Research On Grinding Process Technology Of 300mm Silicon Wafer

Starting from the late 20th century, silicon-based integrated circuit(IC) industry has become the fastest growing industry. It not only developed rapidly itself, but also led to the emergence and improvement of a number of other industry, such as computers, communications, aerospace, precision machinery, etc., which have a huge impact on our lives. The rapid development of semiconductor industry puts forward higher request for silicon wafer, especially for its surface quality,which are characterized by the larger diameter of the silicon wafer and the smaller IC feature size. Traditional mechanical process of silicon wafer is difficult to meet the requirements of the high standard, so the silicon precision grinding, double-sided polishing process are introduced. In this paper, a series of researches are performed about precision grinding process of the 300 mm silicon wafers, in order to enhance the level of roughness of silicon wafer and the quality of silicon surface, at the same time, improve the efficiency of production. The new process can meet the requirements of the follow-up process, and be applied to practical production.First, through experimental study on grinding wheel grain size and main process parameters on wafer surface layer depth and surface roughness effects. Results showed that using smaller size grinding wheel grain, smaller axial feed speed of wheel and bigger wheel speed to the grinding, wafer surface quality is good. And based on the results of Oxidation Induced Stacking Faults(OISF), the 2000# wheel was confirmed as grinding wheel for rough grinding, and the 8000# wheel was confirmed as the grinding wheel for fine grinding.Then, the results showed that the grinding process parameters had no effect on the geometry parameters and map of grinded wafer, but the geometrical parameters of polished wafers are relevant to the map of grinded wafer surface. When the grinded wafers shows "concave" map, which can effectively inhibit the wafer Edge Roll-off phenomenon, it is easier to obtain better Edge geometry parameters of polished wafer. Thus the wafers should be grinded as "U" and "W" map, and the "U" map is the best.Finally, based on the observation of OISF under different grinding removal amount of, the removal was determined as 70?m in rough grinding, and 25?m in fine grinding. The wafers grinded through the process in this paper won the required of 65-90nm feature size.