SiC Coated Halfmoon Parts

Halfmoon Parts, which are coated with premium silicon carbide (SiC), are an essential feature of epitaxy processes as both wafer carriers and thermal conductors. Their specialized half-moon shape provides a method of assembling into a cylindrical form that serves as a fixture within epitaxial reactors. Within the chamber or reactor environment, the wafers need to be secured but also uniformly heated while the critical thin-film deposition takes place. The SiC coated Halfmoon Parts supply just the right amount of mechanical support, thermal stability, and chemical durability to perform these tasks.

Graphite is the substrate material for the Halfmoon Parts and chosen due to its very good thermal conductivity and relatively low weight and strength. The surface of the graphite is covered with a dense high-purity chemical vapor deposited silicon carbide (CVD SiC) surface to be robust against the aggressive environments associated with epitaxial growth. The SiC coating improves the surface hardness of the parts and provides resistance to reactive gases such as hydrogen and chlorine, providing good long-term stability and very limited contamination during the processing. Graphite and SiC work together in the Halfmoon Parts to provide the right balance of mechanical strength with chemical and thermal properties.

One of the most vital roles of the SiC coated Halfmoon Parts is the support of wafers. Wafers are expected to be flat and stable throughout the entire epitaxy to facilitate an even growth of lattice structure in the crystalline layers. Any degree of flexure or instability in the supporting parts may introduce defect layers in the epitaxy and ultimately impact performance of the device. The Halfmoon Parts are carefully manufactured for the ultimate dimensional stability at high temperatures to limit warping potential and provide appropriate wafer placement under any given epitaxial recipe. This structural integrity translates into better epitaxial quality and greater yield.

An equally important function of the Halfmoon Parts is thermal conduction. In an epitaxial chamber, uniform, steady-state thermal conductivity is key to obtaining high quality thin films. The graphite core is ideally suited for thermal conductivity in order to aid in the heating process and facilitate even temperature distribution. The SiC coating protects the core from thermal fatigue, degradation and contamination in the process. Therefore, the wafers can be uniformly be heated in order to achieve uniform temperature transfer and support the development of defect-free epitaxial layers. In other words, for thin film growth processes that demand specific thermal conditions, the SiC coated Halfmoon Parts offer both efficiency and reliability. Longevity is a key aspect of the components. Epitaxy often consists of thermal cycling in elevated temperatures in excess of what common construction materials can endure without degradation.

Cleanliness is another important benefit. Since epitaxy is very sensitive to contamination, using the CVD SiC coating of exceptionally high purity eliminates contamination from the reaction chamber. This minimizes particle generation and protects the wafers from defects. Continued downsizing of device geometries and continuous narrowing of epitaxial process requirements make contamination control crucial to secure consistent production quality.

Semicorex SiC coated Halfmoon Parts not only address cleanliness concerns, they are also flexible and can be adjusted to fit various epitaxial system configurations. They can also be manufactured in certain dimensions, thicknesses of coating, and designs/tolerances that fits hypothetically into the exacting equipment. This flexibility aids in assuring that existing equipment can integrate seamlessly and maintain the most favorable process compatibility.