Polyimide-insulated cube package of stacked semiconductor device chips
First Claim
1. A method for forming a semiconductor structure, comprising the steps of:
- forming a plurality of integrated circuit chips on an upper surface of a wafer, said wafer having a first coefficient of thermal expansion;
forming a sandwich structure of a first insulation layer, a first layer of transfer metallurgy, and a second insulation layer on said wafer, said first and second layers of insulation having coefficients of thermal expansion that approximate that of said wafer and having dielectric constants no greater than approximately 4;
applying a polymer adhesion material on top of said sandwich structure;
drying said polymer adhesion material without full curing;
dicing said wafer to separate said plurality of integrated circuit chips from one another; and
stacking said plurality of integrated circuit chips together and bonding said stacked chips together by heating to a temperature sufficient to cause said polymer adhesion material to cure.
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Accused Products
Abstract
A cube package of stacked silicon semiconductor chips. To accommodate cube packaging, a metal transfer layer is added over the passivated chip face to bring all of the surface electrical contacts to a common chip edge. The metal transfer layer is insulated from the chip face and from the adjacent chip in the stack by polymer layers having a low dielectric constant, and a thermal expansion coefficient matching that of the stacked chips. An adhesive polymer layer is added to strengthen the bond between the first polymer layers and the adjacent chip in the stack, by deposition of the adhesive layer and partial cure at the wafer level, and then full cure when the chips are stacked together to form the cube.
164 Citations
36 Claims
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1. A method for forming a semiconductor structure, comprising the steps of:
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forming a plurality of integrated circuit chips on an upper surface of a wafer, said wafer having a first coefficient of thermal expansion; forming a sandwich structure of a first insulation layer, a first layer of transfer metallurgy, and a second insulation layer on said wafer, said first and second layers of insulation having coefficients of thermal expansion that approximate that of said wafer and having dielectric constants no greater than approximately 4; applying a polymer adhesion material on top of said sandwich structure; drying said polymer adhesion material without full curing; dicing said wafer to separate said plurality of integrated circuit chips from one another; and stacking said plurality of integrated circuit chips together and bonding said stacked chips together by heating to a temperature sufficient to cause said polymer adhesion material to cure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of forming a multi-chip integrated circuit structure, comprising the steps of:
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forming a plurality of integrated circuit chips on a wafer, said wafer having a first coefficient of thermal expansion, each of said plurality of integrated circuit chips having a first passivation layer thereon; forming an interconnection structure on said first passivation layer, comprising a first layer of metal disposed within a first polymer material, said first polymer material having a coefficient of thermal expansion that approximates that of said wafer and a dielectric constant that is less than approximately 4; forming an adhesive polymer layer on said interconnection structure, said adhesive polyimide layer being heated to stabilize without fully curing; dicing said plurality of integrated circuit chips from said wafer; bonding at least one of said plurality of integrated circuit chips to another one of said plurality of integrated circuit chips by bringing a surface of one of said plurality of integrated circuit chips into contact with a surface of another one of said plurality of integrated circuit chips having said layer of adhesive polymer layer thereon, and fully curing said adhesive polymer layer to form a unitized multi-chip body having a plurality of surfaces; depositing a second passivation layer on one of said plurality of surfaces of said unitized body; and forming a second layer of metal that extends through said second passivation layer to contact said first layer of metal. - View Dependent Claims (16, 17)
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18. A method of bonding a first integrated circuit chip to a workpiece, of said first integrated circuit chip being diced from a wafer having a plurality of integrated circuit chip images on a first surface thereon including said first integrated circuit chip image, comprising the steps of
depositing a polymer layer on a first surface of said wafer; -
drying said polymer layer; dicing said wafer; bringing said polymer layer on said first integrated circuit chip into contact with said workpiece; and fully curing said polymer layer. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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25. A method for forming a semiconductor structure comprising the steps of:
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a) forming a plurality of integrated circuit chips on a wafer, each of said plurality of integrated circuit chips having a first passivation layer thereon; b) forming a sandwich structure on said first passivation layer, said structure comprising a first polymeric insulation layer, a first rerouting metal layer and a second polymeric insulation layer; c) dicing said plurality of integrated circuit chips from said wafer; d) bonding at least one of said plurality of integrated circuit chips to another chip to form a unitized multi-chip body having a plurality of surfaces; e) depositing a second passivation layer on one of said plurality of surfaces of said unitized body; and f) forming a second layer of metal that extends through said second passivation layer to contact said first rerouting metal layer. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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Specification