About this document
This Technical Note describes a manufacturing platform for semiconductor chamber parts such as focus rings and edge rings, in which a reaction-filled SiC core and a precursor-derived SiC functional layer take on separate roles. It covers the design principles, the process flow and the evaluation plan. The full report is available in Korean. An English summary is provided on this page.
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Summary
High-end focus rings and edge rings must resist etching and contamination on the plasma-facing surface while meeting dimensional, stiffness and cost requirements across the whole part. Existing SiC routes carry structural limits: cost that scales with thickness, dissimilar interfaces, and free silicon. This note covers a platform that splits these roles between a reaction-filled core and a thin precursor-derived SiC functional layer, then seals the part and finishes it by hot isostatic pressing (HIP).
Conclusion
The platform separates surface performance from core performance. Wear concentrates on the wafer-side inner diameter and the top surface, so a precursor-derived SiC functional layer is placed there to provide etch resistance and low contamination. The core, about 95% of the part volume, carries shape, dimensions, thermal, electrical and mechanical performance, and cost. Functional layer thickness is designed to cover consumption, finishing removal and a margin; consumption is fixed from the etch rate in the customer's chamber and the target replacement interval. The core is made by reaction filling: silicon and carbon react inside the pores of a porous preform and fill them with secondary SiC. Because HIP temperatures overlap or exceed the Si melting point of 1,414 °C, the amount of residual Si in the core determines the manufacturing route. Route A, using a low-free-silicon core, is the primary route for focus rings and edge rings. Route B, using an assembled Si-rich core, treats migration, outflow and penetration of molten Si into the outer layer as process variables to be managed. The functional layer is built on a transition zone formed by impregnating a low-viscosity precursor into the surface pores of the core. This zone anchors the interface through SiC-family material compatibility and mechanical interlocking. One cubic centimeter of precursor leaves about 0.23 cm³ of SiC after crystallization (calculated from manufacturer data). Given this large volume loss, bulk pores are filled by reaction filling, and the precursor is used only for the surface zone and the functional layer. Thin layers are coated, cured and pyrolyzed one at a time so that shrinkage is completed layer by layer. Open pores connected to the surface are not closed by HIP. The part is sealed on every face, with the functional layer on the top and inner surfaces and a minimal sealing layer on the bottom and outer surfaces. Capsule-free HIP, with no detectable helium permeation as the entry condition, is the preferred route. For one focus ring with a 372 mm outer diameter, 302 mm inner diameter and 3.5 mm thickness, the calculated precursor requirement is about 194 g for full-volume polymer infiltration and pyrolysis (PIP) and about 11 g for this platform using a coating liquid with 40 vol% filler. Actual purchase quantities and HIP, machining and inspection costs are estimated separately. The document does not report performance results; it defines them as measurement items at each stage gate. Development runs from coupon-level process windows to small rings, 300 mm full-shape prototypes, evaluation in customer chambers, and volume production with refurbishment. Each stage is judged against CVD SiC and conventional reaction-bonded SiC reference samples. Regardless of route, the final plasma-facing surface must show no detectable free Si. The document also describes refurbishment: removing the worn functional layer, restoring the core reference surface and forming a new functional layer.
Topics
- Equipment parts
