不同碳源浓度下热丝CVD金刚石薄膜的惰性示踪气体发射光谱法研究

Trace rare gases OES:nonintrusive method for the process of CVD diamond film growth under different carbon source

采用热丝化学气相沉积法制备金刚石薄膜,运用惰性示踪气体发射光谱法对等离子基团进行分析。实验所采用的惰性示踪气体为氩气。热丝CVD金刚石薄膜的表面形貌和断面形貌通过SEM进行表征,质量通过Raman光谱表征,从而对等离子体诊断结果进行验证。结果表明:保持其他工艺参数不变时,随碳源混合气体流量不断增加,电子温度总体呈下降趋势,但在50~70cm^3/min出现反常的先增加后下降,在60cm3/min附近时出现最大值,此时的带电粒子到达基片时具有最大通量和能量,与此同时,CO、C_2、CH等几种含碳基团浓度在60cm^3/min处出现最低,气相沉积过程向着金刚石薄膜沉积的方向发展,生长速率达到最大,金刚石薄膜的质量却随碳源混合气体流量的增加而降低。

The diamond films were prepared by hot filament chemical vapor deposition.Trace rare gases optical emission spectroscopy（OES）was used to measure the active species during the diamond growth.The quality and morphology of grown diamond films were characterized by SEM and Raman spectra.When the other parameters were kept constant,with the increasing gas flux of the carbon source,the electron temperature generally decreased.However,if the carbon source flow was between50cm^3/min and 70cm^3/min there appeared an abnormal situation,which was to first increase and then decline,maximum peak at the vicinity of 60cm^3/min,when the charged particles reached the substrate with the maximum flux and energy.Meanwhile,the content of carbon-containing groups,such as CO,C2 and CH,was at there minimum value near vicinity of 60cm3/min minimum.Vapor depositing process went towards the direction to grow diamond film,with maximum growth rate.However,the quality of diamond films decreased as the concentration of carbon source increased.