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US6613632B2
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Fabrication method for a silicon nitride read-only memory
Assignee: Macronix International Co Ltd
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Filing: 2002-05-28
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Granted: 2003-09-02
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Expires: 2022-05-28
Abstract
Abstract A fabrication method for a read-only memory with a silicon nitride floating gate is provided. A first oxide layer and a silicon nitride layer are sequentially formed on a substrate. The silicon nitride layer and the first oxide layer are then patterned to form an opening, exposing a portion of the substrate. An oxidation process is then conducted to form a second oxide layer on the silicon nitride layer and concurrently to form a field oxide layer on the exposed substrate. The second oxide layer, the silicon nitride layer and the first oxide layer are then patterned to form an oxide dielectric layer, a silicon nitride floating gate layer and a tunnel oxide layer.
Inventors
- 👤 Chien-Hung Liu
- 👤 Shyi-Shuh Pan
- 👤 Shou-Wei Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 02:32
CPC Classifications
H; H10; H10B; H10B43/00; H10B43/30; H10B69/00; H10D; H10D64/00; H10D64/01; H10D64/031; H10D64/037
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
110 words
A method for fabricating a silicon nitride floating gate for a read-only memory, comprising: providing a substrate; forming a first oxide layer on the substrate; forming a silicon nitride layer on the first oxide layer; patterning the silicon nitride layer and the first oxide layer to form an opening, exposing a portion of the substrate; forming concurrently a second oxide layer on the silicon nitride layer and a field oxide layer on the substrate exposed by the opening; and patterning the second oxide layer, the silicon nitride layer and the first oxide layer to form an oxide dielectric layer, a silicon nitride floating gate layer and a tunnel oxide layer.
Claim 2
Independent Claim
110 words
A method for fabricating a silicon nitride floating gate for a read-only memory, comprising: providing a substrate; forming a first oxide layer on the substrate; forming a silicon nitride layer on the first oxide layer; patterning the silicon nitride layer and the first oxide layer to form an opening, exposing a portion of the substrate; forming concurrently a second oxide layer on the silicon nitride layer and a field oxide layer on the substrate exposed by the opening; and patterning the second oxide layer, the silicon nitride layer and the first oxide layer to form an oxide dielectric layer, a silicon nitride floating gate layer and a tunnel oxide layer.
Claim 3
Dependent Claim
28 words
The method of claim 1 , wherein the second oxide layer and the field oxide layer are formed at a rate ratio of about 1:35 to about 1:45.
Claim 4
Dependent Claim
35 words
The method of claim 1 , wherein forming concurrently the second oxide layer on the silicon nitride layer and the field oxide layer on the substrate exposed by the opening include performing an oxidation process.
Claim 5
Dependent Claim
13 words
The method of claim 3 , wherein the oxidation process includes wet oxidation.
Claim 6
Dependent Claim
49 words
The method of claim 4 , wherein wet oxidation is conducted at an oxygen flow rate of about 5 L/min to about 30 L/min, a hydrogen flow rate of about 2 L/min to about 20 L/min and a nitrogen flow rate of about 0 L/min to about 30 L/min.
Claim 7
Dependent Claim
23 words
The method of claim 4 , wet oxidation is conducted at a temperature of about 850 degrees Celsius to about 1050 degrees Celsius.
Claim 8
Dependent Claim
17 words
The method of claim 4 , wherein wet oxidation is conducted for about 80 to 120 minutes.
Claim 9
Dependent Claim
20 words
The method of claim 1 , wherein the second oxide layer is about 75 angstroms to about 105 angstroms thick.
Claim 10
Dependent Claim
20 words
The method of claim 1 , wherein the silicon nitride layer is about 120 angstroms to about 180 angstroms thick.
Claim 11
Dependent Claim
20 words
The method of claim 1 , wherein the first oxide layer is about 50 angstroms to about 100 angstroms thick.
Claim 12
Independent Claim
84 words
A method for fabricating a read-only memory, comprising: providing a substrate; forming a first oxide layer and a material layer on the substrate, wherein a portion of the substrate is not covered by the first oxide layer and the material layer; and forming concurrently a second oxide layer on the material layer and a third oxide layer on the exposed substrate, wherein the second oxide layer on a top surface of the material layer and the material layer are retained as a gate dielectric.
Claim 13
Independent Claim
84 words
A method for fabricating a read-only memory, comprising: providing a substrate; forming a first oxide layer and a material layer on the substrate, wherein a portion of the substrate is not covered by the first oxide layer and the material layer; and forming concurrently a second oxide layer on the material layer and a third oxide layer on the exposed substrate, wherein the second oxide layer on a top surface of the material layer and the material layer are retained as a gate dielectric.
Claim 14
Dependent Claim
14 words
The method of claim 11 , wherein the material layer includes silicon nitride layer.
Claim 15
Dependent Claim
28 words
The method of claim 11 , wherein the second oxide layer and the third oxide layer are formed at a rate ratio of about 1:35 to about 1:45.
Claim 16
Dependent Claim
31 words
The method of claim 11 , wherein forming concurrently a second oxide layer on the material layer and a third oxide layer on the exposed substrate includes performing an oxidation process.
Claim 17
Dependent Claim
17 words
The method of claim 14 , wherein performing the oxidation process includes performing a wet oxidation process.
Claim 18
Dependent Claim
51 words
The method of claim 15 , wherein the wet oxidation process is conducted at an oxygen flow rate of about 5 L/min to about 30 L/min, a hydrogen flow rate of about 2 L/min to about 20 L/min and a nitrogen flow rate of about 0 L/min to about 30 L/min.
Claim 19
Dependent Claim
26 words
The method of claim 15 , wherein the wet oxidation process is conducted at a temperature of about 850 degrees Celsius to about 1050 degree Celsius.
Claim 20
Dependent Claim
20 words
The method of claim 15 , wherein the wet oxidation is conducted for about 80 minutes to about 120 minutes.
Claim 21
Dependent Claim
20 words
The method of claim 11 , wherein the second oxide layer is about 75 angstroms to about 105 angstroms thick.
Claim 22
Dependent Claim
19 words
The method of claim 11 , wherein the material layer is about 120 angstroms to about 180 angstroms thick.
Claim 23
Dependent Claim
20 words
The method of claim 11 , wherein the first oxide layer is about 50 angstroms to about 100 angstroms thick.
References Cited (Backward Citations)
US5756390A
Cited
US6187640B1
Cited
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