Patent ID: 6864151

Claim:
A method of forming isolating regions of a semiconductor device, the method comprising: providing a workpiece, the workpiece having at least one first region and at least one second region, the workpiece having a top surface; forming at least one first active area in said at least one first region; patterning the first region with at least one first trench after said step of forming said first active area, the first trench having sidewalls, a bottom, and a first width and a first depth within the workpiece; forming a first insulating layer over the at least one first trench sidewalls and bottom; depositing a semiconductive material in the at least one first trench over the first insulating layer; depositing a photo resist for patterning shallow second trenches over said first and second regions of said substrate; patterning both said first and second regions, each region patterned with at least one second trench, the second trench having a second depth within the workpiece, that is less than the first depth and a second width or than said first width, said second trenches in said first region being located over said first trenches so as to recess said first insulating layer adding semiconductor material in said first trenches; depositing an insulating material in the at least one second trench and in the semiconductive material recess of the at least one first trench; and then forming at least one second active area in the second region.