晶圆键合工艺的灰边缺陷改善研究

Study on improvement of gray edge defects in wafer bonding process

摘要:

晶圆键合技术是背照式(BSI)图像传感器的基本技术和关键工序，键合会产生边缘键合缺陷导致键合质量受影响。本文为有效提升键合质量，对边缘键合缺陷进行改善研究。首先，针对划线(scribe line)区域采用了等离子体增强化学气相沉积（PECVD），对边缘划线区域沉积不同氧化膜厚度，厚度达到40k?以上时，可改善边缘划线区域键合缺陷。其次，研究了化学机械研磨（CMP）过度研磨引起边缘不同区域氧化膜去除量差异。测量了不同研磨压力下边缘不同区域氧化膜厚度，结果表明边缘不同研磨区域氧化膜差值在5000?内时灰边缺陷得到改善。

Abstract:

Wafer bonding technology is the basic technology and key process for backside-illuminated (BSI) image sensors, and the bonding will produce edge bonding defects resulting in the bonding quality being affected. In this paper, in order to effectively improve the bonding quality, the edge bonding defects are improved and researched. Firstly, plasma-enhanced chemical vapor deposition (PECVD) was used for the scribe line area, and different oxide film thicknesses were deposited on the scribe line area, and the bonding defects in the scribe line area can be improved when the thickness reaches 40k? or more. Secondly, the differences in oxide film removal in different regions of the edge caused by chemical-mechanical polishing (CMP) overgrinding were investigated. The thickness of oxide film in different regions of the edge under different grinding pressures was measured. The results showed that the grey edge defects are improved when the difference of oxide film in different grinding regions of the edge is within 5000?.