A method for fabricating a high-density array of crown capacitors with increased
capacitance while reducing process damage to the bottom electrodes is achieved. The process is particularly useful for crown capacitors for future
DRAM circuits with minimum feature sizes of 0.18
micrometer or less. A conformal conducting layer is deposited over trenches in an interlevel
dielectric (ILD) layer, and is polished back to form
capacitor bottom electrodes. A novel
photoresist mask and
etching are then used to pattern the ILD layer to provide a protective interlevel
dielectric structure between capacitors. The protective structures prevent damage to the bottom electrodes during subsequent
processing. The
etching also exposes portions of the outer surface of bottom electrodes for increased
capacitance (>50%). In a first embodiment the ILD structure is formed between pairs of adjacent bottom electrodes, and in a second embodiment the ILD structure is formed between four adjacent bottom electrodes.