Development of a Spatially Controllable Chemical Vapor Deposition System

Abstract

Most conventional chemical vapor deposition (CVD) systems do not have the spatial actuation and sensing capabilities necessary to control deposition uniformity, or to intentionally induce nonuniform deposition patterns for single-wafer combinatorial CVD experiments. In an effort to address these limitations, a novel CVD reactor system has been developed that can explicitly control the spatial profile of gas-phase chemical composition across the wafer surface. In this thesis, the simulation-based design of a prototype reactor system and the results of preliminary experiments performed to evaluate the performance of the prototype in depositing tungsten films are presented. Initial experimental results demonstrate that it is possible to produce spatially patterned wafers using a CVD process by controlling gas phase reactant composition. Based on the evaluation of the first prototype, a second prototype system was designed and constructed, enabling for greater control and programmability. The capability of this prototype for performing combinatorial CVD experiments is discussed. Finally, improvement of intra-segment uniformity and film thickness together with micro structure or composition is discussed.