US5629223A
Expired / Lapsed
US
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Method to prepare hemi-spherical grain (HSG) silicon using a fluorine based gas mixture and high vacuum anneal
Assignee: Round Rock Research LLC
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Filing: 1994-11-15
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Granted: 1997-05-13
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Expires: 2014-11-15
Abstract
Abstract The present invention develops a process for forming hemi-spherical grained silicon storage capacitor plates by the steps of: forming a silicon layer over a pair of neighboring parallel conductive lines, the silicon layer making contact to an underlying conductive region; patterning the silicon layer to form individual silicon capacitor plates; exposing the silicon capacitor plates to a fluorine based gas mixture during an high vacuum annealing period, thereby transforming the silicon capacitor plates into the semi-spherical grained silicon capacitor plates; conductively doping the hemi-spherical grained silicon capacitor plates; forming a capacitor dielectric layer adjacent and coextensive the semi-spherical grained silicon capacitor plates; and forming a second conductive silicon layer superjacent and coextensive the capacitor dielectric layer.
Inventors
- 👤 Randhir P. S. Thakur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:37
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/712; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10D1/716; Y; Y10; Y10S; Y10S438/00; Y10S438/909; Y10S438/964
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
71 words
A process for forming hemi-spherical grained silicon comprising the steps of: forming an amorphous silicon layer; and exposing an amorphous silicon layer to a fluorine based gas mixture during an annealing period, thereby transforming said amorphous silicon layer into said hemi-spherical grained silicon, said fluorine based gas mixture is a gas selected from the group consisting of NF 3 , CF 4 , and C 2 F 4 Cl 2 .
Claim 2
Dependent Claim
71 words
A process for forming hemi-spherical grained silicon comprising the steps of: forming an amorphous silicon layer; and exposing an amorphous silicon layer to a fluorine based gas mixture during an annealing period, thereby transforming said amorphous silicon layer into said hemi-spherical grained silicon, said fluorine based gas mixture is a gas selected from the group consisting of NF 3 , CF 4 , and C 2 F 4 Cl 2 .
Claim 3
Dependent Claim
18 words
The process as recited in claim 1 further comprising the step of conductively doping said hemi-spherical grained silicon.
Claim 4
Dependent Claim
16 words
The process as recited in claim 1, wherein said amorphous silicon is replaced with polycrystalline silicon.
Claim 5
Dependent Claim
19 words
The process as recited in claim 1, wherein said fluorine based gas mixture is diluted with an inert gas.
Claim 6
Dependent Claim
25 words
The process as recited in claim 4, wherein said inert gas is a gas selected from at least one of Ar and N 2 .
Claim 7
Dependent Claim
31 words
The process as recited in claim 1 wherein said annealing period is performed at a temperature of at least 450° C. and at a pressure of 1×10 -3 Torr and less.
Claim 8
Dependent Claim
26 words
The process as recited in claim 1, wherein said temperature is held at a constant temperature of approximately 600° C. during the entire said annealing period.
Claim 9
Dependent Claim
22 words
The process as recited in claim 1, wherein said temperature is ramped up to at least 450° C. during the annealing period.
Claim 10
Dependent Claim
25 words
The process as recited in claim 1, wherein said temperature is ramped up from approximately 560° C. to approximately 620° C. during the annealing period.
Claim 11
Dependent Claim
27 words
The process as recited in claim 1 further comprising the additional step of patterning said amorphous silicon layer after the step of forming said amorphous silicon layer.
Claim 12
Dependent Claim
17 words
The process as recited in claim 1, wherein said process comprises rapid thermal processing chemical vapor deposition.
Claim 13
Dependent Claim
16 words
The process as recited in claim 1, wherein said process comprises low pressure chemical vapor deposition.
Claim 14
Dependent Claim
14 words
The process as recited in claim 1, wherein said process comprises molecular beam epitaxy.
Claim 15
Dependent Claim
109 words
A process for forming hemi-spherical grained silicon capacitor plates, said process comprising the steps of: forming an amorphous silicon layer over a pair of neighboring parallel conductive lines, said amorphous silicon layer making contact to an underlying conductive region; patterning said amorphous silicon layer to form individual silicon capacitor plates; and exposing said silicon capacitor plates to a fluorine based gas mixture during an annealing period, thereby transforming said silicon capacitor plates into said hemi-spherical grained silicon capacitor plates, wherein said fluorine based gas mixture is a gas mixture selected from the group consisting of NF 3 , CF 4 , and C 2 F 4 Cl 2 .
Claim 16
Dependent Claim
109 words
A process for forming hemi-spherical grained silicon capacitor plates, said process comprising the steps of: forming an amorphous silicon layer over a pair of neighboring parallel conductive lines, said amorphous silicon layer making contact to an underlying conductive region; patterning said amorphous silicon layer to form individual silicon capacitor plates; and exposing said silicon capacitor plates to a fluorine based gas mixture during an annealing period, thereby transforming said silicon capacitor plates into said hemi-spherical grained silicon capacitor plates, wherein said fluorine based gas mixture is a gas mixture selected from the group consisting of NF 3 , CF 4 , and C 2 F 4 Cl 2 .
Claim 17
Dependent Claim
20 words
The process as recited in claim 14 further comprising the step of conductively doping said hemi-spherical grained silicon capacitor plates.
Claim 18
Dependent Claim
16 words
The process as recited in claim 14, wherein said amorphous silicon is replaced with polycrystalline silicon.
Claim 19
Dependent Claim
25 words
The process as recited in claim 14, wherein said silicon comprises deposited hemi-spherical grain silicon which is further etched thereby increasing the capacitor plate area.
Claim 20
Dependent Claim
28 words
The process as recited in claim 17, wherein said etching is performed separately using an etch chemical selected from the group comprising hydrofluoric acid (HF) and hydrobromic (HBr).
Claim 21
Dependent Claim
19 words
The process as recited in claim 14, wherein said fluorine based gas mixture is diluted with an inert gas.
Claim 22
Dependent Claim
25 words
The process as recited in claim 19, wherein said inert gas is a gas selected from at least one of Ar and N 2 .
Claim 23
Dependent Claim
33 words
The process as recited in claim 14, wherein said annealing period is performed at a temperature of at least 450° C. and at a pressure of 1×10 -3 Torr to 1×10 -10 Torr.
Claim 24
Dependent Claim
17 words
The process as recited in claim 14, wherein said process comprises rapid thermal processing chemical vapor deposition.
Claim 25
Dependent Claim
16 words
The process as recited in claim 14, wherein said process comprises low pressure chemical vapor deposition.
Claim 26
Dependent Claim
14 words
The process as recited in claim 14, wherein said process comprises molecular beam epitaxy.
Claim 27
Dependent Claim
26 words
The process as recited in claim 14, wherein said temperature is held at a constant temperature of approximately 450° C. during the entire said annealing period.
Claim 28
Dependent Claim
21 words
The process as recited in claim 14, wherein said temperature is ramped up to approximately 450° C. during the annealing period.
Claim 29
Dependent Claim
25 words
The process as recited in claim 14, wherein said temperature is ramped up from approximately 560° C. to approximately 620° C. during the annealing period.
Claim 30
Dependent Claim
146 words
A process for forming hemi-spherical grained silicon storage capacitor plates, said process comprising the steps of: forming an amorphous silicon layer over a pair of neighboring parallel conductive lines, said amorphous silicon layer making contact to an underlying conductive region; patterning said amorphous silicon layer to form individual silicon capacitor plates; exposing said silicon capacitor plates to a fluorine based gas mixture during an high vacuum annealing period, thereby transforming said silicon capacitor plates into said hemi-spherical grained silicon capacitor plates, said fluorine based gas mixture is a gas mixture selected from the group consisting of NF 3 , CF 4 , and C 2 F 4 Cl 2 ; conductively doping said hemi-spherical grained silicon capacitor plates; forming a capacitor dielectric layer adjacent and coextensive said hemi-spherical grained silicon capacitor plates; and forming a second conductive silicon layer superjacent and coextensive said capacitor dielectric layer.
Claim 31
Dependent Claim
146 words
A process for forming hemi-spherical grained silicon storage capacitor plates, said process comprising the steps of: forming an amorphous silicon layer over a pair of neighboring parallel conductive lines, said amorphous silicon layer making contact to an underlying conductive region; patterning said amorphous silicon layer to form individual silicon capacitor plates; exposing said silicon capacitor plates to a fluorine based gas mixture during an high vacuum annealing period, thereby transforming said silicon capacitor plates into said hemi-spherical grained silicon capacitor plates, said fluorine based gas mixture is a gas mixture selected from the group consisting of NF 3 , CF 4 , and C 2 F 4 Cl 2 ; conductively doping said hemi-spherical grained silicon capacitor plates; forming a capacitor dielectric layer adjacent and coextensive said hemi-spherical grained silicon capacitor plates; and forming a second conductive silicon layer superjacent and coextensive said capacitor dielectric layer.
Claim 32
Dependent Claim
16 words
The process as recited in claim 28, wherein said amorphous silicon is replaced with polycrystalline silicon.
Claim 33
Dependent Claim
19 words
The process as recited in claim 28, wherein said fluorine based gas mixture is diluted with an inert gas.
Claim 34
Dependent Claim
25 words
The process as recited in claim 30, wherein said inert gas is a gas selected from at least one of Ar and N 2 .
Claim 35
Dependent Claim
33 words
The process as recited in claim 28, wherein said annealing period is performed at a temperature of at least 450° C. and at a pressure of 1×10 -3 Torr to 1×10 -10 Torr.
Claim 36
Dependent Claim
26 words
The process as recited in claim 28, wherein said temperature is held at a constant temperature of approximately 450° C. during the entire said annealing period.
Claim 37
Dependent Claim
21 words
The process as recited in claim 28, wherein said temperature is ramped up to approximately 450° C. during the annealing period.
Claim 38
Dependent Claim
25 words
The process as recited in claim 28, wherein said temperature is ramped up from approximately 560° C. to approximately 620° C. during the annealing period.
Claim 39
Dependent Claim
16 words
The process as recited in claim 28, wherein said second conductive layer comprises conductively doped silicon.
Claim 40
Dependent Claim
17 words
The process as recited in claim 28, wherein said process comprises rapid thermal processing chemical vapor deposition.
Claim 41
Dependent Claim
16 words
The process as recited in claim 28, wherein said process comprises low pressure chemical vapor deposition.
Claim 42
Dependent Claim
14 words
The process as recited in claim 28, wherein said process comprises molecular beam epitaxy.
References Cited (Backward Citations)
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