US6573197B2
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Thermally stable poly-Si/high dielectric constant material interfaces
Assignee: GlobalFoundries US Inc
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Filing: 2001-04-12
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Granted: 2003-06-03
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Expires: 2021-04-12
Abstract
Abstract The present invention provides a method of fabricating a thermally stable polysilicon/high-k dielectric film stack utilizing a deposition method wherein Si-containing precursor gas which includes silicon and hydrogen is diluted with an inert gas such as He so as to significantly reduce the hydrogen content in the resultant polysilicon film. Semiconductor structures such as field effect transistors (FETs) and capacitors which include at least the thermally stable polysilicon/high-k dielectric film stack are also provided herein.
Inventors
- 👤 Alessandro C. Callegari
- 👤 Evgeni Gousev
- 👤 Michael A. Gribelyuk
- 👤 Paul C. Jamison
- 👤 Dianne L. Lacey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:23
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6502; H10P14/6506; C; C23; C23C; C23C16/00; C23C16/22; C23C16/24; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0113; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01332; H10D64/01336; H10D64/01342; H10D64/01344; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/691; H10D64/693; H10P14/40; H10P14/42; H10P14/43; H10P14/69; H10P14/692; H10P14/6938; H10P14/69398; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6316; H10P14/6318; H10P14/6319; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/6339; H10P14/6921; H10P14/69215; H10P14/6922; H10P14/6927; H10P14/6939; H10P14/69392; H10P14/69393; H10P14/69394; H10P14/69395; H10P14/694; H10P14/6943; H10P14/69433
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
120 words
A method of forming a polysilicon layer on an exposed surface of a high-k dielectric material, said method comprising the steps of: (a) heating a semiconductor structure containing an exposed surface of high-k dielectric material to a temperature of from about 350° to about 700° C. inside a deposition reactor chamber, said high-k dielectric material having a dielectric constant, k, of greater than 8; and (b) depositing a layer of polysilicon on said exposed surface of said high-k dielectric material, wherein said depositing is performed in said reactor chamber using a Si-containing precursor gas which is diluted with an inert gas whereby said layer of polysilicon contains a lower hydrogen content than that obtained from an undiluted Si-containing precursor gas.
Claim 2
Independent Claim
120 words
A method of forming a polysilicon layer on an exposed surface of a high-k dielectric material, said method comprising the steps of: (a) heating a semiconductor structure containing an exposed surface of high-k dielectric material to a temperature of from about 350° to about 700° C. inside a deposition reactor chamber, said high-k dielectric material having a dielectric constant, k, of greater than 8; and (b) depositing a layer of polysilicon on said exposed surface of said high-k dielectric material, wherein said depositing is performed in said reactor chamber using a Si-containing precursor gas which is diluted with an inert gas whereby said layer of polysilicon contains a lower hydrogen content than that obtained from an undiluted Si-containing precursor gas.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said semiconductor structure comprises at least a semiconductor substrate.
Claim 4
Dependent Claim
31 words
The method of claim 2 further comprising forming an interfacial layer on said substrate prior to formation of said high-k dielectric and thereafter forming said high-k dielectric on said interfacial layer.
Claim 5
Dependent Claim
21 words
The method of claim 3 wherein said interfacial layer comprises an oxide, a nitride, an oxynitride, or mixtures and multilayers thereof.
Claim 6
Dependent Claim
33 words
The method of claim 3 wherein said interfacial layer is formed by rapid thermal oxidation (RTO), nitridation (RTN), oxynitridation (RTON), remote or direct plasma oxidation (RO), wet chemical oxidation or any combination thereof.
Claim 7
Dependent Claim
18 words
The method of claim 3 wherein said interfacial layer has a thickness of less than about 10 Å.
Claim 8
Dependent Claim
20 words
The method of claim 6 wherein said interfacial layer has a thickness of from about 2 to about 8 ⊂.
Claim 9
Dependent Claim
26 words
The method of claim 1 wherein said deposition reactor chamber is a chemical vapor deposition reactor chamber or a plasma enhanced chemical vapor deposition reactor chamber.
Claim 10
Dependent Claim
22 words
The method of claim 1 wherein said heating step is performed at a temperature of from about 500° to about 600° C.
Claim 11
Dependent Claim
24 words
The method of claim 1 wherein said depositing step is performed at a base pressure of from about 2 mtorr to about 10 torr.
Claim 12
Dependent Claim
16 words
The method of claim 1 with said hydrogen content is less than about 50 atomic percent.
Claim 13
Dependent Claim
46 words
The method of claim 1 wherein said Si-containing precursor gas is a Si-containing compound or mixtures thereof having the formula H 4−x SiR x wherein R is alkyl, alkene, alkynyl, alkoxy, halide, amine, aryl, cycloalkene or mixtures thereof, and x is 0, 1, 2 or 3.
Claim 14
Dependent Claim
19 words
The method of claim 12 wherein said Si-containing precursor gas comprises silane, disilane, dimethylsilane, diethylsilane, dichlorosilane or mixtures thereof.
Claim 15
Dependent Claim
12 words
The method of claim 13 wherein said Si-containing precursor gas is silane.
Claim 16
Dependent Claim
15 words
The method of claim 1 wherein said Si-containing precursor gas further includes a doping agent.
Claim 17
Dependent Claim
15 words
The method of claim 15 wherein said doping agent is B, As, Sb or P.
Claim 18
Dependent Claim
20 words
The method of claim 1 wherein said inert gas comprises He, Ar, Ne, Xe, Kr, N 2 or mixtures thereof.
Claim 19
Dependent Claim
11 words
The method of claim 17 wherein said inert gas comprises He.
Claim 20
Dependent Claim
34 words
The method of claim 1 further comprising annealing said semiconductor structure at a temperature of from about 800° to about 1050° C. for a time period of from about 1 to about 30 seconds.
Claim 21
Dependent Claim
33 words
The method of claim 19 wherein said annealing is performed at a temperature of from about 950° to about 1005° C. for a time period of from about 5 to about 10 seconds.
Claim 22
Dependent Claim
74 words
A semiconductor structure comprising: a semiconductor substrate having an upper surface; a layer of high-k dielectric material located on said upper surface, said high-k dielectric material having a dielectric constant, k, of greater than 8; and a layer of polysilicon having a hydrogen content of less than about 50 atomic percent located on said layer of high-k dielectric material, wherein an interface exists between said high-k dielectric material and said polysilicon that is uniform.
Claim 23
Dependent Claim
74 words
A semiconductor structure comprising: a semiconductor substrate having an upper surface; a layer of high-k dielectric material located on said upper surface, said high-k dielectric material having a dielectric constant, k, of greater than 8; and a layer of polysilicon having a hydrogen content of less than about 50 atomic percent located on said layer of high-k dielectric material, wherein an interface exists between said high-k dielectric material and said polysilicon that is uniform.
Claim 24
Dependent Claim
21 words
The semiconductor structure of claim 21 wherein said semiconductor substrate comprises diffusion regions which are electrically connected through a channel region.
Claim 25
Dependent Claim
31 words
The semiconductor structure of claim 21 wherein said semiconductor substrate comprises a semiconducting material selected from the group consisting of Si, Ge, SiGe, GaP, InAs, InP, Si/SiGe and Si/SiO 2 /Si.
Claim 26
Dependent Claim
25 words
The semiconductor structure of claim 21 wherein an optional interfacial layer is formed on said semiconductor substrate prior to formation of said high-k dielectric material.
Claim 27
Dependent Claim
22 words
The semiconductor structure of claim 24 wherein said interfacial layer comprises an oxide, a nitride, an oxynitride, or mixtures and multilayers thereof.
Claim 28
Dependent Claim
19 words
The semiconductor structure of claim 24 wherein said interfacial layer has a thickness of less than about 10 Å.
Claim 29
Dependent Claim
21 words
The semiconductor structure of claim 26 wherein said interfacial layer has a thickness of from about 2 to about 8 Å.
Claim 30
Dependent Claim
30 words
The semiconductor structure of claim 21 wherein said high-k dielectric material comprises a binary metal oxide, silicates and aluminates of a binary metal oxide, a perovskite-type oxide and multilayers thereof.
Claim 31
Dependent Claim
40 words
The semiconductor structure of claim 28 wherein said high-k dielectric is a binary metal oxide selected from the group consisting of ZrO 2 , TiO 2 , Ta 2 O 5 , HfO 2 and Al 2 O 3 .
Claim 32
Dependent Claim
13 words
The semiconductor structure of claim 21 wherein said high-k dielectric is ZrO 2.
Claim 33
Dependent Claim
15 words
The semiconductor structure of claim 21 wherein said polysilicon is patterned to provide a capacitor.
Claim 34
Dependent Claim
22 words
The semiconductor structure of claim 21 wherein said polysilicon and said high-k dielectric material are patterned to provide a field effect transistor.
Claim 35
Dependent Claim
15 words
The semiconductor structure of claim 21 wherein said polysilicon is doped with a doping agent.
Claim 36
Dependent Claim
16 words
The semiconductor structure of claim 33 wherein said doping agent is B, As, Sb, or P.
Claim 37
Dependent Claim
11 words
The semiconductor structure of claim 21 wherein said interface is continuous.
Claim 38
Dependent Claim
22 words
The semiconductor structure of claim 21 wherein said interface is substantially planar and has the contour of the underlying high-k dielectric material.
Claim 39
Dependent Claim
98 words
A field effect transistor comprising: a semiconductor substrate having an upper surface; a source and drain region located in said upper surface of said substrate; a channel region positioned between said source and drain regions; a layer of high-k dielectric material located on said upper surface, said high-k dielectric material having a dielectric constant, k, of greater than 8; and a layer of polysilicon having a hydrogen content of less than about 50 atomic percent located on said layer of high-k dielectric material, wherein an interface exists between said high-k dielectric material and said polysilicon that is uniform.
Claim 40
Dependent Claim
98 words
A field effect transistor comprising: a semiconductor substrate having an upper surface; a source and drain region located in said upper surface of said substrate; a channel region positioned between said source and drain regions; a layer of high-k dielectric material located on said upper surface, said high-k dielectric material having a dielectric constant, k, of greater than 8; and a layer of polysilicon having a hydrogen content of less than about 50 atomic percent located on said layer of high-k dielectric material, wherein an interface exists between said high-k dielectric material and said polysilicon that is uniform.
Claim 41
Dependent Claim
12 words
The field effect transistor of claim 37 wherein said interface is continuous.
Claim 42
Dependent Claim
23 words
The field effect transistor of claim 37 wherein said interface is substantially planar and has the contour of the underlying high-k dielectric material.
References Cited (Backward Citations)
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