摘要
为了探讨膜厚对四面体非晶碳薄膜拉曼结构表征和内应力的影响规律,进而确定应力与拉曼光谱之间的关系,采用过滤阴极真空电弧技术以相同的工艺条件在P(100)单晶抛光硅衬底上制备了从3nm^350nm不同厚度的四面体非晶碳薄膜。利用表面轮廓仪和原子力显微镜测试膜厚,表面轮廓仪确定曲率半径并计算薄膜应力,共聚焦拉曼光谱表征薄膜的结构细节。实验发现,随着膜厚的增加,四面体非晶碳薄膜的应力持续下降,当膜厚超过30nm时,应力的下降趋势变得平缓,并保持在小于5GPa的较低水平。随着膜厚的增加,可见光拉曼光谱中衬底硅的一阶和二阶谱峰强度逐渐降低,在50nm^80nm膜厚范围,半高宽最窄,峰强最高,能够最有效地获得拉曼结构信息。随着膜厚的增加和应力的下降,非晶碳一阶谱峰的峰位表现为逐渐向低频偏移。
To investigate the effects of film thickness on Raman characteristics and intrinsic stress of tetrahedral amorphous carbon （ta-C） and to ascertain the correlations between stress and Raman spectra, ta-C films with different film thickness were deposited on a polished P-type （100） monocrystalline silicon substrate by a filtered cathodic vacuum arc technology. The film thickness was measured by a surface profiler and AFM, and stress was calculated according to the curvature of samples examined by the surface profiler while the microstructure of the films was characterized by Raman spectra. It is found that the stress drops continuously and then levels off with the increase of film thickness. When the film thickness exceeds 30 nm, the compressive stress is less than 5 GPa. The intensity of the first and second order peak of the monocrystalline silicon substrate in the Raman spectra gradually decreases with the increase of thickness. For film thicknesses from 50 nm to 80 rim, the full width at half maximum of the peak is a minimum, the intensity of the peak is a maximum, and the clearest Raman signals can be acquired. Additionally, the position of the broad peak gradually shifts to a lower wave number with the increase of thickness and the decease of intrinsic stress.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2006年第1期59-63,共5页
New Carbon Materials
基金
国家"十五"预研(41312040401)
国家863计划新材料领域(2002AA305507)资助项目~~
关键词
四面体非晶碳
过滤阴极真空电弧
拉曼光谱
应力
Tetrahedral amorphous carbon
Filtered cathodic vacuum arc
Raman spectra
Stress
