| 摘要 |
PURPOSE: Provided is a method of forming capped borderless doped polysilicon contacts which is relatively simple to carry out and can be readily used in a manufacturing process. CONSTITUTION: A method of forming a capped and borderless contact of polysilicon on a body of a semiconductor material includes depositing a layer of undoped polysilicon on the surface of the body and forming an opening therethrough to the surface of the body. The side walls of the opening are then coated with a layer of silicon nitride and the opening is then filled with doped polysilicon which forms the contact. The doped and undoped polysilicon are heated in an oxidizing atmosphere to grow a layer of silicon dioxide thereon having a thicker portion over the doped polysilicon then over the undoped polysilicon. The silicon dioxide layer is etched to remove the thinner portion leaving the thicker portion over the doped polysilicon as a capping layer. The undoped polysilicon is then etched away and a layer of a dielectric material is deposited on the body and surrounding the doped polysilicon contact. |
