Optical Quality Diamond Wafer Synthesis by Multi-Cathode DC PACVD

Kwang Yong Eun*, Jae-Kap Lee and Young-Joon Baik,

Thin Film Technology Research Center, Korea Institute of Science and Technology, Korea

Wafer scale diamond films with optical transparency and high thermal conductivity have been synthesized by the multi(7)-cathode direct current plasma assisted chemical vapor deposition (DC PACVD) method. Diamond wafers have been grown on the metal substrates with 76 mm diameter under the deposition pressure of 100 Torr and the input power of 15 kW, respectively. Synthesized free-standing diamond films have been polished and their R_a values range several tens nm. Optical(visible and IR range) and thermal properties of diamond films have been observed. Depending on the methane concentrations, there were large differences in the measured values. A transparent diamond wafer deposited at an optimum condition showed high transmission of 70 % at the 10.6 mm wavelength and high thermal conductivity of 21 W/cmK at room temperature. Variations of transmission and thermal conductivity within a wafer were ± 10%. The tangent loss and Raman spectroscopy of the diamond films have been measured and the included impurity levels have been determined analysis depending on the wafer location and the film thickness by RBS measurement.

Key words: CVD Diamond, dc plasma, optical transmission, thermal conductivity

Prime Novelty: Properties of diamond films deposited by the multi-cathode DC PACVD method

Corresponding author : Kwang Yong Eun

Address : P.O. Box 131, Cheongryang, Seoul, 130-650, Korea

Tel : 82-2-958-5491, Fax : 82-2-958-5489, e-mail : kyeun@kist.re.kr