Tokyo Electron Limited has begun sales of TriasTM SPA, a plasma nitridation system that incorporates nitrogen in gate dielectric films.

As the gate-insulating film becomes thinner to enable faster and lower power semiconductor devices, the gate leakage current and the diffusion of boron in devices increase to the point of degrading performance. To resolve both problems, the nitridation of gate dielectric films has emerged. This process technology can be used to manufacture advanced devices of 130 nm technology node and beyond, with higher speeds and lower power consumption.

Trias SPA applies the unique Slot Plane Antenna (SPA) plasma generation technology, which was created out of the wealth of plasma technology TEL has acquired over many years. SPA is based on the Radial Line Slot Antenna (RLSA) microwave plasma developed by Professor Tadahiro Omi of Tohoku University. The Trias SPA generates high-density, low-electron temperature plasma with excellent uniformity, enabling stable, damage-free plasma processing.

SPA plasma nitridation can be combined with ultra-thin oxide formation using TEL's Fast Thermal Processing System/Low Pressure Oxidation (FTPS/LP-Ox) to create a reliable, productive solution for the high-quality gate dielectric. FTPS/LP-Ox is a high-speed heating and cooling furnace, one of TEL's successful oxidation and diffusion systems. Based on this technology, the electrically equivalent oxide thickness of 1.2 nm has been achieved with leakage reduction 10 times or larger.

The Trias SPA's clean and mild plasma characteristics enable device makers to form highly reliable and low leakage gate dielectrics without additional annealing, resulting in a highly productive solution with low CoO. Also, the SPA nitridation chamber can be combined with the SPA oxidation chamber (to be released) for providing very low temperature gate dielectric integration at 500°C or lower, resulting in low thermal budget.

The Trias SPA is based on TEL's highly reliable and productive Trias 300 mm single-wafer CVD platform. The first Trias SPA model to be released is for use with 200 mm wafers. The system can be extended for use with 300 mm wafers at the customer site. The Trias SPA is designed based on the 200/300-bridge concept, providing excellent convertibility between 200mm and 300mm processes. The nitridation of the advanced gate dielectric film is the first application released for Trias SPA, and TEL is also planning additional future applications for the system. These applications could be front-end-of-line (FEOL) applications, such as thin-film oxidation, thick-film oxidation, and refinement of various films, including high-k materials.