Method for growing field oxide to minimize birds' beak length
AssigneeMicron Technology, Inc.
InventorsRandhir P. S. Thakur, Michael Nuttall, Pai-Hung Pan
Life of this patent
Estimating the term…
Abstract
A method for forming field oxide isolation regions using oxygen implantation is described. An oxidation resistant layer such as silicon nitride is formed on a silicon substrate, and acts as an oxidation mask. An opening is then formed in the nitride layer, where field oxide is desired. In one embodiment of the invention, oxygen is implanted into this opening, followed by thermal oxidation. In a second embodiment of the invention, the opening is thermally oxidized, followed by a deep oxygen implant and anneal. Encroachment of the field oxide under the nitride layer is decreased, resulting in a minimum “birds' beak” length.
Claims29
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming a layer of silicon nitride on the substrate having at least one opening therein;
- oxidizing the substrate at the opening to form a first oxidized layer;
- implanting oxygen into the opening below the first oxidized layer;
- oxidizing the substrate to form a layer of field oxide at the opening having a desired field oxide thickness.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming a layer of silicon nitride by chemical vapor deposition on the substrate having at least one opening therein;
- oxidizing the substrate at the opening to form a first oxidized layer;
- implanting oxygen into the opening below the first oxidized layer;
- oxidizing the substrate to form a layer of field oxide at the opening having a desired field oxide thickness.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming a first oxide layer on the substrate;
- forming an oxidation resistant layer on the substrate having at least one opening therein;
- oxidizing the substrate at the opening to form a second oxidized layer;
- implanting oxygen into the opening below the second oxidized layer;
- oxidizing the substrate to form a layer of field oxide at the opening having a desired field oxide thickness.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming a first oxide layer on the substrate;
- forming a silicon nitride layer on the substrate
- etching at least one opening in the silicon nitride layer;
- oxidizing the substrate at the opening to form a second oxidized layer;
- implanting oxygen into the opening below the second oxidized layer;
- oxidizing the substrate to form a layer of field oxide at the opening having a desired field oxide thickness.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming a first oxide layer on the substrate;
- forming a silicon nitride layer on the substrate
- etching at least one opening in the silicon nitride layer;
- oxidizing the substrate at the opening to form a second oxidized layer;
- implanting oxygen into the opening below the second oxidized layer;
- oxidizing the substrate to form a layer of field oxide at the opening having a desired field oxide thickness;
- removing the silicon nitride layer.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming an oxidation resistant layer on the substrate having at least one opening therein;
- oxidizing the substrate at the opening to form a first oxidized layer;
- aligning the substrate substantially along an axis selected from the group <100>, <111>, <110>;
- implanting oxygen into the opening below the first oxidized layer;
- oxidizing the substrate to form a layer of field oxide at the opening having a desired field oxide thickness.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming an oxidation resistant layer on the substrate having at least one opening therein;
- oxidizing the substrate at the opening to form a first oxidized layer;
- implanting oxygen into the opening below the first oxidized layer;
- oxidizing the substrate by rapid thermal oxidation to form a layer of field oxide at the opening having a desired field oxide thickness.
A method for forming field oxide on a semiconductor substrate, comprising the steps of:
- forming an oxidation resistant layer on the substrate having at least one opening therein;
- oxidizing the substrate at the opening to form a first oxidized layer;
- implanting oxygen into the opening below the first oxidized layer;
- oxidizing the substrate by rapid thermal oxidation to form a layer of field oxide at the opening having a field oxide thickness in the range 1,000-10,000 Å.
Dependencies are inferred from the claim text.