Patent ID: 8668837

Claim:
A method for etching a substrate, the substrate being formed by stacking at least one first layer over at least one second layer, the substrate having a first area inward of a second area thereon, the method comprising: etching the at least one first layer with the first area set to a first temperature and the second area set to a second temperature, wherein the first temperature is greater than the second temperature, wherein the one or more first layers comprises: a BARC layer; a SiON layer disposed below the BARC layer; an ACL (amorphous carbon) layer disposed below the SiON layer; and a TEOS (tetraethylorthosilicate) layer disposed below the ACL layer; and etching the at least one second layer with the first area and the second area set to a third temperature, wherein the one or more second layers comprises: a first silicon nitride layer; a TEOS layer disposed below the silicon nitride layer; a PSG (phosphosilicate glass) layer disposed below the TEOS layer; and a second silicon nitride layer disposed below the PSG (phosphosilicate glass) layer.