US4539050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of semiconductor wafers with a rear side having a gettering action
Assignee: Siltronic AG
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Filing: 1983-10-19
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Granted: 1985-09-03
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Expires: 2003-10-19
Abstract
Abstract For the manufacture of semiconductor wafers with a rear side having a gettering action in subsequent oxidation processes by means of the action of light, especially laser, radiation ("laser damage"), there are advantageously chosen wafers with a fine surface structure that contains faces that are inclined by at least 15 DEG in the actual profile by comparison with the geometrically ideal profile of the surface according to known standards. As a result, in comparison to smooth surfaces, considerable savings in energy and time are achieved.
Inventors
- 👤 Josef Kramler
- 👤 Franz Kuhn-Kuhnenfeld
- 👤 Hans-Adolf Gerber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:59
CPC Classifications
H; H10; H10P; H10P36/00; H10P36/03; H10P34/00; H10P34/40; H10P34/42; Y; Y10; Y10S; Y10S148/00; Y10S148/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
144 words
A process for the manufacture of semiconductor wafers with a rear side having a gettering action by the action of light radiation so as to induce a gettering dislocation network in subsequent high-temperature processes, comprising the steps of: selecting semiconductor wafers each having a rear side that contains in its fine surface structure faces that are inclined by at least 15° with respect to the geometrically ideal surface of the wafer; and melting parts of the rear sides of said wafers by the action of light radiation so as to induce a gettering dislocation network in the surface region of the rear side of the wafers, the incident energy density of said light radiation employed in said melting step being 20 to 80% of the energy density that is necessary for producing a similarly dense dislocation network in a mirror-polished surface of a wafer.
Claim 2
Dependent Claim
144 words
A process for the manufacture of semiconductor wafers with a rear side having a gettering action by the action of light radiation so as to induce a gettering dislocation network in subsequent high-temperature processes, comprising the steps of: selecting semiconductor wafers each having a rear side that contains in its fine surface structure faces that are inclined by at least 15° with respect to the geometrically ideal surface of the wafer; and melting parts of the rear sides of said wafers by the action of light radiation so as to induce a gettering dislocation network in the surface region of the rear side of the wafers, the incident energy density of said light radiation employed in said melting step being 20 to 80% of the energy density that is necessary for producing a similarly dense dislocation network in a mirror-polished surface of a wafer.
Claim 3
Dependent Claim
14 words
The process of claim 1, wherein laser light is used as said light radiation.
Claim 4
Dependent Claim
11 words
The process of claim 1, wherein alkaline-etched semiconductor wafers are selected.
Claim 5
Dependent Claim
17 words
The process of claim 1, wherein said selected semiconductor wafers are subjected to a stacking fault-inducing treatment.
Claim 6
Dependent Claim
11 words
The process of claim 1, wherein said wafers selected are damage-free.
Claim 7
Dependent Claim
28 words
The process of claim 1, wherein said light radiation employed in said melting step is of an intensity which avoids vaporization of said rear side of said wafers.
Claim 8
Dependent Claim
107 words
A process for the manufacture of semiconductor wafers with a rear side having a gettering action by the action of light radiation so as to induce a gettering dislocation network in subsequent high-temperature processes, comprising the steps of: selecting damage-free semiconductor wafers each having a rear side that contains in its fine surface structure faces that are inclined by at least 15° with respect to the geometrically ideal surface of the wafer; and melting parts of the rear sides of said wafers by the action of light radiation so as to induce a gettering dislocation network in the surface region of the rear side of the wafers.
Claim 9
Dependent Claim
107 words
A process for the manufacture of semiconductor wafers with a rear side having a gettering action by the action of light radiation so as to induce a gettering dislocation network in subsequent high-temperature processes, comprising the steps of: selecting damage-free semiconductor wafers each having a rear side that contains in its fine surface structure faces that are inclined by at least 15° with respect to the geometrically ideal surface of the wafer; and melting parts of the rear sides of said wafers by the action of light radiation so as to induce a gettering dislocation network in the surface region of the rear side of the wafers.
Claim 10
Dependent Claim
36 words
The process of claim 7, wherein the incident energy density of said light radiation employed in said melting step is 20 to 80% of the energy density that is necessary for producing a of a wafer.
Claim 11
Dependent Claim
14 words
The process of claim 7, wherein laser light is used as said light radiation.
Claim 12
Dependent Claim
11 words
The process of claim 7, wherein alkaline-etched semiconductor wafers are selected.
Claim 13
Dependent Claim
17 words
The process of claim 7, wherein said selected semiconductor wafers are subjected to a stacking fault-inducing treatment.
Claim 14
Dependent Claim
28 words
The process of claim 7, wherein said light radiation employed in said melting step is of an intensity which avoids vaporization of said rear side of said wafers.
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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) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |