Process study on large-size silicon wafer grinding by using a small-diameter wheel
Process study on large-size silicon wafer grinding by using a small-diameter wheel
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DOI：
10.1299/jamdsm.2015jamdsm0073
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发表时间：
2015-01-01
影响因子：
0.9
通讯作者：
Ojima, Hirotaka
中科院分区：
文献类型：
--
作者：
Ebina, Yutaro;Yoshimatsu, Tomoya;Ojima, Hirotaka
硅（Si）是半导体工业的基本材料。半导体器件的进步给我们的生活带来了便利和舒适。为了提高生产率和经济效益，半导体行业不断寻求使用更大尺寸的硅片。下一代晶圆尺寸预计直径将达到 450 毫米。人们对包括研磨、研磨和抛光在内的许多晶圆工艺进行了研究，研磨技术成为大尺寸硅片制造中最有前途的工艺。目前硅片采用的进给磨削方案中，所使用的砂轮直径一般等于或大于硅片直径。反过来，更大直径的车轮需要更大尺寸的机床和生产线，这导致制造成本增加。本文通过实验和运动学分析研究了使用小直径砂轮磨削大尺寸硅片的可行性，重点研究了砂轮直径对硅片几何形状和表面粗糙度的影响。结果表明，两个轮都在晶圆上产生了中心凸形轮廓，并且小轮比大轮获得了稍好的平整度。除边缘周围的边缘外，晶圆大部分区域的表面粗糙度彼此相似。所有这些实验结果都可以通过本文建立的运动学模型来预测。特别是运动学分析发现，直径等于晶圆半径的小砂轮所形成的切割路径在晶圆边缘周围的边缘处相互平行，直接恶化了表面粗糙度。
Silicon (Si) is a fundamental material in the semiconductor industry. The advancement of semiconductor devices have offered convenience and comfort to our life. In order to raise productivity and economic efficiency, the semiconductor industry keeps looking for use of larger size Si wafers. The next generation wafer is expected to be sized as large as 450 mm in diameter. Many wafering processes including lapping, grinding and polishing have been studied and grinding technology stands out as the most promising process for large-size Si wafer manufacturing. In the current in-feed grinding scheme adopted for Si wafers, the wheel diameter used is generally equal to or larger than the wafer diameter. In turn, larger diameter wheels require larger size machine tools and production lines, which lead to increase in manufacturing costs. In this paper, both experiment and kinematical analysis have been carried out to investigate the feasibility of using small diameter grinding wheels to grind large size Si wafers, mainly focusing on the effects of wheel diameter on wafer geometry and surface roughness. The results show that both wheels generated a central convex profile on the wafer and the small wheel achieved a slightly better flatness than the large wheel. The surface roughness were similar one to another for most area of the wafer except the fringe around its edge. All these experimental results were predicable by the kinematic model established in this paper. Particularly, the kinematic analysis found that the cutting path made by small wheel with diameter equaling to the wafer radius was parallel each other at the fringe around wafer edge, which directly worsened the surface roughness.