Modeling And Simulation For Inductively Coupled Plasma Etching Of Silicon In MEMS Fabrications

In MEMS fabrications for devices and systems, inductively coupled plasma (ICP) etching is a popular technology owing to its convenient operation, excellent anisotropy, high etch rate and low cost. However, the physical mechanism of ICP etching is not clear now, and researches on this process are based on experience and repetitious trials as a result. So it is important to develop a fast and effectual ICP etching model or simulator to forecast, control and optimize the fabrication process. Modeling and simulations of ICP etching is an interesting research preoccupation.The main work and innovations of this dissertation are described as following:1. The ICP equipments, theories and models of forming and transport of plasma, ICP etching and its models, and CAD tools being applicable for ICP etching are introduced and compared.2. After reasonable simplification of correlative reactions and reducing the representative simulated particles, the primary parameters of gas distributings in ICP chamber are simulated using direct simulation Monte Carlo (DSMC) method. The precisions are quite satisfied while the calculated time is shorter.3. A novel spatio-temporal normalized numerical model for etched profile evolution in ICP process is developed based on dynamics of plasma～surface interactions. Etching rate trend is disclosed and the optimal time steps are proposed and verified.4. A novel model for ICP time multiplexed deep etching (TMDE) simulation is developed, with the capability of material identification based on single string algorithm. This model has shorter runtime than other reported models.5. A novel approximate model is presented to simulate the footing effect in TMDE fabrications, with the simulation results of the surface affected by footing effect in accordance to the experiments.