Patent ID: 6740557
Filing Date: 2004-05-25
Classification: H01L

Abstract:
A method of forming split-gate flash m mory cell having a spacer-like floating gate comprising the sequential steps of:providing a substrate having a surface; forming a single layer structure over said substrate; defining a floating gate area in said single layer structure; forming an opening for said floating gate area in said single layer structure; forming a tunnel oxide layer on said surface of said substrate in said opening; forming a floating gate material on said single layer structure, including on the vertical walls of said single layer structure in said opening, and on said tunnel oxide in said opening; forming spacer-like floating gates along the vertical sides of said of said single layer structure in said opening, wherein said spacer-like floating gates have a height and width between about 50 to 10000 Ã¥; removing said single layer structure; defining a source line area between said spacer-like floating gates; performing a source implant between said spacer-like floating gates; forming an oxide layer over said spacer-like floating gates, on said tunnel oxide layer and on the surface of said substrate; forming a controlling material over said oxide layer; etching said controlling material, said oxide layer and said tunnel oxide layer to complete the forming of said spacer-like floating gate; and performing a drain implant.