Diamond turning of silicon substrates in ductile-regime

Silicons are used in both wafer fabrication and infrared optics. Direct machining of silicon single crystal was carried out on a precision lathe equipped with an air spindle to a finish of 2.86 nm rms roughness. The success of the turning process depends on optimizing the machining parameters such as feed rate, depth of cut, tool rake angles, the cutting lubricants and the crystallographic orientation of the crystal being cut. It is shown that the commercial production of an optical surface on brittle materials is made possible by single point diamond turning. (C) 1998 Elsevier Science S.A.