Modeling of Epitaxial Silicon Thin‐Film Growth on a Rotating Substrate in a Horizontal Single‐Wafer Reactor

Abstract

The effect of substrate rotation on transport of reactive gases and epitaxial growth rate is investigated for a horizontal single-wafer reactor using a model and experiments. The governing equations for gas velocity, temperature, and chemical species transport are solved for the SiHCI3-H2 system for Si thin-film preparation. The rotating substrate causes a circulating gas flow region above itself in which an asymmetric and nonuniform SiHCI3 distribution is formed by thermal diffusion and species consumption due to the surface chemical reaction, even when the growth rate profile on the substrate surface is nearly uniform. The thickness of a thin-film grown at any position is obtained by an integral of the local growth rate along a concentric circle on the substrate surface. The good uniformity in the film thickness observed in calculation and measurement is mainly attributed to the averaging effect by integrating the local growth rate, and partially by the species concentration distribution change, both of which are caused by the rotating motion of the substrate.

Silicon epitaxial growth process using trichlorosilane gas in a single-wafer high-speed substrate rotation reactor

“…In the previous study [12], a slow substrate rotation had been shown to have an averaging effect on the epitaxial growth rate along the concentric circle of the rotating silicon substrate, typically in a horizontal reactor. However, such a slow rotation does not influence the entire transport phenomena in the reactor, such as the gas flow, heat and species transport.…”

Reflector Influence on Rapid Heating of Minimal Manufacturing Chemical Vapor Deposition Reactor

“…5, as the classical ways. 15 Because the slow wafer rotation at 4 rpm has the effect of averaging the film growth rate along the concentric circle, 12 the epitaxial film thickness was expected to become flat over the wafer. Silicon carbide has a high thermal conductivity 16 which can help decrease the temperature difference over the wafer.…”

“…Additionally, wafer rotation is a popular and effective method in many CVD reactors for averaging the temperature distribution and the film growth rate over the concentric circle of the wafer. 12 In this study for achieving a quick thermal process, the heating behavior was evaluated using two types of reflectors, i.e., the Type-I reflector made of thick mirror plates used in our previous studies [6][7][8] and the Type-II reflector made of thin plates developed in this study. Additionally, the wafer rotation and the silicon carbide susceptor were shown to be effective for preparing a uniformly thick silicon epitaxial film.…”

Multi-scale modeling of chemical vapor deposition processes for thin film technology

“…4), such as horizontal rectangular duct reactors [14,[76][77][78][79][80][81][82], vertical impinging jet and rotating disk reactors [22,[83][84][85][86][87][88], pancake reactors [89,90], barrel reactors [91][92][93], planetary reactors [94][95][96], hot-wall multi-wafer LPCVD reactors [74,[97][98][99]. Many studies were devoted to low pressure single wafer reactors of the stagnation flow type [21,28,[100][101][102]. Studied CVD processes included atmospheric pressure CVD of epitaxial Si, SiC and CdTe, MOVPE of GaAs, GaN and InP, and low pressure deposition of doped and un-doped poly-Si, tungsten, silicon-dioxide and silicon-nitride.…”