A method for fabricating an insulating layer having contact openings of
varying depths for logic/DRAM circuits is achieved using a single mask
and etch step. After forming stacked or trench capacitors, a planar
insulating layer is formed. Contact openings are etched in the planar
insulating layer to the substrate, and contact openings that extend over
the edge of the stacked or trench capacitor top electrode, having an ARC,
are etched using a novel mask design and a single etching step. This
allows one to make contacts to the substrate without overetching while
making low-resistance contacts to the sidewall of the capacitor top
electrode. In the trench capacitor open areas are formed to facilitate
making contact openings that extend over the top electrode. A series of
contact openings that are skewed or elongated also improve the latitude
in alignment tolerance.