【摘要】 采用自行研制的915 MHz/75 k W高功率微波等离子体化学气相沉积（MPCVD）装置,在输入功率60 k W,沉积气压20 k Pa的条件下制备了直径5英寸的大面积自支撑金刚石膜,并对金刚石膜的厚度,热导率,线膨胀系数,结晶质量,光学透过率等参数进行了表征。实验结果表明,制备的大面积自支撑金刚石厚膜均匀完整,相关性能参数达到较高水平,具有较好质量。热学级金刚石膜的生长厚度超过5 mm,生长速率达到12. 5μm/h;室温25℃热导率2010 W·m^-1·K^-1,180℃条件下的热导率仍达到1320 W·m^-1·K^-1;室温25. 4℃时线膨胀系数为1. 07×10^-6℃^-1,300℃时升高至2. 13×10^-6℃^-1。光学级金刚石膜的生长厚度接近1 mm,生长速率约为2. 3μm/h,厚度偏差小于±2. 7%;双面抛光后的金刚石膜厚度约为700μm,其Raman半峰宽为2. 0 cm^-1,PL谱中未出现明显与氮相关的杂质峰;其光学吸收边约为223 nm,270 nm处的紫外透过率接近60%,在8～25μm范围内的光学透过率超过70%。更多还原

【Abstract】 Thick polycrystalline free-standing diamond films of 5 inch in diameter were deposited by a self-made 915 MHz/75 k W high power microwave plasma chemical vapor deposition（ MPCVD） system with input power of 60 k W and deposition pressure of 20 k Pa. The thickness,thermal conductivity,coefficient of thermal expansion,quality and optical transmission were characterized. The results indicate that the deposited thick free-standing diamond films are uniform,intact and high quality,their relevant performance parameters reaching a high level. Such as the thermal grade diamond film,its thickness is more than 5 mm with growth rate of about 12. 5 μm/h and coefficient of thermal conductivity of about 2010 W·m^-1·K^-1 at25 ℃ and 1320 W·m^-1·K^-1 at 180 ℃ as well as coefficient of thermal expansion of 1. 07 × 10^-6℃^-1 at 25. 4 ℃ and 2. 13× 10^-6℃^-1 at 300 ℃. The thickness of the as-grown optical grade diamond film is close 1 mm with growth rate of about 2. 3μm/h and thickness deviation less than ± 2. 7%. The double polished diamond film is about 700 μm and possesses excellent characteristics such as FWHM of Raman peak of only 2. 0 cm^-1,a cutoff wavelength of 223 nm,UV transmission at 270 nm near 60%,as well as transmission more than 70% in the 8-25 μm range.更多还原