Patent ID: 9691852
Date: 2017-06-27
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a substrate; an element isolation trench formed in the substrate, the element isolation trench has a rectangular or square shape boundary in a planar view, the rectangular or square shape boundary having a first side, a second side opposite to the first side, and a third side perpendicular to both the first and the second side; a plurality of first trenches formed in the substrate and in the planar view, the length of the first trenches extend in a first direction with respect to the first side of the element isolation trench, wherein the plurality of first trenches protrude into enter the boundary of the element isolation trench at the first side of the rectangular or square shape in the first direction towards the third side of the rectangular or square shape and wherein the first trenches are insulative and rectangular in the planar view; a plurality of second trenches formed in the substrate and in the planar view, the length of the second trenches extend in a second direction with respect to the first side of the element isolation trench, the second direction being different from the first direction, wherein the plurality of second trenches protrude into the boundary of the element isolation trench, at the second side of the rectangular or square shape, in the second direction towards the third side of the rectangular or square shape and wherein the second trenches are insulative and rectangular in the planar view; and a first first-conductivity type region formed over a part located on a side of an end of the first trench in the substrate in the cross section view of the substrate through the element isolation trench.