US6627503B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a multilayer dielectric stack
Assignee: Sharp Laboratories of America Inc
•
Filing: 2002-04-30
•
Granted: 2003-09-30
•
Expires: 2022-04-30
Abstract
Abstract A multilayer dielectric stack is provided which has alternating layers of a high-k material and an interposing material. The presence of the interposing material and the thinness of the high-k material layers reduces or eliminate effects of crystallization within the high-k material, even at relatively high annealing temperatures. The high-k dielectric layers are a metal oxide of preferably zirconium or hafnium. The interposing layers are preferably amorphous aluminum oxide, aluminum nitride, or silicon nitride. Because the layers reduce the effects of crystalline structures within individual layers, the overall tunneling current is reduced. Also provided are atomic layer deposition, sputtering, and evaporation as methods of depositing desired materials for forming the above-mentioned multilayer dielectric stack.
Inventors
- 👤 Yanjun Ma
- 👤 Yoshi Ono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:56
CPC Classifications
H; H10; H10P; H10P10/00; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0225; H10D64/01342; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/01344; H10D64/691; H10D64/693
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
103 words
A method of forming a dielectric stack comprising the steps of: a) forming a first dielectric layer on an upper surface of a semiconductor substrate, wherein the first dielectric layer comprises a first dielectric material, which is HfO 2 ; b) forming a second dielectric layer on the first dielectric layer, wherein the second dielectric layer is selected from the group consisting of Al 2 O 3 , AlN, SiN, and Si 3 N 4 ; and c) forming a third dielectric layer above the second dielectric layer, wherein the third dielectric layer comprises the same dielectric material as the first dielectric material.
Claim 2
Independent Claim
103 words
A method of forming a dielectric stack comprising the steps of: a) forming a first dielectric layer on an upper surface of a semiconductor substrate, wherein the first dielectric layer comprises a first dielectric material, which is HfO 2 ; b) forming a second dielectric layer on the first dielectric layer, wherein the second dielectric layer is selected from the group consisting of Al 2 O 3 , AlN, SiN, and Si 3 N 4 ; and c) forming a third dielectric layer above the second dielectric layer, wherein the third dielectric layer comprises the same dielectric material as the first dielectric material.
Claim 3
Dependent Claim
31 words
The method of claim 1 , further comprising the step of annealing the semiconductor substrate at a temperature between approximately 400 and 900 degrees Celsius, whereby the dielectric stack is conditioned.
Claim 4
Dependent Claim
38 words
The method of claim 2 , further comprising the step of depositing an electrode layer over the dielectric stack and the step of patterning the electrode layer and underlying dielectric stack to form a desired integrated circuit structure.
Claim 5
Dependent Claim
28 words
The method of claim 1 , wherein the step of forming the first dielectric layer uses atomic layer deposition to deposit a layer of the first dielectric material.
Claim 6
Dependent Claim
28 words
The method of claim 4 , wherein the step of forming the second dielectric layer uses atomic layer deposition to deposit a layer of the second dielectric material.
Claim 7
Dependent Claim
29 words
The method of claim 1 , wherein the step of forming the first dielectric layer uses atomic layer deposition to deposit a first precursor of the first dielectric material.
Claim 8
Dependent Claim
21 words
The method of claim 6 , further comprising the step of oxidizing the first precursor to form the first dielectric material.
Claim 9
Dependent Claim
16 words
The method of claim 6 , wherein the first precursor is deposited as a self-limiting monolayer.
Claim 10
Dependent Claim
45 words
The method of claim 1 , wherein the step of forming the first dielectric layer uses sputtering of a first target for a predetermined duration and the step of forming the second dielectric layer uses pulsed sputtering of a second target for a predetermined duration.
Claim 11
Dependent Claim
22 words
The method of claim 9 , wherein the duration of sputtering the first target and the second target is controlled by shutters.
Claim 12
Dependent Claim
14 words
The method of claim 9 , wherein sputtering is performed in an oxidizing atmosphere.
Claim 13
Dependent Claim
44 words
The method of claim 1 , wherein the step of forming the first dielectric layer uses evaporation of a first target for a predetermined duration and the step of forming the second dielectric layer uses evaporation of a second target for a predetermined duration.
Claim 14
Dependent Claim
23 words
The method of claim 12 , wherein the duration of evaporation of the first target and the second target is controlled by shutters.
References Cited (Backward Citations)
US4545115A
Cited
US5508092A
Cited
US5195018A
Cited
US5646583A
Cited
US5742471A
Cited
US6015739A
Cited
US6335240B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-09-29 | 2007-03-31 | 2007-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-09-29 | 2011-03-31 | 2011-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-09-29 | 2015-03-31 | 2015-09-30 | $7700.00 | Window Closed / Lapsed |