Production of a trenched strap contact in a memory cell comprises forming a trench capacitor in a substrate, filling an unfilled region with monocrystalline silicon and further processing

摘要

Production of a trenched strap contact between a transistor and a trench capacitor in a memory cell, especially a DRAM cell, comprises: (a) forming a trench capacitor (70) in a substrate (10) having a lower region (12) filled with a first doping filling material and an unfilled region; (b) filling the unfilled region with monocrystalline silicon; (c) forming gate pathways (31, 41) on the substrate surface; (d) etching a contact trench (60) up to base formed by the first doped filling material to form the trench strap contact; (e) depositing a second filling material in the contact trench to form a trenched bridge (61) as part of the strap contact; and (f) heat treating to form a diffusion region (63) as part of the strap contact.