US4896034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of identifying a semiconductor wafer utilizing a light source and a detector
Assignee: Fujitsu Ltd
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Filing: 1988-10-06
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Granted: 1990-01-23
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Expires: 2008-10-06
Abstract
Abstract Automatic identification of each semiconductor wafer during wafer processing is achieved by the invention regardless of layers deposited on a code pattern. The code pattern, preferably, a bar code pattern, is formed on a front surface of the semiconductor wafer, and a light beam including infrared rays is irradiated onto a bottom surface thereof. The infrared rays easily penetrate through the silicon wafer and reflect from the bar code pattern formed on the front surface of the wafer. The reflected beam of infrared rays is received by a detector disposed on a back side of the wafer, and each wafer is identified by decoding the received signal. The bar code pattern can be directly formed by inscribing the wafer surface by a laser beam or inscribing a metal layer deposited thereon.
Inventors
- 👤 Tadashi Kiriseko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:20
CPC Classifications
H; H10; H10W; H10W46/00; H10W46/101; H10W46/106; H10W46/201; H10W46/401
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
142 words
A method of identifying a semiconductor wafer having a front surface, a rear surface, and a rear side, in which a light source transmits an incident light and a light detector having an optical axis receives a reflected light, said method comprising the steps of: (a) forming a code pattern on the front surface of said wafer, said code pattern having first and second regions, each having a reflected light intensity different from each other; (b) irradiating light from said light source including infrared light rays onto the rear surface of the wafer from the rear side of said wafer, said light penetrating through said wafer onto the code pattern and reflecting therefrom; (c) receiving the light reflected from the code pattern with said detector on the rear side of the wafer; and (d) identifying the wafer by decoding the received signal.
Claim 2
Independent Claim
142 words
A method of identifying a semiconductor wafer having a front surface, a rear surface, and a rear side, in which a light source transmits an incident light and a light detector having an optical axis receives a reflected light, said method comprising the steps of: (a) forming a code pattern on the front surface of said wafer, said code pattern having first and second regions, each having a reflected light intensity different from each other; (b) irradiating light from said light source including infrared light rays onto the rear surface of the wafer from the rear side of said wafer, said light penetrating through said wafer onto the code pattern and reflecting therefrom; (c) receiving the light reflected from the code pattern with said detector on the rear side of the wafer; and (d) identifying the wafer by decoding the received signal.
Claim 3
Dependent Claim
30 words
A method for identifying a semiconductor wafer according to claim 1, wherein said forming step comprises inscribing and roughing the front surface of the semiconductor wafer by a laser beam.
Claim 4
Dependent Claim
44 words
A method for identifying a semiconductor wafer according to claim 1, wherein said forming step comprises depositing a metal layer on the front surface of the semiconductor wafer and inscribing and evaporating said metal layer and roughing said metal layer by a laser beam.
Claim 5
Dependent Claim
25 words
A method for identifying a semiconductor wafer according to claim 1, further comprising forming an active element on the front surface of the semiconductor wafer.
Claim 6
Dependent Claim
21 words
A method for identifying a semiconductor wafer according to claim 1, wherein said forming step comprises forming a bar code pattern.
Claim 7
Dependent Claim
42 words
A method for identifying a semiconductor wafer according to claim 1, wherein said semiconductor wafer has a flat orientation edge and wherein said forming step comprises forming a code pattern in a region near the flat orientation edge of the semiconductor wafer.
Claim 8
Dependent Claim
42 words
A method for identifying a semiconductor wafer according to claim 2, further comprising depositing a plurality of layers including an insulating layer and a metal layer on the front surface of the semiconductor wafer on said code pattern after the forming step.
Claim 9
Dependent Claim
39 words
A method for identifying a semiconductor wafer according to claim 7, further comprising forming an active element on the front surface of the semiconductor wafer and depositing said metal layer as a first metal layer of said active element.
Claim 10
Dependent Claim
57 words
A method for identifying a semiconductor wafer according to claim 1, further comprising tilting the optical axis of said detector for receiving the reflected light from a direction for receiving reflected light corresponding to the incident light of the reflection so that the reflected light from the inscribed area is stronger than that from a non-inscribed area.
Claim 11
Dependent Claim
57 words
A method for identifying a semiconductor wafer according to claim 1, further comprising setting the optical axis of said detector for receiving the reflected light to be coincident with a direction for receiving reflected light corresponding to the incident light so that the reflected light from the inscribed area is weaker than that from a non-inscribed area.
Claim 12
Dependent Claim
25 words
A method for identifying a semiconductor wafer according to claim 2, further comprising forming an active element on the front surface of the semiconductor wafer.
Claim 13
Dependent Claim
25 words
A method for identifying a semiconductor wafer according to claim 3, further comprising forming an active element on the front surface of the semiconductor wafer.
Claim 14
Dependent Claim
21 words
A method for identifying a semiconductor wafer according to claim 2, wherein said forming step comprises forming a bar code pattern.
Claim 15
Dependent Claim
21 words
A method for identifying a semiconductor wafer according to claim 3, wherein said forming step comprises forming a bar code pattern.
Claim 16
Dependent Claim
42 words
A method for identifying a semiconductor wafer according to claim 2, wherein said semiconductor wafer has a flat orientation edge and wherein said forming step comprises forming a code pattern in a region near the flat orientation edge of the semiconductor wafer.
Claim 17
Dependent Claim
42 words
A method for identifying a semiconductor wafer according to claim 3, wherein said semiconductor wafer has a flat orientation edge and wherein said forming step comprises forming a code pattern in a region near the flat orientation edge of the semiconductor wafer.
Claim 18
Dependent Claim
57 words
A method for identifying a semiconductor wafer according to claim 2, further comprising tilting the optical axis of said detector for receiving the reflected light from a direction for receiving reflected light corresponding to the incident light of the reflection so that the reflected light from the inscribed area is stronger than that from a non-inscribed area.
Claim 19
Dependent Claim
57 words
A method for identifying a semiconductor wafer according to claim 2, further comprising tilting the optical axis of said detector for receiving the reflected light from a direction for receiving reflected light corresponding to the incident light of the reflection so that the reflected light from the inscribed area is stronger than that from a non-inscribed area.
References Cited (Backward Citations)
US4368979A
Cited
US4825093A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-22 | 1993-07-24 | 1994-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-22 | 1997-07-24 | 1998-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-22 | 2001-07-24 | 2002-01-23 | $7700.00 | Window Closed / Lapsed |