EP0198944A1
Expired / Lapsed
EP
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Scanning acoustic microscope
Assignee: International Business Machines Corp
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Filing: 1985-04-26
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Granted: —
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Expires: 2005-04-26
Abstract
Abstract The scanning acoustic microscope comprises a solid lens body (1) consisting of two sections (2, 5) of materials having different sound propagation characteristics but matching acoustic impedances. A lens (4) is arranged at the interface (3) of said sections (2, 5) having its focal point falling into the apex (8) of a sharply pointed tip (7) formed at the free surface of one (5) of the sections. Tip (7) and specimen (10) to be investigated are immersed in a coupling medium (9) having a relatively high absorption coefficient. The lens body (1) carries a transducer (11) on its surface (6) opposite the tip (7) for sending plane sound waves through said lens (4) and said tip (7) onto the specimen (10). The reflected and transmitted waves are received by the transducer (11) attached to the lens body (1) and a transducer (21) arranged on the rear side of the specimen, respectively. By appropriate processing of their output signals, high- resolution (10 nm) images of the specimen (10) can be obtained.
Inventors
- 👤 Erich Paul Dr. Stoll
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 18:40
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/06; G01N29/0654; G01N29/0681; G01H; G01H3/00; G01H3/10; G01H3/12; G01H3/125; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
186 words
Scanning acoustic microscope comprising an acoustic lens formed in a solid body interfacing with a coupling medium in which a specimen to be inspected is immersed, at least one transducer for generating/detecting sound waves in said solid body, and means for raster-scanning the focal point of said lens across the specimen, characterized in that said solid body (1) is composed of a first section (2) of a material having a first velocity of sound, and a second section of a material having a second velocity of sound lower than said first velocity of sound, that one transducer (11) is fixed on the free surface of said first section (2) of the solid body, and that said lens (4) is formed at the interface (3) between said first and second sections (2, 5) of the solid body (1), the focal point of said lens (4) falling into a sharp tip (7) formed at the surface (6) of said second section (5) opposite said lens (4), said tip (7) being immersed in said coupling medium (9) and being adapted to be raster-scanned with respect to said specimen (10).
Claim 2
Dependent Claim
186 words
Scanning acoustic microscope comprising an acoustic lens formed in a solid body interfacing with a coupling medium in which a specimen to be inspected is immersed, at least one transducer for generating/detecting sound waves in said solid body, and means for raster-scanning the focal point of said lens across the specimen, characterized in that said solid body (1) is composed of a first section (2) of a material having a first velocity of sound, and a second section of a material having a second velocity of sound lower than said first velocity of sound, that one transducer (11) is fixed on the free surface of said first section (2) of the solid body, and that said lens (4) is formed at the interface (3) between said first and second sections (2, 5) of the solid body (1), the focal point of said lens (4) falling into a sharp tip (7) formed at the surface (6) of said second section (5) opposite said lens (4), said tip (7) being immersed in said coupling medium (9) and being adapted to be raster-scanned with respect to said specimen (10).
Claim 3
Dependent Claim
45 words
Microscope in accordance with claim 1, characterized in that a first transducer (11) is attached to the free surface of the first section (2) of said solid body (1), and that a second transducer (21) is placed on the remote side of the specimen (10).
Claim 4
Dependent Claim
64 words
Microscope in accordance with claim 1, characterized in that the materials of said sections (2, 5) are chosen such that their respective acoustic impedances match in that the product of the sound velocity and density of the material of the first section (2) is at least approximately equal to the product of sound velocity and density of the material of the second section (5).
Claim 5
Dependent Claim
64 words
Microscope in accordance with claim 1, characterized in that the lens (4) at the interface (3) between the sections (2, 5) making up said solid body (1) extends into said first section (2) and has a focal length on the order of 1 mm with the focal point falling into the apex (8) of said tip (7) extending from said second section (5) .
Claim 6
Dependent Claim
52 words
Microscope in accordance with claim 1, characterized in that said solid body (1) has a diameter of about 1 mm, said lens (4) has a diameter of between 50 µm and 600 µm, and that the thicknesses of said sections (2, 5) of the solid body (I) have approximately a 2:1 relationship.
Claim 7
Dependent Claim
25 words
Microscope in accordance with claim 1, characterized in that the relationship of the greatest diameter of said tip (7) to its length is approximately 1:3...4.
Claim 8
Dependent Claim
25 words
Microscope in accordance with claim 1, characterized in that said tip (7) is sharpened to an apex (8) having a radius of approximately 10 nanometers.
Claim 9
Dependent Claim
41 words
Microscope in accordance with claim 1, characterized in that said point (7) and said specimen (10) are immersed in a coupling medium (9) having a relatively high absorption coefficient in the frequency range in which said transducer (11, 21) is operated.
Claim 10
Dependent Claim
24 words
Microscope in accordance with claim 8, characterized in that said coupling medium (9) is chosen from the group comprising water, carbon tetrachloride and benzene.
Claim 11
Dependent Claim
35 words
Microscope in accordance with claim 3, characterized in that the first section (2) of the solid body (1) consists of sapphire (A1 2 0 3 ) and that the second section (5) consists of metal.
References Cited (Backward Citations)
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