Patent US5596522A successfully refreshed from Google Patents.
US5596522A
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Homogeneous compositions of microcrystalline semiconductor material, semiconductor devices and directly overwritable memory elements fabricated therefrom, and arrays fabricated from the memory elements
Assignee: Ovonyx Inc
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Filing: 1995-08-02
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Granted: 1997-01-21
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Expires: 2015-08-02
Abstract
Abstract A unique class of microcrystalline semiconductor materials which can be modulated, within a crystalline phase, to assume any one of a large dynamic range of different Fermi level positions while maintaining a substantially constant band gap over the entire range, even after a modulating field has been removed. A solid state, directly overwritable, electronic and optical, non-volatile, high density, low cost, low energy, high speed, readily manufacturable, multibit single cell memory based upon the novel switching characteristics provided by said unique class of semiconductor materials, which memory exhibits orders of magnitude higher switching speeds at remarkably reduced energy levels. The novel memory of the instant invention is in turn characterized, inter alia, by numerous stable and non-volatile detectable configurations of local atomic order, which configurations can be selectively and repeatably accessed by input signals of varying levels.
Inventors
- 👤 Stanford R. Ovshinsky
- 👤 Stephen J. Hudgens
- 👤 David Strand
- 👤 Wolodymyr Czubatyj
- 👤 Jesus Gonzalez-Hernandez
- 👤 Hellmut Fritzsche
- 👤 Quiyi Ye
- 👤 Sergey A. Kostylev
- 👤 Benjamin S. Chao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:51
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/56; C; C01; C01B; C01B19/00; C01B19/007; G11C11/5678; G11C13/00; G11C13/0002; G11C13/0004; H; H10; H10B; H10B63/00; H10B63/20; H10B63/80; H10N; H10N70/00; H10N70/20; H10N70/231; H10N70/235; H10N70/801; H10N70/821; H10N70/826; H10N70/841; H10N70/881; H10N70/882; H10N70/8828; G11C13/04; G11C2213/00; G11C2213/70; G11C2213/72
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
143 words
A method of modulating the position of the Fermi level relative to a band edge in a microcrystalline semiconductor material into any one of a plurality of metastable detectable positions; said material characterized by a large dynamic range of substantially different electrical conductivities with a substantially constant optical band gap over said entire range; said method including the steps of: providing a homogeneous body of chalcogenide alloy material; applying a pulse to said material to modulate the position of the Fermi level thereof to a selected position relative to a band edge of the semiconductor material so as to obtain a given conductivity value within the large dynamic range of electrical conductivities; and terminating the application of the programming pulse to said memory material while maintaining the position of the Fermi level thereof at substantially the selected position to which it was modulated.
Claim 2
Independent Claim
143 words
A method of modulating the position of the Fermi level relative to a band edge in a microcrystalline semiconductor material into any one of a plurality of metastable detectable positions; said material characterized by a large dynamic range of substantially different electrical conductivities with a substantially constant optical band gap over said entire range; said method including the steps of: providing a homogeneous body of chalcogenide alloy material; applying a pulse to said material to modulate the position of the Fermi level thereof to a selected position relative to a band edge of the semiconductor material so as to obtain a given conductivity value within the large dynamic range of electrical conductivities; and terminating the application of the programming pulse to said memory material while maintaining the position of the Fermi level thereof at substantially the selected position to which it was modulated.
Claim 3
Dependent Claim
40 words
The method of claim 1 including the further step of forming said semiconductor material of a material selected from the group consisting of Se, Te, Ge, Sb, Bi, Pb, Sn, As, S, Si, P, O and mixtures or alloys thereof.
Claim 4
Dependent Claim
50 words
The method of claim 2 including the further step of forming said semiconductor material of a material including Te, Ge and Sb in the ratio Te a Ge b Sb 100- (a+b) where the subscripts are in atomic percentages which total 100% of the constituent elements and a≦70 and 5≦b≦50.
Claim 5
Dependent Claim
9 words
The method of claim 3 wherein 48≦a≦58 and 8≦b≦40.
Claim 6
Dependent Claim
30 words
The method of claim 1 wherein the modulation of the Fermi level position of the semiconductor material results in a modulation of the electrical and optical properties of said material.
Claim 7
Dependent Claim
30 words
The method of claim 4 wherein said modulation of the electrical and optical properties of the material are observed as changes in the resistance and reflectance of the material, respectively.
Claim 8
Dependent Claim
24 words
The method of claim 6 wherein the range of electrical conductivities of the material provides for a dynamic range of resistance and reflectance values.
Claim 9
Dependent Claim
33 words
The method of claim 7 wherein said material can be modulated to any resistance or reflectance value within said dynamic range by the input of at least one pulse of a selected energy.
Claim 10
Dependent Claim
17 words
The method of claim 8 wherein said at least one pulse is of selected power and duration.
Claim 11
Dependent Claim
61 words
The method of claim 1 including the further step of repeating the application/termination of the energy pulse to modulate the semiconductor material to the same or a different electrical conductivity within said range, wherein the material is characterized by the ability to be modulated to any electrical conductivity within the range regardless of the conductivity to which it was previously modulated.
Claim 12
Independent Claim
188 words
A method of modulating the electrical conductivity of a multielement composition of microcrystalline semiconductor material, the constituent elements of which are intercoupled to define the lattice structure of the crystallites of the material; and said modulation accomplished by varying the concentration of free charge contributed by the atoms of at least one of said constituent elements of said multielement composition, said method including the steps of: providing a composition of microcrystalline semiconductor material which includes a volume fraction of crystallites, said crystallites defined by a lattice structure which incorporates atoms of each of the constituent elements in said composition; applying an electrical signal to said material so as to add or subtract charge carriers contributed by said one of the constituent elements in said composition, whereby the electrical conductivity of the material is modulated to a new value which is dependent upon the concentration of free charge contributed by said one constituent element; and maintaining the concentration of free charge determined by the applied signal, and the new value of electrical conductivity of the material remaining constant even after terminating the application of said signal to said material.
Claim 13
Independent Claim
188 words
A method of modulating the electrical conductivity of a multielement composition of microcrystalline semiconductor material, the constituent elements of which are intercoupled to define the lattice structure of the crystallites of the material; and said modulation accomplished by varying the concentration of free charge contributed by the atoms of at least one of said constituent elements of said multielement composition, said method including the steps of: providing a composition of microcrystalline semiconductor material which includes a volume fraction of crystallites, said crystallites defined by a lattice structure which incorporates atoms of each of the constituent elements in said composition; applying an electrical signal to said material so as to add or subtract charge carriers contributed by said one of the constituent elements in said composition, whereby the electrical conductivity of the material is modulated to a new value which is dependent upon the concentration of free charge contributed by said one constituent element; and maintaining the concentration of free charge determined by the applied signal, and the new value of electrical conductivity of the material remaining constant even after terminating the application of said signal to said material.
Claim 14
Dependent Claim
23 words
The method of claim 11 including the further step of forming the semiconductor material of a composition including at least one chalcogenide element.
Claim 15
Dependent Claim
16 words
The method of claim 12 wherein said composition including at least one chalcogenide element is homogenous.
Claim 16
Dependent Claim
40 words
The method of claim 11 including the further step of forming said semiconductor material of a material selected from the group consisting of Se, Te, Ge, Sb, Bi, Pb, Sn, As, S, Si, P, O and mixtures or alloys thereof.
Claim 17
Dependent Claim
50 words
The method of claim 14 including the further step of forming said semiconductor material of a material including Te, Ge and Sb in the ratio Te a Ge b Sb 100- (a+b) where the subscripts are in atomic percentages which total 100% of the constituent elements and a≦70 and 5≦b≦50.
Claim 18
Dependent Claim
9 words
The method of claim 15 wherein 48≦a≦58 and 8≦b≦40.
Claim 19
Dependent Claim
23 words
The method of claim 11 including the further step of providing said applied signal in the form of at least one electrical pulse.
Claim 20
Dependent Claim
36 words
The method of claim 17 wherein at least one of the constituent elements is a chalcogenide and said modulation of free charge carrier concentration is accomplished by modulating the lattice interactions of the lone pair electrons.
Claim 21
Dependent Claim
36 words
The method of claim 11 wherein at least one of the constituent elements is a chalcogenide and said modulation of free charge carrier concentration is accomplished by modulating the lattice interactions of the lone pair electrons.
Claim 22
Dependent Claim
52 words
The method of claim 11 including the further step of repeating the application/termination of said signal to modulate the semiconductor material to the same or a different conductivity, wherein the material is characterized by the ability to be modulated to a conductivity regardless of the conductivity to which it was previously modulated.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2000-01-21 | 2000-07-22 | 2001-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-21 | 2004-07-22 | 2005-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-21 | 2008-07-22 | 2009-01-21 | $7700.00 | Window Closed / Lapsed |