Patent US5468974A successfully refreshed from Google Patents.
US5468974A
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Control and modification of dopant distribution and activation in polysilicon
Assignee: LSI Corp
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Filing: 1994-05-26
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Granted: 1995-11-21
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Expires: 2014-05-26
Abstract
Abstract Dopant distribution and activation in polysilicon is controlled by implanting electrically neutral atomic species which accumulate along polysilicon grain boundaries. Exemplary atomic species include noble gases and Group IV elements other than silicon.
Inventors
- 👤 Sheldon Aronowitz
- 👤 Yen-Hui J. Ku
- 👤 Yu-Lam Ho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:26
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10D; H10D62/00; H10D62/50; H10D62/53; H10P30/208; H10P30/225; Y; Y10; Y10S; Y10S257/00; Y10S257/905; Y10S438/00; Y10S438/934
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
74 words
A process for controlling dopant distribution and activation in polysilicon which comprises: implanting into polysilicon a dopant and an atomic species which is electrically neutral in said polysilicon and is capable of interacting with said dopant, said atomic species being characterized by accumulating along grain boundaries and being capable of blocking diffusion of said dopant along said grain boundaries of said polysilicon; and annealing the resulting polysilicon containing said dopant and said atomic species.
Claim 2
Dependent Claim
74 words
A process for controlling dopant distribution and activation in polysilicon which comprises: implanting into polysilicon a dopant and an atomic species which is electrically neutral in said polysilicon and is capable of interacting with said dopant, said atomic species being characterized by accumulating along grain boundaries and being capable of blocking diffusion of said dopant along said grain boundaries of said polysilicon; and annealing the resulting polysilicon containing said dopant and said atomic species.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein said atomic species is further characterized as being incapable of entering into substitutional sites in a silicon crystal lattice.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein said atomic species is a noble gas.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein said noble gas is capable of forming a complex with said dopant.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein said noble gas is argon.
Claim 7
Dependent Claim
17 words
The process of claim 3 wherein atoms of said noble gas are capable of repelling said dopant.
Claim 8
Dependent Claim
11 words
The process of claim 6 wherein said noble gas is neon.
Claim 9
Dependent Claim
25 words
The process of claim 1 wherein said atomic species is implanted into polysilicon at a dose which is effective to amorphize regions of said polysilicon.
Claim 10
Dependent Claim
26 words
The process of claim 8 wherein said atomic species is a noble gas and said dose is at least about 1×10 15 atoms per square centimeter.
Claim 11
Dependent Claim
25 words
The process of claim 1 wherein said atomic species is further characterized as being capable of entering into substitutional sites in a silicon crystal lattice.
Claim 12
Dependent Claim
17 words
The process of claim 1 wherein said atomic species is a Group IV element other than silicon.
Claim 13
Dependent Claim
12 words
The process of claim 11 wherein said Group IV element is germanium.
Claim 14
Dependent Claim
27 words
The process of claim 8 wherein said atomic species is a Group IV element and said dose is at least about 1×10 14 atoms per square centimeter.
Claim 15
Dependent Claim
69 words
A process for controlling the distribution and activation of dopant in a polysilicon layer which comprises: ion implanting boron into said polysilicon layer, ion implanting a predetermined dose of neon into the boron-containing polysilicon layer; and annealing said boron- and neon-containing polysilicon layer, thereby providing a boron doped polysilicon layer having a predetermined boron concentration profile wherein boron distribution to the bottom of said polysilicon layer has been enhanced.
Claim 16
Dependent Claim
69 words
A process for controlling the distribution and activation of dopant in a polysilicon layer which comprises: ion implanting boron into said polysilicon layer, ion implanting a predetermined dose of neon into the boron-containing polysilicon layer; and annealing said boron- and neon-containing polysilicon layer, thereby providing a boron doped polysilicon layer having a predetermined boron concentration profile wherein boron distribution to the bottom of said polysilicon layer has been enhanced.
Claim 17
Dependent Claim
60 words
The process of claim 14 wherein said boron is implanted at a dose of about 2×10 15 BF 2 + /cm 2 at 90 keV, said neon is implanted at a dose of about 1×10 15 Ne + /cm 2 at about 20 keV, and said annealing step is performed in nitrogen at about 875° C. for about 30 minutes.
Claim 18
Dependent Claim
68 words
A process for controlling the distribution and activation of dopant in a polysilicon layer which comprises: ion implanting a predetermined dose of argon into said polysilicon layer, ion implanting boron into said polysilicon layer, and annealing said boron- and argon-containing polysilicon layer, whereby providing a boron doped polysilicon layer having a predetermined boron concentration profile wherein boron distribution to the bottom of said polysilicon layer has been retarded.
Claim 19
Dependent Claim
68 words
A process for controlling the distribution and activation of dopant in a polysilicon layer which comprises: ion implanting a predetermined dose of argon into said polysilicon layer, ion implanting boron into said polysilicon layer, and annealing said boron- and argon-containing polysilicon layer, whereby providing a boron doped polysilicon layer having a predetermined boron concentration profile wherein boron distribution to the bottom of said polysilicon layer has been retarded.
Claim 20
Dependent Claim
60 words
The process of claim 16 wherein said argon is implanted at a dose of about 1×10 15 Ar + /cm 2 at about 100 keV, said boron is implanted at a dose of about 2×10 15 BF 2 + /cm 2 at about 90 keV, and said annealing step is performed in nitrogen at about 875° for about 30 minutes.
Claim 21
Dependent Claim
68 words
The process of claim 16 wherein said argon is implanted at a dose of about 1×10 15 Ar + /cm 2 to 2×10 15 Ar + /cm 2 at about 60 keV, said boron is implanted at a dose of about 2×10 15 BF 2 + /cm 2 at about 50 keV, and said annealing step is performed in nitrogen at about 850° C. for about 30 minutes.
Claim 22
Dependent Claim
76 words
A semiconductor structure having predetermined dopant distribution which comprises: a polysilicon layer containing dopant species and an atomic species which is electrically neutral in said polysilicon and is capable of interaction with said dopant species, said atomic species being accumulated along grain boundaries and blocking diffusion of dopant along said grain boundaries of said polysilicon layer, said atomic species being present in a predetermined concentration such that interaction with dopant species provides a predetermined distribution profile.
Claim 23
Dependent Claim
76 words
A semiconductor structure having predetermined dopant distribution which comprises: a polysilicon layer containing dopant species and an atomic species which is electrically neutral in said polysilicon and is capable of interaction with said dopant species, said atomic species being accumulated along grain boundaries and blocking diffusion of dopant along said grain boundaries of said polysilicon layer, said atomic species being present in a predetermined concentration such that interaction with dopant species provides a predetermined distribution profile.
Claim 24
Dependent Claim
22 words
The semiconductor structure of claim 19 wherein said atomic species is incapable of entering into substitutional sites in a silicon crystal lattice.
Claim 25
Dependent Claim
14 words
The semiconductor structure of claim 19 wherein said atomic species is a noble gas.
Claim 26
Dependent Claim
12 words
The semiconductor structure of claim 21 wherein said noble gas is argon.
Claim 27
Dependent Claim
12 words
The semiconductor structure of claim 21 wherein said noble gas is neon.
Claim 28
Dependent Claim
22 words
The semiconductor structure of claim 19 wherein said atomic species is capable of entering into substitutional sites in a silicon crystal lattice.
Claim 29
Dependent Claim
18 words
The semiconductor structure of claim 19 wherein said atomic species is a Group IV element other than silicon.
Claim 30
Dependent Claim
13 words
The semiconductor structure of claim 25 wherein said Group IV element is germanium.
Claim 31
Dependent Claim
16 words
A semiconductor structure which comprises a polysilicon layer prepared according to the process of claim 1.
Claim 32
Dependent Claim
16 words
A semiconductor structure which comprises a polysilicon layer prepared according to the process of claim 14.
Claim 33
Dependent Claim
16 words
A semiconductor structure which comprises a polysilicon layer prepared according to the process of claim 16.
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