Patent US5377071A successfully refreshed from Google Patents.
US5377071A
Expired / Lapsed
US
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Sensor apparatus and method for real-time in-situ measurements of sheet resistance and its uniformity pattern in semiconductor processing equipment
Assignee: Texas Instruments Inc
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Filing: 1992-09-25
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Granted: 1994-12-27
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Expires: 2012-09-25
Abstract
Abstract A system 20 for measuring the sheet resistance of a conductive layer on the top surface of a semiconductor wafer 22 is disclosed herein. In one embodiment, the system includes a chuck 30 electrically coupled to the backside surface of the wafer 22. The chuck 30 is capable of supporting the wafer 22 electrostatically. A signal source 40 provides an excitation signal to the wafer 22 and circuitry for monitoring an induced signal is provided. The sheet resistance on the top surface of the wafer 22 is determined from the measurements of the excitation and induced electrical signals. Other systems and methods are also disclosed.
Inventors
- 👤 Mehrdad M. Moslehi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:48
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/72; H10P72/722; C; C23; C23C; C23C16/00; C23C16/44; C23C16/458; C23C16/4582; C23C16/4583; C23C16/52; H10P74/00; H10P74/20; H10P74/207; Y; Y10; Y10T; Y10T279/00; Y10T279/23; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
104 words
A sheet resistance sensor comprising: a main chuck body for supporting a semiconductor wafer, said semiconductor wafer having a frontside and a backside opposite said frontside; at least two sensor electrodes formed in a surface of said main chuck body, said electrodes insulated from each other and from said main chuck body and said sensor electrodes electrically coupled to said backside of said wafer, and wherein no sensor electrode is coupled to the frontside of said semiconductor wafer; and circuitry connected to said sensor electrodes for sending and receiving an AC electrical signal to probe a sheet resistance of said frontside of said wafer.
Claim 2
Dependent Claim
104 words
A sheet resistance sensor comprising: a main chuck body for supporting a semiconductor wafer, said semiconductor wafer having a frontside and a backside opposite said frontside; at least two sensor electrodes formed in a surface of said main chuck body, said electrodes insulated from each other and from said main chuck body and said sensor electrodes electrically coupled to said backside of said wafer, and wherein no sensor electrode is coupled to the frontside of said semiconductor wafer; and circuitry connected to said sensor electrodes for sending and receiving an AC electrical signal to probe a sheet resistance of said frontside of said wafer.
Claim 3
Dependent Claim
11 words
The sensor of claim 1 wherein said wafer is supported electrostatically.
Claim 4
Dependent Claim
28 words
The sensor of claim 2 and further comprising a second set of at least two chuck electrodes formed in said main chuck body for electrostatically supporting said wafer.
Claim 5
Dependent Claim
20 words
The sensor of claim 2 and further comprising means for physically supporting said wafer prior to electrostatically supporting said wafer.
Claim 6
Dependent Claim
15 words
The sensor of claim 1 and further comprising means for heating or cooling said wafer.
Claim 7
Dependent Claim
13 words
The sensor of claim 1 wherein said main chuck body comprises boron nitride.
Claim 8
Dependent Claim
10 words
The sensor of claim 1 wherein said electrodes comprise aluminum.
Claim 9
Dependent Claim
14 words
The sensor of claim 1 wherein said electrodes comprise a high temperature metal alloy.
Claim 10
Dependent Claim
30 words
The sensor of claim 1 wherein said sensor electrodes further comprise an insulating layer such that said electrodes are electrically and capacitively coupled to said backside surface of said wafer.
Claim 11
Dependent Claim
23 words
The system of claim 1 wherein said AC electrical signal is a sinusoidal signal with a frequency between about 10 and 50 MHz.
Claim 12
Dependent Claim
19 words
The sensor of claim 1 wherein said at least two sensor electrodes comprise at least two concentric annular electrodes.
Claim 13
Dependent Claim
38 words
The sensor of claim 1 wherein said chuck is part of a semiconductor wafer processing equipment and said sensor is usable as an in-situ sensor for performing real-time measurements of conductive layers on said frontside of said wafer.
Claim 14
Dependent Claim
18 words
The sensor of claim 1 wherein said sensor electrodes are capacitively coupled to said backside of said wafer.
Claim 15
Independent Claim
115 words
A method of measuring out put signals at selected locations on the top surface of a semiconductor wafer comprising the steps of: providing a chuck electrically coupled to the backside surface of said wafer, said chuck capable of supporting said wafer electrostatically; electrically coupling at least two sensor electrodes to the backside surface of said wafer, and wherein no sensor electrode is coupled to the frontside of said semiconductor wafer; applying an RF excitation signal to said wafer through at least one of said sensor electrodes; monitoring at least one induced output signal through another of said sensor electrodes, said induced output signal related to the sheet resistance on the top surface of said wafer.
Claim 16
Independent Claim
115 words
A method of measuring out put signals at selected locations on the top surface of a semiconductor wafer comprising the steps of: providing a chuck electrically coupled to the backside surface of said wafer, said chuck capable of supporting said wafer electrostatically; electrically coupling at least two sensor electrodes to the backside surface of said wafer, and wherein no sensor electrode is coupled to the frontside of said semiconductor wafer; applying an RF excitation signal to said wafer through at least one of said sensor electrodes; monitoring at least one induced output signal through another of said sensor electrodes, said induced output signal related to the sheet resistance on the top surface of said wafer.
Claim 17
Dependent Claim
43 words
The method of claim 14 wherein said wafer is supported electrostatically by applying a periodic signal to at least two electrodes formed in said chuck and adjacent to said wafer, wherein said periodic signal has a frequency between about 100 and 10,000 Hz.
Claim 18
Dependent Claim
17 words
The method of claim 14 wherein said applying step comprises the step of applying an RF current.
Claim 19
Dependent Claim
17 words
The method of claim 14 and further comprising simultaneously performing a fabrication process to effect said wafer.
Claim 20
Dependent Claim
12 words
The method of claim 17 wherein said fabrication process comprises an etch.
Claim 21
Dependent Claim
15 words
The method of claim 17 wherein said fabrication process is performed in at low pressure.
Claim 22
Dependent Claim
16 words
The method of claim 17 wherein said fabrication process is performed in a plasma enhanced environment.
Claim 23
Dependent Claim
12 words
The method of claim 17 wherein said fabrication process comprises a deposition.
Claim 24
Dependent Claim
25 words
The method of claim 21 wherein said fabrication process comprises a deposition of a metal selected from the group consisting of tungsten, aluminum or titanium.
Claim 25
Dependent Claim
14 words
The method of claim 21 wherein said fabrication process comprises a chemical vapor deposition.
Claim 26
Dependent Claim
57 words
An electrostatic chuck comprising: a main chuck body; a set of sensor electrodes formed in said main chuck body wherein said sensor electrodes are electrically coupled to a semiconductor wafer for probing said wafer; and a set of chuck electrodes formed in said main chuck body wherein said chuck electrodes are capable of supporting said wafer electrostatically.
Claim 27
Dependent Claim
57 words
An electrostatic chuck comprising: a main chuck body; a set of sensor electrodes formed in said main chuck body wherein said sensor electrodes are electrically coupled to a semiconductor wafer for probing said wafer; and a set of chuck electrodes formed in said main chuck body wherein said chuck electrodes are capable of supporting said wafer electrostatically.
Claim 28
Dependent Claim
13 words
The chuck of claim 24 wherein said main chuck body comprises boron nitride.
Claim 29
Dependent Claim
13 words
The chuck of claim 24 wherein said sensor and chuck electrodes comprise aluminum.
Claim 30
Dependent Claim
17 words
The chuck of claim 24 wherein said sensor and chuck electrodes comprise a high temperature metal alloy.
Claim 31
Dependent Claim
16 words
The chuck of claim 24 wherein said sensor and chuck electrodes further comprise an insulating layer.
Claim 32
Dependent Claim
18 words
The chuck of claim 24 wherein said set of sensor electrodes comprises a set of annular concentric electrodes.
Claim 33
Dependent Claim
18 words
The chuck of claim 29 wherein said set of chuck electrodes comprises a set of annular concentric electrodes.
Claim 34
Dependent Claim
19 words
The chuck of claim 29 wherein each of said annular concentric electrodes is divided into more than one portion.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |