US5880040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gate dielectric based on oxynitride grown in N2 O and annealed in NO
Assignee: Macronix International Co Ltd
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Filing: 1996-04-15
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Granted: 1999-03-09
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Expires: 2016-04-15
Abstract
Abstract A new technique for the formation of high quality ultrathin gate dielectrics is proposed. Gate oxynitride was first grown in N 2 O and then annealed by in-situ rapid thermal NO-nitridation. This approach has the advantage of providing a tighter nitrogen distribution and a higher nitrogen accumulation at or near the Si--SiO 2 interface than either N 2 O oxynitride or nitridation of SiO 2 in the NO ambient. It is applicable to a wide range of oxide thickness because the initial rapid thermal N 2 O oxidation rate is slow but not as self-limited as NO oxidation. The resulting gate dielectrics have reduced charge trapping, lower stress-induced leakage current and significant resistance to interface state generation under electrical stress.
Inventors
- 👤 Shi-Chung Sun
- 👤 Chun-Hon Chen
- 👤 Lee-Wei Yen
- 👤 Chun-Jung Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:36
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/01344; H10D64/60; H10D64/66; H10D64/68; H10D64/693
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
118 words
A method for manufacturing a dielectric layer on a silicon substrate, comprising: first heating a surface of the silicon substrate and exposing the heated surface of the silicon substrate to a first gas, said first gas being introduced into a chamber and comprising N 2 O, to cause growth of a layer of SiO 2 on the surface, said layer of SiO 2 including nitrogen; and second heating the layer of SiO 2 and exposing the heated layer of SiO 2 to a second gas, said second gas being introduced into the chamber and comprising NO, to cause formation of silicon to nitrogen bonds in an interfacial region between the layer of SiO 2 and the silicon substrate.
Claim 2
Independent Claim
118 words
A method for manufacturing a dielectric layer on a silicon substrate, comprising: first heating a surface of the silicon substrate and exposing the heated surface of the silicon substrate to a first gas, said first gas being introduced into a chamber and comprising N 2 O, to cause growth of a layer of SiO 2 on the surface, said layer of SiO 2 including nitrogen; and second heating the layer of SiO 2 and exposing the heated layer of SiO 2 to a second gas, said second gas being introduced into the chamber and comprising NO, to cause formation of silicon to nitrogen bonds in an interfacial region between the layer of SiO 2 and the silicon substrate.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the first gas consists essentially of N 2 O.
Claim 4
Dependent Claim
13 words
The method of claim 1, wherein the second gas consists essentially of NO.
Claim 5
Dependent Claim
70 words
The method of claim 1, wherein first heating the surface of the silicon substrate and exposing the heated surface of the silicon substrate to the first gas includes: placing the silicon substrate in a rapid thermal process chamber, filling the rapid thermal process chamber with the first gas, heating the surface of the silicon substrate to a first reaction temperature, and after a first reaction time, cooling the silicon substrate.
Claim 6
Dependent Claim
58 words
The method of claim 4, including after cooling the silicon substrate, removing the first gas from the rapid thermal process chamber, and wherein the second heating and exposing step includes: filling the rapid thermal process chamber with the second gas, heating the layer to a second reaction temperature, and after a second reaction time, cooling the silicon substrate.
Claim 7
Dependent Claim
42 words
The method of claim 5, including after cooling the silicon substrate: removing the second gas from the rapid thermal process chamber; and heating the layer and exposing the heated layer to an inert gas to anneal the layer and the interfacial region.
Claim 8
Dependent Claim
34 words
The method of claim 1, including after the second heating and exposing step: third heating the layer and exposing the heated layer to an inert gas to anneal the layer and the interfacial region.
Claim 9
Dependent Claim
30 words
The method of claim 1, wherein the combination of the first and second heating and exposing steps result in a dielectric layer having a thickness of less than 12 nanometers.
Claim 10
Dependent Claim
30 words
The method of claim 1, wherein the combination of the first and second heating and exposing steps result in a dielectric layer having a thickness between 2.5 and 10 nanometers.
Claim 11
Dependent Claim
30 words
The method of claim 1, wherein the combination of the first and second heating and exposing steps result in a dielectric layer having a thickness between 4 and 8 nanometers.
Claim 12
Dependent Claim
41 words
The method of claim 1, wherein the combination of the first and second heating and exposing steps result in the nitrogen in the layer of SiO 2 having a concentration in a range of from 0.1% to 0.7% by atomic weight.
Claim 13
Dependent Claim
39 words
The method of claim 1, wherein the combination of the first and second heating and exposing steps result in the nitrogen in the interfacial region having a concentration in a range of from 1% to 7% by atomic weight.
Claim 14
Dependent Claim
20 words
The method of claim 1, wherein the first reaction temperature is in a range of about 900° and 1200° C.
Claim 15
Dependent Claim
20 words
The method of claim 1, wherein the second reaction temperature is in a range of about 900° and 1200° C.
Claim 16
Independent Claim
181 words
A method for in situ rapid thermal growth of a nitrided SiO 2 layer on a silicon substrate, comprising: placing the silicon substrate in a rapid thermal process chamber, introducing a first gas into the process chambers, said first gas comprising N 2 O, heating the surface of the silicon substrate to a first reaction temperature to cause growth of a layer of SiO 2 on the surface, said layer of SiO 2 including nitrogen, and after a first reaction time, cooling the silicon substrate; removing the first gas from the process chamber, introducing a second gas into the process chamber, said second gas comprising NO, heating the layer of SiO 2 to a second reaction temperature to cause formation of silicon to nitrogen bonds in an interfacial region between the layer of SiO 2 and the silicon substrate, and after a second reaction time, cooling the silicon substrate; and removing the second gas from the reaction chamber, filing the process chamber with an inert gas, and heating the layer to anneal the layer of SiO 2 and the interfacial region.
Claim 17
Independent Claim
181 words
A method for in situ rapid thermal growth of a nitrided SiO 2 layer on a silicon substrate, comprising: placing the silicon substrate in a rapid thermal process chamber, introducing a first gas into the process chambers, said first gas comprising N 2 O, heating the surface of the silicon substrate to a first reaction temperature to cause growth of a layer of SiO 2 on the surface, said layer of SiO 2 including nitrogen, and after a first reaction time, cooling the silicon substrate; removing the first gas from the process chamber, introducing a second gas into the process chamber, said second gas comprising NO, heating the layer of SiO 2 to a second reaction temperature to cause formation of silicon to nitrogen bonds in an interfacial region between the layer of SiO 2 and the silicon substrate, and after a second reaction time, cooling the silicon substrate; and removing the second gas from the reaction chamber, filing the process chamber with an inert gas, and heating the layer to anneal the layer of SiO 2 and the interfacial region.
Claim 18
Dependent Claim
15 words
The method of claim 15, wherein the first gas consists essentially of N 2 O.
Claim 19
Dependent Claim
13 words
The method of claim 15, wherein the second gas consists essentially of NO.
Claim 20
Dependent Claim
19 words
The method of claim 15, wherein the nitrided SiO 2 layer has a thickness of less than 12 nanometers.
Claim 21
Dependent Claim
19 words
The method of claim 15, wherein the nitrided SiO 2 layer has a thickness between 2.5 and 10 nanometers.
Claim 22
Dependent Claim
19 words
The method of claim 15, wherein the nitrided SiO 2 layer has a thickness between 4 and 8 nanometers.
Claim 23
Dependent Claim
33 words
The method of claim 15, wherein the nitrided SiO 2 layer has nitrogen in the layer of SiO 2 in a concentration in a range of from 0.1% to 0.7% by atomic weight.
Claim 24
Dependent Claim
31 words
The method of claim 15, wherein the nitrided SiO 2 layer has nitrogen in the interfacial region having a concentration in a range of from 1% to 7% by atomic weight.
Claim 25
Dependent Claim
17 words
The method of claim 15, wherein the first reaction temperature is between about 900° and 1200° C.
Claim 26
Dependent Claim
17 words
The method of claim 15, wherein the second reaction temperature is between about 900° and 1200° C.
Claim 27
Dependent Claim
16 words
The method of claim 15, wherein the first reaction time is between 15 and 90 seconds.
Claim 28
Dependent Claim
16 words
The method of claim 15, wherein the second reaction time is between 15 and 90 seconds.
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