| 摘要 |
PURPOSE:To prevent alloy spikes by allowing a polycrystalline Si layer to remain only in the contact hole. CONSTITUTION:After a contact hole is opened, a polysilicon layer 7 is grown, phosphorus is diffused to lower the specific resistance of the polysilicon. Then, the irregular surface is buried with positive type photoresist 8 to be coated so that the surface becomes smooth. After passing the annealing step of the resist, the resist is removed by an oxygen plasma in the uniform thickness from the surface. At this time, the resist of the contact part deepened in the removed thickness remains at this time, and an oxygen plasma treating time to remove the resist on field oxidized film and the gate polysilicon is selected. With the resist remaining in the contact hole as a mask, the polysilicon layer is etched. |
