| The impact of semiconductors on the economy and society is significant. Semiconductor integrated circuits (ICs) will be among the basic building blocks for the future. Silicon wafers are used to manufacture more than 90% of ICs. Wafer manufacturers are always under tremendous pressure to meet the ever-increasing demand for lower cost and better quality from the semiconductor industry.; The goal of this research was to provide new knowledge of silicon wafer grinding necessary for the further reduction in manufacturing cost of silicon wafers. A three-dimensional mathematical wafer shape model was established by which three technical issues in wafer grinding were studied and addressed, including spindle adjustment for wafer grinding machines, grinding mark elimination, and central bump elimination. The wafer shape model in this research focused on the major influential factors on the wafer shape, i.e. the chuck and wafer grinding setup parameters (chuck and wheel diameters, wheel tilt angles). From the research, the optimal adjustment axes were found without the "cross-talking" phenomenon. From the research, it was shown that using a straight conic chuck or a smaller grinding wheel could effectively reduce the grinding marks. From the research, it could also be seen that the central surface irregularities (central bump and central dimple) could be eliminated by using a steep chuck or a chuck made of silicon, and a more rigid wheel. Matlab was used as a computation tool to facilitate the computer simulation and problem analysis. The experiments were also undertaken to verify the analytical results.; The findings in this research filled in the blanks in research literature, and provided theoretical guidance for wafer manufacturing. The results will also be valuable to wafer manufacturing of other semiconductor materials such as germanium, AlN, GaAs, and SiC. |
