FORMING METHOD OF TRIPLE LAYER FOR FINE PATTERNING

摘要

A set of triple photoresist layers is used for the removal of side wall layer by restricting the formation of remnants at the side walls of the lower photoresist at removing SOG layer. Of the lower photoresist, middle SOG layer and upper photoresist deposited on polysilicon, the upper photoresist and SOG layer is etched selectively according to the pattern, and the remaining first photoresist is etched completely, SOG layer is removed by anisotropic etching, the lower photoresist is removed by RIE. Finally SOG layer is removed by wet etching using buffered oxide etchant.