Patent ID: 7960241

Claim:
A manufacturing method for double-side capacitor of stack DRAM comprising steps of: forming an isolating trench and a plurality of capacitor trenches in an oxide layer wherein each of the isolating trench and the capacitor trenches has an electrode layer on a sidewall thereof; forming a sacrificial structure in the isolating trench and the capacitor trenches, respectively; forming a first covering layer and a second covering layer on the sacrificial structure; modifying a part of the second covering layer on the sacrificial structure of the capacitor trenches, and modifying the second covering layer on the sacrificial structure of the isolating trench; removing the un-modified second covering layer on the sacrificial structure of the capacitor trenches, then removing the first covering layer under the un-modified second covering layer on the sacrificial structure of the capacitor trenches to expose the sacrificial structure of the capacitor trenches; removing a part of the sacrificial structure of the capacitor trenches to expose the electrode layer on the sidewall of the capacitor trenches; removing the exposed electrode layer on the sidewall of the capacitor trenches to expose the oxide layer; and removing the sacrificial structure in the isolating trench and the capacitor trenches, and removing the oxide layer between the capacitor trenches so that the electrode layers of the capacitor trenches are constructed as a plurality of double-side capacitors.