Flash memory and manufacturing method therefor
First Claim
1. A method of manufacturing a flash memory which is provided with a floating gate, a control gate, and an erase gate, each of said floating gate, said control gate and said erase gate being mutually insulated from one another, in which erasing of data is performed by extracting electrons from an edge of a corner of said floating gate via an insulation film, into said erase gate, said method comprising the steps of:
- forming said float gate which is made of polysilicon and exposing a corner surface of said floating gate;
forming a silicon oxide layer on said floating gate having a uniform thickness at the corner surface of said floating gate, using a CVD process; and
forming a silicon thermal oxide film after said forming of said silicon oxide layer on said floating gate using a CVD process.
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Accused Products
Abstract
In a flash memory that has a floating gate, a control gate, and an erase gate that are all mutually insulated, in which data erasing is performed by extracting electrons from the corner edge of the floating gate to the erase gate via an insulation film, the insulation film between the floating gate and the erase gate is formed so as to have a uniform thickness at its corner part.
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Citations
7 Claims
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1. A method of manufacturing a flash memory which is provided with a floating gate, a control gate, and an erase gate, each of said floating gate, said control gate and said erase gate being mutually insulated from one another, in which erasing of data is performed by extracting electrons from an edge of a corner of said floating gate via an insulation film, into said erase gate, said method comprising the steps of:
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forming said float gate which is made of polysilicon and exposing a corner surface of said floating gate;
forming a silicon oxide layer on said floating gate having a uniform thickness at the corner surface of said floating gate, using a CVD process; and
forming a silicon thermal oxide film after said forming of said silicon oxide layer on said floating gate using a CVD process. - View Dependent Claims (2, 3, 4)
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5. A method of manufacturing a flash memory which is provided with a floating gate, a control gate, and an erase gate, each of said floating gate, said control gate and said erase gate being mutually insulated from one another, in which erasing of data is performed by extracting electrons from an edge of a corner of said floating gate via an insulation film, into said erase gate, said method comprising the steps of:
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forming said float gate which is made of polysilicon and exposing a corner surface of said floating gate;
forming a silicon oxide layer on said floating gate having a uniform thickness at the corner surface of said floating gate, using a CVD process; and
performing thermal oxidation in an oxidizing atmosphere that includes a nitrogen compound, after said forming of said silicon oxide film on said floating gate using a CVD process. - View Dependent Claims (6, 7)
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Specification