US 7,541,643 B2
Semiconductor device
Syotaro Ono, Yokohama (Japan); Wataru Saito, Kawasaki (Japan); and Yusuke Kawaguchi, Hayama-machi (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan)
Filed on Apr. 07, 2006, as Appl. No. 11/399,448.
Claims priority of application No. 2005-110594 (JP), filed on Apr. 07, 2005.
Prior Publication US 2006/0231917 A1, Oct. 19, 2006
Int. Cl. H01L 29/76 (2006.01); H01L 29/94 (2006.01)
U.S. Cl. 257—341  [257/342; 438/588] 18 Claims
OG exemplary drawing
 
1. A semiconductor device, comprising:
a first semiconductor layer of a first conductivity type;
a pillar layer including a first semiconductor pillar layer of a first conductivity type and a second semiconductor pillar layer of a second conductivity type, said first and second semiconductor pillar layers formed alternately on said first semiconductor layer along a direction of a surface of said first semiconductor layer;
a first main electrode electrically connected to said first semiconductor layer;
a semiconductor base layer of a second conductivity type formed on a surface of said pillar layer;
a semiconductor diffusion layer of a first conductivity type formed selectively on a surface of said semiconductor base layer;
a second main electrode formed to have a junction with said semiconductor base layer and said semiconductor diffusion layer; and
a control electrode formed via an insulating film in an area ranging from said semiconductor diffusion layer to said first semiconductor pillar layer to form a channel between said semiconductor diffusion layer and said first semiconductor pillar layer;
wherein said pillar layer is formed not only in a device region but also in an end region outside said device region; and
wherein at the same depth position in said device region and said end region, an impurity dose amount Q11 [cm-2] to said first semiconductor pillar layer in said device region, an impurity dose amount Q21 [cm-2] to said second semiconductor pillar layer in said device region, an impurity dose amount Q12 [cm-2] to said first semiconductor pillar layer in said end region, and an impurity dose amount Q22 [cm-2] to said second semiconductor pillar layer in said end region, meet the relationship of Q21/Q11<Q22/Q12.