| 摘要 |
PROBLEM TO BE SOLVED: To form a strap, without damaging an electrical constitution element and improve reliability by forming the plug strap by using highly selective oxide and nitride etching. SOLUTION: A first electric element contains a trench 10 filled with polysilicon, and a second electric element adheres a nitride layer 36 by the alignment on a device that includes a diffusion area 34. Then, an insulating layer 38 is adhered, and only the polysilicon trench 10 and the part of the insulating layer 38 that corresponds to the diffusion area closest to the trench are exposed. The exposed part of the insulating layer 38 is removed by applying highly selective oxide and nitride etching. Thus, the silicon oxide cap 12 of the polysilicon trench 10 and the silicide 34 in the diffusion area are dug down to expose the trench, and a strap hole is completed. Then, a conductive material is adhered in the hole, and a strap 42 which electrically connects the trench capacitor 10 with the diffusion area 34 is formed. |
