Patent ID: 7846812

Claim:
A method of forming trench isolation, comprising: forming mask lines over a semiconductor substrate; forming sidewall spacers laterally over sidewalls of the mask lines, the sidewall spacers respectively having a first sidewall spacer edge in physical touching contact with one of the sidewalls of the mask lines and a second sidewall spacer edge opposite the first sidewall spacer edge, the second sidewall spacer edge not being in physical touching contact with any sidewall of the mask lines; etching first trench lines into semiconductive material of the semiconductor substrate between the sidewall spacers using the mask lines and sidewall spacers as a first etching mask; depositing first isolation material to within and overfilling the first trench lines within the semiconductive material to be received between adjacent of the sidewall spacers and to be received elevationally over the mask lines and sidewall spacers, the second sidewall spacer edge being in physical touching contact with the first isolation material; removing the first isolation material effective to expose the mask lines; after the removing, etching the mask lines from the substrate selectively relative to the sidewall spacers; after etching the mask lines from the substrate, etching second trench lines into semiconductive material of the semiconductor substrate using the sidewall spacers and the first isolation material within the first trench lines as a second etching mask, the second sidewall spacer edge being in physical touching contact with the first isolation material during the etching of the second trench lines into the semiconductive material, the first sidewall spacer edge being laterally exposed during the etching of the second trench lines into the semiconductive material; depositing second isolation material to within and overfilling the second trench lines within the semiconductive material; and removing the sidewall spacers from the substrate after the etching of the second trench lines into the semiconductive material.