LOCOS with sidewall spacer for different capacitance density capacitors
AssigneeTexas Instruments Incorporated
InventorHenry Litzmann Edwards
Life of this patent
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Abstract
An integrated circuit (IC) includes a first capacitor, a second capacitor, and functional circuitry configured together with the capacitors for realizing at least one circuit function in a semiconductor surface layer on a substrate. The capacitors include a top plate over a LOCal Oxidation of Silicon (LOCOS) oxide, wherein a thickness of the LOCOS oxide for the second capacitor is thicker than a thickness of the LOCOS oxide for the first capacitor. There is a contact for the top plate and a contact for a bottom plate for the first and second capacitors.
Claims20
A method of fabricating an integrated circuit (IC), comprising:
- depositing a first oxygen diffusion barrier (ODB) layer on a pad oxide layer on a semiconductor surface layer on a substrate;
- patterning and then etching the first ODB layer to form a 1st first ODB layer opening and at least a 2nd first ODB layer opening, wherein a width of the 2nd first ODB layer opening is larger than a width of the 1st first ODB layer opening;
- growing a first LOCal Oxidation of Silicon (LOCOS) layer in the 1st first ODB layer opening and in the 2nd first ODB layer opening;
- depositing a second ODB layer and then depositing a sacrificial sidewall film on the second ODB layer;
- etching the sacrificial sidewall film to form a spacer in the 2nd first ODB layer opening but not in the 1st first ODB layer opening which remains blocked by the sacrificial sidewall film and removing the second ODB layer where not protected by the sacrificial sidewall film;
- stripping the sacrificial sidewall film;
- growing a second LOCOS layer in the 2nd first ODB layer opening but not in the 1st first ODB layer opening;
- removing the first and the second ODB layer, and
- forming a top plate over the first opening to complete a first capacitor and over the second opening to complete a second capacitor.
A method of fabricating an integrated circuit (IC), comprising:
- depositing a first oxygen diffusion barrier (ODB) layer over a substrate;
- patterning and etching the first ODB layer to form a first opening and a second opening, wherein a width of the second opening is larger than a width of the first opening;
- forming a first oxide layer in the first opening and in the second opening, the first oxide layer having a thickness in the range of 200 Å to 1000 Å;
- depositing a second ODB layer and then depositing a sacrificial sidewall film on the second ODB layer;
- etching the sacrificial sidewall film to form a spacer in the second opening but not in the first opening which remains blocked by the sacrificial sidewall film and removing the second ODB layer where not protected by the sacrificial sidewall film;
- stripping the sacrificial sidewall film;
- increasing the thickness of the first oxide layer in the second opening while the first opening is covered by the second ODB layer;
- removing the first and the second ODB layers;
- and
- forming a top plate over the first opening to complete a first capacitor and over the second opening to complete a second capacitor, where the first oxide layer is thicker in the second capacitor than in the first capacitor.
A method of fabricating an integrated circuit (IC), comprising:
- forming a first oxide region and a second oxide region;
- forming an oxygen diffusion barrier over the first oxide region and only partially over the second oxide region;
- thermally oxidizing the second oxide region while the oxygen diffusion barrier remains over the first oxide region so that the second oxide region increases to a second thickness greater than a first thickness of the first oxide region;
- removing the oxygen diffusion barrier;
- and
- forming a top plate over the first oxide region to complete a first capacitor and over the second oxide region to complete a second capacitor.
Dependencies are inferred from the claim text.