TW245810B - Buried contact structure and fabricating method - Google Patents

Abstract

A fabricating method of buried contact structure, which is applicable to the first-type Si substrate with active region defined by field oxide, includes the following steps: 1. forming one gate oxide on the first-type Si substrate; 2. forming one polysilicon layer on the gate oxide and field oxide; 3. defining the polysilicon layer into one gate electrode on the destined position of gate oxide and one interconnecting wire on the field oxide by etching procedure, and forming one opening between the gate electrode and the interconnecting wire; 4. forming one oxide on the gate electrode, the interconnecting wire and the opening; 5. implanting the second-type dopant into the Si substrate through the opening, forming lightly doped source/drain area in the Si substrate under the opening; 6. forming one first spacer on the oxide layer of interconnecting wire side and one second spacer on the oxide layer of gate electrode side; 7. removing the first spacer and its contacting oxide, defining one buried contact area and exposing the interconnecting wire side; 8. With the second spacer as mask, through the opening implanting the second-type dopant to form heavily doped source/drain area in the Si substrate, which is located between the lightly doped source/drain and the field oxide; 9. forming one metal silicide layer between the interconnecting wire side and the buried contact area, finishing the fabricating method of the buried contact structure.