Improvement of DRIE simulation method for process development application

Abstract

TSV (Through silicon via) is the new generation of packaging technology in integrated circuits industry. DRIE (deep reactive ion etching) process is the critical technology for TSV manufacturing. The simulation on DRIE has been researched a lot for process development. However it is still difficult to involve the equipment parameters directly in the simulation which is an obstacle to the application of simulation. In this paper, we try to develop a practical simulation method to involve the critical parameters of DRIE process such as coil power. The DRIE simulation is based on the two-dimensional topography evolution method that we have developed. The alternation etching of polymer and silicon in the Bosch process is modeled. Physical models for etching and deposition are included. A string-cell hybrid method based on string structure and cell structure is used. In order to connect the DRIE equipment parameters with the model parameters, the isotropic and ion etching rate of both silicon and polymer are considered respectively. The effects of coil power are described analytically and empirically. The extraction of the parameters of the function is performed by fitting the functions to experimental data. The functions are incorporated into the DRIE simulator. The functions can realize robust numerical simulation. The application of the simulator for the DRIE process development is demonstrated. The simulation results are verified by the experimental results.