CA2249094A1 - Method of manufacturing optical waveguide device using inductively coupled plasma system - Google Patents
Method of manufacturing optical waveguide device using inductively coupled plasma system Download PDFInfo
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- CA2249094A1 CA2249094A1 CA002249094A CA2249094A CA2249094A1 CA 2249094 A1 CA2249094 A1 CA 2249094A1 CA 002249094 A CA002249094 A CA 002249094A CA 2249094 A CA2249094 A CA 2249094A CA 2249094 A1 CA2249094 A1 CA 2249094A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
- H01J37/32082—Radio frequency generated discharge
- H01J37/321—Radio frequency generated discharge the radio frequency energy being inductively coupled to the plasma
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/13—Integrated optical circuits characterised by the manufacturing method
- G02B6/136—Integrated optical circuits characterised by the manufacturing method by etching
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12166—Manufacturing methods
- G02B2006/12173—Masking
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Abstract
A method of manufacturing an optical waveguide device using an inductively coupled plasma device is provided. In this method, a lower cladding layer and a core layer are sequentially formed on a substrate. A mask pattern isformed on the core layer. The substrate is loaded on a cathode electrode of an inductively coupled plasma system. A plasma from a reaction gas is generated by applying first and second RF power respectively to the cathode electrode and an inductively coupled plasma coil, to pattern an exposed core layer into an optical waveguide. Then, an upper cladding layer covering the optical waveguide is formed.
Description
CA 02249094 l998-09-30 METHOD OF MANUFACTURING OPTICAL WAVEGUIDE DEVICE
USING INDUCTIVELY COUPLED PLASMA SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to a method of manufacturing a device for optical communications, and more particularly, to a method of manufacturing an optical waveguide device.
USING INDUCTIVELY COUPLED PLASMA SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to a method of manufacturing a device for optical communications, and more particularly, to a method of manufacturing an optical waveguide device.
2. Description of the Related Art An optical waveguide device is a basic optical transmission device for transmitting an optical signal, among several optical devices constituting a lightwave circuit.
The optical waveguide device includes lower and upper cladding layers formed on a substrate, and an optical waveguide for waveguiding light formed between the lower and upper cladding layers. The optical waveguide must be uniformly patterned to transmit light. To do this, a process for forming a core layer on the lower cladding layer and patterning the core layer is required.
The core layer is patterned by an etch process using a reactive ion etching (RIE) system as shown in FIG. 1.
To be more specific, a core layer and a mask pattern exposing a predetermined area of the core layer are sequentially formed on a substrate 40.
The mask pattern is usually formed of photoresist. The resultant substrate 40 isloaded on a cathode electrode 43 of the RIE system as shown in FIG. 1. Radio frequency (RF) power generated by a RF power generator 41 is applied to the cathode electrode 43, and a direct current (DC) bias is applied to an upper electrode 45 spaced apart a predetermined distance and opposite to the cathode electrode 43. Simultaneously, a reactive gas is supplied into the RIE system to allow plasma to be generated from the reactive gas by the RF power applied to the cathode electrode 43. The thus-generated plasma reaches the substrate 40 and reacts with the core layer exposed by the mask pattern, thereby patterning the CA 02249094 l998-09-30 core layer. Then, the mask pattern, i.e., a remaining photoresist pattern, is removed.
In such an etching method using the RIE system, the etch speed is low.
For example, when a silica layer is used as the core layer, the etch speed is very low, i.e., about 300A/min to 500~/min. Thus, in order to form an optical waveguide by etching a core layer having a thickness of about 8,um or more, etching for period of about 3 to 5 hours is required. Therefore, the productivity of a process for manufacturing an optical waveguide device is degraded.
A method of increasing RF power can be used to increase the etch speed.
In this method, the concentration of the generated plasma is increased by increasing the RF power, to thus increase the energy for etching. However, when increasing the RF power, another problem may occur in that the DC bias voltage applied to the upper electrode 45 increases to an abnormal level. Such an increase in DC bias may damage the optical waveguide or the lower cladding layer and substrate. This kind of damage lowers the characteristics of a lightwave circuit including an optical waveguide device.
Meanwhile, when the mask pattern is formed of photoresist, failure in photoresist pattern may be produced due to a restriction in the resolution depending on the thickness of the photoresist. This failure in photoresist pattern may generate defects in the profile or shape of the core layer pattern, i.e., optical waveguide. Thus, an optical transmission error may be generated.
To be more specific, the optical waveguide must generally be about 8,um high. Thus, the photoresist pattern thickness required for an etching process must be kept without being completely consumed until the core layer is completely etched out. An etch selection ratio of a material layer, i.e., a silica layer, used as the core layer to the photoresist pattern is about 1:1. Thus, a photoresist pattern having a thickness of about 10,um or more is required to etch the core layer having a thickness of around 8,um.
The restriction in the resolution is accompanied by exposure and development process for forming the photoresist pattern having the above-mentioned large thickness. Accordingly, photoresist pattern failures may begenerated by the exposure or development inferiorities. Also, failure may be generated on the profile or shape of the core layer pattern, i.e., ihe optical CA 02249094 l998-09-30 waveguide obtained by the process for patterning the core layer using the failedphotoresist pattern.
SUMMARY OF THE INVENTION
To solve the above problems, it is an objective of the present invention to provide a method of manufacturing an optical waveguide, by which productivity isincreased since a core layer patterning process can be performed at high speeds.It is another objective of the present invention to provide a method of manufacturing an optical waveguide, by which the profile, shape, or another aspect of an optical waveguide formed by achieving a thinner mask pattern can beimproved by introducing a mask pattern having a high etch selectivity with respect to a core layer.
To achieve the first objective, in a method of manufacturing an optical waveguide, first, a lower cladding layer and a core layer are formed on a substrate. The core layer is a silica layer, an optical polymer layer, or a single crystal oxide layer.
A mask pattern exposing the core layer is formed on the core layer. The mask pattern is formed of a photoresist layer, an amorphous silicon layer, or a silicide layer. Alternatively, the mask pattern may be formed of a metal layer such as a chrome layer or a titanium layer. The metal layer is formed by sputtering or electron beam deposition.
The step of forming the mask pattern is performed as follows. A photoresist pattern exposing the core layer is formed on the core layer. The metal layer is formed on the resultant structure on which the photoresist pattern is formed. A
metal mask pattern exposing the core layer is formed by removing the photoresistpattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
Alternatively, the step of forming the mask pattern may be formed as follows. The metal layer is formed on the core layer. A photoresist pattern exposing the metal layer is formed on the metal layer. A metal mask pattern exposing the core layer is formed by patterning the exposed metal layer using the photoresist pattern as a patterning mask. The step of patterning the exposed metal layer is performed using a dry or wet etching method.
CA 02249094 l998-09-30 The substrate having the mask pattern formed thereon is formed on a cathode electrode of an inductively coupled plasma system including the cathode electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode.
A plasma from a reaction gas is generated by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide.
The reaction gas includes a fluoride gas such as a carbon tetrafluoride gas or asulfur hexafluoride gas. Then, an upper cladding layer covering the optical waveguide is formed.
To achieve the second objective, in a method of manufacturing an optical waveguide device, a lower cladding layer and a core layer are sequentially on a substrate. The core layer is a silica layer, an optical polymer layer, or a single crystal oxide layer.
A metal mask pattern exposing the core layer is formed on the core layer.
The metal mask pattern is formed of a chrome layer or a titanium layer. The metal mask pattern is formed by sputtering or electron beam deposition.
The step of forming the metal mask pattern is performed as follows. A
photoresist pattern exposing the core layer is formed on the core layer. The metal layer is formed on the resultant structure on which the photoresist pattern is formed. A metal mask pattern exposing the core layer is formed by removing the photoresist pattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
Alternatively, the step of forming the metal mask pattern may be performed as follows. The metal layer is formed on the core layer. A photoresist pattern exposing the metal layer is formed on the metal layer. A metal mask pattern exposing the core layer is formed by patterning the exposed metal layer using the photoresist pattern as a patterning mask. The step of patterning the exposed metal layer is performed using a dry or wet etching method.
The substrate having the metal mask pattern formed thereon is formed on a cathode electrode of an inductively coupled plasma system including the cathode CA 02249094 l998-09-30 electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode.
A plasma from a reaction gas is generated by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide.
The reaction gas includes a fluoride gas such as a carbon tetrafluoride gas or asulfur hexafluoride gas. Then, an upper cladding layer covering the optical waveguide is formed.
According to the present invention, productivity is increased since a core layer patterning process can be performed at high speeds. Also, a mask pattern having a high etch selectivity with respect to the core layer is employed, thus allowing improvement of the profile or shape of the optical waveguide formed by accomplishing a thinner mask pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objectives and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a cross-section of a reactive ion etching (RIE) system;
FIGS. 2 through 5 are cross-sectional views illustrating a method of preparing a mask pattern which is used in manufacturing an optical waveguide device according to a first embodiment of the present invention;
FIG. 6 is a cross-sectional view illustrating a step for manufacturing an optical waveguide using the mask pattern prepared according to the first embodiment of the present invention;
FIG. 7 is a cross-section of an inductively coupled plasma system which is used in manufacturing an optical waveguide;
FIG. 8 is a cross-sectional view illustrating a step of completing the optical waveguide device according to the first embodiment of the present invention; and CA 02249094 l998-09-30 FIGS. 9 through 11 are cross-sectional views illustrating a method of manufacturing an optical waveguide device according to a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the present invention can be modified into various other forms, and the scope of the present invention must not be interpreted as being restricted by the embodiments. The embodiments are provided to more completely explain the present invention to those skilled in the art. In the drawings, the shapes or else of members are exaggerated or simplified for clarity.
Like reference numerals in the drawings denote the same members.
FIGS. 2 through 5 are cross-sectional views illustrating a method of preparing a mask pattern which is used in manufacturing an optical waveguide device according to a first embodiment of the present invention.
FIG. 2 shows the step of forming a lower cladding layer 200 and a core layer 300 on a substrate 100.
To be more specific, the lower cladding layer 200 and the core layer 300 are sequentially formed on a flat substrate 100 made of silicon or glass. The core layer 300 is patterned later as an optical waveguide. Thus, the core layer 300 is formed of a material through which light can be guided or propagated. Also, the core layer 300 is formed of a material having a larger refractive index than thelower cladding layer 200.
For example, in the case of a silica optical waveguide, a silica layer containing oxidized silicon (SiO2) as a main component is used as the core layer300. Alternatively, the core layer 300 may be formed as an organic material layer such as a single crystal oxide layer or an optical polymer. The present embodiment takes as an example the case of using a silica layer as the core layer 300, but the present invention is not limited to the embodiment.
FIG. 3 shows the step of forming a photoresist pattern 450 on the core layer 300.
To be more specific, the photoresist pattern 450 exposing a predetermined area of the core layer 300 is formed on the core layer 300. Here, the photoresist pattern 450 covers a portion of the core layer 300 to be etched out later.
CA 02249094 l998-09-30 FIG. 4 shows the step of forming a metal layer 500 on the entire surface of the resultant structure on which the photoresist pattern 450 is formed.
The metal layer 500 is formed on the entire surface of the resultant structure on which the photoresist pattern 450 is formed. The metal layer 500 isformed of a metal having a large etch selectivity with respect to the core layer300. That is, when the silica layer is used as the core layer 300, the metal layer 500 is formed of titanium (Ti) or chromium (Cr). Preferably, the metal layer 500 is formed of chromium (Cr).
The metal layer 500 is formed by a deposition method using a sputtering system or an electron beam deposition system.
FIG. 5 shows the step of forming a mask pattern 550.
The mask pattern 550 is formed by removing the photoresist pattern 450 and the metal layer 500 formed on the photoresist pattern 450 using a lift-off method. The lift-off method is performed using a chemical solvent. Here, the chemical solvent must be able to solve and remove the photoresist pattern 450 according to the quality of the material of the photoresist pattern 450. For example, acetone or the like is used as the chemical solvent. The chemical solvent solves and removes the photoresist pattern 450.
When the photoresist pattern 450 is solved, the metal layer 500 deposited on the photoresist pattern 450 is also removed. Thus, only the metal layer 500 deposited directly on the core layer 300 exposed by the photoresist pattern 450 remains, thereby forming the mask pattern 550.
As described above, the mask pattern 550 is formed of a material having a large etch selectivity with respect to the lower core layer 300. Accordingly, the mask pattern 550 can be formed more thinly than a mask pattern formed of photoresist. Thus, the metal mask pattern 550 can be accurately formed by the lift-off method.
The present embodiment describes the mask pattern 550 formed of the chrome layer as described above, but the material of the mask pattern 550 can vary according to the material of the core layer 300 to be patterned later. For example, the mask pattern 550 can use a metal layer such as titanium layer, a polymer layer such as a photoresist layer, an oxide layer such as an oxidized silicon layer, a dielectric layer such as amorphous silicon layer, or a silicide layer.
CA 02249094 l998-09-30 FIG. 6 is a cross-sectional view illustrating a step for forming an optical waveguide 350 by patterning the core layer 300. FIG. 7is a cross-section of an inductively coupled plasma (ICP) system which is used in forming the optical waveguide 350.
The ICP system is comprised of a cathode electrode 600, an upper electrode 700 spaced apart a predetermined distance and opposite to the cathode electrode 600, and an ICP coil 900. A first RF power generated by a first RF
power generator 800 is applied to the cathode electrode 600, and a DC bias is applied to the upper electrode 700. Also, a second RF power is applied to the ICP coil 900. The entire configuration of the ICP system is similar to that of aconventional RIE system, except that the ICP coil 900 is introduced, and that the second RF power is applied to the ICP coil 900.
As described above, a substrate 100 on which the core layer 300 and the mask pattern 550 are formed is loaded on the cathode electrode 600 of the ICP
system. A reactive gas is supplied into the ICP system via a gas supply line (not shown). A first RF power is applied to the cathode electrode 600, a second RF
power is applied to the ICP coil, and a DC bias is applied to the upper electrode 700.
The elements of the reaction gas supplied into the ICP system are excited to a plasma phase by the first and second RF powers applied respectively to the cathode electrode 600 and the ICP coil 900. Here, the plasma is generated in various forms according to conditions such as the first RF power, the second RF
power, a partial pressure in the ICP system, the type of reaction gas, the supply amount of the reaction gas, or the output of the ICP system.
The plasma contains elements of the reaction gas, ions excited from the reaction gas, a reactive radical, electrons, etc. Here, the excited ions are accelerated by the first RF power applied to the cathode electrode 600, and the accelerated ions collide with the substrate 100. This ion bombardment causes selective etching of the core layer 300 exposed by the mask pattern 550.
At this time, the movement of electrons (e~) in the plasma is changed by the second RF power applied to the ICP coil 900. That is, the electrons in the plasma make a spiraling motion as well as a rectilinear motion. Accordingly, the electrons and the elements of the reaction gas, or the electrons and the ions in the plasma CA 02249094 l998-09-30 are more likely to collide with each other. Thus, the probability of generating plasma increases, to thus increase the concentration of plasma.
This increase in the concentration of plasma indicates an increase in the concentration of the ions in the plasma, radicals, or electrons. Such an increase in ions, etc. augments an ion bombardment effect, thus allowing faster etching of the core layer 300 exposed by the mask pattern 550.
In the present embodiment, a reaction gas including a fluoride gas is used as the reaction gas. For example, a carbon tetrafluoride gas (CF4) which can generate carbon fluoride ion (CFX) and fluorine radical, or a sulfur hexafluoride gas (SF6) which can generate fluorine ion and fluorine radical is supplied as the reaction gas.
This supplied fluoride gas is excited into a plasma phase by the first RF
power applied to the cathode electrode 600 and the second RF power applied to the ICP coil 900. At this time, CFX, CFX, Fx, F-, F and electron (e-) exist within plasma which is generated when CF4 is used as the reaction gas. Also, SFX; SFX+, Fx, F+, F and e- exist within a plasma which is generated when SF6 is used as the reaction gas.
Here, the F+ or CFX is accelerated by the first RF power applied to the cathode electrode 600, and collides with the substrate 100. Accordingly, the core layer 300 is etched by the ion bombardment due to the F+ or CFX.
As described above, the concentration of ions which causes the ion bombardment due to the spiral motion of the e- within the plasma by the second RF power applied to the ICP coil 900, such as F+ or CFx, is increased. Thus, the etch speed of the core layer 300 becomes higher.
In the present embodiment, an optical waveguide 350 having a thickness of about 8,um or more can be formed using concrete etch conditions which will be exemplified later. For example, about 10sccm (standard cubic centimeter per minute) to 50sccm of an SF6 or CF4 gas is supplied to an ICP system. Here, the air pressure in the lCP system is maintained at about 3 to 30mTorr. Also, about 10 to 400W of the first RF power is applied to the cathode electrode 600, and about 100 to 1500W of the second RF power is applied to the ICP coil 900.
Under the above-described etch conditions, the silica layer used as the core layer 300 can be etched at an etch speed of about 3000A/min or higher. Here, CA 02249094 l998-09-30 when a chrome layer is used as the mask pattern 550, it can accomplish the etch selectivity with the core layer 300 (i.e., the chrome layer) of about 1 :65. That is, when the chrome layer used as the mask pattern 550 is consumed by about 1A, the silica layer used as the core layer 300 is etched by a thickness of about 65A
and removed.
Accordingly, the mask pattern 550, i.e., the chrome layer, can be introduced more thinly. A thinner lower photoresist layer for patterning the chrome layer using the lift-off method can also be introduced, allowing accomplishment of a photoresist pattern in high-resolution. Thus, the profile or shape of the chromelayer pattern formed by the lift-off method, i.e., the mask pattern 550, is improved, so that a mask pattern 550 having a more accurate pattern is achieved.
An etch method performed under the etch condition of using the fluoride-family gas provides high anisotropic etching characteristics. Thus, the sidewalls of the optical waveguide 350 are sloped at almost right angles to the surface of the substrate 100. That is, the optical waveguide 350 having an excellent sidewall profile can be achieved, and more uniform sidewall characteristics can be obtained.
According to the first embodiment of the present invention, the optical waveguide 350 of 8,um or higher thickness having an excellent profile can be formed in a shorter time by the above-described effect.
FIG. 8 is a cross-sectional view illustrating a step of completing the optical waveguide device by forming an upper cladding layer 250 covering the optical waveguide 350.
After the mask pattern 550 remaining on the waveguide 350 is removed, the upper cladding layer 250 covering the waveguide 350 is formed. The upper cladding layer 250 is formed of a material having a lower refractive index than the material of the waveguide 350. Preferably, the upper cladding layer 250 is formed of the same material as that of the lower cladding layer 200.
FIGS. 9 through 11 are cross-sectional views illustrating a method of manufacturing an optical waveguide device according to a second embodiment of the present invention.
The same reference numerals in the second embodiment as those in the first embodiment denote the same members. In the first embodiment, the mask CA 02249094 l998-09-30 pattern 550 is formed by patterning the metal layer 500 using the lift-off method.
However, in the second embodiment, a mask pattern 550a is formed by patterning a metal layer 500a using a selective etching process.
Referring to FIG. 9, the lower cladding layer 200 and the core layer 300 are sequentially formed on the substrate 100 as in the hrst embodiment. The metal layer 500a having a large etch selectivity with respect to the core layer 300 isformed on the core layer 300 according to the material of the core layer 300 to be etched. For example, the metal layer 500a is formed of Ti or Cr. The metal layer500a is formed by sputtering or electron beam deposition.
FIG. 10 is a cross-sectional view illustrating the step of forming the mask pattern 550a by patterning the metal layer 500a.
A photoresist pattern 450a exposing a part of the metal layer 500a is formed on the metal layer 500a. The exposed metal layer 500a is etched by using the photoresist pattern 450a as an etch mask, thereby forming the mask pattern 550a, i.e., a metal mask pattern, exposing a part of the core layer 300. A wet etching method or a dry etching method using a plasma can be used to etch the metal layer 500a.
The mask pattern 550a is formed of a metal having a large etch selectivity with respect to the lower core layer 300, so that it can be formed thinly. The photoresist pattern 450a for forming the mask pattern 550a can also be formed thinly, thus allowing formation of a photoresist pattern 450a in high-resolution.
Therefore, the profile or shape of the mask pattern 550a is improved.
FIG. 11 is a cross-sectional view illustrating the step of forming an optical waveguide 350 by patterning the core layer 300.
The optical waveguide 350 is formed by etching a part of the exposed core layer 300 using an etching method using an ICP system. For example, the core layer 300 is selectively patterned by a reaction gas such as SF6 or CF4 gas.
Thus, the effect as described in the first embodiment can be obtained. Then, theremaining etch mask 550a is removed, thus forming the upper cladding layer 250 as shown in FIG. 8.
As described above, the core layer can be patterned more quickly by using the reaction gas such as SF6 orCF4 and the ICP system which can generate CA 02249094 l998-09-30 fluorine ions or fluorocarbon ions. Therefore, productivity of manufacturing theoptical waveguide device can be improved.
Also, a high etch selectivity with the core layer can be accomplished by introducing a metal mask pattern, etc., so that a thinner mask pattern can be introduced. Furthermore, high anisotropic etching characteristics can be achieved, allowing an excellent profile close to the perpendicularity of the optical waveguide to be formed.
The present invention was described in detail with reference to the above-described embodiments, but the present invention is not limited to the embodiments. It is apparent that various modifications or improvements may be effected within the technical spirit of the present invention by those skilled in the art.
The optical waveguide device includes lower and upper cladding layers formed on a substrate, and an optical waveguide for waveguiding light formed between the lower and upper cladding layers. The optical waveguide must be uniformly patterned to transmit light. To do this, a process for forming a core layer on the lower cladding layer and patterning the core layer is required.
The core layer is patterned by an etch process using a reactive ion etching (RIE) system as shown in FIG. 1.
To be more specific, a core layer and a mask pattern exposing a predetermined area of the core layer are sequentially formed on a substrate 40.
The mask pattern is usually formed of photoresist. The resultant substrate 40 isloaded on a cathode electrode 43 of the RIE system as shown in FIG. 1. Radio frequency (RF) power generated by a RF power generator 41 is applied to the cathode electrode 43, and a direct current (DC) bias is applied to an upper electrode 45 spaced apart a predetermined distance and opposite to the cathode electrode 43. Simultaneously, a reactive gas is supplied into the RIE system to allow plasma to be generated from the reactive gas by the RF power applied to the cathode electrode 43. The thus-generated plasma reaches the substrate 40 and reacts with the core layer exposed by the mask pattern, thereby patterning the CA 02249094 l998-09-30 core layer. Then, the mask pattern, i.e., a remaining photoresist pattern, is removed.
In such an etching method using the RIE system, the etch speed is low.
For example, when a silica layer is used as the core layer, the etch speed is very low, i.e., about 300A/min to 500~/min. Thus, in order to form an optical waveguide by etching a core layer having a thickness of about 8,um or more, etching for period of about 3 to 5 hours is required. Therefore, the productivity of a process for manufacturing an optical waveguide device is degraded.
A method of increasing RF power can be used to increase the etch speed.
In this method, the concentration of the generated plasma is increased by increasing the RF power, to thus increase the energy for etching. However, when increasing the RF power, another problem may occur in that the DC bias voltage applied to the upper electrode 45 increases to an abnormal level. Such an increase in DC bias may damage the optical waveguide or the lower cladding layer and substrate. This kind of damage lowers the characteristics of a lightwave circuit including an optical waveguide device.
Meanwhile, when the mask pattern is formed of photoresist, failure in photoresist pattern may be produced due to a restriction in the resolution depending on the thickness of the photoresist. This failure in photoresist pattern may generate defects in the profile or shape of the core layer pattern, i.e., optical waveguide. Thus, an optical transmission error may be generated.
To be more specific, the optical waveguide must generally be about 8,um high. Thus, the photoresist pattern thickness required for an etching process must be kept without being completely consumed until the core layer is completely etched out. An etch selection ratio of a material layer, i.e., a silica layer, used as the core layer to the photoresist pattern is about 1:1. Thus, a photoresist pattern having a thickness of about 10,um or more is required to etch the core layer having a thickness of around 8,um.
The restriction in the resolution is accompanied by exposure and development process for forming the photoresist pattern having the above-mentioned large thickness. Accordingly, photoresist pattern failures may begenerated by the exposure or development inferiorities. Also, failure may be generated on the profile or shape of the core layer pattern, i.e., ihe optical CA 02249094 l998-09-30 waveguide obtained by the process for patterning the core layer using the failedphotoresist pattern.
SUMMARY OF THE INVENTION
To solve the above problems, it is an objective of the present invention to provide a method of manufacturing an optical waveguide, by which productivity isincreased since a core layer patterning process can be performed at high speeds.It is another objective of the present invention to provide a method of manufacturing an optical waveguide, by which the profile, shape, or another aspect of an optical waveguide formed by achieving a thinner mask pattern can beimproved by introducing a mask pattern having a high etch selectivity with respect to a core layer.
To achieve the first objective, in a method of manufacturing an optical waveguide, first, a lower cladding layer and a core layer are formed on a substrate. The core layer is a silica layer, an optical polymer layer, or a single crystal oxide layer.
A mask pattern exposing the core layer is formed on the core layer. The mask pattern is formed of a photoresist layer, an amorphous silicon layer, or a silicide layer. Alternatively, the mask pattern may be formed of a metal layer such as a chrome layer or a titanium layer. The metal layer is formed by sputtering or electron beam deposition.
The step of forming the mask pattern is performed as follows. A photoresist pattern exposing the core layer is formed on the core layer. The metal layer is formed on the resultant structure on which the photoresist pattern is formed. A
metal mask pattern exposing the core layer is formed by removing the photoresistpattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
Alternatively, the step of forming the mask pattern may be formed as follows. The metal layer is formed on the core layer. A photoresist pattern exposing the metal layer is formed on the metal layer. A metal mask pattern exposing the core layer is formed by patterning the exposed metal layer using the photoresist pattern as a patterning mask. The step of patterning the exposed metal layer is performed using a dry or wet etching method.
CA 02249094 l998-09-30 The substrate having the mask pattern formed thereon is formed on a cathode electrode of an inductively coupled plasma system including the cathode electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode.
A plasma from a reaction gas is generated by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide.
The reaction gas includes a fluoride gas such as a carbon tetrafluoride gas or asulfur hexafluoride gas. Then, an upper cladding layer covering the optical waveguide is formed.
To achieve the second objective, in a method of manufacturing an optical waveguide device, a lower cladding layer and a core layer are sequentially on a substrate. The core layer is a silica layer, an optical polymer layer, or a single crystal oxide layer.
A metal mask pattern exposing the core layer is formed on the core layer.
The metal mask pattern is formed of a chrome layer or a titanium layer. The metal mask pattern is formed by sputtering or electron beam deposition.
The step of forming the metal mask pattern is performed as follows. A
photoresist pattern exposing the core layer is formed on the core layer. The metal layer is formed on the resultant structure on which the photoresist pattern is formed. A metal mask pattern exposing the core layer is formed by removing the photoresist pattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
Alternatively, the step of forming the metal mask pattern may be performed as follows. The metal layer is formed on the core layer. A photoresist pattern exposing the metal layer is formed on the metal layer. A metal mask pattern exposing the core layer is formed by patterning the exposed metal layer using the photoresist pattern as a patterning mask. The step of patterning the exposed metal layer is performed using a dry or wet etching method.
The substrate having the metal mask pattern formed thereon is formed on a cathode electrode of an inductively coupled plasma system including the cathode CA 02249094 l998-09-30 electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode.
A plasma from a reaction gas is generated by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide.
The reaction gas includes a fluoride gas such as a carbon tetrafluoride gas or asulfur hexafluoride gas. Then, an upper cladding layer covering the optical waveguide is formed.
According to the present invention, productivity is increased since a core layer patterning process can be performed at high speeds. Also, a mask pattern having a high etch selectivity with respect to the core layer is employed, thus allowing improvement of the profile or shape of the optical waveguide formed by accomplishing a thinner mask pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objectives and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a cross-section of a reactive ion etching (RIE) system;
FIGS. 2 through 5 are cross-sectional views illustrating a method of preparing a mask pattern which is used in manufacturing an optical waveguide device according to a first embodiment of the present invention;
FIG. 6 is a cross-sectional view illustrating a step for manufacturing an optical waveguide using the mask pattern prepared according to the first embodiment of the present invention;
FIG. 7 is a cross-section of an inductively coupled plasma system which is used in manufacturing an optical waveguide;
FIG. 8 is a cross-sectional view illustrating a step of completing the optical waveguide device according to the first embodiment of the present invention; and CA 02249094 l998-09-30 FIGS. 9 through 11 are cross-sectional views illustrating a method of manufacturing an optical waveguide device according to a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the present invention can be modified into various other forms, and the scope of the present invention must not be interpreted as being restricted by the embodiments. The embodiments are provided to more completely explain the present invention to those skilled in the art. In the drawings, the shapes or else of members are exaggerated or simplified for clarity.
Like reference numerals in the drawings denote the same members.
FIGS. 2 through 5 are cross-sectional views illustrating a method of preparing a mask pattern which is used in manufacturing an optical waveguide device according to a first embodiment of the present invention.
FIG. 2 shows the step of forming a lower cladding layer 200 and a core layer 300 on a substrate 100.
To be more specific, the lower cladding layer 200 and the core layer 300 are sequentially formed on a flat substrate 100 made of silicon or glass. The core layer 300 is patterned later as an optical waveguide. Thus, the core layer 300 is formed of a material through which light can be guided or propagated. Also, the core layer 300 is formed of a material having a larger refractive index than thelower cladding layer 200.
For example, in the case of a silica optical waveguide, a silica layer containing oxidized silicon (SiO2) as a main component is used as the core layer300. Alternatively, the core layer 300 may be formed as an organic material layer such as a single crystal oxide layer or an optical polymer. The present embodiment takes as an example the case of using a silica layer as the core layer 300, but the present invention is not limited to the embodiment.
FIG. 3 shows the step of forming a photoresist pattern 450 on the core layer 300.
To be more specific, the photoresist pattern 450 exposing a predetermined area of the core layer 300 is formed on the core layer 300. Here, the photoresist pattern 450 covers a portion of the core layer 300 to be etched out later.
CA 02249094 l998-09-30 FIG. 4 shows the step of forming a metal layer 500 on the entire surface of the resultant structure on which the photoresist pattern 450 is formed.
The metal layer 500 is formed on the entire surface of the resultant structure on which the photoresist pattern 450 is formed. The metal layer 500 isformed of a metal having a large etch selectivity with respect to the core layer300. That is, when the silica layer is used as the core layer 300, the metal layer 500 is formed of titanium (Ti) or chromium (Cr). Preferably, the metal layer 500 is formed of chromium (Cr).
The metal layer 500 is formed by a deposition method using a sputtering system or an electron beam deposition system.
FIG. 5 shows the step of forming a mask pattern 550.
The mask pattern 550 is formed by removing the photoresist pattern 450 and the metal layer 500 formed on the photoresist pattern 450 using a lift-off method. The lift-off method is performed using a chemical solvent. Here, the chemical solvent must be able to solve and remove the photoresist pattern 450 according to the quality of the material of the photoresist pattern 450. For example, acetone or the like is used as the chemical solvent. The chemical solvent solves and removes the photoresist pattern 450.
When the photoresist pattern 450 is solved, the metal layer 500 deposited on the photoresist pattern 450 is also removed. Thus, only the metal layer 500 deposited directly on the core layer 300 exposed by the photoresist pattern 450 remains, thereby forming the mask pattern 550.
As described above, the mask pattern 550 is formed of a material having a large etch selectivity with respect to the lower core layer 300. Accordingly, the mask pattern 550 can be formed more thinly than a mask pattern formed of photoresist. Thus, the metal mask pattern 550 can be accurately formed by the lift-off method.
The present embodiment describes the mask pattern 550 formed of the chrome layer as described above, but the material of the mask pattern 550 can vary according to the material of the core layer 300 to be patterned later. For example, the mask pattern 550 can use a metal layer such as titanium layer, a polymer layer such as a photoresist layer, an oxide layer such as an oxidized silicon layer, a dielectric layer such as amorphous silicon layer, or a silicide layer.
CA 02249094 l998-09-30 FIG. 6 is a cross-sectional view illustrating a step for forming an optical waveguide 350 by patterning the core layer 300. FIG. 7is a cross-section of an inductively coupled plasma (ICP) system which is used in forming the optical waveguide 350.
The ICP system is comprised of a cathode electrode 600, an upper electrode 700 spaced apart a predetermined distance and opposite to the cathode electrode 600, and an ICP coil 900. A first RF power generated by a first RF
power generator 800 is applied to the cathode electrode 600, and a DC bias is applied to the upper electrode 700. Also, a second RF power is applied to the ICP coil 900. The entire configuration of the ICP system is similar to that of aconventional RIE system, except that the ICP coil 900 is introduced, and that the second RF power is applied to the ICP coil 900.
As described above, a substrate 100 on which the core layer 300 and the mask pattern 550 are formed is loaded on the cathode electrode 600 of the ICP
system. A reactive gas is supplied into the ICP system via a gas supply line (not shown). A first RF power is applied to the cathode electrode 600, a second RF
power is applied to the ICP coil, and a DC bias is applied to the upper electrode 700.
The elements of the reaction gas supplied into the ICP system are excited to a plasma phase by the first and second RF powers applied respectively to the cathode electrode 600 and the ICP coil 900. Here, the plasma is generated in various forms according to conditions such as the first RF power, the second RF
power, a partial pressure in the ICP system, the type of reaction gas, the supply amount of the reaction gas, or the output of the ICP system.
The plasma contains elements of the reaction gas, ions excited from the reaction gas, a reactive radical, electrons, etc. Here, the excited ions are accelerated by the first RF power applied to the cathode electrode 600, and the accelerated ions collide with the substrate 100. This ion bombardment causes selective etching of the core layer 300 exposed by the mask pattern 550.
At this time, the movement of electrons (e~) in the plasma is changed by the second RF power applied to the ICP coil 900. That is, the electrons in the plasma make a spiraling motion as well as a rectilinear motion. Accordingly, the electrons and the elements of the reaction gas, or the electrons and the ions in the plasma CA 02249094 l998-09-30 are more likely to collide with each other. Thus, the probability of generating plasma increases, to thus increase the concentration of plasma.
This increase in the concentration of plasma indicates an increase in the concentration of the ions in the plasma, radicals, or electrons. Such an increase in ions, etc. augments an ion bombardment effect, thus allowing faster etching of the core layer 300 exposed by the mask pattern 550.
In the present embodiment, a reaction gas including a fluoride gas is used as the reaction gas. For example, a carbon tetrafluoride gas (CF4) which can generate carbon fluoride ion (CFX) and fluorine radical, or a sulfur hexafluoride gas (SF6) which can generate fluorine ion and fluorine radical is supplied as the reaction gas.
This supplied fluoride gas is excited into a plasma phase by the first RF
power applied to the cathode electrode 600 and the second RF power applied to the ICP coil 900. At this time, CFX, CFX, Fx, F-, F and electron (e-) exist within plasma which is generated when CF4 is used as the reaction gas. Also, SFX; SFX+, Fx, F+, F and e- exist within a plasma which is generated when SF6 is used as the reaction gas.
Here, the F+ or CFX is accelerated by the first RF power applied to the cathode electrode 600, and collides with the substrate 100. Accordingly, the core layer 300 is etched by the ion bombardment due to the F+ or CFX.
As described above, the concentration of ions which causes the ion bombardment due to the spiral motion of the e- within the plasma by the second RF power applied to the ICP coil 900, such as F+ or CFx, is increased. Thus, the etch speed of the core layer 300 becomes higher.
In the present embodiment, an optical waveguide 350 having a thickness of about 8,um or more can be formed using concrete etch conditions which will be exemplified later. For example, about 10sccm (standard cubic centimeter per minute) to 50sccm of an SF6 or CF4 gas is supplied to an ICP system. Here, the air pressure in the lCP system is maintained at about 3 to 30mTorr. Also, about 10 to 400W of the first RF power is applied to the cathode electrode 600, and about 100 to 1500W of the second RF power is applied to the ICP coil 900.
Under the above-described etch conditions, the silica layer used as the core layer 300 can be etched at an etch speed of about 3000A/min or higher. Here, CA 02249094 l998-09-30 when a chrome layer is used as the mask pattern 550, it can accomplish the etch selectivity with the core layer 300 (i.e., the chrome layer) of about 1 :65. That is, when the chrome layer used as the mask pattern 550 is consumed by about 1A, the silica layer used as the core layer 300 is etched by a thickness of about 65A
and removed.
Accordingly, the mask pattern 550, i.e., the chrome layer, can be introduced more thinly. A thinner lower photoresist layer for patterning the chrome layer using the lift-off method can also be introduced, allowing accomplishment of a photoresist pattern in high-resolution. Thus, the profile or shape of the chromelayer pattern formed by the lift-off method, i.e., the mask pattern 550, is improved, so that a mask pattern 550 having a more accurate pattern is achieved.
An etch method performed under the etch condition of using the fluoride-family gas provides high anisotropic etching characteristics. Thus, the sidewalls of the optical waveguide 350 are sloped at almost right angles to the surface of the substrate 100. That is, the optical waveguide 350 having an excellent sidewall profile can be achieved, and more uniform sidewall characteristics can be obtained.
According to the first embodiment of the present invention, the optical waveguide 350 of 8,um or higher thickness having an excellent profile can be formed in a shorter time by the above-described effect.
FIG. 8 is a cross-sectional view illustrating a step of completing the optical waveguide device by forming an upper cladding layer 250 covering the optical waveguide 350.
After the mask pattern 550 remaining on the waveguide 350 is removed, the upper cladding layer 250 covering the waveguide 350 is formed. The upper cladding layer 250 is formed of a material having a lower refractive index than the material of the waveguide 350. Preferably, the upper cladding layer 250 is formed of the same material as that of the lower cladding layer 200.
FIGS. 9 through 11 are cross-sectional views illustrating a method of manufacturing an optical waveguide device according to a second embodiment of the present invention.
The same reference numerals in the second embodiment as those in the first embodiment denote the same members. In the first embodiment, the mask CA 02249094 l998-09-30 pattern 550 is formed by patterning the metal layer 500 using the lift-off method.
However, in the second embodiment, a mask pattern 550a is formed by patterning a metal layer 500a using a selective etching process.
Referring to FIG. 9, the lower cladding layer 200 and the core layer 300 are sequentially formed on the substrate 100 as in the hrst embodiment. The metal layer 500a having a large etch selectivity with respect to the core layer 300 isformed on the core layer 300 according to the material of the core layer 300 to be etched. For example, the metal layer 500a is formed of Ti or Cr. The metal layer500a is formed by sputtering or electron beam deposition.
FIG. 10 is a cross-sectional view illustrating the step of forming the mask pattern 550a by patterning the metal layer 500a.
A photoresist pattern 450a exposing a part of the metal layer 500a is formed on the metal layer 500a. The exposed metal layer 500a is etched by using the photoresist pattern 450a as an etch mask, thereby forming the mask pattern 550a, i.e., a metal mask pattern, exposing a part of the core layer 300. A wet etching method or a dry etching method using a plasma can be used to etch the metal layer 500a.
The mask pattern 550a is formed of a metal having a large etch selectivity with respect to the lower core layer 300, so that it can be formed thinly. The photoresist pattern 450a for forming the mask pattern 550a can also be formed thinly, thus allowing formation of a photoresist pattern 450a in high-resolution.
Therefore, the profile or shape of the mask pattern 550a is improved.
FIG. 11 is a cross-sectional view illustrating the step of forming an optical waveguide 350 by patterning the core layer 300.
The optical waveguide 350 is formed by etching a part of the exposed core layer 300 using an etching method using an ICP system. For example, the core layer 300 is selectively patterned by a reaction gas such as SF6 or CF4 gas.
Thus, the effect as described in the first embodiment can be obtained. Then, theremaining etch mask 550a is removed, thus forming the upper cladding layer 250 as shown in FIG. 8.
As described above, the core layer can be patterned more quickly by using the reaction gas such as SF6 orCF4 and the ICP system which can generate CA 02249094 l998-09-30 fluorine ions or fluorocarbon ions. Therefore, productivity of manufacturing theoptical waveguide device can be improved.
Also, a high etch selectivity with the core layer can be accomplished by introducing a metal mask pattern, etc., so that a thinner mask pattern can be introduced. Furthermore, high anisotropic etching characteristics can be achieved, allowing an excellent profile close to the perpendicularity of the optical waveguide to be formed.
The present invention was described in detail with reference to the above-described embodiments, but the present invention is not limited to the embodiments. It is apparent that various modifications or improvements may be effected within the technical spirit of the present invention by those skilled in the art.
Claims (20)
1. A method of manufacturing an optical waveguide device, comprising the steps of:
sequentially forming a lower cladding layer and a core layer on a substrate;
forming a mask pattern exposing the core layer on the core layer;
loading the substrate on which the mask pattern is formed, on a cathode electrode of an inductively coupled plasma system including the cathode electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode;
generating a plasma from a reaction gas by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide;
and forming an upper cladding layer covering the optical waveguide.
sequentially forming a lower cladding layer and a core layer on a substrate;
forming a mask pattern exposing the core layer on the core layer;
loading the substrate on which the mask pattern is formed, on a cathode electrode of an inductively coupled plasma system including the cathode electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode;
generating a plasma from a reaction gas by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide;
and forming an upper cladding layer covering the optical waveguide.
2. The method of manufacturing an optical waveguide device as claimed in claim 1, wherein the core layer is a layer selected from the group consisting of a silica layer, an optical polymer layer, and a single crystal oxide layer.
3. The method of manufacturing an optical waveguide device as claimed in claim 1, wherein the mask pattern is formed of a layer selected from the group consisting of a photoresist layer, an amorphous silicon layer, and a silicide layer.
4. The method of manufacturing an optical waveguide device as claimed in claim 1, wherein the mask pattern is formed of a metal layer.
5. The method of manufacturing an optical waveguide device as claimed in claim 4, wherein the metal layer is a layer selected from the group consisting of a chrome layer and a titanium layer.
6. The method of manufacturing an optical waveguide device as claimed in claim 4, wherein the metal layer is formed by sputtering or electron beam deposition.
7. The method of manufacturing an optical waveguide device as claimed in claim 4, wherein the step of forming the mask pattern comprises the substeps of:
forming a photoresist pattern exposing the core layer, on the core layer;
forming the metal layer on the resultant structure on which the photoresist pattern is formed; and forming a metal mask pattern exposing the core layer by removing the photoresist pattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
forming a photoresist pattern exposing the core layer, on the core layer;
forming the metal layer on the resultant structure on which the photoresist pattern is formed; and forming a metal mask pattern exposing the core layer by removing the photoresist pattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
8. The method of manufacturing an optical waveguide device as claimed in claim 4, wherein the step of forming the mask pattern comprises the substeps of:
forming the metal layer on the core layer;
forming a photoresist pattern exposing the metal layer, on the metal layer;
and forming a metal mask pattern exposing the core layer by patterning the exposed metal layer using the photoresist pattern as a patterning mask.
forming the metal layer on the core layer;
forming a photoresist pattern exposing the metal layer, on the metal layer;
and forming a metal mask pattern exposing the core layer by patterning the exposed metal layer using the photoresist pattern as a patterning mask.
9. The method of manufacturing an optical waveguide device as claimed in claim 8, wherein the step of patterning the exposed metal layer is performed using a dry or wet etching method.
10. The method of manufacturing an optical waveguide device as claimed in claim 1, wherein the reaction gas includes a fluoride gas.
11. The method of manufacturing an optical waveguide device as claimed in claim 10, wherein the fluoride gas is one selected from the group consisting of a carbon tetrafluoride gas and a sulfur hexafluoride gas.
12. A method of manufacturing an optical waveguide device, comprising the steps of:
sequentially forming a lower cladding layer and a core layer on a substrate;
forming a metal mask pattern exposing the core layer on the core layer;
loading the substrate on which the metal mask pattern is formed, on a cathode electrode of an inductively coupled plasma system including the cathode electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode;
generating a plasma from a reaction gas by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide;
and forming an upper cladding layer covering the optical waveguide.
sequentially forming a lower cladding layer and a core layer on a substrate;
forming a metal mask pattern exposing the core layer on the core layer;
loading the substrate on which the metal mask pattern is formed, on a cathode electrode of an inductively coupled plasma system including the cathode electrode, an upper electrode opposing the cathode electrode at predetermined intervals, and an inductively coupled plasma coil interposed between the upper electrode and the cathode electrode;
generating a plasma from a reaction gas by supplying the reaction gas to the inductively coupled plasma system and applying first and second RF power respectively to the cathode electrode and the inductively coupled plasma coil, to pattern the core layer exposed by the mask pattern, into an optical waveguide;
and forming an upper cladding layer covering the optical waveguide.
13. The method of manufacturing an optical waveguide device as claimed in claim 12, wherein the core layer is a layer selected from the group consisting of a silica layer, an optical polymer layer, and a single crystal oxide layer.
14. The method of manufacturing an optical waveguide device as claimed in claim 12, wherein the metal mask pattern is formed of a layer selected from the group consisting of a chrome layer and a titanium layer.
15. The method of manufacturing an optical waveguide device as claimed in claim 12, wherein the metal mask pattern is formed by sputtering or electron beam deposition.
16. The method of manufacturing an optical waveguide device as claimed in claim 12, wherein the step of forming the metal mask pattern comprises the substeps of:
forming a photoresist pattern exposing the core layer, on the core layer;
forming the metal layer on the resultant structure on which the photoresist pattern is formed; and forming a metal mask pattern exposing the core layer by removing the photoresist pattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
forming a photoresist pattern exposing the core layer, on the core layer;
forming the metal layer on the resultant structure on which the photoresist pattern is formed; and forming a metal mask pattern exposing the core layer by removing the photoresist pattern while simultaneously removing a part of the metal layer formed on the photoresist pattern.
17. The method of manufacturing an optical waveguide device as claimed in claim 12, wherein the step of forming the metal mask pattern comprises the substeps of:
forming the metal layer on the core layer;
forming a photoresist pattern exposing the metal layer, on the metal layer;
and forming a metal mask pattern exposing the core layer by patterning the exposed metal layer using the photoresist pattern as a patterning mask.
forming the metal layer on the core layer;
forming a photoresist pattern exposing the metal layer, on the metal layer;
and forming a metal mask pattern exposing the core layer by patterning the exposed metal layer using the photoresist pattern as a patterning mask.
18. The method of manufacturing an optical waveguide device as claimed in claim 17, wherein the step of patterning the exposed metal layer is performed using a dry or wet etching method.
19. The method of manufacturing an optical waveguide device as claimed in claim 12, wherein the reaction gas includes a fluoride gas.
20. The method of manufacturing an optical waveguide device as claimed in claim 19, wherein the fluoride gas is one selected from the group consisting of a carbon tetrafluoride gas and a sulfur hexafluoride gas.
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019970050964A KR19990030653A (en) | 1997-10-02 | 1997-10-02 | Optical waveguide manufacturing method |
| KR97-50965 | 1997-10-02 | ||
| KR97-50967 | 1997-10-02 | ||
| KR1019970050967A KR19990030656A (en) | 1997-10-02 | 1997-10-02 | Optical waveguide manufacturing method |
| KR1019970050966A KR19990030655A (en) | 1997-10-02 | 1997-10-02 | Optical waveguide manufacturing method |
| KR97-50964 | 1997-10-02 | ||
| KR1019970050965A KR100429850B1 (en) | 1997-10-02 | 1997-10-02 | Method for fabricating optical waveguide, especially increasing resolution of the waveguide |
| KR97-50966 | 1997-10-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2249094A1 true CA2249094A1 (en) | 1999-04-02 |
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ID=27483234
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002249094A Abandoned CA2249094A1 (en) | 1997-10-02 | 1998-09-30 | Method of manufacturing optical waveguide device using inductively coupled plasma system |
Country Status (5)
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|---|---|
| JP (1) | JPH11167037A (en) |
| CN (1) | CN1213782A (en) |
| CA (1) | CA2249094A1 (en) |
| FR (1) | FR2769376A1 (en) |
| GB (1) | GB2329873B (en) |
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| KR100361097B1 (en) * | 2000-12-13 | 2002-11-21 | 우리로광통신주식회사 | Fabricating method of optical waveguide using inductively coupled plasma etcher |
| US20020158047A1 (en) * | 2001-04-27 | 2002-10-31 | Yiqiong Wang | Formation of an optical component having smooth sidewalls |
| JP2005148468A (en) * | 2003-11-17 | 2005-06-09 | Sony Corp | Optical waveguide, light source module and optical information processing device |
| KR101235834B1 (en) * | 2010-12-08 | 2013-02-21 | 한국기계연구원 | Method of forming protruding patterns using a polymer layer as a etching protection layer |
| AU2022354956A1 (en) * | 2021-10-01 | 2024-04-18 | PsiQuantum Corp. | Patterning methods for photonic devices |
Family Cites Families (17)
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|---|---|---|---|---|
| JPS6032844B2 (en) * | 1977-06-16 | 1985-07-30 | 住友電気工業株式会社 | Method of manufacturing optical waveguide |
| JPS592008A (en) * | 1982-06-28 | 1984-01-07 | Nippon Telegr & Teleph Corp <Ntt> | Production of embedding type quartz optical waveguide |
| JPS63194206A (en) * | 1987-02-09 | 1988-08-11 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of quartz optical waveguide |
| EP0507885B1 (en) * | 1990-01-04 | 1997-12-03 | Mattson Technology Inc. | A low frequency inductive rf plasma reactor |
| JPH03291605A (en) * | 1990-04-10 | 1991-12-20 | Furukawa Electric Co Ltd:The | Forming of optical waveguide |
| JPH04147201A (en) * | 1990-10-11 | 1992-05-20 | Sumitomo Electric Ind Ltd | Quartz-based optical waveguide and its manufacture |
| JPH05215929A (en) * | 1992-02-03 | 1993-08-27 | Hitachi Cable Ltd | Manufacture of glass waveguide |
| JPH05307125A (en) * | 1992-04-28 | 1993-11-19 | Japan Energy Corp | Production of optical waveguide |
| DE69531880T2 (en) * | 1994-04-28 | 2004-09-09 | Applied Materials, Inc., Santa Clara | Method for operating a CVD reactor with a high plasma density with combined inductive and capacitive coupling |
| US5607542A (en) * | 1994-11-01 | 1997-03-04 | Applied Materials Inc. | Inductively enhanced reactive ion etching |
| KR100322695B1 (en) * | 1995-03-20 | 2002-05-13 | 윤종용 | Method for manufacturing ferroelectric capacitor |
| JPH08262250A (en) * | 1995-03-22 | 1996-10-11 | Toshiba Mach Co Ltd | Production of optical waveguide and device therefor |
| JP3951003B2 (en) * | 1995-11-17 | 2007-08-01 | 俊夫 後藤 | Plasma processing apparatus and method |
| JP3492833B2 (en) * | 1995-11-28 | 2004-02-03 | リコー光学株式会社 | Manufacturing method of metal mask for dry etching, metal mask for dry etching, and deep etching method |
| JPH09167696A (en) * | 1995-12-15 | 1997-06-24 | Sony Corp | Inductive coupling plasma processing device |
| US5667631A (en) * | 1996-06-28 | 1997-09-16 | Lam Research Corporation | Dry etching of transparent electrodes in a low pressure plasma reactor |
| TW373268B (en) * | 1997-02-21 | 1999-11-01 | Applied Materials Inc | Low temperature etch process utilizing power splitting between electrodes in AN RF plasma reactor |
-
1998
- 1998-09-30 JP JP10277548A patent/JPH11167037A/en active Pending
- 1998-09-30 CN CN 98120207 patent/CN1213782A/en active Pending
- 1998-09-30 CA CA002249094A patent/CA2249094A1/en not_active Abandoned
- 1998-10-01 FR FR9812305A patent/FR2769376A1/en not_active Withdrawn
- 1998-10-02 GB GB9821310A patent/GB2329873B/en not_active Expired - Fee Related
Also Published As
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|---|---|
| GB9821310D0 (en) | 1998-11-25 |
| GB2329873A (en) | 1999-04-07 |
| CN1213782A (en) | 1999-04-14 |
| JPH11167037A (en) | 1999-06-22 |
| FR2769376A1 (en) | 1999-04-09 |
| GB2329873B (en) | 1999-11-10 |
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