气体循环条件下等离子体喷射CVD金刚石膜的生长稳定性和品质

Growth stability and quality of plasma jet CVD diamond films under gas recycling condition

在气体循环条件下采用H2、CH4和Ar的混合气体,利用100kW直流电弧等离子喷射CVD系统,在850和950℃下在Mo衬底上沉积了不同厚度的金刚石膜;并利用扫描电镜(SEM)、X射线衍射(XRD)和Raman光谱对膜的形貌、品质、取向和残余应力进行了分析.结果表明:在850℃下,随着金刚石膜厚度的增加,膜的品质不断提高,残余应力逐渐减小,且残余应力为拉应力,膜的生长稳定性很好;在反应气体流速不变的条件下,相比950℃沉积的厚度为120μm的金刚石膜,在850℃下沉积的厚度为110μm的金刚石膜有更好的生长稳定性,膜的品质更高,残余应力更小.

A mixture of H2, CH4 and Ar gas was used as feed gas under gas recycling condition. Diamond films with different thicknesses were deposited on molybdenum substrates by a 100 kW DC arc plasma jet CVD system at 850 and 950 ℃. The morphology, quality, orientation and residual stress of diamond films were analyzed by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and Raman spectroscopy. The results show that the quality of diamond films increases and the residual stress in diamond films decreases with increasing film thickness at 850 ℃. Diamond films with good growth stability were obtained and the tensile residual stress in diamond films was observed. The diamond film of 110μm in thickness deposited at 850 ℃ has a better growth stability, a higher quality and a smaller residual stress than the diamond film of 120 μm in thickness deposited at 950 ℃ when the flow rate of reaction gases is kept unchanged.