Patent ID: 6815274
Filing Date: 2004-11-09
Classification: H01L,Y10S

Abstract:
A method for forming Resist Protect Oxide (RPO) applied for sub-micron salicidation, comprising steps of:providing a semiconductor substrate; and creating a patterned layer of ONO over areas of said substrate that must be shielded from process of salicidation, said creating a patterned layer of ONO comprising: (i) patterning an upper or first layer of silicon dioxide by applying a wet-etch to the upper or first layer of silicon dioxide; (ii) patterning a central layer of silicon nitride, using the patterned first layer of silicon dioxide as a hardmask, by applying a wet nitride removal process to the layer of silicon nitride; and (iii) patterning a lower or second layer of silicon dioxide, using the patterned first layer of silicon dioxide and the patterned central layer of silicon nitride as a mask, by applying a wet-etch to the lower of second layer of silicon oxide.