AVS 56th International Symposium & Exhibition
    Plasma Science and Technology Wednesday Sessions
       Session PS2+MN-WeA

Paper PS2+MN-WeA3
Ion Trajectory Prediction at High-Aspect-Ratio Hole Etching by the Combination of On-Wafer Monitoring and Sheath Modeling

Wednesday, November 11, 2009, 2:40 pm, Room B2

Session: High Aspect Ratio and Deep Etching for 3D Integration and Memory
Presenter: H. Ohtake, Tohoku University, Japan
Authors: H. Ohtake, Tohoku University, Japan
S. Fukuda, Tohoku University, Japan
B. Jinnai, Tohoku University, Japan
T. Tatsumi, OKI Semiconductor Miyagi Co., Ltd., Japan
S. Samukawa, Tohoku University, Japan
Correspondent: Click to Email
The abnormal etching profiles, such as bowing, etch stop and twisting, have been reported at high-aspect-ratio hole etching. To avoid the failures, we have to predict the ion trajectory and etching profile precisely by analyzing the sheath area around the hole. In this presentation, we developed the ion-trajectory prediction system at high-aspect-ratio hole by combining the on-wafer monitoring technique and sheath modeling for explaining and predicting the etch stop and twisting. Since our developed on-wafer sensors provide the surface potential, the electron density/ temperature and side-wall resistance of the hole, we can simulate the distribution of electric field in the hole. This system revealed that the sidewall conductivity strongly affects the charge-up and ion trajectory in the high-aspect-ratio hole. It also predict the etch stop and twisting phenomena. Consequently, we believe this prediction system is an effective tool for developing the nano-scaled fabrication.