Bonding process with inhibited oxide formation
AssigneeSiTime Corporation
InventorsPaul M. Hagelin, Charles I. Grosjean
Life of this patent
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Abstract
First and second contacts are formed on first and second wafers from disparate first and second conductive materials, at least one of which is subject to surface oxidation when exposed to air. A layer of oxide-inhibiting material is disposed over a bonding surface of the first contact and the first and second wafers are positioned relative to one another such that a bonding surface of the second contact is in physical contact with the layer of oxide-inhibiting material. Thereafter, the first and second contacts and the layer of oxide-inhibiting material are heated to a temperature that renders the first and second contacts and the layer of oxide-inhibiting material to liquid phases such that at least the first and second contacts alloy into a eutectic bond.
Claims27
A method of forming a wafer-to-wafer bond, the method comprising:
- forming, on a first wafer, a first contact from a first conductive material subject to surface oxidation when exposed to air;
- disposing a layer of oxide-inhibiting material over a bonding surface of the first contact;
- forming, on a second wafer, a second contact from a second conductive material that, upon heating while in physical contact with the first conductive material, will form a eutectic bond;
- positioning the first and second wafers relative to one another such that a bonding surface of the second contact is in physical contact with the layer of oxide-inhibiting material;
- and
- heating the first and second contacts and the layer of oxide-inhibiting material to one or more temperatures that render the first and second contacts and the layer of oxide-inhibiting material to liquid phases such that the first and second contacts and the layer of oxide-inhibiting material alloy into a ternary eutectic bond;
- wherein
- forming the first contact from the first conductive material subject to surface oxidation comprises forming the first contact from at least one of silicon, germanium or a silicon-germanium alloy, and
- forming the second contact from the second conductive material comprises forming the second contact from at least one of aluminum, aluminum-silicon alloy, aluminum-copper alloy or aluminum-silicon-copper alloy.
A method of forming a wafer-to-wafer bond, the method comprising:
- forming, on a first wafer, a first contact from a first conductive material subject to surface oxidation when exposed to air;
- disposing a layer of oxide-inhibiting material over a bonding surface of the first contact;
- forming, on a second wafer, a second contact from a second conductive material that, upon heating while in physical contact with the first conductive material, will form a eutectic bond;
- positioning the first and second wafers relative to one another such that a bonding surface of the second contact is in physical contact with the layer of oxide-inhibiting material;
- and
- heating the first and second contacts and the layer of oxide-inhibiting material to one or more temperatures that render the first and second contacts and the layer of oxide-inhibiting material to liquid phases such that the first and second contacts and the layer of oxide-inhibiting material alloy into a ternary eutectic bond;
- wherein heating the first and second contacts and the layer of oxide-inhibiting material comprises, prior to positioning the first and second wafers relative to one another, heating the first contact and the layer of oxide-inhibiting material to a first temperature that renders the first contact and the layer of oxide-inhibiting material to liquid phases such that the first contact and the layer of oxide-inhibiting material form an alloy.
A method of forming a wafer-to-wafer bond, the method comprising:
- forming, on a first wafer, a first contact from a first conductive material subject to surface oxidation when exposed to air;
- disposing a layer of oxide-inhibiting material over a bonding surface of the first contact;
- forming, on a second wafer, a second contact from a second conductive material that, upon heating while in physical contact with the first conductive material, will form a eutectic bond;
- positioning the first and second wafers relative to one another such that a bonding surface of the second contact is in physical contact with the layer of oxide-inhibiting material;
- and
- heating the first and second contacts and the layer of oxide-inhibiting material to one or more temperatures that render the first and second contacts and the layer of oxide-inhibiting material to liquid phases such that the first and second contacts and the layer of oxide-inhibiting material alloy into a ternary eutectic bond;
- wherein heating the first and second contacts and the first and second layers of the oxide-inhibiting material to liquid phases comprises heating the first contact and the first layer of oxide-inhibiting material disposed thereon to liquid phase and heating the second contact and the second layer of oxide-inhibiting material disposed thereon to liquid phase prior to positioning the first and second wafers relative to one another.
Dependencies are inferred from the claim text.