Claims
- 1. A process for controlling the surface geometry of a substrate of ion beam-sensitive material including the steps of:
- a. forming a resist layer on a surface of said substrate of said material;
- b. exposing said resist layer to controlled optical interference patterns, whereby selected regions of said resist layer may be removed thereby leaving a resist mask on the surface of said substrate; and
- c. exposing said substrate and mask thereon to an ion beam for machining and partially etching away exposed regions of said substrate, whereby very fine line widths may be achieved for these etched regions and a very high resolution may be obtained in said process while simultaneously minimizing the temperatures to which said substrate and mask are subjected during said process.
- 2. The process as defined in claim 1 wherein the exposure of said resist mask includes projecting a plurality of laser beams of a predetermined wavelength onto said resist layer at a predetermined angle with respect to the plane of said layer, whereby the optical interference of said beams causes exposure of said resist with a predetermined variation across the surface of said resist layer, and said angle may be varied to in turn vary the exposure pattern of said resist layer and the line widths of the resist mask formed therefrom.
- 3. The process defined in claim 2 which includes projecting a pair of laser beams from a common source onto the surface of said resist layer and causing an exposure of said resist layer with a sinusoidal variation across the surface thereof at a period of D =(.lambda./2) sin .alpha., where .alpha. is the angle that said beams make with respect to a line perpendicular to the plane of said resist layer.
- 4. The process defined in claim 1 wherein the formation of said resist layer includes depositing a photoresist layer on a gallium arsenide substrate, whereby mesa-like channels may be formed in said gallium arsenide substrate during the controlled ion beam etching thereof, and the light propagation in said channels may be sustained as a result of the desired bandgap energy of said gallium arsenide.
- 5. The process as defined in claim 1 wherein the formation of said resist layer includes depositing a photoresist layer on the surface of a substrate layer of metallization, whereby selected regions of said metallization may be ion beam etched away to expose the material underlying said metallization and enabling said metallization to serve either as a mask against subsequently implanted high energy particles or as a metal grid of a desired machined geometry.
- 6. The process defined in claim 1 wherein said ion beam sensitive material is a light propagation layer of semiconductive material which has either been epitaxially deposited or ion beam formed as a surface layer of a larger substrate material, so that the boundary of said larger substrate layer and said light propagating layer may be utilized to confine the light propagated in certain portions of said layer after channels have been formed in the latter.
- 7. The process defined in claim 6 which includes ion beam machining said light propagating layer down to a depth at least that of the boundary between said light propagating layer and the underlying substrate to thereby form a plurality of individual parallel light propagating channels.
- 8. The process defined in claim 6 which includes ion beam machining said light propating layer to a depth less than that of the boundary between said light propagating layer and its underlying substrate, whereby light intercoupling between parallel channels formed in said light propagating layer may be achieved.
- 9. The process defined in claim 7 wherein strips of optical coupling material are disposed between adjacent parallel channels and more closely match the refractive index of the channel than does air, whereby the specific refractive index of said coupling material may be selected in accordance with the desired electro-optical coupling between adjacent waveguide channels.
Parent Case Info
This is a continuation of application Ser. No. 336,679, filed Feb. 28, 1973 now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (1)
Number |
Date |
Country |
451,332 |
May 1968 |
CH |
Non-Patent Literature Citations (2)
Entry |
"Efficient Wire-Grid Duplexer Polarizer for CO.sub.2 Lasers," P. K. Cheo et al., Applied Physics Letters, vol. 18, No. 12, pp. 565-567, 6-1971. |
"Thin-Film Distributed-Feedback Laser Fabricated by Ion Milling", D. P. Schinke et al., Appl. Phys. Lett., vol. 21, No. 10, 8-1972. |
Continuations (1)
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Number |
Date |
Country |
Parent |
336679 |
Feb 1973 |
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