Method for capping copper in semiconductor devices
First Claim
1. A method for making a semiconductor device, comprising the steps of:
- forming a copper member within a semiconductor device, wherein the copper member has an exposed surface;
forming a copper silicide layer on the exposed copper member surface; and
depositing a layer comprising silicon nitride on the copper silicide layer.
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Accused Products
Abstract
A silicon nitride layer (34) has improved adhesion to underlying copper interconnect members (30) through the incorporation of an intervening copper silicide layer (32). Layer (32) is formed in-situ with a plasma enhanced chemical vapor deposition (PECVD) process for depositing silicon nitride layer (34). To form layer (32), a semiconductor substrate (12) is provided having a desired copper pattern formed thereon. The copper pattern may include copper interconnects, copper plugs, or other copper members. The substrate is placed into a PECVD reaction chamber. Silane is introduced into the reaction chamber in the absence of a plasma to form a copper silicide layer on any exposed copper surfaces. After a silicide layer of a sufficient thickness (for example, 10 to 100 angstroms) is formed, PECVD silicon nitride is deposited. The copper silicide layer improves adhesion, such that silicon nitride layer is less prone to peeling away from underlying copper members.
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Citations
21 Claims
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1. A method for making a semiconductor device, comprising the steps of:
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forming a copper member within a semiconductor device, wherein the copper member has an exposed surface; forming a copper silicide layer on the exposed copper member surface; and depositing a layer comprising silicon nitride on the copper silicide layer. - View Dependent Claims (2, 3, 4, 5, 21)
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6. A method for making a semiconductor device, comprising the steps of:
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providing a semiconductor substrate; forming a dielectric layer overlying the substrate, the dielectric layer having an opening formed therein; depositing a copper layer over the dielectric layer such that copper substantially fills the opening; removing any portions of the copper layer beyond the opening, leaving a surface of the copper layer within the opening exposed; and capping the copper surface with a diffusion barrier material using a chemical vapor deposition process; wherein the step of capping comprises the steps of; forming a copper silicide layer by reacting a vapor species comprising silicon with the copper surface; and
thenforming a layer comprising silicon nitride on the copper silicide layer by reacting the vapor species comprising silicon with a vapor species comprising nitrogen. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for making a semiconductor device comprising the sequential steps of:
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providing a semiconductor substrate having an overlying dielectric layer; forming a copper member overlying the substrate, the copper member having an exposed surface; placing the substrate in a chemical vapor deposition reaction chamber; introducing silane into the reaction chamber to form a copper silicide layer on the exposed copper surface; generating a plasma within the chamber; and introducing silane and ammonia into the reaction chamber in presence of the plasma to deposit a silicon nitride capping layer on the copper silicide layer. - View Dependent Claims (18, 19, 20)
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Specification