Patent ID: 6893938

Claim:
A method of patterning a semiconductor device, comprising: providing a substrate, the substrate comprising a plurality of device regions having a first etching zone comprised of at least one first material, and at least one second etching zone disposed below said first etching zone comprised of at least one second material, said at least one first material having a different etch selectivity than said at least one second material; depositing a first hard mask over the substrate, the first hard mask comprising a first selected material; depositing a second hard mask over the first hard mask, the second hard mask comprising a second selected material, the second selected material being different from the first selected material; depositing a photoresist over the second hard mask; patterning the photoresist; transferring the pattern of the photoresist to the second hard mask; transferring the pattern of the photoresist to the first hard mask; and patterning the substrate with at least the second hard mask and first hard mask to form isolation regions between the device regions of the substrate.