Semiconductor device and manufacturing method thereof

Claim 1

A semiconductor memory device comprising: a semiconductor substrate having a first conductivity type; a trench capacitor provided in the semiconductor substrate and having a charge accumulation region; a gate electrode provided on the semiconductor substrate via a gate insulating film; a gate side wall insulating film provided on a side surface of the gate electrode; drain and source regions provided in the semiconductor substrate and having a second conductivity type; an isolation insulating film provided adjacent to the trench capacitor in the semiconductor substrate to cover an upper surface of the charge accumulation region; a buried strap region having the second conductivity type, the buried strap region being provided to electrically connect an upper portion of the charge accumulation region to the source region in the semiconductor substrate; a first pocket implantation region having the first conductivity type, the first pocket implantation region being provided below the source region and being spaced apart from the strap region; and a second pocket implantation region having the first conductivity type, the second pocket implantation region being provided below the drain region.

Claim 10

A method of manufacturing a semiconductor device, comprising: sequentially forming a trench capacitor, an element isolation region, a buried strap region having a second conductivity type, and a gate insulating film in a semiconductor substrate having a first conductivity type; depositing a conductive film on the gate insulating film to form a plurality of gates; ion-implanting an impurity of the first conductivity type into the semiconductor substrate sequentially from at least two directions having an angle of more than 0° with respect to a direction perpendicular to the semiconductor substrate by using the plurality of gates as a mask to provide first and second pocket implantation regions; forming a source region in the semiconductor substrate to be positioned on the first pocket implantation region; and forming a drain region in the semiconductor substrate so that the second pocket implantation region is disposed under a region corresponding to a lower portion of the drain region.

Claim 11

A method of manufacturing a semiconductor device, comprising: sequentially forming a trench capacitor, an element isolation region, a buried strap region having a second conductivity type, and a gate insulating film in a semiconductor substrate having a first conductivity type; depositing a conductive film on the gate insulating film to form a plurality of gates; ion-implanting an impurity of the first conductivity type into the semiconductor substrate sequentially from at least two directions having an angle of more than 0° with respect to a direction perpendicular to the semiconductor substrate by using the plurality of gates as a mask to provide first and second pocket implantation regions; forming a source region in the semiconductor substrate to be positioned on the first pocket implantation region; and forming a drain region in the semiconductor substrate so that the second pocket implantation region is disposed under a region corresponding to a lower portion of the drain region.