银薄膜沉积工艺优化研究

Study on the Optimization of Silver Film Deposition Process

采用单因素优化法对沉积条件进行优化以获得低电阻率的银薄膜。研究了溅射功率、气压和衬底温度对银薄膜的电阻率和沉积速率的影响。结果表明:低功率和高气压有利于降低电阻率。这是由于该条件下沉积速率较低,使银原子充分迁移,改善了晶格完整性。适当加热衬底也可降低电阻率,但不宜超过100℃。为了抑制薄膜在高温下的"团聚",在溅射气体氩气中加入氮气。SEM、AFM和XRD的结果表明:氮气促进了(111)取向晶粒的生长,抑制了"团聚",细化了晶粒。加入氮气后薄膜的表面粗糙度和电阻率也提高了,但经过退火后均下降。该结果对控制银薄膜的晶粒取向,获得热稳定的低电阻率的银薄膜具有一定的意义。

Single factor optimization method was used to optimize the deposition parameters to obtain silver films with low resistivity.The influences of sputtering power,pressure and temperature on the resistivity and deposition rate of silver films were investigated.The results show that low sputtering power and high pressure are beneficial to reduce the resistivity.This should be ascribed to the low deposition rate under such conditions,which favors the migration of Ag atoms,thereby improving lattice integrity.Increasing substrate temperature can also reduce resistivity,but should not exceed 100 oC.In order to suppress agglomeration,nitrogen gas(N2)was added to the argon sputtering gas.Scanning electron microscopy(SEM),atomic force microscopy(AFM)and X-ray diffraction(XRD)spectra show that the(111)orientation of Ag lattice was promoted by N2,thus leading to suppression of agglomeration and refined grains.The surface roughness(RMS)and resistivity increased when N2 was added,but decreased after annealing,which may be caused by desorption of the residual nitrogen from the film during annealing.The results are useful for controlling the grain orientation of silver films and obtaining thermally stable silver films with low resistivity.