ＳｉウエハのＣｈｅｍｏ‐Ｍｅｃｈａｎｉｃａｌ‐Ｇｒｉｎｄｉｎｇ（ＣＭＧ）に関する研究 第１報 ＣＭＧ砥石の開発

Abstract

At ductile-mode grinding, the material is removed within a plastic region so that no crack remains on the corresponding surface after machining. By effectively using this mechanism, fixed abrasive process is seen as a promising solution to replace the lapping and polishing processes in manufacturing of large scale Si wafer. In principle, however, there is still plastic strains developed. This fact makes it very difficult to completely remove the damaged subsurface layer by fixed abrasives. To achieve a perfectly damage-free surface, this research has proposed a new chemo-mechanical-grinding (CMG) process by adding chemical effect into the grinding process. First described in this paper are the experimental results showing the feasibilities of the CMG process in reducing subsurface damage. Based on the preliminary test results, CMG wheels which contain chemically active abrasives and additives have been developed and characterized with a wide range of pH from acidity to alkalinity accordingly. The CMG has been mainly evaluated by the grinding performance on bear Si wafers, comparing to grinding with diamond wheels. From the technical and economical points of view, CMG is also highly expected to perform planarization function instead of chemical mechanical polishing (CMP) process. The primary tests of CMG have been done on shallow trench isolation (STI) patterned wafer to investigate the pattern dependency.