Patent ID: 6867091

Claim:
A method for forming a trench capacitor comprising the steps of: providing a substrate; forming a mask layer of a predetermined pattern on the substrate to expose a portion of the substrate; forming a trench in the exposed portion of the substrate; forming a conductive diffusion region in the substrate at the periphery of the lower portion of the trench; forming a dielectric layer on the surface of the trench; filling the trench with a photoresist layer, and making the top of the photoresist layer at least not lower than the top of the conductive diffusion region; removing the dielectric layer on the surface of the trench not covered by the photoresist layer; forming a low temperature oxide layer on the surface of the trench not covered by the photoresist layer; removing the photoresist layer in the trench; and filling the trench with a conductive layer and making the top of the conductive layer lower than the bottom of the low temple oxide layer.