chemical vapor deposition

Silicon carbide (SiC) is a promising material for high power and high frequency devices due to its wide bandgap, high break down field and high thermal conductivity. The most established technique for growth ofepitaxial layers of SiC is chemical vapor deposition (CVD) at around 1550 °C using silane, SiH4, and lighthydrocarbons e g propane, C3H8, or ethylene, C2H4, as precursors heavily diluted in hydrogen. For high-voltagedevices made of SiC thick (> 100 μm), low doped epilayers are needed. Normal growth ...

The High Electron Mobility Transistor (HEMT) is a commonly used transistor for microwave and high power amplifiers around the world today. Typical application areas are space radio telescopes and cellular phones. Conventional HEMTs on today’s market use a Gallium,Arsenide (GaAs) substrate with an Aluminium, Gallium, Arsenide (AlGaAs) top layer; this old working horse has material limitations and scientists has pushed the GaAs material to its theoretical limit during the last50 years. New techniques ...

A CVD reactor concept featuring a segmented design allows individual regions of a wafer to be exposed to different precursor concentrations simultaneously during a run resulting in different thickness profiles on the wafer and a thickness gradient at the boundaries between segment regions. Different recipes were cycled through each of the segments in a sequence of deposition experiments to develop a model relating precursor concentration to film thickness in each segment region. As a demonstration of spatial programmability, the system ...

A computational toolbox was developed to perform full wafer response surface modeling of combinatorial chemical vapor deposition wafers. It consists of a library of MATLAB object-oriented functions that are based on accurate quadrature methods. The toolbox was tested using three sets of artificially generated wafers. Once the validity of the toolbox was demonstrated, it was used to model tungsten deposition with a Spatially Programmable CVD reactor. As a result, a model of the form T = b1(sqh2s1) + b2(sqh2s2) + ...

Project Title: Development of a Spatially Controllable Chemical Vapor Deposition System 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 ...