss Reduction Study

In the Fin Field-Effect Transistor (FinFET) process, the aspect ratio between Fin trench and Fin pitch has reached more than 5:1. STI is formed by flowable CVD(FCVD) deposition with steam ox anneal. The size of Fin CD has a great influence on the process window of the subsequent process. We can reduce Fin CD loss by adjusting the FCVD STI anneal process. In this paper, we discuss how to reduce Fin CD loss 6% by adjusting the temperature of FCVD STI anneal process and the properties of FCVD films change at different annealing temperatures. Finding the optimal conditions for process integration.