Gate Oxide Fabrication Method for MOS Devices

In an increasingly mobile world of go-anywhere, do-everything personal products, the semiconductor industry is locked into a search for technologies that support lower power consumption and enhanced reliability in highly integrated LSI.

Toshiba Corporation has announced a major breakthrough for the desirable combination of all metal-oxide semiconductors and end products.

This breakthrough attacks the problem with a fabrication process that uses deuterium in its gaseous state.

While previous studies had confirmed the effectiveness of deuterium annealing in reducing interface-defect generation at the gate oxide-silicon substrate interface, this process has advanced to the level of suppressing SILC and cutting it by 30 per cent.

The process burns deuterium in ambient oxygen during the gate oxidation process, introducing deuterium atoms into the gate oxide as growing SiO2 film.

Tests confirm that the process achieves more stable chemical bonding of deuterium atoms than the annealing process.

SILC suppression was rendered even more effective by replacing SiH4 gas with SiD4 gas during polycrystalline silicon deposition of the gate electrode. The number of deuterium atoms in the SiO2 film after polycrystalline silicon deposition by SiD4 gas was 10 times larger than achieved with deuterium oxidation alone.

This oxidation process has the potential to be a real-world solution compatible with conventional oxidation process.

Suppression of SILC can be achieved by changing from hydrogen gas, widely used for the gate oxidation process, to deuterium gas.

Item provided courtesy of Industry Search