公开(公告)号：US09837423B2

公开(公告)日：2017-12-05

申请号：US14967765

申请日：2015-12-14

Applicant: Samsung Electronics Co., Ltd.

Inventor： Jeonghoon Oh ,  Ilgweon Kim ,  Hyon Namkung

IPC: H01L29/10 ,  H01L27/10 ,  H01L27/108

CPC classification number: H01L27/10891 ,  H01L27/10814 ,  H01L27/10876

Abstract: A device isolation region is formed, delimiting an active region in a substrate. A word line is formed, extending across the active region and the device isolation region and buried therein. A bit line is formed crossing the word line on the substrate. A channel is formed adjacent the word line, the channel having a retrograde doping profile having a doping concentration that increases away from a top surface of the active region. Formation of the channel includes performing a field ion implantation in the active region having a projected range near a bottom of the device isolation region.