Utilizing a protective plug to maintain the integrity of the FTP shrink hinge
First Claim
1. A process for forming a metal hinge post structure over an electrically conductive electrode comprising the steps of:
- forming a patterned spacer layer having a top surface on said electrically conductive electrode, said patterned spacer layer defining at least one hinge post aperture extending from said top surface through said spacer layer to said electrode layer;
forming a metal layer over said spacer layer;
forming an oxide layer over said metal layer;
depositing a protective layer over said oxide layer, said protective layer deposited to a first thickness over said top surface of said spacer layer and to a second thickness in said at least one hinge post aperture, said second thickness greater than said first thickness;
etching said protective layer to expose said oxide layer, such that only a layer of said protective material remains at the bottom of said at least one hinge post aperture;
anisotropically etching said oxide layer such that a cup-shaped layer of oxide remains in said at least one hinge post aperture; and
cleaning said metal layer and said at least one hinge post aperture.
1 Assignment
0 Petitions
Accused Products
Abstract
As robust hinge post structure for use with torsional hinged devices such as micromirrors and method of manufacturing is disclosed. The fabrication process uses a protective layer such as BARC on the bottom of the aperture used to form the hinge post structure to protect an oxide layer during an etching step. The oxide layer, in turn protects the metal layer at the bottom of the aperture. Therefore, the metal layer, the oxide layer, and the protective layer prevent the erosion and/or pitting of the bottom electrode during a cleaning process, and provide additional support to the structure.
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Citations
24 Claims
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1. A process for forming a metal hinge post structure over an electrically conductive electrode comprising the steps of:
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forming a patterned spacer layer having a top surface on said electrically conductive electrode, said patterned spacer layer defining at least one hinge post aperture extending from said top surface through said spacer layer to said electrode layer;
forming a metal layer over said spacer layer;
forming an oxide layer over said metal layer;
depositing a protective layer over said oxide layer, said protective layer deposited to a first thickness over said top surface of said spacer layer and to a second thickness in said at least one hinge post aperture, said second thickness greater than said first thickness;
etching said protective layer to expose said oxide layer, such that only a layer of said protective material remains at the bottom of said at least one hinge post aperture;
anisotropically etching said oxide layer such that a cup-shaped layer of oxide remains in said at least one hinge post aperture; and
cleaning said metal layer and said at least one hinge post aperture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A process for forming a multiplicity of metal hinge post structures over an electrically conductive electrode for supporting a reflective pixel having surface dimensions of less than 10 μ
- m comprising the steps of;
forming a patterned spacer layer having a top surface on said electrically conductive electrode, said patterned spacer layer defining a multiplicity of hinge post apertures extending from said top surface through said spacer layer to said electrode layer;
forming a layer of “
binge”
metal over said spacer layer, including said multiplicity of hinge post apertures;
forming an oxide layer of aluminum and titanium over said layer of “
binge”
metal, including said multiplicity of hinge post apertures;
depositing a BARC layer over said oxide layer including said multiplicity of hinge post apertures, said BARC layer deposited to a first thickness over said top surface of said spacer layer and to a second thickness in said multiplicity of hinge post apertures, said second thickness greater than said first thickness;
etching said BARC layer to expose said oxide layer, such that only a layer of BARC material remains at the bottom of said multiplicity of hinge post apertures;
anisotropically plasma etching said oxide layer such that a cup-shaped layer of oxide remains in said multiplicity of hinge post apertures; and
cleaning said metal layer, and said multiplicity of hinge post apertures.
- m comprising the steps of;
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19. A hinge post structure formed over a substrate including a conductive electrode comprising:
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an electrically conductive electrode;
at least one cup-shaped metal structure formed above said electrically conductive electrode, said at least one cup-shaped metal structure defining sidewalls a planar bottom portion next to said electrically conductive electrode;
an oxide layer formed on said planar bottom portion sidewalls of said at least one cup-shaped metal structure; and
a protective layer covering said oxide layer formed on said planar bottom portion. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification