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US3840749A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for electron beam alignment with a semiconductor member

Assignee: Westinghouse Electric Corp
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Filing: 1973-10-01
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Granted: 1974-10-08
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Expires: 1993-10-01
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Abstract

Abstract A method and apparatus are provided for alignment of an electron beam with precisely located areas of a major surface of a semiconductor member. The semiconductor member generates cathodoluminecence of intensity corresponding to the thickness thereof. The semiconductor member has formed adjacent a major surface at least one and preferably at least two widely spaced detector marks of predetermined shape capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam. To align, an electron beam to be aligned has alignment beam portions corresponding to at least one detector mark and of predetermined cross-sectional shapes. The alignment beam portions are projected onto the major surface of the semiconductor member in the vicinity of the corresponding detector marks. And the cathodoluminescence generated by the member at least in the vicinity of the member is detected by detecting means. The electron beam is moved relative to the semiconductor member while continuing said detection until the detected cathodoluminescence indicates optimum alignment of each alignment portion thereof with a corresponding detector mark. Preferably, said alignment method is used in producing a very accurate component pattern in electroresist layer on the major surface of the semiconductor member with either a scanning electron beam or a patterned electron beam generated by a photocathode source.

Inventors

  • 👤 Keeffe T O
  • 👤 A Simon

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 13:47
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045; H10; H10P; H10P95/00

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 201 words
A method of precision aligning an electron beam with selected areas of a major surface of a semiconductor member comprising the steps of: A. forming on a major surface of a semiconductor member capable of generating cathodoluminescence corresponding in intensity to the thickness of the member at least one detector mark of predetermined shape, each said detector mark being capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam; B. causing at least one electron beam to be aligned to be projected onto the major surface of the member, said electron beam having at least one alignment beam portion corresponding to at least one detector mark and having a predetermined crosssectional shape; C. detecting cathodoluminescence generated by the member at and adjacent where each said alignment beam portion overlaps and irradiates a corresponding detector mark; D. moving the aligning electron beam relative to the member while continuing step C to detect irradiation of corresponding detector marks by the alignment beam portions; and E. positioning the electron beam relative to the semiconductor member where the detected cathodoluminescence indicates optimum alignment of the alignment beeam portions and corresponding detector marks.
Claim 2
Independent Claim 201 words
A method of precision aligning an electron beam with selected areas of a major surface of a semiconductor member comprising the steps of: A. forming on a major surface of a semiconductor member capable of generating cathodoluminescence corresponding in intensity to the thickness of the member at least one detector mark of predetermined shape, each said detector mark being capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam; B. causing at least one electron beam to be aligned to be projected onto the major surface of the member, said electron beam having at least one alignment beam portion corresponding to at least one detector mark and having a predetermined crosssectional shape; C. detecting cathodoluminescence generated by the member at and adjacent where each said alignment beam portion overlaps and irradiates a corresponding detector mark; D. moving the aligning electron beam relative to the member while continuing step C to detect irradiation of corresponding detector marks by the alignment beam portions; and E. positioning the electron beam relative to the semiconductor member where the detected cathodoluminescence indicates optimum alignment of the alignment beeam portions and corresponding detector marks.
Claim 3
Dependent Claim 50 words
A method of precision aligning an electron beam with selected areas of a major surface of a semiconductor member as set forth in claim 1 wherein: forming the detector mark includes providing a well in the member in the predetermined shape, and the cathodoluminescence generated is detected through the member.
Claim 4
Dependent Claim 50 words
A method of precision aligning an electron beam with selected areas of a major surface of a semiconductor member as set forth in claim 1 wherein: forming the detector mark includes providing a mesa on the member in the predetermined shape, and the cathodoluminescence generated is detected through the member.
Claim 5
Dependent Claim 47 words
A method of precision aligning an electron beam with selected areas of a major surface of a semiconductor member as set forth in claim 1 wherein: forming the detector mark includes positioning an opaque layer on the major surface of the semiconductor member in the predetermined shape.
Claim 6
Dependent Claim 61 words
A method of precision aligning an electron beam with selected areas of a major surface of the semiconductor member as set forth in claim 1 wherein: forming the detector mark includes positioning an opaque layer on the major surface of the semiconductor member to circumscribe an exposed portion of the major surface wherein the exposed portion is of the predetermined shape.
Claim 7
Dependent Claim 47 words
A method of precision aligning an electron beam with selected areas of a major surface of the semiconductor member as set forth in claim 1 wherein: a detector mark is of substantially the same predetermined shape as the predetermined cross-sectional shape of a corresponding alignment beam portion.
Claim 8
Dependent Claim 51 words
A method of precision aligning an electron beam with selected areas of a major surface of the semiconductor member as set forth in claim 1 wherein: the electron beam to be aligned is a scanning electron beam for selectively irradiating an electroresist layer on the major surface of the semiconductor member.
Claim 9
Dependent Claim 53 words
A method of precision aligning an electron beam with selected areas of a major surface of a semiconductor member as set forth in claim 7 wherein: the major surface of the member is divided into contiguous fields for selective irradiation, and the detector marks are positioned symmetrically along boundaries of said contiguous fields.
Claim 10
Independent Claim 214 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member comprising the steps of: A. forming on a major surface of a semiconductor member capable of generating cathodoluminescence corresponding in intensity to the thickness of the member at least two widely spaced apart detector marks of predetermined shape, each said detector mark being capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam; B. causing a patterned electron beam with alignment beam portions corresponding to the detector marks to be projected by a photocathode source onto the major surface of the member, each said alignment beam portion corresponding to a detector mark and having a predetermined cross-sectional shape; C. detecting the cathodoluminescence generated by the member at least at and adjacent where the alignment beam portions overlap and irradiate the marks; D. moving the patterned electron beam relative to the member while continuing step C to detect irradiation of the detector marks by the alignment beam portions; and E. positioning the alignment beam portions relative to the detector marks where the detected cathodoluminescence indicates optimum alignment of the corresponding alignment beam portions and the detector marks.
Claim 11
Independent Claim 214 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member comprising the steps of: A. forming on a major surface of a semiconductor member capable of generating cathodoluminescence corresponding in intensity to the thickness of the member at least two widely spaced apart detector marks of predetermined shape, each said detector mark being capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam; B. causing a patterned electron beam with alignment beam portions corresponding to the detector marks to be projected by a photocathode source onto the major surface of the member, each said alignment beam portion corresponding to a detector mark and having a predetermined cross-sectional shape; C. detecting the cathodoluminescence generated by the member at least at and adjacent where the alignment beam portions overlap and irradiate the marks; D. moving the patterned electron beam relative to the member while continuing step C to detect irradiation of the detector marks by the alignment beam portions; and E. positioning the alignment beam portions relative to the detector marks where the detected cathodoluminescence indicates optimum alignment of the corresponding alignment beam portions and the detector marks.
Claim 12
Dependent Claim 56 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member as set forth in claim 9 wherein: forming each detector mark includes providing a well in the member in the predetermined shape, and the cathodoluminescence generated is detected through the member.
Claim 13
Dependent Claim 56 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member as set forth in claim 9 wherein: forming each detector mark includes providing a mesa on the member in the predetermined shape, and the cathodoluminescence generated is detected through the member.
Claim 14
Dependent Claim 53 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member as set forth in claim 9 wherein: forming each detector mark includes positioning an opaque layer on the major surface of the semiconductor member in the predetermined shape.
Claim 15
Dependent Claim 67 words
A method of precision aligning a patTerned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member as set forth in claim 9 wherein: forming each detector mark includes positioning an opaque layer on the major surface of the semiconductor member to circumscribe an exposed portion of the major surface wherein the exposed portion is of the predetermined shape.
Claim 16
Dependent Claim 53 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member as set forth in claim 9 wherein: each detector mark is of substantially the same predetermined shape as the predetermined cross-sectional shape of a corresponding alignment beam portion.
Claim 17
Dependent Claim 86 words
A method of precision aligning a patterned electron beam generated by a photocathode source with selected areas of a major surface of a semiconductor member as set forth in claim 9 wherein: steps D and E are automatically performed by electrically processing the electrical signal output corresponding to the detected cathodoluminescence on modulation of the movement of the alignment beam portions over the corresponding detector marks, and steps D and E automatically are terminated at optimum alignment of the corresponding alignment beam portions and detector marks.
Claim 18
Dependent Claim 331 words
Apparatus for selectively irradiating precisely located areas of a major surface of a semiconductor member comprising: A. a photocathode source for generating a patterned beam of electrons including at least one alignment beam portion of predetermined cross-sectional shape; B. a semiconductor member capable of generating cathodoluminescence of intensity corresponding to the thickness thereof and having adjacent a major surface thereof at least one detector mark corresponding to each said alignment beam portion, each said detector mark being of a predetermined shape and capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam; C. means for positioning the semiconductor member in a spaced relation to the photocathode source of the patterned beam; D. means for applying a potential between the semiconductor member and the photocathode source whereby electrons from the photocathode source are directed to and selectively irradiate portions of the major surface of the member; E. electromagnetic means for directing the patterned beam of electrons from the photocathode source to irradiate selected portions of the major surface of the member close to the precisely located areas and directing each alignment beam portion to irradiate selected portions of the surface portions of the major surface of the substrate close to a detector mark; F. detector means for detecting the cathodoluminescence generated by the member at least at and adjacent the detector marks and producing an electrical signal corresponding to the area of the detector mark irradiated by the alignment beam portions; and G. electrical means for moving the patterned beam of electrons relative to the member responsive to said electrical signal from the detector means to cause the alignment beam portions to substantially align with the respective detector marks, whereby the patterned beam of electrons from the photocathode is located and oriented relative to the semiconductor member so that precisely located areas of the major surface of the semiconductor member can be selectively irradiated with the patterned electron beam.
Claim 19
Dependent Claim 331 words
Apparatus for selectively irradiating precisely located areas of a major surface of a semiconductor member comprising: A. a photocathode source for generating a patterned beam of electrons including at least one alignment beam portion of predetermined cross-sectional shape; B. a semiconductor member capable of generating cathodoluminescence of intensity corresponding to the thickness thereof and having adjacent a major surface thereof at least one detector mark corresponding to each said alignment beam portion, each said detector mark being of a predetermined shape and capable of providing a differential in cathodoluminescence generated by the member corresponding to the area of the mark irradiated by an electron beam; C. means for positioning the semiconductor member in a spaced relation to the photocathode source of the patterned beam; D. means for applying a potential between the semiconductor member and the photocathode source whereby electrons from the photocathode source are directed to and selectively irradiate portions of the major surface of the member; E. electromagnetic means for directing the patterned beam of electrons from the photocathode source to irradiate selected portions of the major surface of the member close to the precisely located areas and directing each alignment beam portion to irradiate selected portions of the surface portions of the major surface of the substrate close to a detector mark; F. detector means for detecting the cathodoluminescence generated by the member at least at and adjacent the detector marks and producing an electrical signal corresponding to the area of the detector mark irradiated by the alignment beam portions; and G. electrical means for moving the patterned beam of electrons relative to the member responsive to said electrical signal from the detector means to cause the alignment beam portions to substantially align with the respective detector marks, whereby the patterned beam of electrons from the photocathode is located and oriented relative to the semiconductor member so that precisely located areas of the major surface of the semiconductor member can be selectively irradiated with the patterned electron beam.
Claim 20
Dependent Claim 57 words
Apparatus for selectively irradiating precisely located areas of a major surface of a semiconductor member as set forth in claim 16 wherein: the patterned beam of electrons generated by the photocathode source includes at least two spaced apart alignment beam portions having predetermined cross-sectional shapes substantially the same as the predetermined shapes of the corresponding detector marks.
Claim 21
Dependent Claim 104 words
Apparatus for selectively irradiAting precisely located areas of a major surface of a semiconductor substrate as set forth in claim 17 wherein: the electrical means includes modulation means for oscillating the movement of each alignment beam portion on a corresponding detector mark, phase detection means for detecting along orthogonal axis the error from alignment of the corresponding alignment beam portions and detector marks and outputting an electrical signal corresponding thereto, and actuating means for changing the electrical input to the electromagnetic means responsive to the electrical signal from the phase detector means to bring the alignement beam portions and the detector marks into alignment.

References Cited (Backward Citations)

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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) 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

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