Etch stop layer using polymers for integrated circuits
AssigneeAdvanced Micro Devices, Inc.
InventorsJacob D. Haskell, Subhash Gupta
Life of this patent
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Abstract
An etch stop layer (22) for permitting distinguishing between two similar layers (20, 24), such as two oxide layers, during etching is provided. The etch stop layer comprises a silicon-oxyhalide polymer, preferably a silicon-oxyfluoride polymer. Use of the polymer as an etch stop layer permits closer placement of metal conductor surfaces (12, 12') and contacts (14').
Claims19
A process for etching through one dielectric layer having a given etch rate to an underlying dielectric layer having a similar etch rate comprising interposing a polymer layer between said dielectric layers, said polymer consisting essentially of a non-organic silicon-oxyhalide polymer.
A process for forming via contacts to underlying conducting interconnects formed over semiconductor substrates, comprising:
- (a) depositing and patterning a metal layer on said substrate;
- (b) forming a layer of a first dielectric material on a surface associated with said substrate;
- (c) etching said first dielectric layer back to said metal layer to form a substantially planar surface;
- (d) exposing said first dielectric layer to an atmosphere of SiX.sub.4, where X is halogen, and oxygen excited by a radio-frequency field to form a layer of a silicon-oxyhalide polymer thereon;
- (e) forming a layer of a second dielectric on said polymer layer;
- (f) patterning said second dielectric layer by etching vias therethrough to said polymer layer to expose portions of said polymer layer in said via;
- (g) etching said exposed portions to expose a portion of said conducting interconnect;
- and
- (h) forming a conducting layer in said via in electrical and physical contact with said conducting interconnect.
A process for etching through one dielectric layer having a given etch rate to an underlying dielectric layer having a similar etch rate comprising interposing a silicon-oxyhalide polymer layer between said dielectric layers, said silicon-oxyhalide polymer layer formed on a surface of said underlying dielectric layer by exposing said surface of said underlying dielectric layer to an atmosphere of SIX.sub.4, where X is halogen, and oxygen excited by a radio-frequency field prior to formation of said one dielectric layer over said underlying dielectric layer, wherein said oxygen ranges from about 5 to 90%, the balance said SIX.sub.4.
Dependencies are inferred from the claim text.