SiC薄膜的制备及其对气氛的响应研究

Preparation of SiC Films and Study of Their Response to Gases

在CH4,H2,SiH4混合气体中用热丝化学气相沉积(HFCVD)法生长SiC薄膜。利用XRD、原子力显微镜(AFM)对SiC薄膜的表面形貌和晶体结构进行测试分析,结果表明,薄膜的确是SiC,其厚度为310nm。对该薄膜在较高温度(250℃)下进行气敏特性测试,发现其对乙醇、乙醚有较好的敏感特性。进一步研究表明,不同的薄膜制备工艺条件对薄膜的气敏特性有一定的影响,其中H2流量,掺杂(N2)浓度对薄膜气敏特性影响较大。

Silicon carbide thin films were prepared by hot filament chemical vapor deposition （HFCVD） in mixture gases of CH4, H2 and SiHa.The surface micrography and the structural properties of the films were analyzed by atomic force microscope （AFM） and X-ray diffractometer （XRD）. It shows that the material is indeed SiC and the film thickness is 310 nm, The sensitivity of the films to diethyl ether （（CH3CH2）2O） and ethanol （CH3CH2OH） sensing properties is measured at high temperature （250℃）. The results show that the films has good gas sensitivity. Further investigations show that the sensitivity of the films is influenced on the different technology of preparation and is great affected on a hydrogen flow rate and doped concentration （N2）,