| Title |
The Effect of Bias on the Critical Concentration Against W - filament and Thin Film Growth Behavior in CVD Diamond Thin Film Growth |
| Authors |
이철로(Cheoul Ro Lee); 김관식(Kwan Sik Kim); 임재영(Jae Young Leem); 정광화(Kwang Hwa Chung); 천병선(Byung Sun Chun) |
| Abstract |
In the hot W-filament CVD(HFCVD) diamond thin film growing, the filament becomes carburized and changes its resistance when the vol. % of CH₄gas is higher than the critical value. The effects of tmeperature and the negative bias of W-filament on the critical CH₄concentration were studied. The critical CHa concentration increased as temperature dropped and was almost proportional to the negative bias applied to W-filament. The diamond thin films grown with the assistance of electron bombardment (EACVD) were compared with those grown by usual HFCVD. The EACVD method gave higher film growth rate and smaller grain size than HFCVD method, and as the voltage difference between the filament and the Si substrate increased the higher growth rate and the smaller grain size were resulted. In the diamond films grwon by HFCVD the triangular microstructures were frequently seen on {111} plane, while none was found on the films grown by EACVD, suggesting that EACVD produces better quality diamond thin film than HFCVD. The XRD and RHEED diffraction patterns of all these films grown by EACVD showed the same patterns as those of natural diamond, confirming that the diamond films grown in this study were of good quality. |