Patent ID: 7372103

Claim:
A MOS field plate trench transistor device having a trench structure extending in a first direction in a semiconductor region comprising: a source region and a drain region formed in the semiconductor region with a first conductivity type and, between the source region and the drain region, a body region is formed with a second conductivity type, which is opposite to the first conductivity type; a gate electrode device formed in between in the interior of the trench structure in a manner insulated by an insulation region; and a mesa region is located in the semiconductor region as intermediate region in a direction running perpendicular to the first direction and with respect to an adjacent MOS transistor device has a width D Mesa , the value of which corresponds to the value of the width D Trench of the trench structure in this direction or exceeds said value and does not go beyond 1.5 times said value, so that the following holds true: D Trench ≦D Mesa ≦1.5 ·D Trench′ where D Mesa is the average value of the width of the mesa region at the level of the pn junction between the body region and the drain region and the width of the mesa region at 80% of the depth of the trench structure and in which the mesa region is provided with a contact hole to the body region.