IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Thursday Sessions
       Session PS-ThA

Invited Paper PS-ThA1
Predicitve Profile Evolution Simulation in Plasma Etching

Thursday, November 1, 2001, 2:00 pm, Room 104

Session: Feature Profile Evolution
Presenter: V. Vahedi, Lam Research Corporation
Authors: V. Vahedi, Lam Research Corporation
D. Cooperberg, Lam Research Corporation
L.B. Braly, Lam Research Corporation
R.A. Gottscho, Lam Research Corporation
Correspondent: Click to Email
The ability to predict feature profile evolution as a function of initial patterned profile and process set points will enable reduction in process development time and cost, speed process transfer, and inspire novel process integration approaches. Feature profile simulators have been used in prior studies to qualitatively capture the evolution of both etching and depositing processes. These simulations combined with results from molecular and/or ion beam experiments, chemical analysis of passivation and selvedge layers, plasma diagnostics of density, temperature, and composition have been used to help refine the understanding of the dominant surface mechanisms governing feature evolution and microscopic uniformity. Despite these efforts, our understanding of the complicated surface reaction mechanisms and gas phase kinetics which govern etching and/or deposition of films for commercial applications is incomplete and has prevented truly predictive profile evolution simulations. Commercial etch applications are designed for processing complex film stacks and must meet challenging specifications for mask and stop layer selectivities, sidewall-angle and/or shape, feature width, dense versus isolated feature loading, corner rounding, etch rate, uniformity, and productivity. These demands often require the use of multiple reactive process gases leading to many ion and reactive neutral species. Under these conditions, a semi-empirical approach is the most reasonable way to develop a feature evolution simulation. Our approach is to reduce the complexity of the system using a reduced set of incident species, etch and deposition mechanisms often investigated in the literature under less complex conditions where fluxes have been measured or modeled, blanket etch/deposition rates as a function of reactor settings, and a limited amount of cross-sectional SEM and Langmuir probe data to calibrate the profile simulator. In the current work, we outline a method for calibrating a semi-empirical process simulator and present simulations for Cl2/BCl3 plasma etching of resist patterned Al/0.5%Cu lines. The simulator has been used to predict feature profile evolution as a function of inductively coupled power, RF bias power, and Cl2:BCl3 flow ratio. A silicon trench isolation process simulator may also be discussed.