SiC Wafer Cassette

Semicorex SiC wafer cassette, also known as a tiled wafer boat, was developed specifically for oxidation, diffusion, and annealing operations at temperatures in excess of 1200°C. The cassettes provide significant mechanical support, as well as alignment for many wafers at once during high-temperature furnace use, and exhibit great mechanical and dimensional stability during thermal stress and afterwards.  The demand for ultra-pure and thermally stable materials for wafer handling systems is increasing as semiconductor devices decrease in size and increase in performance.

The cassette is made from high-purity silicon carbide, there are also coatings that can be applied for even greater benefits as well. SiC has excellent thermal shock, corrosion, and dimensional deformation stability.  SiC has unique hardness, chemical inertness, and thermal conductivity such that it is an ideal material for this process environment. SiC, relative to quartz and alumina alternatives will not diminish its mechanical and chemical properties at high processing temperatures, thereby reducing the risk of contamination and improving wafer process uniformity during the manufacturing processes.

The ultra-high purity of the SiC wafer cassette exhibits resistance to metallic or ionic contaminants entering into the process chamber; something that is absolutely necessary for high purity to meet process requirements for advanced semiconductor fabrication processes. By minimizing sources of contaminants silicon carbide cassettes will increase wafer yield and device reliability.

Semicorex's precision machining technology allows for each cassette to be produced with tight tolerances, uniform slot pitch, and parallel alignment. The precision machining of the materials supports smooth wafer loading and unloading, which reduces the chance of scratches while handling wafers. The precise slot spacing allows for uniform temperature and airflow across all wafers, which promotes uniformity in oxidation and diffusion while decreasing process variability.

SiC has excellent thermal conductivity, dimensional stability, and provides reliable performance under repeated thermal cycling. The material is stable and does not warp or crack; its high stiffness maintains structural integrity with high temperature over long periods of time, significantly decreasing the mechanical stress on wafers while limiting the likelihood of unwanted particles generated from handling due to friction or micro-vibration.

In addition, SiC's inertness towards chemicals protects the wafers from reaction to the process gases (e.g. oxygen, hydrogen, ammonia) typically involved during processing. The wafer cassettes are stable in oxidizing and unoxidizing atmospheres, and can be incorporated into the furnace workflow across a number of processes such as oxidation, diffusion, LPCVD, and annealing.

To meet specific process requirements, Semicorex offers customized SiC wafer cassettes in various sizes, slot counts, and configurations. Each unit undergoes rigorous quality inspection and surface treatment to ensure smoothness, cleanliness, and dimensional accuracy. Optional surface polishing further reduces particle generation and enhances compatibility with automated wafer handling systems.