| 摘要 |
<p>For isolating active regions in an electrically programmable and erasable memory device, a first layer (48) of insulating material is formed on a substrate (30), a layer (50) of conductive material is formed on the first layer (48) of insulating material and a plurality of spaced apart trenches (38) are formed through the first layer (48) of insulating material, the layer (50) of conductive material, and into the substrate (30). A second layer (44) of insulation material is formed on sidewall portions (39) of the trenches (38). A block (46) of insulation material is formed in the trenches (38). For each of the trenches (38) an edge portion (52) of the layer (50) of conductive material extends over and overlaps with the first layer (48) of insulating material and possibly a portion of the insulation material block (46) by a predetermined distance DELTA . For each of the trenches (38), the predetermined distance DELTA is selected so that after back end processing is performed to the substrate (30) and the conductive layer (50), the edge portion (52) of the conductive layer (50) is aligned to the sidewall portion (39) of the isolation trench (38). <IMAGE></p> |
