利用微电子测试图形监控CCD工艺

Monitoring the Quality of CCD Process by Microelectronic Test Patterns

本文根据硅CCD摄像器件的特点和要求,设计出一套可用来监控硅CCD工艺的测试图形,并把此套图形应用于实际的CCD工艺。实验分析其它工艺参数的同时,重点对存贮时间Tc和界面态密度Nss进行了研究。认为工艺过程引起存贮时间的下降,是由于工艺诱生位错的影响,而工艺诱生位错主要由多晶硅层上二次栅氧化的界面应力所导致;认为界面态密度主要取决于栅氧化和退火工艺,与中间工序的关系不明显。整个实验表明,用微电子测试图形监控CCD工艺、分析器件失效,是可行可靠的。

According to the characteristics and requirement of Si-CCD device, a system of microelectronic test patterns to monitor the quality of Si-CCD process has been designed and applied to actual Si-CCD process. We focused on researching the storage time Tc and the surface state density Nss while analysing other parameters. This paper suggests that in the process the decrease of the storage time is due to the induced dislocation which has resulted from intergranular stress on the polycrystalline silicon in second gird oxide growth, and that surface state density mainly depends on grid oxide growth and annealing, and is not obviously related to the sequence of process. The whole experiment demonstrates that monitoring the quality of CCD process and analysing failure of the device by microelectronic test patterns is practical and reliable.