3英寸锗基HgCdTe表面ZnS钝化膜的应力研究

Study of Stress in ZnS Passivation Films Prepared on 3 Inch Ge-based HgCdTe

针对大面积碲镉汞表面钝化膜的应力问题,基于磁控溅射技术在3 in Ge基碲镉汞表面采用不同工艺条件沉积了ZnS钝化膜,并对其进行了退火处理。利用台阶仪和原子力显微镜(AFM)对ZnS钝化膜的应力及表面形貌进行了表征分析,结果表明:在磁控溅射方法中适当提高沉积温度和降低溅射功率,有效降低了ZnS钝化膜应力,平均应力由原来的924 MPa减小到749 MPa,且提高了应力分布均匀性;此外,退火处理有效降低了钝化膜的应力,并改善了ZnS薄膜的晶粒大小一致性和致密度。该研究为减小大尺寸碲镉汞表面钝化膜应力提供了思路。

ZnS passivation films were deposited and annealed onto 3-in Ge-based HgCdTe surfaces by magnetron sputtering technology with different process conditions.The stress and surface morphology of ZnS passivation films were characterized by a step profiler and an atomic force microscope(AFM).The results show that by increasing deposition temperature and reducing sputtering power appropriately,the stress in ZnS passivation films is effectively reduced and the uniformity of stress distribution is improved.Furthermore,the average stress decreased from 924 MPa to 749 MPa.In addition,the annealing treatment of the ZnS films was found to effectively reduce the passivation stress whilst also improve the grain size uniformity and increase the density of the films.These results can provide insights for reducing the stress in passivation films and for the development of methods that deposit passivation films onto larger HgCdTe surfaces.