Claims
- 1. Process for controlling a reactive etching process of a stack of layers with at least one first layer of high refractive index material and, above it, a second layer of low refractive index material, the first layer being MeO.sub.x Me being a metal whose atomic mass is at least 44, x being selected so that the coefficient of absorption k of the layer material at light of wavelength .lambda.=308 nm is k.sub.308 .ltoreq.0.01, the second layer being SiO.sub.2, the process comprising: etching the second layer using a gas without a chlorine fraction, the point at which the surface of the first layer is reached being detected and subsequent using another gas which has a chlorine fraction, for further etching.
- 2. Process according to claim 1, wherein the stack being etched in a stepped manner for the formation of an at least one step in thickness.
- 3. Process according to claim 1, wherein x is selected so that k.sub.308 .ltoreq.0.003.
- 4. Process according to claim 1, wherein Me is Ta and x is 2.5, the dielectric layer being applied being Ta.sub.2 O.sub.5.
- 5. Process according to claim 1, wherein Me is Hf and x is 2, the dielectric layer being applied being HfO.sub.2.
- 6. Process according to claim 1, wherein said other gas comprises a combination of Cl.sub.2 with at least one of further gases H.sub.2, F.sub.2, CF.sub.4, SF.sub.6.
- 7. Process of claim 1, including homogeneously distributing said gas and said another gas over a surface region to be etched, thereby distributing said gas and said other gas substantially vertically onto said surface region.
- 8. Process of claim 1, including activating at least one of said gas and said other gas, using at least one of charges particles selected from the group consisting of electrons and ions.
- 9. Process of claim 1, including enhancing at least one of said etching and of said further etching by photons.
- 10. Process of claim 1, including providing a carrier electrode to carry the stack of layers, and a counter-electrode spaced from the carrier electrode, and maintaining a glow discharge between the electrode in a direction of discharge for acitivating at least one of said gas and said another gas and supplying said at least one of said gas and said another gas using a nozzle for directing gas substantially in the direction of the discharge.
- 11. Process of claim 1, including supplying at least one of said gas and said another gas through a gas inlet and cooling said gas inlet.
- 12. Process of claim 1, further providing said low refractive index material as a doped material.
- 13. Process of claim 12, further comprising the step of detecting the moment when said first layer is reached by said reactive etching process by detecting a change of emitted light radiation.
- 14. Process of claim 13, wherein the other layer is doped with alkaline earth ions.
- 15. Process of claim 1, wherein said stack of layers with at least two layers is deposited on a glass substrate containing alkaline earth ions.
- 16. Process of claim 1, including directing at least one light beam with a spectral range in which said stack of layers is transmitting onto and through one side of said stack which is not being etched, to an opposite side of said stack which is being etched, and monitoring refracted light of said beam as an indication of etch depths.
- 17. Process according to claim 1, wherein
- Me=Y and
- x=1.5
- and consequently the layer is Y.sub.2 O.sub.3.
- 18. Process of claim 1, including using for etching said first layer, a fluorine containing gas.
- 19. Process according to claim 1, wherein the other gas comprises CHClF.sub.2.
- 20. Process according to claim 19, wherein the other gas includes at least one of He, CHF.sub.3 and H.sub.2.
- 21. A process for fabrication of a mask for UV-laser ablation in a semiconductor technique, comprising the steps of:
- applying a dielectric layer of HfO.sub.2 onto a base of a substrate, so that the coefficient of absorption k of said dielectric layer material at light with a wave-length .lambda.=308 nm is
- k.sub.308 .ltoreq.0.01
- and mask patterning said dielectric layer by reactive plasma etching.
- 22. Process according to claim 21, wherein k.sub.308 .ltoreq.0.003.
- 23. Process according to claim 21, wherein a gas which is activated for the etching comprises CHClF.sub.2.
- 24. Process according to claim 23, wherein the gas to be activated further includes at least one of He, CHF.sub.3 and H.sub.2.
- 25. Process according to claim 21, wherein a gas to be activated for the etching comprises a combination of Cl.sub.2 with at least one of the further gases H.sub.2, F.sub.2, CF.sub.4, and SF.sub.6.
- 26. Process according to claim 21, including, before the etching step, covering the dielectric layer at least partially with a layer of low refractive index material as compared to the dielectric layer, and reactively etching the layer of low refractive index with an activated gas which is essentially without a chlorine fraction and which has a fluorine fraction which etches the HfO.sub.2 layer at a substantially reduced rate.
- 27. Process according to claim 21, wherein a further layer is disposed on said dielectric layer and wherein said further layer is reactively etched with a gas which is essentially free of a Cl.sub.2 fraction in such a way that said dielectric layer acts as an etch stop layer for said etching of said further layer.
- 28. Process according to claim 21, including homogeneously distributing a gas during the etching using a nozzle over a surface region to be etched, the gas being distributed substantially vertically onto the surface region, a density of reactive gas species in the gas being selected to be substantially homogeneous near the surface region.
- 29. Process according to claim 21, including activating a gas during the etching using at least one of the charged particles selected from the group consisting of electrons and ions.
- 30. Process according to claim 21, including enhancing the etching step using photons.
- 31. Process according to claim 21, including providing a carrier electrode and a counter-electrode spaced from the carrier electrode, maintaining a glow discharge between the carrier electrode and the counter-electrode for activating a gas, and supply the gas to the dielectric layer using a nozzle for directing the gas substantially in the direction of the discharge.
- 32. Process according to claim 21, including supplying a gas during the etching through a gas inlet and cooling the gas inlet.
- 33. Process according to claim 21, wherein at least one other layer made of low reflective index material, is applied under said dielectric layer so that at a moment when the other layer is reached by the etching, a change of emitted light radiation occurs which can be detect.
- 34. Process according to claim 33, wherein the other layer is doped with alkaline earth ions.
- 35. Process according to claim 21, wherein the substrate comprises glass containing alkaline earth ions which generates emitted light radiation detectably different from emitted light of said dielectric layer when exposed to a reactive glow discharge-enhanced etching process the etching including activating a gas using a reactive glow discharge.
- 36. Process according to claim 21, further comprising directing at least one light beam with a spectral range in which the dielectric layer is light-transmitting, onto and through one side of the dielectric layer, which is not reactively etched to an opposite side of the dielectric layer, which is being reactively etched, and evaluating etching depths from monitoring refracted light of said light beam, and drawing conclusions about a remaining coating thickness of material on the opposite side of the structural element from changes in the reflected light.
- 37. Process according claim 21, including using for the etching of the HfO.sub.2 layer a fluorine-containing gas.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2292/92 |
Jul 1992 |
CHX |
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Parent Case Info
This application is a division of application Ser. No. 07/970,080, filed Nov. 2, 1992, now abandoned.
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0049799 |
Apr 1982 |
EPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
970080 |
Nov 1992 |
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