Patent ID: 6803625
Filing Date: 2004-10-12
Classification: H01L

Abstract:
A split-gate flash memory cell having a trench source with tilted walls comprising:a substrate having a top surface; a gate oxide formed on said top surface of said substrate; a pair of floating gates formed on said gate oxide; an interpoly oxide conformally formed over each of said pair of floating gates; a control gate formed over each of said pair of floating gates; a trench formed within said top substrate between said pair of floating gates, said trench having tilted walls extending downward within said substrate from said interpoly oxide conformally formed over said pair of floating gates and terminating at the narrow bottom of said trench; a thermal oxide layer conformally lining said tilted walls and narrow bottom of said trench; a source region extending from said titled walls and narrow bottom of said trench to a laterally enlarged diffused area under each of said pair of floating gates.