Abstract: In a first aspect, a level shifter circuit for use in a memory array is provided that includes (1) a first voltage domain powered by a first voltage; (2) a second voltage domain powered by a second voltage; (3) level shifter circuitry that converts an input signal from the first voltage domain to the second voltage domain; and (4) isolation circuitry that selectively isolates the first voltage domain from the second voltage domain so as to selectively prevent current flow between the first voltage domain and the second voltage domain. Numerous other aspects are provided.

Abstract: A method is provided for forming patterned features using a conductive hard mask, where the conductive hard mask protects those features during a subsequent trench etch to form Damascene conductors providing electrical connection to those features from above. The thickness of the hard mask provides a margin to avoid overetch during the trench etch which may be harmful to device performance. The method is advantageously used in formation of a monolithic three dimensional memory array.