EP0328281A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Directable aperture etched in silicon
Assignee: Ford-Werke GmbH
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Filing: 1989-01-30
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Granted: —
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Expires: 2009-01-30
Abstract
Abstract A method is described for anisotropically etching an aperture into a monocrystaline substrate such that the angle of the aperture with respect to the nominal crystaline planes of the substrate may be preselected. Etchant pits through opposing planar surfaces are offset from one another by a preselected longitudinal offset trigonometrically related to the desired aperture angle. Other selected parameters trigonometrically related to the aperture angle include the angle of intersection of the intersecting crystaline planes, the substrate thickness and the depth of each of the etchant pits.
Inventors
- 👤 Edward Nathan Sickafus
- 👤 Mati Mikkor
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 04:13
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/16; B41J2/1621; B41J2/1631; B41J2/1626; B41J2/1629; B41J2/1635; H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/644
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
298 words
A method for anisotropically etching an aperture into a monocrystaline substrate such that the angle of the aperture plane with respect to the nominal crystaline planes of the substrate may be preselected, said method comprising the steps of: dimensioning said substrate with top and bottom planar surfaces substantially parallel to said nominal crystaline planes, the spacing between said top and bottom planar surfaces being trigonometrically related to said preselected angle of said aperture plane; anisotropically etching a first etchant pit through said top planar surface and against said nominal crystaline planes to a preselected distance from said bottom planar surface which is trigonometrically related to said preselected angle of said aperture plane, said first etchant pit having plane surface sides along intersecting crystaline planes to said nominal crystaline planes, the intersection of said plane surface sides with said top planar surface defining a first pair of longitudinal edges and a first pair of transverse edges of said first etchant pit; and anisotropically etching a second etchant pit through said bottom planar surface and against said nominal crystaline planes to a preselected distance from said top planar surface which is trigonometrically related to said preselected angle of said aperture plane, a portion of said second etchant pit intersecting a portion of said first etchant pit to define said aperture, said second etchant pit having plane surface sides along said intersecting crystaline planes, the intersection of said plane surface sides with said bottom planar surface defining a second pair of longitudinal edges and a second pair of transverse edges of said second etchant pit, one of said second pair of transverse edges being longitudinally offset from an opposing one of said first pair of transverse edges by a preselected longitudinal offset trigonometrically related to said angle of said aperture plane.
Claim 2
Independent Claim
298 words
A method for anisotropically etching an aperture into a monocrystaline substrate such that the angle of the aperture plane with respect to the nominal crystaline planes of the substrate may be preselected, said method comprising the steps of: dimensioning said substrate with top and bottom planar surfaces substantially parallel to said nominal crystaline planes, the spacing between said top and bottom planar surfaces being trigonometrically related to said preselected angle of said aperture plane; anisotropically etching a first etchant pit through said top planar surface and against said nominal crystaline planes to a preselected distance from said bottom planar surface which is trigonometrically related to said preselected angle of said aperture plane, said first etchant pit having plane surface sides along intersecting crystaline planes to said nominal crystaline planes, the intersection of said plane surface sides with said top planar surface defining a first pair of longitudinal edges and a first pair of transverse edges of said first etchant pit; and anisotropically etching a second etchant pit through said bottom planar surface and against said nominal crystaline planes to a preselected distance from said top planar surface which is trigonometrically related to said preselected angle of said aperture plane, a portion of said second etchant pit intersecting a portion of said first etchant pit to define said aperture, said second etchant pit having plane surface sides along said intersecting crystaline planes, the intersection of said plane surface sides with said bottom planar surface defining a second pair of longitudinal edges and a second pair of transverse edges of said second etchant pit, one of said second pair of transverse edges being longitudinally offset from an opposing one of said first pair of transverse edges by a preselected longitudinal offset trigonometrically related to said angle of said aperture plane.
Claim 3
Independent Claim
298 words
A method for anisotropically etching an aperture into a monocrystaline substrate such that the angle of the aperture plane with respect to the nominal crystaline planes of the substrate may be preselected, said method comprising the steps of: dimensioning said substrate with top and bottom planar surfaces substantially parallel to said nominal crystaline planes, the spacing between said top and bottom planar surfaces being trigonometrically related to said preselected angle of said aperture plane; anisotropically etching a first etchant pit through said top planar surface and against said nominal crystaline planes to a preselected distance from said bottom planar surface which is trigonometrically related to said preselected angle of said aperture plane, said first etchant pit having plane surface sides along intersecting crystaline planes to said nominal planes, the intersection of said plane surface sides with said top planar surface defining a rectangle having a left transverse edge, a right transverse edge and a pair of longitudinal edges; and anisotropically etching a second etchant pit through said bottom planar surface and against said nominal crystaline planes to a preselected distance from said top planar surface which is trigonometrically related to said preselected angle of said aperture plane, a portion of said second etchant pit intersecting a portion of said first etchant pit to define said aperture, said second etchant pit having plane surface sides along said intersecting crystaline planes, the intersection of said plane surface sides with said bottom planar surface defining a rectangle having a left transverse edge, a right transverse edge and a pair of longitudinal edges, said left transverse edge of said second etchant pit being longitudinally offset to the left of said right transverse edge of said first etchant pit by a preselected longitudinal offset trigonometrically related to said angle of said aperture plane.
Claim 4
Independent Claim
298 words
A method for anisotropically etching an aperture into a monocrystaline substrate such that the angle of the aperture plane with respect to the nominal crystaline planes of the substrate may be preselected, said method comprising the steps of: dimensioning said substrate with top and bottom planar surfaces substantially parallel to said nominal crystaline planes, the spacing between said top and bottom planar surfaces being trigonometrically related to said preselected angle of said aperture plane; anisotropically etching a first etchant pit through said top planar surface and against said nominal crystaline planes to a preselected distance from said bottom planar surface which is trigonometrically related to said preselected angle of said aperture plane, said first etchant pit having plane surface sides along intersecting crystaline planes to said nominal planes, the intersection of said plane surface sides with said top planar surface defining a rectangle having a left transverse edge, a right transverse edge and a pair of longitudinal edges; and anisotropically etching a second etchant pit through said bottom planar surface and against said nominal crystaline planes to a preselected distance from said top planar surface which is trigonometrically related to said preselected angle of said aperture plane, a portion of said second etchant pit intersecting a portion of said first etchant pit to define said aperture, said second etchant pit having plane surface sides along said intersecting crystaline planes, the intersection of said plane surface sides with said bottom planar surface defining a rectangle having a left transverse edge, a right transverse edge and a pair of longitudinal edges, said left transverse edge of said second etchant pit being longitudinally offset to the left of said right transverse edge of said first etchant pit by a preselected longitudinal offset trigonometrically related to said angle of said aperture plane.
Claim 5
Dependent Claim
55 words
A method as claimed in claim 1 or 2, wherein said preselected distance of said first etchant pit from said second planar surface is substantially equal to said preselected distance of said second etchant pit from said first planar surface whereby said first and second etchant pits are concurrently formed in a single etchant step.
Claim 6
Dependent Claim
69 words
A method as claimed in claim 1, 2 or 3, wherein said preselected angle is trigonometrically related to said preselected longitudinal offset (ΔL), said preselected distance of said first etchant pit from said second planar surface (d), the angle of intersection between said intersecting planes and said nominal planes (φ), and said spacing between said top planar surface and said bottom planar surface (t) by the following trigonometric relation:
Claim 7
Dependent Claim
186 words
A method as claimed in claim 2, for anisotropically etching a second aperture into said substrate such that the angle of said second aperture plane with respect to said nominal crystaline planes of said substrate may be preselected, said method further comprising the step of anisotropically etching a third etchant pit through said bottom planar surface and against said nominal crystaline planes to a preselected distance from said top planar surface which is trigonometrically related to said preselected angle of said aperture plane, a portion of said third etchant pit intersecting a portion of said first etchant pit to define said second aperture, said third etchant pit having plane surface sides along said intersecting crystaline planes, the intersection of said plane surface sides with said bottom planar surface defining a rectangle having a left transverse edge, a right transverse edge and a pair of longitudinal edges, said right transverse edge of said third etchant pit being longitudinally offset to the left of said right transverse edge of said first etchant pit by a preselected longitudinal offset trigonometrically related to said angle of said second aperture plane.
Claim 8
Independent Claim
15 words
A method as claimed in any preceding claim, wherein said substrate comprises a silicon substrate.
Claim 9
Independent Claim
31 words
A method as claimed in any preceding claim, wherein said nominal crystaline planes comprise {100} planes and said intersecting crystaline planes comprise {111} planes and said angle φ is approximately 54.7°.
Claim 10
Dependent Claim
27 words
A method as claimed in claim 7, wherein said plane surface sides of said first etchant pit and said second etchant pit are substantially pyramidal in shape.
Claim 11
Independent Claim
35 words
A method as claimed in any one of claims 1 to 6, wherein said nominal crystaline planes comprise {110} planes and said intersecting crystaline planes comprise {111} planes and said angle φ is approximately 90°.
References Cited (Backward Citations)
No citation records indexed.
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