Patent ID: 6107126
Filing Date: 2000-08-22
Classification: H01L

Abstract:
A method for fabricating a Read Only Memory, (ROM), cell on a semiconductor substrate with device region and programmable cell region, said method comprising the step of:forming a plurality of field oxide regions on said semiconductor substrate;forming a first conductive well and a second conductive well in said device region of said semiconductor substrate, a second conductive well in said programmable cell region of said substrate;forming a first photoresist over said second conductive well in said device region;performing a first conductivity type ion implantation into said first conductive well in said device region for anti-punchthrough and into said second conductive type well in said programmable cell region to form buried channel by using said first photoresist layer as implant mask;removing said photoresisit; andforming a CMOS transistor on said device region, a NMOS transistor on said programmable cell region.