微波PCVD法大尺寸透明自支撑金刚石膜的制备及红外透过率

采用微波PCVD方法制备出直径50mm膜厚300um的大尺寸透明自支撑金刚石膜.在甲烷体积分数2%的条件下制备的透明自支撑金刚石膜经过两面抛光后在500cm-1-4000cm-1红外波段范同内红外透过率达到70%,但是其生长速率只有1um/h-2um/h.在体积分数4%甲烷浓度下制备的自支撑透明金刚石膜,其生长速率达到7um/h～8um/h,经过两面抛光之后膜厚为260um的金刚石膜的在500cm-1～4000cm-1红外波段范围内红外透过率达到60%左右,而且膜中心和边缘区的红外透过率基本相同.这些结果为大尺寸金刚石厚膜在红外窗口上的实际应用奠定了基础.

IR transmittance of large-sized free-standing transparent diamond films prepared by MWPCVD

Large-sized free-standing transparent diamond films of 50 mm diameter and 300 um thickness were prepared by microwave plasma chemical vapor deposition (MWPCVD). The growth rate of the diamond film was only 1-2 um/h when the diamond film was grown at a methane concentration of 2%, and the infrared (IR) transmittance reached 70% in the range of 500-4000cm-1 after the film was polished on both sides. A high growth rate of 7-8 um/h was achieved for the film grown at a methane concentration of 4%. The thickness of the film was 260 um after it was polished on both sides and its IR transmittance in the range of 500-4000cm-1 reached about 60%. Meanwhile, the IR transmittance was almost the same in the central and fringe regions. These results imply a promising application of large-sized thick diamond films in IR windows.