Etching methods for a magnetic memory cell stack
AssigneeApplied Materials, Inc.
InventorsJeng H. Hwang, Guangxiang Jin, Xiaoyi Chen
Life of this patent
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Abstract
A method and apparatus for etching a magnetic memory cell stack are described. More particularly, HCl is used as a main etchant gas for etching a magnetic memory cell stack. HCl is used in part to reduce corrosion and improve selectivity. Additionally, use of an amorphous carbon or hydrocarbon based polymer resin for a hard mask is described, as well as a post-etch passivation with a water rinse, a water vapor plasma treatment or an ammonia plasma treatment. Moreover, in an embodiment, a diffusion barrier layer dispose most of the magnetic memory cell stack is etched with hydrogen and fluorine containing gas in a separate process
Claims30
A method for forming a magnetic memory cell, comprising:
- loading a semiconductor wafer into an etch process chamber, the semiconductor wafer having at least one masking layer, the at least one masking layer formed over a set of layers for forming the magnetic memory cell, the set of layers including a subset of layers, the subset of layers including at least two magnetic layers separated by an electron barrier layer and including an anti-magnetic layer;
- and
- plasma etching through openings formed in the at least one masking layer, the plasma etching including flowing at least one plasma source gas into the etch process chamber, the at least one plasma source gas including HCl.
A method for plasma etching in a plasma reactor to provide a magnetic memory cell stack, comprising:
- positioning a work piece in the plasma reactor, the work piece including at least one magnetic material layer selected from NiFe, CoFe, NiFeCo, and Ru;
- flowing a plasma source material into the plasma reactor, the plasma source material including HCl;
- generating a plasma from the plasma source material;
- and
- exposing the work piece to the plasma to etch the at least one magnetic material layer.
For a process chamber configured to allow an operator thereof to select a gaseous mixture for etching a portion of a magnetic memory cell stack, the portion of the magnetic memory cell stack having two magnetic orientation material layers separated by a tunnel barrier layer and having an anti-magnetic material layer, the gaseous mixture comprising:
- HCl as a main etchant gas to etch the portion of the magnetic memory cell stack.
A method for forming a magnetic memory cell, comprising:
- loading a semiconductor wafer into a first etch process chamber, the semiconductor wafer having at least one masking layer, the at least one masking layer formed over a set of layers for forming the magnetic memory cell, the set of layers including a subset of layers, the subset of layers including at least two magnetic layers separated by an electron barrier layer and including an anti-magnetic layer, the subset of layers not including a diffusion barrier layer, the diffusion barrier layer located below the subset of layers;
- first plasma etching the subset of layers through openings formed in the at least one masking layer, the first plasma etching including flowing a first plasma source gas into the first etch process chamber, the first plasma source gas including HCl;
- removing the semiconductor wafer from the first etch process chamber;
- loading the semiconductor wafer into a second etch process chamber;
- and
- second plasma etching the diffusion barrier layer of the semiconductor wafer, the second plasma etching including flowing a second plasma source gas into the second etch process chamber, the second plasma source gas including a hydrogen and fluorine gas.
A method for plasma etching in a plasma reactor to provide a magnetic memory cell stack, comprising:
- positioning a work piece in the plasma reactor, the work piece including an anti-magnetic material layer selected from PtMn and IrMn;
- flowing a plasma source material into the plasma reactor, the plasma source material including HCl;
- generating a plasma from the plasma source material;
- and
- exposing the work piece to the plasma to etch the anti-magnetic material layer.
Dependencies are inferred from the claim text.