Tungsten-plug process
First Claim
1. A method of forming tungsten plug metallization without dog-bone and without junction damage in the fabrication of integrated circuits comprising:
- providing semiconductor structures in and on a semiconductor substrate;
providing an insulating layer covering said semiconductor structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate;
depositing a glue layer conformally over the surface of said insulating layer and within said contact opening;
forming a tungsten plug within said contact opening;
removing said glue layer except for portions of said glue layer underneath said tungsten plug and portions of said glue layer on the lower sides of said tungsten plug wherein ditches are left on the upper sides of said tungsten plug where said glue layer has been removed;
filling said ditches around said tungsten plug with a dielectric material;
depositing a second metallization over said insulating layer and said tungsten plug;
patterning said second metallization wherein said patterned second metallization does not extend over one side portion of said tungsten plug;
that is, there is no dog-bone formation; and
wherein there is no junction damage through said side portion of said tungsten plug not covered by said second metallization because said dielectric material filling said ditches protects said glue layer from being etched away completing fabrication of said integrated circuit.
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Accused Products
Abstract
A method of metallization using a tungsten plug is described. A contact hole is opened to the semiconductor substrate through an insulating layer covering semiconductor structures in and on the semiconductor substrate. A glue layer is deposited conformally over the surface of the insulating layer and within the contact opening. A tungsten plug is formed within the contact opening. The glue layer is removed except for portions of the glue layer underneath the tungsten plug and on the lower sides of the tungsten plug. Ditches are left on the upper sides of the tungsten plug where the glue layer has been removed. The ditches around the tungsten plug are filled with a dielectric material. A second metallization is deposited and patterned. The patterned second metallization does not extend over one side portion of the tungsten plug; that is, there is no dog-bone formation. There is no junction damage through the side portion of the tungsten plug not covered by the second metallization because the dielectric material filling the ditches protects the glue layer from being etched away. In a second embodiment of the invention, after the contact hole is opened, the insulating layer is reflowed forming an overhang around the contact hole. A glue layer is deposited conformally over the surface of the insulating layer and within the contact opening. A tungsten plug is formed within the contact opening.
88 Citations
20 Claims
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1. A method of forming tungsten plug metallization without dog-bone and without junction damage in the fabrication of integrated circuits comprising:
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providing semiconductor structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; forming a tungsten plug within said contact opening; removing said glue layer except for portions of said glue layer underneath said tungsten plug and portions of said glue layer on the lower sides of said tungsten plug wherein ditches are left on the upper sides of said tungsten plug where said glue layer has been removed; filling said ditches around said tungsten plug with a dielectric material; depositing a second metallization over said insulating layer and said tungsten plug; patterning said second metallization wherein said patterned second metallization does not extend over one side portion of said tungsten plug;
that is, there is no dog-bone formation; and
wherein there is no junction damage through said side portion of said tungsten plug not covered by said second metallization because said dielectric material filling said ditches protects said glue layer from being etched away completing fabrication of said integrated circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of forming tungsten plug metallization without dog-bone and without junction damage in the fabrication of integrated circuits comprising:
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providing semiconductor structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; reflowing said insulating layer wherein an overhang forms on either side of said contact hole; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; forming a tungsten plug within said contact opening wherein a keyhole void is formed within said tungsten plug; depositing a second metallization over said insulating layer and said tungsten plug; patterning said second metallization wherein said patterned second metallization does not extend over one side portion of said tungsten plug;
that is, there is no dog-bone formation; and
wherein there is no junction damage through said side portion of said tungsten plug not covered by said second metallization because said overhang of said insulating material protects said glue layer from being etched away;
completing fabrication of said integrated circuit. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification