纳米金刚石膜/{100}晶面多晶金刚石膜台阶法快速生长研究

Fast fabrication of nanocrystalline and{100}faceted polycrystalline diamond films by using stepped method

通过高功率微波等离子体化学气相沉积(MPCVD)以及台阶式基底排列方法,可以在一次沉积过程中同时沉积纳米晶粒及<100>取向的{100}面多晶金刚石薄膜。详细比较在同一次沉积中同时制备的多种不同类别的金刚石产物的生长速率。采用台阶法并添加少量空气,微波功率从2.0k W增加至3.2 kW,在下面大硅片上生长的纳米金刚石膜的平均生长速率可从0.3μm/h增大到3.0μm/h;而在上面小硅片上生长的纳米金刚石膜的平均生长速率从3.8μm/h也增加到11.2μm/h,同时产物也转变为{100}晶面的多晶膜。另外,在上面小硅片上生长的金刚石膜的边角效应明显,在边界生长的金刚石产物的生长速率更高,从17.0μm/h增大到27.1μm/h。该结果表明少量氮气和氧气同时添加对金刚石生长的形貌多样性调节作用和对生长速率的提升作用强烈依赖于生长条件。

Nanocrystalline and<100>oriented{100}faceted polycrystalline diamond films can be deposited simultaneously in one deposition run by high power microwave plasma chemical vapor deposition(MPCVD)and using stepped method for substrate arrangement.Focus was made on comparing the difference on diamond products and their growth rate in one deposition run and among different growth processes.When microwave power was increased from 2.0 kW to 3.2 kW,the growth rate of nanocrystalline diamond(NCD)film grown on the bottom big Si wafer was enhanced from 0.3μm/h up to 3.0μm/h;while the growth rate for diamond products grown on the top small Si slices was 3.8μm/h for NCD film at 2.0 kW and raised to 11.2μm/h for<100>oriented{100}faceted large-grained polycrystalline diamond film at 3.2 kW.Furthermore,the diamond products near the edge and corner of the small Si slice are different from that grown on the center of the same substrate,namely the edge effect is pronounced,and the growth rate was further improved,ranging from 17.0μm/h up to 27.1μm/h.This work clearly demonstrates the versatility of N2 and O2 addition on diamond growth by using stepped method and further deepen the understanding of the complicated diamond growth process by high power MPCVD.