公开(公告)号：US20050224874A1

公开(公告)日：2005-10-13

申请号：US11148805

申请日：2005-06-09

申请人： Srinivasan Chakravarthi ,  Pr Chrdambaram ,  Robert Bowen ,  Haowen Bu

发明人： Srinivasan Chakravarthi ,  Pr Chrdambaram ,  Robert Bowen ,  Haowen Bu

IPC分类号： H01L21/265 ,  H01L21/336 ,  H01L21/425 ,  H01L29/10 ,  H01L29/78

CPC分类号： H01L29/6653 ,  H01L21/26586 ,  H01L29/1083 ,  H01L29/6659 ,  H01L29/7833 ,  Y10S438/91

摘要： A method of forming a retrograde well in a transistor is provided. A transistor structure having a substrate, a gate, and a gate oxide layer between the substrate and the gate is formed. The substrate includes a channel region located generally below the gate. A first dopant is implanted into the channel region. A second dopant is implanted into the substrate to form a doped source region and a doped drain region. A third dopant is implanted into the gate oxide layer. A source/drain anneal is performed to form a source and a drain in the doped source region and the doped drain region, respectively. The source/drain anneal causes a portion of the first dopant in the channel region to be attracted by the third dopant into the gate oxide layer.