Abstract
In this study, we fabricated the single layer and hybrid granular structured diamond films on silicon wafer by using the microwave plasma enhanced chemical vapor deposition (MPECVD).The hybrid diamond films are composed of two kinds of diamond grain size. We wish we can find the optimized parameter. We observed the morphologies of films by SEM and detected the roughness of surface by AFM. The crystal structure of our samples are analyzed by using X-ray diffractometer and TEM. Also, the bonding properties are characterized by Raman Spectroscopy. In the end, we measure the thermal conductivity by 3ω method. We deposited NCD film as top layer, and MCD as bottom layer in the NCD/MCD sample. When the thickness ratio (bottom/top) increase from 0 to 0.878, the thermal conductivity get higher from 30.34 W/mK to 41.46 W/mK. When the thickness ratio of UNCD/MCD increase from 0 to 0.925, thermal conductivity increase from 8.68 W/mK to 16.94 W/mK. Furthermore, UNCD/MCD have the smaller roughness than NCD/MCD.