Method of making contact for semiconductor device
First Claim
1. A method of making a semiconductor device conductive contact on a body of a semiconductor material comprising the steps of:
- forming a layer of undoped polysilicon on a surface of the body;
forming an opening through the undoped polysilicon layer to the surface of the body;
filling said opening with doped polysilicon;
growing a layer of silicon dioxide on the doped and undoped polysilicon with the thickness of the silicon dioxide layer being thicker over the doped polysilicon than over the undoped polysilicon;
removing all of the silicon dioxide layer from over the undoped polysilicon while leaving a portion of the silicon dioxide over the doped polysilicon; and
removing the undoped polysilicon layer.
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0 Petitions
Accused Products
Abstract
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.
15 Citations
14 Claims
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1. A method of making a semiconductor device conductive contact on a body of a semiconductor material comprising the steps of:
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forming a layer of undoped polysilicon on a surface of the body; forming an opening through the undoped polysilicon layer to the surface of the body; filling said opening with doped polysilicon; growing a layer of silicon dioxide on the doped and undoped polysilicon with the thickness of the silicon dioxide layer being thicker over the doped polysilicon than over the undoped polysilicon; removing all of the silicon dioxide layer from over the undoped polysilicon while leaving a portion of the silicon dioxide over the doped polysilicon; and removing the undoped polysilicon layer. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of making a conductive contact to a surface of a body of a semiconductor material comprising the steps of:
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depositing on the surface of the body a layer of undoped polysilicon; forming an opening through the undoped polysilicon layer to the surface of the body; coating side walls of the opening with a layer of silicon nitride; filling the remaining portion of the opening with doped polysilicon; heating the doped and undoped polysilicon in an oxidizing atmosphere to grow a layer of silicon dioxide thereon which is thicker over the doped polysilicon than over the undoped polysilicon; etching the silicon dioxide layer so as to remove a portion thereof over the undoped polysilicon while leaving a portion of the silicon dioxide layer over the doped polysilicon; removing the undoped polysilicon; and forming a layer of a dielectric material on the body surface surrounding the doped polysilicon. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification