WO1992000609A1 - Plasma etching indium tin oxide using a deposited oxide mask - Google Patents

Plasma etching indium tin oxide using a deposited oxide mask Download PDF

Info

Publication number
WO1992000609A1
WO1992000609A1 PCT/US1991/004347 US9104347W WO9200609A1 WO 1992000609 A1 WO1992000609 A1 WO 1992000609A1 US 9104347 W US9104347 W US 9104347W WO 9200609 A1 WO9200609 A1 WO 9200609A1
Authority
WO
WIPO (PCT)
Prior art keywords
ito
plasma
layer
deposited
deposited oxide
Prior art date
Application number
PCT/US1991/004347
Other languages
French (fr)
Inventor
Paul L. Roselle
Original Assignee
Eastman Kodak Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eastman Kodak Company filed Critical Eastman Kodak Company
Publication of WO1992000609A1 publication Critical patent/WO1992000609A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • H01L31/1884—Manufacture of transparent electrodes, e.g. TCO, ITO

Definitions

  • the present invention relates to the plasma etching of indium tin oxide.
  • Solid state CCD image sensors often employ a double polysilicon gate structure to form the sensor electrodes.
  • Such a structure has the first polysilicon electrode (poly-1) separated from the second polysilicon electrode ( ⁇ oly-2) by a thin insulating layer of silicon dioxide.
  • Poly—1 is slightly overlapped by poly-2.
  • the systematic variation of the potential applied to these electrodes referred to as clocking, permits the device to function.
  • clocking permits the device to function.
  • light passes through the polysilicon electrodes and creates electron hole pairs in the underlying silicon. These electrons are accumulated prior to clocking the polysilicon electrodes to remove the accumulated charge.
  • the polysilicon electrodes, through which light must pass, are not entirely transparent. This lack of transparency results in the reduction of sensitivity and spectral response of the image sensor.
  • indium tin oxide would be an effective electrode for such a device.
  • the use of an indium tin oxide electrode enhances the blue response and overall sensitivity of a frame transfer image sensor.
  • the effective ASA of the device could be increased by as much as a factor of two.
  • ITO can be used as an antistatic coating on materials such as webs used in the manufacture of photosensitive materials. Thereagain, it is difficult to use such a material because it is not practical to pattern it. Disclosure of the Invention
  • a plasma containing methyl radicals (CH 3 ») and Ar ions can effectively etch indium tin oxide, anisotropically.
  • a deposited oxide mask in place of a photoresist mask, the masking oxide is not attacked by the process so higher etch power can be used resulting in higher ITO etch rates (600-700A/min.).
  • a method of etching a layer of ITO on a substrate comprising the steps of: forming a deposited oxide layer on the ITO layer; coating and patterning a microlithographic photoresist layer on the deposited oxide layer to expose portions of the deposited oxide layer; etching the exposed deposited oxide portions and removing the patterned photoresist layer; and igniting a plasma containing CH 3 * where the CH 3 » etch the exposed ITO portions thereby transferring the pattern into the ITO, anisotropically.
  • FIG. 1 is a schematic, in partial cross--sec ⁇ ,.ion, of a conventional plasma etcher which uses radio frequency energy to ignite and sustain the plasma;
  • FIG. 2 is a schematic, in partial cross—section, of another plasma etcher which uses microwave energy to ignite and sustain the plasma; and FIG. 3a-c shows various steps in patterning an ITO layer employing a deposited oxide mask formed on an Si0 2 insulating layer provided on a silicon substrate.
  • a plasma is a state of matter in which the gases in a vessel with a total pressure less than atmospheric pressure are partially ionized by an electric field.
  • an electric field can be from a radio frequency generator, microwave frequency generator or DC voltage field.
  • a plasma ignited by the action of such an electric field on a mixture of CH ⁇ gas, and Ar gas, will contain methyl radicals (CH 3 «) as well as other species generated from the cracking of the molecules of CH ⁇ .
  • CH 3 « methyl radicals
  • concentrations of the various species in the plasma depend upon the power and frequency of the electric field applied, the pressure.of the plasma, and the concentrations of the gases used.
  • the selectivity of the plasma to photoresist is also dependent upon the process parameters used. Power is an especially critical parameter in that higher powers result in higher ITO etch rates but also cause photoresist reticulation for this process. Higher powers do not affect Si0 2 etch rates.
  • CH, and Ar mixtures are not the only means of producing methyl radicals (CH 3 ») and that mixtures of ethane, propane, or other organic compounds will result in methyl radical creation in plasma and will, in so doing, ' etch ITO.
  • a wafer 18 is placed on a lower electrode 15 which is connected to an RF radiation source 28. Vacuum is achieved in the chamber by the use of an oil diffusion pump and rotary vacuum pump, not shown.
  • the lower electrode 15 is heated by resistive heaters 16 located on the back of the electrode.
  • the CH, and Ar gases are admitted into the chamber through a diffuser 26.
  • the flows of the gases are regulated by mass flow controllers 24 and 30.
  • Process pressure in the vessel is controlled by a vacuum throttle valve 21. When the desired flow rates, pressure and temperature are achieved, a plasma of CH, and Ar is ignited in a space 30 between the lower electrode 15, on which the wafer 18 sits, and an upper electrode 12.
  • the resultant CH 3 » generated in region 30 will react with the ITO- on the wafer 18 volatilizing the ITO off the wafer to be pumped away by the vacuum pump.
  • the partial pressure of CH must be maintained below the polymerization point of the plasma.
  • Such polymerization produced by too high of a pressure and/or too high of a concentration of CH, will prevent ITO from etching uniformly.
  • the use of Ar is effective in achieving higher etch rates through ion bombardment of the surface of the ITO.
  • the source of the plasma excitation is a microwave generator 10 located on top of the vacuum chamber.
  • a wafer 20 is placed on a lower electrode 19 which can be biased by an additional power source if needed.
  • Vacuum is achieved with a vacuum pump (not shown) .
  • CH, and Ar gases are admitted into the plasma generation region 17.
  • the flows of the gases are .controlled by mass flow controllers 14 and 26 and the pressure in the chamber is maintained by a throttle valve 25.
  • the microwave energy is sent' into the plasma generating region 17 through a wave guide 11 where it partially ionizes the gases into a plasma state.
  • the CH 3 » species generated in this plasma travel to the wafer 20 and etch the exposed ITO off of the wafer.
  • FIGS. 3a-c show the process of pattern transfer for the definition of ITO where the etched ITO is to be used as a gate electrode.
  • microlithographic photoresist mask 34 has been coated and patterned in a conventional manner on the surface of a deposited oxide layer 32 which has been deposited on an ITO layer 31 deposited on an Si0 2 layer 28 on a silicon substrate 26.
  • ITO is most usually deposited by RF sputter deposition.
  • Oxide can be deposited using conventional deposition techniques such as chemical vapor deposition, plasma enhanced vapor deposition and electron—cyclotron resonance based deposition.
  • the key factor for the deposited oxide is that the temperature of deposition stay below about 800 ⁇ C. Above 850 ⁇ C ITO undergoes a phase change that would make it unsuitable for this use.
  • the deposited oxide layer 32 has been etched by either a conventional wet HF oxide etch or plasma oxide etch, and thereafter the photoresist has been removed by a conventional 0 2 plasma strip. This transfers the photoresist pattern into the deposited oxide and exposes the ITO layer 31 for the next step.
  • the ITO layer 31 has been etched anisotropically by the plasma of CH-» and Ar thereby transferring the deposited oxide pattern into the ITO and stopping on the Si0 2 layer 28. Measurements have shown that the plasma of CH 3 » and Ar + that etches the ITO has a high selectivity to both the masking deposited oxide 32 and the underlying Si0 2 layer 28.
  • etching of ITO is believed to be caused by methyl radicals reacting with indium and tin to create volatile organometallic compounds as shown by the following reaction: plasma CH 4 +Ar > CH 3 » +In+Sn+0-»-In(CH 3 ) 3 t+Sn(CH 3 ) 4 f+COt+Ar +
  • FIG. 1 An etcher similar to the one represented by FIG. 1 was used to etch ITO.
  • the radio frequency used to ignite and sustain the plasma was 13.56 megahertz at 85 watts forward power .
  • the wafer was heated to a temperature of 70°C.
  • the chamber was
  • ITO is transparent and can be most effectively used as electrodes in CCD image sensors.
  • the present method facilitates patterning ITO.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Drying Of Semiconductors (AREA)

Abstract

The use of a deposited oxide mask permits higher power to be used when ITO is etched by a plasma containing CH3. and AR+ thereby increasing the etch rate of ITO.

Description

P ASMA ETCHING INDIUM TIN OXIDE USING A DEPOSITED OXIDE MASK Technical Field
The present invention relates to the plasma etching of indium tin oxide. Background Art
Solid state CCD image sensors often employ a double polysilicon gate structure to form the sensor electrodes. Such a structure has the first polysilicon electrode (poly-1) separated from the second polysilicon electrode (ρoly-2) by a thin insulating layer of silicon dioxide. Poly—1 is slightly overlapped by poly-2. The systematic variation of the potential applied to these electrodes, referred to as clocking, permits the device to function. In the case of frame transfer CCD image sensors, light passes through the polysilicon electrodes and creates electron hole pairs in the underlying silicon. These electrons are accumulated prior to clocking the polysilicon electrodes to remove the accumulated charge. The polysilicon electrodes, through which light must pass, are not entirely transparent. This lack of transparency results in the reduction of sensitivity and spectral response of the image sensor.
Due to its transparency, it has been recognized that indium tin oxide would be an effective electrode for such a device. The use of an indium tin oxide electrode enhances the blue response and overall sensitivity of a frame transfer image sensor. In fact, it has been recognized that if indium tin oxide were to be used in such a device the effective ASA of the device could be increased by as much as a factor of two. -.One reason that ITO has not been used on such devices is because it is difficult to pattern such material. Heretofore, the only practical method for etching indium tin oxide has been by immersion in a hot hydroiodic acid solution. Such an acid etches the material isotropically and is not selective to photoresist. These two reasons alone show the difficulties involved in using ITO for microelectronic applications where small features are defined by photoresist lithography.
It has also been recognized that ITO can be used as an antistatic coating on materials such as webs used in the manufacture of photosensitive materials. Thereagain, it is difficult to use such a material because it is not practical to pattern it. Disclosure of the Invention
It is the object of this invention to provide a new method for the etching of indium tin oxide.
A plasma containing methyl radicals (CH3») and Ar ions can effectively etch indium tin oxide, anisotropically. By using a deposited oxide mask, in place of a photoresist mask, the masking oxide is not attacked by the process so higher etch power can be used resulting in higher ITO etch rates (600-700A/min.).
The above object is achieved in a method of etching a layer of ITO on a substrate, comprising the steps of: forming a deposited oxide layer on the ITO layer; coating and patterning a microlithographic photoresist layer on the deposited oxide layer to expose portions of the deposited oxide layer; etching the exposed deposited oxide portions and removing the patterned photoresist layer; and igniting a plasma containing CH3* where the CH3» etch the exposed ITO portions thereby transferring the pattern into the ITO, anisotropically. Brief Description of the Drawings
FIG. 1 is a schematic, in partial cross--secτ,.ion, of a conventional plasma etcher which uses radio frequency energy to ignite and sustain the plasma;
FIG. 2 is a schematic, in partial cross—section, of another plasma etcher which uses microwave energy to ignite and sustain the plasma; and FIG. 3a-c shows various steps in patterning an ITO layer employing a deposited oxide mask formed on an Si02 insulating layer provided on a silicon substrate. Mode of Carrying Out the Invention
With reference to FIGS. 1, 2 and 3a-3c, a process for the plasma etching of indium tin oxide is described.
A plasma is a state of matter in which the gases in a vessel with a total pressure less than atmospheric pressure are partially ionized by an electric field. As is well understood, such an electric field can be from a radio frequency generator, microwave frequency generator or DC voltage field.
A plasma, ignited by the action of such an electric field on a mixture of CH^ gas, and Ar gas, will contain methyl radicals (CH3«) as well as other species generated from the cracking of the molecules of CH^. As in any plasma, the concentrations of the various species in the plasma depend upon the power and frequency of the electric field applied, the pressure.of the plasma, and the concentrations of the gases used. The selectivity of the plasma to photoresist is also dependent upon the process parameters used. Power is an especially critical parameter in that higher powers result in higher ITO etch rates but also cause photoresist reticulation for this process. Higher powers do not affect Si02 etch rates. It should be understood that CH, and Ar mixtures are not the only means of producing methyl radicals (CH3») and that mixtures of ethane, propane, or other organic compounds will result in methyl radical creation in plasma and will, in so doing,' etch ITO.
For an etcher as represented in FIG. 1, a wafer 18 is placed on a lower electrode 15 which is connected to an RF radiation source 28. Vacuum is achieved in the chamber by the use of an oil diffusion pump and rotary vacuum pump, not shown. The lower electrode 15 is heated by resistive heaters 16 located on the back of the electrode. The CH, and Ar gases are admitted into the chamber through a diffuser 26. The flows of the gases are regulated by mass flow controllers 24 and 30. Process pressure in the vessel is controlled by a vacuum throttle valve 21. When the desired flow rates, pressure and temperature are achieved, a plasma of CH, and Ar is ignited in a space 30 between the lower electrode 15, on which the wafer 18 sits, and an upper electrode 12. The resultant CH3» generated in region 30 will react with the ITO- on the wafer 18 volatilizing the ITO off the wafer to be pumped away by the vacuum pump. The partial pressure of CH, must be maintained below the polymerization point of the plasma. Such polymerization produced by too high of a pressure and/or too high of a concentration of CH, will prevent ITO from etching uniformly. The use of Ar is effective in achieving higher etch rates through ion bombardment of the surface of the ITO.
For an etcher system as represented in FIG. 2, the source of the plasma excitation is a microwave generator 10 located on top of the vacuum chamber. A wafer 20 is placed on a lower electrode 19 which can be biased by an additional power source if needed. Vacuum is achieved with a vacuum pump (not shown) . CH, and Ar gases are admitted into the plasma generation region 17. The flows of the gases are .controlled by mass flow controllers 14 and 26 and the pressure in the chamber is maintained by a throttle valve 25. When the plasma is to be ignited the microwave energy is sent' into the plasma generating region 17 through a wave guide 11 where it partially ionizes the gases into a plasma state. The CH3» species generated in this plasma travel to the wafer 20 and etch the exposed ITO off of the wafer.
FIGS. 3a-c show the process of pattern transfer for the definition of ITO where the etched ITO is to be used as a gate electrode. In FIG. 3a it is seen that microlithographic photoresist mask 34 has been coated and patterned in a conventional manner on the surface of a deposited oxide layer 32 which has been deposited on an ITO layer 31 deposited on an Si02 layer 28 on a silicon substrate 26. ITO is most usually deposited by RF sputter deposition. Oxide can be deposited using conventional deposition techniques such as chemical vapor deposition, plasma enhanced vapor deposition and electron—cyclotron resonance based deposition. The key factor for the deposited oxide is that the temperature of deposition stay below about 800βC. Above 850βC ITO undergoes a phase change that would make it unsuitable for this use.
In FIG. 3b the deposited oxide layer 32 has been etched by either a conventional wet HF oxide etch or plasma oxide etch, and thereafter the photoresist has been removed by a conventional 02 plasma strip. This transfers the photoresist pattern into the deposited oxide and exposes the ITO layer 31 for the next step. In FIG 3c the ITO layer 31 has been etched anisotropically by the plasma of CH-» and Ar thereby transferring the deposited oxide pattern into the ITO and stopping on the Si02 layer 28. Measurements have shown that the plasma of CH3» and Ar+ that etches the ITO has a high selectivity to both the masking deposited oxide 32 and the underlying Si02 layer 28. Example
Without limiting the generality of this invention, the mechanism of etching of ITO is believed to be caused by methyl radicals reacting with indium and tin to create volatile organometallic compounds as shown by the following reaction: plasma CH4+Ar > CH3 »+In+Sn+0-»-In(CH3)3t+Sn(CH3)4f+COt+Ar+
ITO
Other starting gases can be used provided they form a plasma having CH3». The following is believed to be the mechanism which explains why ionized argon increases the etch rate. When ionized in the plasma, Ar+ will strike the surface of the ITO with an energy that is derived from the RF power applied to the electrode on which the wafer resides. The mass of the argon ion combined with its incident energy results in bond breakage in the ITO being bombarded. This bond breakage in the IT0 provides more chemically active sites where the CH3» can react to form volatile products of ITO. Hence, the etch rate of ITO is increased when Ar is used in the plasma and increases with higher power.
An etcher similar to the one represented by FIG. 1 was used to etch ITO. The radio frequency used to ignite and sustain the plasma was 13.56 megahertz at 85 watts forward power . The wafer was heated to a temperature of 70°C. The chamber was
—6 evacuated to a base pressure of 1 x 10 prior to the admission of the CH^ and argon gases. The flow rate for the gases was 50 seem for CH, gas and 95 seem for Ar resulting in a total flow rate of 145 seem. t A process pressure of 75 Mtorr was maintained during the etch. The sputter deposited ITO etched at a rate of 600 angstroms per minute and the process showed very high" selectivity to the deposited oxide mask and the underlying silicon dioxide. Cross-sectional scanning electron micrographs of the etched ITO showed the etch to be highly anisotropic with no evidence of undercutting the deposited oxide mask. Industrial Applicability and Advantages
ITO is transparent and can be most effectively used as electrodes in CCD image sensors. The present method facilitates patterning ITO.

Claims

CLAIMS :
1. A method of etching a layer of ITO on a substrate comprising the steps of:
(a) depositing an oxide layer on the ITO 5 layer;
(b) coating and patterning a microlithographic photoresist layer on the deposited oxide layer to expose portions of the deposited oxide layer;
10 (c) etching the exposed deposited oxide portions and removing the patterned photoresist layer; and
(d) igniting a plasma containing CH3» where the CH3» etch the exposed ITO portions 15 thereby transferring the pattern into the ITO, anisotropically and selectively.
2. The method of claim 1 wherein the plasma is formed by mixing CH, gas and Ar gas in a chamber at a pressure selected to prevent excessive
'20 polymerization; and igniting a plasma of the CH, by subjecting the mixture to RF or microwave radiation or other suitable electric field.
25
30
35
PCT/US1991/004347 1990-06-26 1991-06-19 Plasma etching indium tin oxide using a deposited oxide mask WO1992000609A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US54392290A 1990-06-26 1990-06-26
US543,922 1990-06-26

Publications (1)

Publication Number Publication Date
WO1992000609A1 true WO1992000609A1 (en) 1992-01-09

Family

ID=24170070

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1991/004347 WO1992000609A1 (en) 1990-06-26 1991-06-19 Plasma etching indium tin oxide using a deposited oxide mask

Country Status (3)

Country Link
EP (1) EP0489143A1 (en)
JP (1) JPH05501785A (en)
WO (1) WO1992000609A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5888410A (en) * 1996-04-01 1999-03-30 Denso Corporation Dry etching method and manufacturing method of manufacturing EL element using same
US6010919A (en) * 1996-04-11 2000-01-04 Nippon Soken, Inc. Method for manufacturing semiconductor devices by use of dry etching

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4878993A (en) * 1988-12-22 1989-11-07 North American Philips Corporation Method of etching thin indium tin oxide films
EP0377365A1 (en) * 1988-12-19 1990-07-11 ETAT FRANCAIS représenté par le Ministre des Postes, Télécommunications et de l'Espace Process for etching a metal oxide layer with simultaneous deposition of a polymer film, use of this process in the production of a transistor

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0377365A1 (en) * 1988-12-19 1990-07-11 ETAT FRANCAIS représenté par le Ministre des Postes, Télécommunications et de l'Espace Process for etching a metal oxide layer with simultaneous deposition of a polymer film, use of this process in the production of a transistor
US4878993A (en) * 1988-12-22 1989-11-07 North American Philips Corporation Method of etching thin indium tin oxide films

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Japanese Journal of Applied Physics, volume 27, no. 9, September 1988, T. Minami et al.: "Reactive ion etching of transparent conducting tin oxide films using electron cyclotron resonance hydrogen plasma", pages L1753-L1756, see page L1755, right-hand column, paragraph 2; table 1 *
Journal of Vacuum Science & Technology B, volume 7, no. 5, September/October1989, American Vacuum Society (New York, US) T.R. Hayes et al.: "Reactive ion etching of InP using CH4/H2 mixtures: Mechanisms of etching and anisotropy", pages 1130-1140, see abstract; page 1131, left-hand column, paragraph 3 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5888410A (en) * 1996-04-01 1999-03-30 Denso Corporation Dry etching method and manufacturing method of manufacturing EL element using same
US6010919A (en) * 1996-04-11 2000-01-04 Nippon Soken, Inc. Method for manufacturing semiconductor devices by use of dry etching

Also Published As

Publication number Publication date
EP0489143A1 (en) 1992-06-10
JPH05501785A (en) 1993-04-02

Similar Documents

Publication Publication Date Title
US5032221A (en) Etching indium tin oxide
US5171401A (en) Plasma etching indium tin oxide
KR100465947B1 (en) Plasma processing of tungsten using a gas mixture comprising a fluorinated gas and oxygen
JP3969864B2 (en) Method for etching indium tin oxide
WO1998000874A1 (en) Dry etching of transparent electrodes in a low pressure plasma reactor
JPH02244507A (en) Etching method for indium tin oxide thin layer and formation method for transporent conductive pattern
KR100580782B1 (en) Dry-etching of indium and tin oxides
KR100457728B1 (en) Dry etching of indium and tin oxides with C2H5I gas
US5230771A (en) Plasma etching indium tin oxide using a deposited silicon nitride mask
KR100433098B1 (en) Method of anisotropic plasma etching using non-chlorofluorocarbon, fluorine-based chemistry
US5344525A (en) Process for etching semiconductor devices
WO1992000609A1 (en) Plasma etching indium tin oxide using a deposited oxide mask
US5340438A (en) Low temperature insitu image reversal process for microelectric fabrication
JPH11111695A (en) Method of forming platinum thin-film pattern and method of manufacturing semiconductor device
WO1991019325A1 (en) Optical emission spectroscopy to determine etch completion of indium tin oxide
KR100489921B1 (en) Dry-etching of indium and tin oxides
KR100263611B1 (en) Method for trench fabrication
Horiike Emerging etching techniques
Fleddermann Plasma etching of PLZT: Review and future prospects
KR100232158B1 (en) Bst etching method
VOSHCHENKOV Fundamentals of plasma etching for silicon technology (Part 1)
CA2063371C (en) Selective etching of refractory metal nitrides
JPH0650733B2 (en) Method of forming thin film
EP0704886A1 (en) Process for etching cobalt silicide layers
JPH08274097A (en) Semiconductor device and its manufacture

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1991912466

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1991912466

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1991912466

Country of ref document: EP