Porous SiC Chuck

Semicorex Porous SiC Chuck is a ceramic part that has been assembled with precision for safe, efficient handling of wafer substrates for semiconductor applications through process steps such as inspection, testing, and lithography. The chuck is manufactured of micro-porous silicon carbide ceramic (SiC). SiC has mechanical strength, chemical resistance, and thermal stability properties needed for cutting-edge semiconductor manufacturing environments.

An essential characteristic of the Porous SiC Chuck is its unique microstructure, which exhibits a porosity of 35%-40%. With the porosity of the chuck tightly controlled, the overlying design allows vacuum suction to be evenly dispensed across the chuck generating consistent stable and non-contact support for typically delicate wafer substrates: silicon or GaN, and other compound semiconductors.  The vacuum suction mode avoids both particle contamination and mechanical damage, thereby preserving wafer integrity during the process.

The ceramic body of the chuck is primarily high purity SiC, with other ceramics, such as alumina (Al2O3), potentially used for a limited number of functional layers depending on the application. The research and development of the material allow the pore size and distribution to be managed to design airflow and holding force depending on wafer sizes and process conditions. If it is important to control the vacuum on thinner wafers, smaller pore size will be incorporated. For faster flow rates where appropriate, the larger pore size will be used.

Porous SiC Chucks exhibit color variation as a result of the variable pore sizes, ceramic compositions, and firing conditions. The SiC chucks tend to be black or dark gray as the color of silicon carbide is either gray or black, however chucks with large alumina content tend to be off-white in color. The variances in color have no effect on the performance of the product and only represent the engineered properties that were created for specific applications to comply with specific customer needs.

In high-end wafer processing tools, thermal stability and chemical inertness are the two most important features. Silicon carbide provides excellent resistance to corrosion gases and thermal cycling. The Porous SiC Chuck successfully operates in vacuum chambers and plasma etch tools, and it continues to perform well with rapidly changing temperatures. Their ability to maintain the dimmensional stability of the chuck ensures that the wafer remains in the same location, even though accuracy requirements can be below sub-micron depending of the process contributing to the dimensional stabilized ensures accuracy.

Semicorex Porous SiC Chucks are made using authorized forming and sintering procedures which provide uniform porosity, high flexural strength, and low thermal expansion. Each chuck is inspected for pore structure, flatness and vacuum performance to ensure a dependable and repeatable product. Custom designs are also available to accommodate specific wafer sizes and system integration requirements such as back-side gas flow channels or mounting features.

In conclusion, the Porous SiC Chuck is a high reliability substrate support system which has been carefully designed to work in conjunction with the requirements for precision wafer processing. With a high vacuum holding ability, customizable pore structure, and outstanding material stability, it is an indispensable product in today's semiconductor fabrication lines.