Deposition of Nanocrystalline Diamond Films on Pure Ti by CH4/H2 Microwave Plasma CVD
Cheolmun YIM, Dohoon SHIN, Yusuke HAYASHI, Keishi IRIE, Ri-ichi MURAKAMI and Yun-hae KIM
Abstract:In contrast on microcrystalline diamond film, nanocrystalline diamond film has a flat and smooth surface. Therefore, nanocrystalline diamond film is desirable in application field of tribology. In this study, the nanocrystalline diamond film and the microcrystalline diamond film were deposited on pure titanium using CH4/H2 MPCVD method. The diamond film deposition was carried out under the deposition temperature of approximately 1173K and the deposition pressure of 8.0kPa. CH4 concentration was changed from 0.5mol% to 5mol%. The deposition time was changed from 4hrs to 12hrs. The diamond film surface was observed by scanning electron microscopy (SEM). In the laser Raman spectra, the sharp peak of sp3-bonded carbon was attributed to 1332cm-1 at microcrystalline diamond films. The band near 1140cm-1 was related to the feature of nanocrystalline diamond film. Diamond films were also analyzed using X-ray diffraction. It is confirmed from XRD profile that (111) and (220) exists in the nanocrystalline diamond film. Surface roughness of diamond films decreased with increasing CH4 concentration. But, the surface roughness of diamond films was close to approximately 50nm when CH4 concentration was changed from 2mol% to 5mol%. It was confirmed that the nanocrystalline diamond film can be deposited by CH4/H2 MPCVD method under CH4 concentration from 2mol% to 5mol%. Key Words:Mircocrystalline diamond, Nanocrystalline diamond, Pure titanium substrate, Surface roughness, MPCVD