Process of vertically stacking multiple wafers supporting different active integrated circuit (IC) devices
First Claim
1. A method of vertically stacking wafers, comprising:
- selectively depositing a plurality of metallic lines on opposing surfaces of adjacent wafers;
bonding the adjacent wafers, via respective metallic lines on opposing surfaces of the adjacent wafers, to establish electrical connections between active devices on vertically stacked wafers; and
forming one or more vias to establish electrical connections between the active devices on the vertically stacked wafers and an external interconnect.
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Accused Products
Abstract
A method of vertically stacking wafers is provided to form three-dimensional (3D) wafer stack. Such method comprising: selectively depositing a plurality of metallic lines on opposing surfaces of adjacent wafers; bonding the adjacent wafers, via the metallic lines, to establish electrical connections between active devices on vertically stacked wafers; and forming one or more vias to establish electrical connections between the active devices on the vertically stacked wafers and an external interconnect. Metal bonding areas on opposing surfaces of the adjacent wafers can be increased by using one or more dummy vias, tapered vias, or incorporating an existing copper (Cu) dual damascene process.
289 Citations
32 Claims
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1. A method of vertically stacking wafers, comprising:
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selectively depositing a plurality of metallic lines on opposing surfaces of adjacent wafers;
bonding the adjacent wafers, via respective metallic lines on opposing surfaces of the adjacent wafers, to establish electrical connections between active devices on vertically stacked wafers; and
forming one or more vias to establish electrical connections between the active devices on the vertically stacked wafers and an external interconnect. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of forming vertically stacked wafers, comprising:
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depositing a plurality of metallic lines on opposing surfaces of top and bottom wafers;
forming a conductive plug;
bonding the adjacent wafers, via respective metallic lines, to form vertically stacked wafers; and
forming at least one via on the top wafer to establish electrical connections between the active devices on the vertically stacked wafers and an external interconnect, by selectively etching through the top wafer until stopped by the conductive plug, depositing an oxide layer to insulate a sidewall of the via, depositing a barrier/seed layer on the bottom of the via, and filling the via with a conduction metal to serve as electrical connections between active devices on the vertically stacked wafers and the external interconnect. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A three-dimensional (3-D) vertically stacked wafer system, comprising:
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a first wafer including an active region to support one or more integrated circuit (IC) devices;
a second wafer including an active region to support one or more integrated circuit (IC) devices;
metallic lines deposited on opposing surfaces of the first and second wafers at designated areas to establish metal bonding between the first and second wafers in a stack and provide electrical connections between active IC devices on the first and second wafers in the stack; and
one or more vias formed, via the active region of the first wafer, to serve as electrical connections between the active IC devices on the first and second wafers in the stack and an external interconnect. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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27. A three-dimensional (3-D) vertically stacked wafer system, comprising:
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a first stack of wafers in which adjacent wafers are bonded, via metallic lines deposited on opposing surfaces of the adjacent wafers at designated areas to establish metal bonding between the adjacent wafers and provide electrical connections between active IC devices on the adjacent wafers;
a first stack of wafers in which adjacent wafers are bonded, via metallic lines deposited on opposing surfaces of the adjacent wafers at designated areas to establish metal bonding between the adjacent wafers and provide electrical connections between active IC devices on the adjacent wafers; and
one or more vias formed on opposing surfaces of the first stack of wafers and the second stack of adjacent wafers to serve as electrical connections between the active IC devices on the first and second stacks of wafers and an external interconnect. - View Dependent Claims (28, 29, 30, 31, 32)
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Specification