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US 5,352,622 AGranted
Stacked capacitor with a thin film ceramic oxide layer
AssigneeNational Semiconductor Corporation
InventorHenry W. Chung
Life of this patent
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Abstract
A self-aligned thin-film ceramic oxide stacked capacitor on an underlying semiconductor substrate using a spin-on ceramic oxide fabricated by forming conductive pillars and the lower electrode, forming a temporary layer, building up the semiconductor substrate around the temporary layer, removing the temporary layer, and then spinning on the ceramic oxide. This results in a ceramic oxide stacked capacitor with the conformal thin-film ceramic oxide encapsulated by the top electrode.
Claims16
A method of fabricating a thin-film ceramic oxide stacked capacitor on an underlying semiconductor substrate, the method comprising the steps of:
- forming a layer of insulating material on the semiconductor substrate;
- forming an opening in the layer of insulating material to expose a surface region of the semiconductor substrate;
- forming a pillar of an electrically conductive material within the opening such that a bottom surface of the pillar is in electrical contact with the surface region of the semiconductor substrate and an exposed sidewall surface of the pillar extends above a top surface of the layer of insulating material, the pillar having a top portion of a lower electrode formed thereon;
- forming a side portion of the lower electrode on the exposed sidewall surface of the pillar;
- forming a temporary layer on a surface of the lower electrode;
- forming a layer of molding material around the temporary layer;
- removing the temporary layer so that an insulating mold is formed for a subsequent thin-film layer of ceramic oxide;
- forming the thin-film layer of ceramic oxide on the lower electrode and in the mold;
- forming an upper electrode on the thin-film layer of ceramic oxide, whereby the upper electrode functions as one plate of the thin-film ceramic oxide stacked capacitor, the thin-film layer of ceramic oxide functions as a dielectric, and the lower electrode functions as the other plate of the thin-film ceramic oxide stacked capacitor.
6 more elements
A method of fabricating a thin-film ceramic oxide stacked capacitor on an underlying semiconductor substrate, the method comprising the steps of:
- forming a layer of insulating material on a surface of the substrate;
- forming an opening in the layer of insulating material to expose a surface region of the substrate;
- depositing a first layer of electrically conductive material over a surface of the layer of insulating material so that the first layer of electrically conductive material fills the opening in the layer of insulating material;
- depositing a second layer of electrically conductive material on the first layer of electrically conductive material;
- etching the first and second layers of electrically conductive material to form an electrically conductive pillar so that a bottom surface of the pillar is in electrical contact with the surface region of the substrate and an exposed sidewall surface of the pillar extends above a top surface of the layer of insulating material, the pillar having a top portion of a lower electrode formed thereon;
- depositing a third layer of electrically conductive material on the exposed sidewall surface of the electrically conductive pillar, the top portion of the lower electrode, and the layer of insulating material;
- etching the third layer of electrically conductive material to form the lower electrode;
- forming a layer of temporary material on a surface of the lower electrode;
- forming a layer of an insulating molding material on a surface of the layer of temporary material and the layer of insulating material;
- etching the layer of temporary material until the layer of temporary material is completely removed so that a trench is formed between the lower electrode and the layer of molding material;
- forming a layer of ceramic oxide on a surface of the lower electrode and a surface of the layer of molding material so that the layer of ceramic oxide fills the trench created by the removal of the layer of temporary material;
- removing the layer of molding material to form a thin-film layer of ceramic oxide having a substantially uniform thickness over the surface of the lower electrode and in the mold;
- depositing a fourth layer of electrically conductive material on a surface of the thin-film layer of ceramic oxide and the layer of insulating material;
- and
- etching the fourth layer of electrically conductive material to form the upper electrode so that the fourth layer of electrically conductive material encapsulates the thin-film layer of ceramic oxide.
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Dependencies are inferred from the claim text.