Patent ID: 7951666

Claim:
A method of forming a capacitor structure, said method comprising: providing a semiconductor substrate; forming, in said semiconductor substrate, a first trench and a second trench adjacent to said first trench; forming, in said semiconductor substrate, a first doped region adjacent to a first bottom surface and first sidewalls of said first trench and a second doped region in contact with said first doped region and adjacent to a second bottom surface and second sidewalls of said second trench; forming a dielectric liner lining said first trench adjacent to said first bottom surface and said first sidewalls; and filling said first trench and said second trench with a conductive fill material such that said conductive fill material in said first trench is physically and electrically separated from said first doped region by said dielectric liner lining said first trench and further such that said conductive fill material in said second trench is physically and electrically connected to said second doped region and, through said second doped region, electrically connected to said first doped region; said forming of said dielectric liner and said filling of said first trench and said second trench with said conductive fill material comprising: after said forming of said first doped region and said second doped region, depositing a thin conformal dielectric layer onto said first bottom surface and said first sidewalls of said first trench and onto said second bottom surface and said second sidewalls of said second trench; depositing a first layer of said conductive fill material so as to fill said first trench and said second trench with said conductive fill material; recessing said first layer of said conductive fill material and said thin conformal dielectric layer in said second trench without recessing said first layer of said conductive fill material and said thin conformal dielectric layer in said first trench so as to expose at least an upper section of said second trench; and depositing a second layer of said conductive fill material so as to refill said second trench such that said second layer of said conductive fill material in said upper section of said second trench is in contact with said second doped region.