Patent ID: 8772860
Filing Date: 2014-07-08
Classification: H01L

Abstract:
1. A method for forming a FINFET transistor structure, comprising: providing a substrate and a fin structure disposed on said substrate, wherein said fin structure comprises a mask layer, a buffer layer, a cap layer, a fin conductive layer and a spacer surrounding said mask layer, said buffer layer, said cap layer and said fin conductive layer; performing a substrate etching step comprising a vertical etching step and a lateral etching step to form a first recess and a second recess connecting to said first recess in said substrate, wherein said second recess has a protruding side extending to and under said fin structure; forming an oxide to fill said first recess and said second recess; removing said spacer after said oxide filling up said first recess and said second recess; and forming a gate structure comprising a gate dielectric layer and a gate material layer, said gate structure partially surrounding said fin structure, wherein said gate dielectric layer is disposed outside of said second recess.