Patent US4820650A successfully refreshed from Google Patents.
US4820650A
Expired / Lapsed
US
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Introducing lattice defect with ice particles in semiconductor wafer
Assignee: Mitsubishi Electric Corp
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Filing: 1987-11-16
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Granted: 1989-04-11
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Expires: 2007-11-16
Abstract
Abstract The invention employs ice for introducing lattice defect into a semiconductor wafer, and is constructed to introduce particles of ice into the semiconductor wafer by ionizing (24) and accelerating (25) the particles of ice, whereby backside damage can be provided on the semiconductor wafer without leaving a pollutant source of the semiconductor wafer.
Inventors
- 👤 Akemi Nagae
- 👤 Shinichi Satou
- 👤 Takaaki Fukumoto
- 👤 Toshiaki Ohmori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:32
CPC Classifications
H; H10; H10P; H10P36/00; H10P36/03; Y; Y10; Y10S; Y10S438/00; Y10S438/938
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
73 words
A method of introducing lattice defect into a back surface of a semiconductor wafer, comprising the steps of; preparing particles of ice (A), transporting said particles of ice prepared (27), ionizing and accelerating said particles of ice (24, 25), placing in the path of said accelerated particles of ice said semiconductor wafer into which said lattice defect is to be introduced, so that said accelerated particles of ice impinge upon said semiconductor wafer.
Claim 2
Independent Claim
73 words
A method of introducing lattice defect into a back surface of a semiconductor wafer, comprising the steps of; preparing particles of ice (A), transporting said particles of ice prepared (27), ionizing and accelerating said particles of ice (24, 25), placing in the path of said accelerated particles of ice said semiconductor wafer into which said lattice defect is to be introduced, so that said accelerated particles of ice impinge upon said semiconductor wafer.
Claim 3
Dependent Claim
22 words
A method according to claim 1, which further comprises the step of introducing impurities into said back surface of said semiconductor wafer.
Claim 4
Dependent Claim
28 words
A method according to claim 2, wherein said step of introducing the lattice defect into the back surface of the semiconductor wafer comprises the steps of ion implantation.
Claim 5
Dependent Claim
28 words
A method according to claim 3, wherein said impurities belong to any of the groups III, IV, V and VIII or a compound which includes any of them.
Claim 6
Dependent Claim
103 words
A method according to claim 4, wherein said step of preparing said particles of ice comprises the step of preparing a container for holding said particles of ice prepared, said step for ionizing and accelerating said particles of ice comprises the step of preparing a container whose pressure can be controllably reduced, said means for transporting said particles of ice comprises the steps of: setting said container to be the first pressure, setting said container to be the second pressure lower than said first pressure, and transporting said particles of ice by using the difference between said first pressure and said second pressure.
Claim 7
Dependent Claim
27 words
A method according to claim 5, wherein said step of ionizing and accelerating said particles of ice comprises the step of using an electron shower device (24).
Claim 8
Dependent Claim
20 words
A method according to claim 6, wherein the particulate diameter of said particles of ice is 1 to 50 μm.
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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) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |