摘要
研究了锗(Ge)量子点薄膜表面形貌随退火温度的变化及其相应的电学特性。以锗烷为主要反应气体,应用等离子增强化学气相沉积法(PECVD)在300℃温度、p-硅(100)基片上沉积了锗量子点薄膜,然后分别在400℃、500℃、600℃温度下退火。应用原子力显微镜(AFM)系统地观察了锗量子点薄膜的二维、三维图像,发现原位生长的锗量子点尺寸起伏大、薄膜表面比较粗糙。退火后,锗量子点分布趋于均匀,并且随退火温度的升高,量子点呈一定的取向排列,表面变得平整。通过电流-电压(I-V)和电容-电压(C-V)测试,发现锗量子点薄膜具有良好的电学特性。随退火温度的升高,电流、电容显著增大,漏电流减小,说明退火后,锗量子点薄膜晶界和粗糙度减小,使样品的表面、界面特性更好。
We studied the electronic properties and morphologies of Ge/Si quantum dots（QDs） films with annealing temperature.Ge QDs were prepared on p-Si（100） substrate by plasma enhanced chemical vapor deposition（PECVD） using GeH4 as the reactant gas under temperature of 300 ℃,then annealing at temperatures of 400 ℃,500 ℃,and 600 ℃ respectively.The two and three dimensional（2D,3D） morphologies of the samples were systematically observed by means of atomic force microscope（AFM）.We found that the originally grown Ge QDs are unhomogenerously distributed on the substrate,the size of the QDs waves,and the film looks rough.After annealing,the QDs tend to be homogeneous,and the films become flat and smooth.With the annealing temperature increasing,the QDs tend to be arranged in an orientation and their surface becomes flat.The samples show good electrical properties investigated by current-voltage（I-V） and capacitance-voltage（C-V） measurements.With the annealing temperature increasing,the current and capacitance increases significantly,while the leakage decreases.The results show that the annealed samples have good properties of surface and interface because of the decrease of the crystal bounds and roughness of the QDs.
出处
《苏州科技学院学报（自然科学版）》
CAS
2011年第4期45-48,52,共5页
Journal of Suzhou University of Science and Technology （Natural Science Edition）
基金
国家自然科学基金资助项目(60976071
60776004)
绍兴市科技计划项目(2009A21054)
