氩气浓度对氮掺杂金刚石膜的影响

Influence of Ar Concentration on Nitrogen-doped Diamond Film

采用直流热阴极等离子体化学气相沉积(DC-PCVD)方法,以三聚氰胺(C3H6N6)的甲醇(CH3OH)饱和溶液为掺杂源,通过改变反应气氛中的Ar浓度,在P型Si(111)基片上沉积了氮掺杂纳米金刚石膜。采用扫描电子显微镜、拉曼光谱仪、X射线衍射仪、霍尔测试系统等分析了不同Ar浓度对氮掺杂金刚石膜生长特性的影响。结果表明:随着Ar浓度的增加,膜的晶粒尺寸逐渐减小,表面变得光滑平整;由拉曼G峰漂移引起的压应力先减小后增大;膜的导电性能变好。且由于C3H6N6的引入,使得在较低的Ar浓度下(H2/Ar流量比为100/100时),即可制得晶粒尺寸在30～50 nm的高质量的金刚石膜样品,远低于H2/Ar体系的Ar浓度为90%的阈值。

Nitrogen-doped nanocrystalline diamond film were deposited on p-type Si substrates with saturated solution of C3H6N6 in CH3OH as nitrogen source by DC hot-cathode plasma chemical vapour deposition（PCVD） with different Ar concentration.The prepared nitrogen-doped diamond films were analyzed by SEM,XRD,Raman spectroscopy and Hall system,so the influences of Ar concentration on the doped diamond film are shown.With the increase of Ar concentration,the grain sizes of the films decrease and the airplane surface is presented;because the residual compressive stress influenced by the shift of the Raman G-peak decreases firstly and then increases;the conductivity of the films become better.With the introduction of C3H6N6,the high qualified diamond films with 30-50 nanometers crystalline are prepared in the condition of low Ar circumstance.The flow ratio of H2/Ar is 100/100,where the content of Ar is strongly lower than the threshold in H2/Ar systems.