National Science Council

Tsao-Ming Hong

Chia-Fu Chen

Sheng-Hsiung Chen

The present invention provides a process for selectively depositing diamond films, which includes two stages of diamond deposition and the gas source used is a mixture of C.sub.x H.sub.y plus CO.sub.2 or C.sub.x H.sub.y O.sub.z plus CO.sub.2. In the period between the first and second stage, the substrate is immersed in an aqueous solution of HF plus HNO.sub.3. The obtained diamond films exhibit good crystallinity and selectivity and the growth rate is fast.

Process for selectively depositing diamond films

The present invention provides a process for depositing diamond by chemical vapor deposition without using conventionally-used hydrogen, which is an explosive gas, as a reaction gases. The process includes contacting a substrate with a two-component gas mixture, under the conditions of a substrate temperature of 150.degree. C.-900.degree. C., a pressure of 1-50 torr, an input microwave power of 250-450 W. The two-component gas mixture is a hydrocarbon (C.sub.x H.sub.y) plus CO.sub.2 with a flow rate ratio of the C.sub.x H.sub.y to CO.sub.2 of 0.2-0.8, or a gasified liquid state oxygen-containing hydrocarbon (C.sub.x H.sub.y O.sub.z) plus CO.sub.2 with a flow rate ratio of the C.sub.x H.sub.y O.sub.z to CO.sub.2 of 12-17. High quality diamond can be obtained even at low temperature of 180.degree. C.

Process for depositing diamond by chemical vapor deposition

A method of forming boron-doped diamond film by, chemical vapor deposition (CVD) utilizing two-component system reactant gas doped with trimethyl borate.

Growing community of inventors

Changhua Hsien, Taiwan

Tsao-Ming Hong