采用扫描电子显微镜和电学分析技术研究了电荷耦合器件（CCD）多晶硅层间绝缘介质对器件可靠性的影响。研究结果表明，常规热氧化工艺制作的多晶硅介质层，在台阶侧壁存在薄弱区，多晶硅层间击穿电压仅20V，器件在可靠性试验后容易因多晶硅层间击穿而失效。采用LPCVD淀积二氧化硅技术消除了多晶硅台阶侧壁氧化层薄弱区，其层间击穿电压大于129V，明显改善了器件可靠性。

The effects of inter-layer dielectric of polysilicon on the reliability of charge-coupled devices (CCD) were studied by means of scanning electron microscopy (SEM) and electrical measurement. It is found that, the break-down voltage of polysilicon dielectric prepared by routine thermal oxydation is about 20V due to the existing weakness in side of polysilicon step, which leads to poor reliability of CCD. The silicon oxide deposited by low-pressure chemical vapor deposition (LPCVD) eliminates the weakness of polysilicon oxide, the break-down voltage of the dielectric between two layers polysilicon is greater than 129V, and so the reliability of CCD is improved evidently.