PHOTOMAGNETIC CATALYSIS

Abstract: Catalyzing or effectuating a chemical reaction in a substance by application of a magnetic field, preferably a magnetic field combined with electromagnetic radiation.

Description: PHOTO AGNETIC CATALYSIS Background of the Invention This invention relates to catalyzing or effectuating a chemical reaction in a substance by application of a magnetic field, preferably a magnetic field combined with electromagnetic radiation. It is known in the art that chemical reactions such as polymerization can be catalyzed by application of electromagnetic radiation, e.g., ultraviolet light. Typically the light is applied continuously for relatively long periods of time, e.g., thirty minutes. Some efforts have been made to use flash lamps for this purpose, as described in my U.S. Patents Nos. 3,782,889 and 4,167,669. In one aspect, the invention relates to curing photoresist materials used in the manufacture of integrated circuits. Integrated circuits are manufactured by forming extremely tiny electrical circuits on the face of a semiconductor (e.g., silicon) wafer. Usually many exact copies of the same circuit are deposited on one wafer, and the wafer is then cut into small pieces, or "chips", with one circuit on each chip. The electrical circuit on each chip will typically consist of many individual components; for example, a so-called "64K dynamic RAM" chip, a type recently introduced for use in computer memories, has enough components to provide storage for approximately 64,000 characters. Presently the semiconductor industry is striving to make the next leap upward in component density, to the 256K dynamic OMPI - , v/ιro RAM, which will provide storage for approximately 256,000 characters. To accomplish that increased component density, there must be an accompanying shrinkage in component size. The dimensions of the components and the electrical pathways that connect them together must be made much narrower. Cordes et al., "Resist Materials for High Resolution Photoli hography", presented at SPIΞ Semiconductor Microlithography VI Seminar (1981) suggests that the 256K dynamic RAM will require dimensions as small as 1.0 to 1.5 microns. There is also great interest in achieving dimensions of much less than 1.0 micron. The process generally used for forming electrical circuits on semiconductor wafers includes the steps of (1) applying a material known as a photoresist to the wafer, (2) illuminating the photoresist through a mask to define the pattern of tiny circuits, (3) developing the photoresist and removing (e.g., by chemical washes) either the illuminated or the unilluminated portions, (4) curing (or hardening) the remaining portions of the mask, (5) treating (e.g., with ion implantation, plasma etching, thermal bakes, or other processes) the cured wafer so as to affect only the portions not protected by hardened photoresist, and (6) removing the hardened photoresist. The photoresist materials most commonly used heretofore have been negative photresists (i.e., those in which the unilluminated portions are removed prior to curing) . But to achieve the very narrow dimensions required by the 256K dynamic RAM and other new chips, there has been considerable interest for a number OMPI - Λ < of years in replacing the conventional negative photoresist with a positive photoresist (i.e., one in which illuminated portions are first removed) , to take advantage of the inherently better resolution possible in a positive process. But efforts to satisfactorily cure positive photoresists have not been completely satisfactory. A currently popular technique for curing these photoresists, which are typically based on novolak resins, is to cure by long (e.g., 20 to 30 minutes minutes) exposure to continuous, deep ultraviolet radiation ("deep-UV", less than 300 nanometers and preferably less than 260 nanometers). Such curing is described in Allen et al., "Deep ϋ.V. Hardening of Positive Photoresist Patterns", Journal of the Electrochemical Society, Accelerated Brief Communications (1982) and in Tracy et al. , "Mask Considerations in the Plasma Etching of Aluminum", Solid State Technology (1982). Furthermore, it has been suggested (e.g., by Allen et al., supra) that only deep-UV radiation should be used, to the exclusion of near-UV (wavelengths above 300 nanometers) , which is thought to deleteriously affect curing. Cured photoresist must be resistant to the various treatments, such as ion implantation, plasma etching, and thermal baking, applied to semiconductor wafers during their manufacture. Unfortunately, many of these treatments elevate the temperature of the resist to above the temperature at which it would ordinarily begin plastic flow. Unless the resist can be cured to withstand such elevated temperatures without plastic flow, dimensional integrity of the circuit pattern can be lost and solvents can be OMPI released ("outgassed") from the resist (causing, among other things, loss of vacuum and automatic shutdown in some ion implantation equipment). In addition to the need to raise the flow temperature by curing, there is also a need to harden the resist sufficiently for it to withstand the ion bombardment it receives during ion implantation without being degraded (e.g., surface bubbling, reticulation, cracking, or edge rounding). Allen et al. and Tracy et al. describe some of the undesirable consequences of insufficient curing. Summary of the Invention I have discovered that a magnetic field can be used to catalyze chemical reactions (e.g., polymerization) in a substance. In preferred embodiments, the magnetic field is combined with electromagnetic radiation; the magnetic field and radiation are applied, at least for a time, simultaneously; the radiation is provided by discharge of a flash lamp and has components in the ultraviolet spectrum; both the magnetic field and radiation are time varying (e.g., a plurality of applied pulses); the average magnetic induction is on the same order as or less than the ambient level provided by the earth's magnetic field, whereas the peak induction is much greater (e.g., greater than 25 gauss); the peak level 2 of radiation is 0.1 joules/cm at the surface of the substance; the substance is a carbon composite, a photoresist (e.g., a novolak-resin-based photoresist coating on a semiconductor wafer), an opaque material, a liquid drawn through a pipe, the plastic wall of a pipe (or the plastic insulation on a cable) , a coating on a sheet, or a material that would require exposure to deep-UV radiation if catalyzed by exposure to continuous radiation; the radiation is provided by a flash lamp (e.g., one to which a potential of greater than 4000 volts is applied) ; the flash lamp can be wound in a helix, in which case the substance can be moved through the interior of the helix, or the lamp can be wound in a flat spiral (e.g., one with circular windings) , in which case the substance can be moved in a plane generally parallel to and spaced from the lamp; the magnetic field can be generated by a separate wound electrical conductor (e.g., a wire spiral or helix). The invention provides greatly improved catalysis of chemical reactions. For example, the invention has been applied to curing thermoset resins, i.e., ones normally cured in ovens; excellent curing has been achieved in a tiny fraction of the time normally required using ovens. The invention provides a new technique for curing positive photoresists, one that provides greatly improved resistance of the cured photoresist to ion implantation, plasma etching, thermal baking and other treatments given to semiconductor wafers. The technique provides greater hardness and greatly elevated flow temperatures for the cured photoresist. It has the additional advantages of reduced curing time, greater curing uniformity across the wafer, and greater curing reliability * Also, the cured photoresist remains easily removable (by conventional processes) after completion of treatment. A further advantage is that the technique allows some thermal baking steps to be eliminated; e.g., thermal baking to induce outgassing prior to other treatments may typically be unnecessary because the curing so elevates the plastic flow temperature of the resist that outgassing typically no longer occurs. As applied to curing photoresists, the invention features, in a first aspect, curing the class of photoresists materials consisting of positive photoresists, deep-UV photoresists, and novolak- resin-based photoresists by exposing the photoresist to a magnetic field of greater than ambient strength (i.e., greater than the 0.5 gauss provided by the earth's magnetic field). In preferred embodiments, the photoresist is exposed also to light, preferably light in the near-UV or longer wavelength range as opposed to the deep-UV range; both the light and magnetic field are generated using a flash discharge arc lamp (e.g., an elongated tube wound in a circular spiral or other shape in which adjacent tube portions have current flowing the same direction) ; the magnetic field has a peak magnetic induction of greater than 25 gauss at the photoresist layer; a plurality of light and magnetic discharges are provided by the lamp; the lamp is spaced from the photoresist layer by less than 10 centimeters (and preferably less than 6 centimeters) ; the current 2 density in the lamp is greater than 400 amperes/cm . In another aspect the invention features curing the same class of photoresists by exposing them -to the light output of a flash discharge arc lamp. In another aspect the invention features curing apparatus having means for generating a magnetic field of greater than ambient strength without the generation of light (e.g., a spiral of wire driven by current pulses) and means for positioning the photoresist in the magnetic field. In preferred embodiments, a separate means is provided for generating light (e.g., a flash discharge arc lamp triggered simultaneously to generating the magnetic field). In another aspect the invention features apparatus for curing photoresists, the apparatus including a flash discharge arc lamp composed of an elongated tube wound in a flat configuration in which adjacent tube portions have current flowing in the same direction (e.g., a circular spiral), means for discharging an electrical pulse though the lamp with an electric potential of greater than 4,000 volts, and means for positioning the lamp so that its light output strikes the photoresist. in those preferred embodiments in which negligible light is generated in the deep-UV range, the invention has the further advantage of permitting the flash tube to be operated at low power per unit length, resulting in long tube life. Other advantages and features of the invention will be apparent from the following description of preferred embodiments and from the claims. Description of the Preferred Embodiments Drawings Fig. 1 is a perspective, somewhat diagrammatic, view of a first preferred embodiment. Fig. 2 is a cross-sectional view taken along 2-2 in Fig. 1. Fig. 3 is a partial plan view looking up along 3-3 in Fig. 2, showing the flash lamp. Fig. 4 is a simplified schematic of the electrical circuit driving the flash tube. Fig. 5 is a graphical representation of the spectral content of the radiation emitted by the flash tube of said Fig. 1 embodiment. Figs. 6 and 7 are graphs presenting results of tests conducted on wafers cured with the embodiment of Fig. 1. Figs. 8, 9, and 10 show a second preferred embodiment. Fig. 11 is a perspective, somewhat diagrammatic, view of a third preferred embodiment. Fig. 12 is a cross-sectional view of a fourth preferred embodiment. Fig. 13 is a cross-sectional view of a fifth preferred embodiment. Fig. 14 is a cross-sectional view of a sixth preferred embodiment. Fig. 15 is a perspective view of a seventh preferred embodiment. OMPI s r- , V/ΓPO . Description Referring to Figs. 12-15, there are shown three embodiments in which wire coils 2, which generate a magnetic field, are combined with flash lamps 4, which generate electromagnetic radiation (e.g., ultraviolet light) and augment the magnetic field. The current flowing through"the lamp and coils is in pulses, thereby producing a pulsed magnetic field and pulsed radiation. in Fig. 12 the field and radiation are applied to a planar object 5 (e.g., a graphite-epoxy composite or the photoresist coating on a semiconductor wafer). In Figs. 13 and 15, the coils and lamp are helical and are wrapped around a pipe 7 (e.g., with a transparent quartz wall) , and the field and radiation are applied to liquid industrial chemicals flowing through the pipe. In Fig. 13 the turns of the lamp and wire coils are interspersed, whereas in Fig. 15 they are separated. in Fig. 14, the lamp and coils are also helical, but the object receiving the catalyzing field is a solid tubular member (e.g., the insulation on a wire cable or the wall of a plastic pipe) . Actual tests of the invention have been conducted in several applications. One such application has been curing photoresist materials used in the manufacture of integrated circuits. Example 1. Figs. 1-7 relate to the equipment and process used to test the invention for curing a positive photoresist of the type requiring exposure to deep-UV light when curing is done by long exposure to continuous radiation (hereinafter a "deep-UV photoresist") . Referring to Figs. 1 to 3, there is shown a flash tube (or flash discharge arc lamp) 10 consisting of an elongated quartz (ultraviolet free, Germasil) tube filled with Xenon gas, wound in a flat spiral, and supported within housing 12 on the underside of reflector 14. Electrodes 16, 18 at the ends of the tube are connected via cables (not shown) to an electronic control unit 20 (Xenon RCS-7000, manufactured by Xenon Corporation, Wilmington, Massachusetts) . A trigger wire (nickel) 22 is wrapped around the exterior of the lamp 10 and is also connected to control unit 20. Air hose 24, which also carries the cables to the lamp, is connected between control unit 20 and lamp housing 12. Air supplied through the hose passes through holes (not shown) in reflector 14, to cool flash tube 10. Beneath lamp 10 there is positioned a semiconductor wafer 26, which is supported on the upper surface of work table 28 (which, in large scale operations, would probably be replaced by a moving conveyor carrying a succession of wafers) . The wafer has a photoresist layer 30 on its upper surface. Control unit 20 provides a DC voltage of greater than 5000 volts across flash tube electrodes 16, 18. A simplified schematic of the control unit and flash tube is shown in Fig. 4. A storage capacitor C is connected in parallel with the flash tube, and an inductor L is connected in series. A trigger circuit (which includes a capacitor discharging through a transformer) generates a succession of high-voltage (approximately 30,000 V) pulses, which are supplied to trigger wire 22 wrapped around flash tube 10. Unoxidized wafers (4 inch diameter) were coated with Kodak 820 positive resist, a deep-UV photoresist. The resist film had a thickness of 12,700 Angstroms (plus or minus 200 Angstroms) . All wafers were exposed identically to a mask that included lines with 1.5 micron width as well as other dimensions as large as 0.25 inches. Conventional developing steps were performed to remove illuminated portions of the photoresist. The wafers were then cured by exposing them under flash tube 10 for periods of time ranging from 5 to 40 seconds. The flash tube was spaced a distance of 5.0 cm from the upper surface of the wafer. The spectral output of the tube was as shown in Fig. 5, with negligible energy in the deep-UV range of wavelengths below 260 nanometers. No component of the radiation below 260 nanometers had a relative output greater than 20%. There was also little radiation at wavelengths below 300 nanometers, which is another upper boundary sometimes used to define the deep-UV range. All components below 300 nanometers had less than about 40% relative output. Radiation was predominantly in the wavelength range above 300 OMPI nanometers, the so-called near-UV range. The flash tube and control unit had the following characteristics: tube arc length 90 inches tube internal diameter 7 mm tube external diameter 9 mm shape of tube 7-turn spiral diameter D of spiral " approximately 7 inches gas filling tube Xenon at 250 mm pressure current density in tube 850 amps/cm pulse length 240 microseconds pulse rate 10 pulses per second potential 9500 volts capacitance, C 12 microfarads inductance, L 675 microhenries Pulse length was measured between the points at which the light output is one-third of the maximum light output. After curing was completed some of the wafers were baked at temperatures varying between 150 and 250 degrees C for thirty minutes, to determine the resistance of the cured photoresist to elevated temperatures. After baking the photoresist patterns were measured for deviations in line width. Plots of the variation in line width (microns variation in width) versus bake temperature are given in Fig. 5 for an uncured wafer and for cured wafers with four different curing times (5, 10, 20, and 40 seconds). Wafers cured under the flash tube for 20 and 40 seconds showed no variation in line width even at bake temperatures as high as 250 degrees C. The wafer cured for 40 seconds was then rebaked in a 300 degree C oven for an additional 30 minutes, and rechecked for variation in line width. Again, no variation was found. Another group of wafers was exposed to high dose ion implantation consisting of an arsenic implant at 150 KeV with a dose of 5E 15 on an implanter without wafer cooling. After implantation the resist patterns were measured for variation in line width. Uncured wafers suffered a variation of about 275 millimicrons, whereas wafers cured for 10 seconds- or longer showed almost no variation. But the principal impairment caused by ion implantation was not variation in line width but loss of surface integrity. The resist patterns on the uncured wafers were excessively bubbled, reticulated, and cracked. This was also true to some degree of wafers cured for only 5 or 10 seconds. The wafer cured for 20 seconds showed a significant reduction in such characteristics, and had only a slight amount of edge rounding. The wafer cured for 40 seconds showed no such characteristics and no edge rounding. Example _ Another test of the invention as applied to curing a photoresist is described in Figs. 8, 9, and 10 and in the following paragraphs. Figs. 8, 9, and 10 describe a further alternative embodiment, which is the subject of my pending application Serial No. 401,318 (which is hereby incorporated by reference). Fig. 8 and Fig. 9 are plan and cross-sectional views of the post development cure. Wafer 110 is positioned on work table 111 with developed photoresist coating 112 facing flash lamp 114. Flash lamp 114 is flashed to effect the post development cure. The details of the method are best explained by example. Semiconductor wafer 10 was 3 inches in diameter and carried a developed photoresist coating 1.5 microns thick of AZ-5000 a positive photoresist of AZ Photoresist Products, So erville, New Jersey. Flash lamp parameters: arc length 16 inches bore 7 mm outside diameter 9 mm shape 3-turn spiral spiral diameter 3 inches fill Xenon at 250 mm pressure 2 current density 1560 amps/cm pulse length 140 microseconds pulse rate 7 pulses per second voltage 3200 volts capacitance 32 microfarads inductance 100 microhenries In this example, the spacing between the surface of photoresist 112 and the outside of the lamp envelope was 7.0 mm. The full time of exposure was two seconds. The spectral distribution of the lamp output was substantially that shown in solid curve 1 of Fig. 10. The photoresist was completely cured. The parameters given in the above example are subject to considerable variation. Lamps have been made in a zig-zag (serpentine) and other shapes. Lamps may be operated in series, in parallel or in a combination. The spacing between the lamp and the photoresist is preferably less than 10.0 cm and most preferably less than 6.0 cm for efficiency. The pulse rate is preferably greater than one pulse per second. The electrical current density in the lamp is preferably OMPI Vv'IPO 2 greater than 400 amps/sec and preferrably less than 2 2000 amperes/cm . The pulse length, fill pressure and gas mixture are important in obtaining the desired spectral output. Variations can be used as long as they do not cause substantial changes in the spectral output. In the sample above, there was negligible loss in resolution and after the integrated circuits had been formed, the photoresist removed cleanly in the removal step. Fig. 10 depicts the spectral distribution curve (curve 1) that has produced the unexpected results. It shows high output in the 800 to 1100 nanometer wavelength region. Curve 2 shows the deep-UV spectral distribution that the prior art regarded as necessary to cure positive photoresists. Example 3_ A graphite-epoxy composite material (manufactured by Fiberite Corporation) of the type used for high-strength, light weight structural elements was cured using the apparatus of Figs. 1-5. Approximately twelve 2 inch by 2 inch layers of the composite were stacked together and vacuum compressed, to give interlayer adhesion. The compressed stack was approximately 1/10 inch thick. The composite was positioned about 5.0 cm from the lamp and exposed for approximately five minutes, at the end of which period curing was complete. To achieve the same curing by the conventional baking process would take several hours. The spectral output of the tube was as shown in Fig. 5, with negligible energy in the deep-UV range of wavelengths below 260 nanometers. The flash tube and control unit had the following characteristics: tube arc length 90 inches tube internal diameter 7 mm tube external diameter 9 mm shape of tube 7-turn spiral diameter D of spiral approximately 7 inches gas filling tube Xenon at 250 mm pressure 2 current density in tube 850 amps/cm pulse length 240 microseconds pulse rate 10 pulses per second potential . 9500 volts capacitance, C 12 microfarads inductance, L 675 microhenries Pulse length was measured between the points at which the light output is one-third of the maximum light output. Example _4 A thermoset insulating varnish (General Electric 702C Solventless Varnish) , an unsaturated polyester resin, of the type used to impregnate DC traction motors was cured using the apparatus of Figs. 1-5. Approximately one teaspoonful of the varnish was spread onto a glass slide to a thickness of approximately 1/16 inch. The slide was positioned . approximately 5.0 cm beneath the flash lamp and exposed for 120 seconds, at the end of which period curing was complete. To achieve the same curing by the conventional baking process would take 4 to 6 hours. The spectral output of the tube was as shown in Fig. 5, with negligible energy in the deep-UV range of O PI * ΛYIPO wavelengths below 260 nanometers. The flash tube and control unit had the following characteristics: tube arc length 90 inches tube internal diameter 7 mm tube external diameter 9 mm shape of tube 7-turn spiral diameter D of spiral approximately 7 inches gas filling tube Xenon at 250 mm pressure 2 current density in tube 850 amps/cm pulse length 240 microseconds pulse rate 10 pulses per second potential 9500 volts capacitance, C 12 microfarads inductance, L 675 microhenries Pulse length was measured between the points at which the light output is one-third of the maximum light output. Another preferred embodiment is shown in Fig. 11, wherein a wire 50 wound in a spiral, positioned beneath the flash tube, and connected electrically in series therewith (so that current passing through the lamp also passes through the wire) is provided to strengthen the magnetic field. It is believed that the improved catalysis (e.g., curing) achieved by the invention is due to the high magnetic field generated in conjunction with the light output. It is estimated that the magnetic field produced has a peak magnetic induction of the order of 75 gauss at the photoresist. A peak magnetic induction of at least 25 gauss is preferable. The magnetic field has an average magnetic induction of only 0.15 gauss, a level low enough not to damage electrical components (e.g., integrated circuits, including those already formed on a semiconductor wafer being treated) . The magnetic field is believed to work in conjunction with the light, e.g., to promote the growth of larger polymerized molecules, and thus, in the photoresist application, greater hardness and higher flow temperature. It is thought that this is achieved by virtue of the magnetic field acting to reduce the influence of competitive mechanisms that tend, in the absence of the field, to stop the polymerization process. One way in which the light and magnetic field may cooperate is as follows: The light raises the photoresist molecules to a first elevated energy state in which they are made paramagnetic. Then, the magnetic field raises the molecules to an even higher energy state. The result is that the molecules remain in an elevated energy state for a longer time interval and thus there is more time for them to combine and form larger molecules. The magnetic field has an advantage over light in that it can deeply penetrate opaque materials such as photoresists. Measurements of photoresist layers cured with the magnetic field show evidence of- very deep curing. To enhance the magnetic field, the flash tube has a long length per unit area of lamp coverage (achieved in some preferred embodiments by winding the elongated tube in a spiral with little separation between the revolutions), is positioned close to the photoresist layer, and is driven at the high voltages and currents. OKPI Given that the strength of the magnetic field increases with the magnitude of the current flowing through the tube, it is generally desirable to choose lamp configurations that enhance current flow by reducing lamp impedance. But it appears that a serpentine shape lamp, in which adjacent tube portions would have oppositely directed current flow and in which there would therefore be reduced lamp impedance, provides a less powerful magnetic field than the spiral design of the preferred embodiment, owing (it is ' believed) to a cancellation effect on magnetic fields generated by adjacent tube portions. The serpentine tube may, however, be advantageous in some applications. An advantage of generating the magnetic field and light using an elongated tube bent into a wide area configuration (e.g., a flat spiral), versus using an ordinary straight tube (and reflector for spreading out the light) , is that the magnetic field is stronger and more uniform at the photoresist layer. Another advantage of that configuration is that the lamp power per unit tube length can be kept lower, thereby resulting in much longer tube life. Other Embodiments Other embodiments are within the scope of the following claims. For example, it may be possible to achieve catalysis solely with a magnetic field. It may be possible to use a continuous magnetic field in combination with a pulsed light. It may also be possible to use continuous light. Different shape flash tubes, e.g., a non circular spiral, may be OMM used; preferably the lamp tube should be wound in a configuration in which adjacent tube portions have current flowing in the same direction. Claims What is claimed is:

Claims: Claims 1. The method of catalyzing a chemical reaction in a substance of a type in which a chemical reaction can be catalyzed by a magnetic field, said method comprising the step of applying to said substance a magnetic field of sufficient (and greater than ambient) strength to catalyze said chemical reaction, said magnetic field being generated by means other than a discharge through a flat spiral or flat serpentine flash lamp. 2. The method of claim 1 wherein said substance is of a type in which a chemical reaction can be catalyzed by the combined effects of a magnetic field and electromagnetic radiation and wherein said method further comprises the step of applying electromagnetic radiation to said substance. 3. The method of claim 2 wherein said magnetic field and electromagnetic radiation are applied, at least for a time, simultaneously. 4. The method of claim 2 wherein said electromagnetic radiation is the discharge from a flash lamp. 5. The method of claim 4 wherein said electromagnetic radiation includes components in the ultraviolet spectrum. 6. The method of claim 2 wherein said magnetic field and electromagnetic radiation are time varying and the peak magnetic induction exceeds ambient levels. 7. The method of claim 6 wherein the average magnetic induction is on the same order of or less than ambient levels. 8. The method of claim 6 wherein said magnetic field is pulsed from one level to another. 9. The method of claim 8 wherein at said one level there is applied substantially zero magnetic induction. 10. The method of claim 8 wherein a plurality of pulses are applied to said substance. 11. The method of claim 8 wherein said electromagnetic radiation is pulsed from one level to anothe . 12. The method of claim 2 wherein said electromagnetic radiation has a peak intensity greater 2 than 0.1 joules/cm at the surface of said substance. 13. The method of claim 12 wherein said magnetic field has a peak magnetic induction greater than 25 gauss at the surface of said substance. 14. The method of claim 2 wherein said catalyzed chemical reaction includes polymerization. 15. The method of claim 14 wherein said substance comprises unsaturated monomers. 16. The method of claim 2 wherein said substance consists of a carbon composite structure. 17. The method of claim 2 wherein said substance consists of an opaque material so thick that said chemical reaction cannot be catalyzed throughout its depth by exposure only to electromagnetic radiation. 18. The method of claim 2 wherein said substance is moved with respect to said magnetic field and electromagnetic radiation while said chemical reaction is being catalyzed. 19. The method of claim 18 wherein said substance consists of a liquid drawn through a pipe which is exposed to said magnetic, field and electromagnetic radiation. 20. The method of claim 18 wherein said substance consists of the plastic wall of a pipe drawn past said magnetic field and electromagnetic radiation. 21. The method of claim 18 wherein said substance consists of a coating on a continuously moving sheet. 22. The method of curing the class of photoresist materials consisting of positive photoresists, deep-UV photoresists, and novolak-resin- based photoresists, comprising the steps of positioning said photoresist material in the path of light generated by a flash discharge arc lamp and discharging at least one electrical pulse through said lamp. OMPI 23. The method of curing the class of photoresist materials consisting of positive photoresists, deep-UV photoresists, and novolak-resin- based photoresists, comprising the step of positioning said photoresist material in a magnetic field of greater than ambient strength. 24. The method of claim 23 further comprising exposing said photoresist material to light as well as said magnetic field. 25. The method of claim 24 wherein said light and magnetic field are applied to said material simultaneously. 26. The method of claim 25 wherein said 'light is generated by discharging at least one electrical pulse through a flash discharge arc lamp. 27. The method o claim 23 wherein said magnetic field provides a peak magnetic induction at the photoresist of greater than 25 gauss. 28. The method of claim 27 wherein said magnetic field is time varying. 29. The method of claim 28 wherein said magnetic field is pulsed. 30. The method of claim 26 wherein said light has negligible spectral content at wavelengths below 260 nanometers, negligible meaning that the relative intensity of spectral components below 260 nanometers is less than 20 percent. 31. The method of claim 26 wherein said light is composed predominantly of near-UV or greater wavelength radiation. 32. The method of claim 22 wherein said light has negligible spectral content at wavelengths below 260 nanometers, negligible meaning that the relative intensity of spectral components below 260 nanometers is less than 20 percent. 33. The method of claim 22 wherein said light is composed predominantly of near-UV or greater wavelength radiation. 34. The method of claim 22 wherein said flash lamp generates a short duration magnetic field upon being discharged. 35. The method of claim 34 wherein said lamp comprises an elongated tube wound in a flat configuration in which adjacent tube portions have current flowing in the same direction. 36. The method of claim 35 wherein said configuration is a spiral. 37. The method of claim 36 wherein there are in excess of four revolutions in said spiral. 38. The method of claim 35 wherein around the exterior of said tube is wound a trigger wire for generating said flash discharge. OMPI 39. The method of claim 29 wherein a plurality of flash discharges are applied to said wafer 40. The method of claim 39 wherein the exposed surface of said photoresist material is spaced from said lamp by less than 10.0 cm. 41. The method of claim 40 wherein the repetition rate of said discharges is greater than one pulse per second. 42. The method of claim 29 wherein said lamp extends across at least 80% of the area of said wafer. 43. The method of claim 38 wherein the exposed surface of said phtoresist material is spaced from said lamp by less than 6.0 cm. 44. The method of claim 29 wherein the current density in said lamp during said discharge 2 is greater than 400 amperes/cm . 45. Apparatus for catalyzing a chemical reaction in a substance, said apparatus comprising a flash lamp comprising an elongated tube wound in a manner selected to enhance the magnetic field generated thereby, means for discharging an electrical pulse through said lamp by applying a potential across said lamp of greater than 4000 volts, and means for positioning said substance with respect to said lamp so that the light and magnetic output of said lamp strikes said substance. 46. The apparatus of claim 45 wherein said flash lamp is wound in a helix and said means for positioning said substance comprises means for moving said substance through the interior of said helix. 47. The apparatus of claim 46 wherein said tube is wound in a flat spiral and said means for positioning said substance comprises means for moving said substance in a plane generally parallel and spaced from said flat spiral. 48. The apparatus of claim 45 wherein said substance is a photoresist material. 49. The apparatus of claim 48 wherein said light has negligible spectral content at wavelengths below 260 nanometers, negligible meaning that the relative intensity of spectral components below 260 nanometers is less than 20 percent. 50. The apparatus of claim 48 wherein said light is composed predominantly of near-UV or greater wavelength radiation. 51. The apparatus of claim 48 wherein said tube is wound in a flat configuration in which adjacent tube portions have current flowing in the same direction. 52. The apparatus of claim 51 wherein said tube is wound in a spiral. 53. The apparatus of claim 48 further comprising means for generating a plurality of said flash discharges. 54. The apparatus of claim 52 wherein the repetition rate of said discharges is greater than one pulse per second. 55. The apparatus of claim 52 wherein the windings of said spiral are circular. 56. Apparatus for catalyzing a chemical reaction in a substance, said apparatus comprising magnet means for generating a magnetic field without the generation of light, and means for positioning said substance with., respect to said magnet means so that said magnetic field envelopes said substance. 57. The apparatus of claim 56 wherein said magnet means comprises an elongated electrical conductor wound so as to enhance said magnetic field. 58. The apparatus of claim 57 wherein said electrical conductor is wound in a flat spiral and said means for positioning said substance comprises means for positioning said substance in a plane generally parallel to said spiral and spaced therefrom. 59. The apparatus of claim 56 wherein said electrical conductor is wound in a helix and said means for positioning said substance comprises means for moving said substance through the interior of said helix. 60. The apparatus of claim 58 wherein the windings of said spiral are circular. 61. The apparatus of claim 59 wherein said means for positioning said substance comprises a pipe passing through said helix for carrying said substance past said magnet means. 62. The apparatus of claim 46 wherein .said means for positioning said substance comprises a pipe passing through said helix for carrying said substance past said magnet means. 63. The apparatus of claim 45 wherein the magnetic field generated by said flash lamp produces a magnetic induction of greater than 25 gauss at the position of said substance. 64. The apparatus of claim 56 wherein the magnetic field generated by said flash lamp produces a magnetic induction of greater than 25 gauss at the position of said substance. 65. The apparatus of claim 56 wherein said substance is a photoresist material. 66. The apparatus of claim 65 further comprising light means for exposing said photoresist to light. 67. The apparatus of claim 66 further comprising means for synchronizing said light and magnet means so that said light and magnetic field are applied simultaneously to said photoresist. 68. The apparatus of claim 67 wherein-said light is generated by discharging at least one electrical pulse through a flash discharge arc lamp. 69. The apparatus of claim 65 wherein said magnetic field provides a peak magnetic induction at the photoresist of greater than 25 gauss. 70. The apparatus of claim 69 wherein said magnetic field is time varying. 71. The apparatus of claim 70 wherein said magnetic field is pulsed. 72. The apparatus of claim 66 wherein said light has negligible spectral content at wavelengths below 260 nanometers, negligible meaning that the relative intensity of spectral components below 260 nanometers is less than 20 percent. 73. The apparatus of claim 66 wherein said light is composed predominantly of near-UV or greater wavelength radiation. 74. The apparatus of claim 68 wherein said magnet means comprises an electrical conductor separate from said lamp. 75. The apparatus of claim 74 wherein said lamp comprises an elongated tube wound in a flat configuration and positioned so that its light output strikes the exposed surface of said photoresist and wherein said electrical conductor forming said magnet means is also wound in a flat configuration and the planes of said flat lamp and flat wound conductor are generally parallel to the plane of the photoresist. 76. The apparatus of claim 75 wherein said electrical conductor is positioned between said lamp and said photoresist. 77. The apparatus of claim 74 wherein said electrical conductor is wound in a spiral. 78. The apparatus of claim 74 wherein said wire is electrically connected in series with said lamp, 79. The method of claim 22 wherein said class of photoresists consists only of positive photoresists. 80. The method of claim 22 wherein said class of photoresists consists only of deep-UV photoresists. 81. The method of claim 22 wherein said class of photoresists consists only of novolak-resin-based photoresists. 82. The method of claim 23 wherein said class of photoresists consists only of positive photoresists. 83. The method of claim 23 wherein said class of photoresists consists only of deep-UV photoresists. 84. The method of claim 23 wherein said class of photoresists consists only of novolak-resin-based photoresists. OMPI

Inventors: PANICO C RICHARD, PANICO, C., RICHARD
Applicants: XENON CORP, XENON CORPORATION
Application year: 1983
Main classification: B01J19
IPC codes: B01J19, B05D3, G03F7