Manufacturing method of capacitor lower electrode and semiconductor storage device using the same
View Patent ↗A manufacturing method of capacitor lower electrode of the instant disclosure comprises the steps of: providing a semiconductor substrate; forming a sacrificial laminate on the semiconductor substrate; forming a plurality of capacitor trenches in the sacrificial laminate; forming a plurality of lower electrode structures in the capacitor trenches respectively; etching back the sacrificial laminate to a desired thickness to expose an upper portion of each of the lower electrode structures; forming a liner layer to conformally cover the sacrificial laminate and the upper portions of the lower electrode structures; patterning the liner layer to form an insulating spacer on the sidewalls of each of the upper portions, wherein two adjacent insulating spacers are configured to have a self-aligned opening positioned therebetween; and performing a wet-etching process to remove the sacrificial laminate through the self-aligned openings.
1. A semiconductor storage device, comprising:
a semiconductor substrate;
a sacrificial laminate arranged on the semiconductor substrate, wherein the semiconductor substrate has a plurality of capacitor trenches formed therein, wherein the sacrificial laminate comprises a first oxide layer arranged on the semiconductor substrate, a lattice reinforced layer having a plurality of through-holes arranged on the first oxide layer, and a second oxide layer arranged on the lattice reinforced layer;
a plurality of lower electrode structures arranged in the capacitor trenches respectively, wherein each electrode structure has an upper portion protruding out of the surface of the sacrificial laminate; and
a plurality of insulating spacers, each of which is arranged on the sidewalls of each of the upper portions, wherein two adjacent insulating spacers are configured to have a self-aligned opening positioned therebetween.
2. The semiconductor storage device according to claim 1 , wherein the semiconductor substrate includes a substrate, a plurality of buried bit lines, a plurality of bit line contacts, and a plurality of conductive structures, the buried bit lines are arranged in the substrate, the bit line contacts are arranged in the substrate at intervals of the buried bit lines, the conductive structures are arranged on the bit line contacts respectively for electrically connecting to the lower electrode structures.
3. The semiconductor storage device according to claim 1 , further comprises a liner layer and a photoresist layer, the semiconductor substrate has an array region and a periphery region outside the array region, the lower electrode structures are positioned in the array region, the liner layer conformally covers the sacrificial laminate and the lower electrode structures, the photoresist layer covers the liner layer within the periphery region.
4. The semiconductor storage device according to claim 1 , further comprises a liner layer and a photoresist layer, the semiconductor substrate has an array region defined thereon and a periphery region outside the array region, the liner layer conformally covers the sacrificial laminate and the lower electrode structures, the photoresist layer covers the liner layer within the periphery region.