Sponsored by New Energy and Industrial Technology Development Organization (NEDO) and the Ministry of Education, Science and Culture (MESC) of Japan, this project has developed an advanced machining system for ⌀ 300mm silicon wafer, using fixed abrasive instead of conventional free slurry, to provide a totally integrated solution for achieving the surface roughness R a <1nm (R y <5-6nm) and the global flatness <0.2μm/⌀ 300mm. Use of state-of-the-art technologies for ultra precision machine tools has made it possible to precisely control the motion and repeatability of each cutting edge. The behavior of each grain and its effect on surface generation become analytical in 2D manner [J JSPE 68(1) (2002) 125]. Taking one step further, this paper has developed a 3D model for infeed grinding which is often used in silicon grinding systems, and mathematically described the cutting path and effects on the surface roughness and flatness.