US3840809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-destructive measurement of dielectric properties
Assignee: International Business Machines Corp
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Filing: 1972-12-04
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Granted: 1974-10-08
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Expires: 1992-12-04
Abstract
Abstract An apparatus for measuring certain properties of dielectric materials such as the net charge injected into the dielectric and the centroid of the distribution of the net charge by monitoring simultaneously the amount of charge injected into the dielectric material, from a charge injection source, and the corresponding change in the voltage required to restore the surface potential of the charge injector to its original state.
Inventors
- 👤 B Yun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:11
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/2607; G01R31/2637
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
82 words
An apparatus for determining the position of the centroid of the distribution of charges in a dielectric comprising: a source of charges means injecting said charges into the dielectric from said source, means coupled to the dielectric for measuring the amount of charges injected into the dielectric, and means coupled to the charge measuring means for converting the measured amount of charges injected into the dielectric into a measurement of the centroid of the distribution of the charges injected into the dielectric.
Claim 2
Independent Claim
82 words
An apparatus for determining the position of the centroid of the distribution of charges in a dielectric comprising: a source of charges means injecting said charges into the dielectric from said source, means coupled to the dielectric for measuring the amount of charges injected into the dielectric, and means coupled to the charge measuring means for converting the measured amount of charges injected into the dielectric into a measurement of the centroid of the distribution of the charges injected into the dielectric.
Claim 3
Dependent Claim
26 words
The apparatus of claim 1 wherein said measuring means includes means for utilizing the measured amount of injected charges to determine the capacitance of the dielectric.
Claim 4
Independent Claim
161 words
An apparatus for determining the location of the centroid of charges in a dielectric structure comprising: a dielectric structure having a first surface and a second surface, a source of charges coupled to the first surface of the structure, voltage means for applying a distinct D.C. voltage across the structure and the source of charges to cause charges to be injected into the structure from the source, charge detector means coupled to the source for measuring the amount of charge injected into the structure, capacitance measuring means coupled to the source for measuring the change in capacitance in the structure caused by the injection of said charges, means for applying a voltage corresponding to said measured change in capacitance across the structure and the source, and means coupled to said charge detector means and said applyiNg means for determining the location of the centroid of the distribution of charges in the dielectric with respect to the second surface of the dielectric.
Claim 5
Independent Claim
161 words
An apparatus for determining the location of the centroid of charges in a dielectric structure comprising: a dielectric structure having a first surface and a second surface, a source of charges coupled to the first surface of the structure, voltage means for applying a distinct D.C. voltage across the structure and the source of charges to cause charges to be injected into the structure from the source, charge detector means coupled to the source for measuring the amount of charge injected into the structure, capacitance measuring means coupled to the source for measuring the change in capacitance in the structure caused by the injection of said charges, means for applying a voltage corresponding to said measured change in capacitance across the structure and the source, and means coupled to said charge detector means and said applyiNg means for determining the location of the centroid of the distribution of charges in the dielectric with respect to the second surface of the dielectric.
Claim 6
Dependent Claim
12 words
Apparatus of claim 3 wherein said source of charges is a semiconductor.
Claim 7
Dependent Claim
21 words
The apparatus of claim 3 wherein said voltage means comprises a source of D.C. pulses and a source of A.C. signals.
Claim 8
Dependent Claim
22 words
The apparatus of claim 3 wherein said charge detector means comprises an integrating operational amplifier ohmically connected to the source of charges.
Claim 9
Dependent Claim
33 words
The apparatus of claim 6 wherein said amplifier has a capacitor coupled between its input and its output which capacitor is equal in value to the measured maximum capacitance of the dielectric structure.
Claim 10
Dependent Claim
25 words
The apparatus of claim 3 wherein said capacitance measuring means comprises a phase locking amplifier coupled to a linearizing amplifier and an integrating operational amplifier.
Claim 11
Dependent Claim
21 words
The apparatus of claim 3 wherein said applying means comprising a feedback loop between the measuring means and the voltage means.
Claim 12
Dependent Claim
150 words
The apparatus of claim 3 wherein said means for determining the location of the centroid of charges in the dielectric comprises a summing circuit having a first input coupled to the charge detector means and a second input coupled to the capacitance measuring means and an output, a first divider circuit having a first input coupled to said charge detector means and a second input coupled to the measuring means and an output, a second divider circuit having a first input coupled to the output of said summing circuit and a second input coupled to the measuring means and an output, and a multiplier having an input coupled to the output of the first divider, an input coupled to the output of the second divider and an output wherein the output of said multiplier is a determination of the centroid of the net distribution of charge in said dielectric structure.
Claim 13
Independent Claim
162 words
An apparatus for determining the location of the centroid of charges in a dielectric structure comprising: an electrode coupled to the dielectric structure, a source of charges coupled to the dielectric structure, voltage means for applying distinct superimposed voltages across the electrode, the structure and the source of charges to cause charges to be injected into the structure from the source, charge detector means coupled to the structure for measuring the amount of charge injected into the structure, capacitance measuring means coupled to the charge detector means for measuring the change in capacitance in the structure caused by the injection of said charges, said capacitance measuring means including means for applying a voltage corresponding to said measured change in capacitance to the electrode, and means coupled to said charge detector means and said capacitance measuring means for determining the location of the centroid of the distribution of charges in the dielectric with respect to the interface between the dielectric and the electrode.
Claim 14
Independent Claim
162 words
An apparatus for determining the location of the centroid of charges in a dielectric structure comprising: an electrode coupled to the dielectric structure, a source of charges coupled to the dielectric structure, voltage means for applying distinct superimposed voltages across the electrode, the structure and the source of charges to cause charges to be injected into the structure from the source, charge detector means coupled to the structure for measuring the amount of charge injected into the structure, capacitance measuring means coupled to the charge detector means for measuring the change in capacitance in the structure caused by the injection of said charges, said capacitance measuring means including means for applying a voltage corresponding to said measured change in capacitance to the electrode, and means coupled to said charge detector means and said capacitance measuring means for determining the location of the centroid of the distribution of charges in the dielectric with respect to the interface between the dielectric and the electrode.
Claim 15
Independent Claim
128 words
An apparatus for determining the thickness of each layer of a dielectric structure having at least two layers of different dielectric comprising: a source of charge coupled to said structure, voltage means for applying two distinct superimposed voltages across the structure and the source to cause charges to be injected into the structure from the source charge detector means coupled to the structure for measuring the amount of charge injected into the structure, capacitance-voltage measuring means for measuring the change in capacitance in the structure caused by the injection of said charges, feedback means for applying said measured change in capacitance to the structure as a voltage, and means coupled to said charge detector means and said feedback means for determining the thickness of each of the layers.
Claim 16
Independent Claim
128 words
An apparatus for determining the thickness of each layer of a dielectric structure having at least two layers of different dielectric comprising: a source of charge coupled to said structure, voltage means for applying two distinct superimposed voltages across the structure and the source to cause charges to be injected into the structure from the source charge detector means coupled to the structure for measuring the amount of charge injected into the structure, capacitance-voltage measuring means for measuring the change in capacitance in the structure caused by the injection of said charges, feedback means for applying said measured change in capacitance to the structure as a voltage, and means coupled to said charge detector means and said feedback means for determining the thickness of each of the layers.
Claim 17
Dependent Claim
95 words
The apparatus of claim 2 wherein said converting means includes means which electronically satisfies the equation ( Delta VFB/(- Delta qi/Co)) (1 + Sm) Td where Delta VFB is the measured change in capacitance detected by the capacitance measuring circuit - Delta qi/Co is the measured output of the charge detector after the surface of the charge injector has been restored to its original state Sm is the minimum measured slope of a plot of (-( Delta qi/Co) -Delta VFB) vs Delta VFB and Td is the thickness of the thickest dielectric in the structure.
Claim 18
Dependent Claim
52 words
The apparatus of claim 1 wherein said injecting means includes an AC signal superimposed on a pulsed DC signal applied across the dielectric to cause charges to be injected into the dielectric from said source and to measure the change in capacitance of the dielectric caused by the injection of the charges.
Claim 19
Dependent Claim
18 words
The apparatus of claim 1 wherein said measuring means includes means for determining the capacitance of the structure.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |