`Case 6:20-cv-00636—ADA Document 70 Filed 03/10/21 Page 1 of 202
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`EXHIBIT 5
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`EXHIBIT 5
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`
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`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 2 of 202
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`PATENT
`Customer Number 22,852
`Attorney Docket No. 9140.0016-02
`
`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`Commissioner for Patents
`P.O. Box 1450
`Alexandria, VA 22313-1450 ·
`
`Prior Application Art Unit: 2823
`
`Prior Application Examiner: ESTRADA, Michelle
`
`SIR: This is a request for filing a
`0 Continuation 0 Continuation-in-Part [2J Divisional Application under 37 C.F.R. § l .53(b)
`of pending prior Application No. 10/101,863 filed March 16, 2002, ofHongmei ZHANG,
`Mukundan NARASINHAN, Ravi B. MULLAPUDI, and Richard E. DEMARAY for BIASED
`PULSE DC REACTIVE SPUTTERING OF OXIDE FILMS.
`1.
`Enclosed is a complete copy of the prior application including the oath or
`Declaration and drawings, if any, as originally filed. I hereby verify that the
`attached papers are a true copy of prior Application No. 10/101,863 as originally
`filed on March 16, 2002, which is incorporated herein by reference.
`A Preliminary Amendment is enclosed.
`The filing fee is calculated on the basis of the claims existing in the prior
`application as amended in the Preliminary Amendment filed herewith.
`
`2.
`
`3.
`
`Page 1 of 472
`
`
`
`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 3 of 202
`
`Basic Utility Application Filing Fee
`Search Fee
`
`Examination Fee
`
`Page 2of3
`
`$300
`
`$500
`
`$200
`
`$ 300.00
`
`500.00
`
`200.00
`
`Number of Claims
`7 -
`2 -
`
`Basic
`
`Extra
`
`20
`
`3
`
`0 x $ 50
`
`0 x $200
`
`+$360
`If over 100 pages, add $250 for
`each additional 50 pages or
`fraction thereof.
`
`Total Claims
`Independent Claims
`LJ Presentation of Multiple Dep. Claim(s)
`Total Application Pages
`(specification, drawings, and printed
`sequence or computer listing)
`Subtotal
`Reduction by 1/2 if small entity
`TOTAL APPLICATION FILING FEE
`
`66
`
`0
`
`0
`
`0
`
`0
`
`$ 1,000.00
`- 0
`$ 1,000.00
`
`4. ~ The Commissioner is hereby authorized to charge the fee of$1,000.00 to Deposit
`Account No. 06-0916.
`
`5. ~ The Commissioner is hereby authorized to charge any fees which may be required
`including fees due under 37 C.F.R. § 1.16 and any other fees due under 37 C.F.R.
`§ 1.17, or credit any overpayment during the pend ency of this application to
`Deposit Account No. 06-0916.
`
`6.
`
`7.
`
`8.
`
`[2J
`
`[2J
`
`[g].
`
`The prior application is assigned ofrecord to: Symmorphix, Inc.
`The power of attorney in the prior application is to FINNEGAN, HENDERSON,
`FARABOW, GARRETT & DUNNER, L.L.P., Customer No. 22,852
`Since the power does not appear in the original declaration, a copy of the power in
`the prior application is enclosed.
`9. ~ Please address all correspondence to FINNEGAN, HENDERSON, FARABOW,
`GARRETT and DUNNER, L.L.P., Customer Number 22,852.
`10. ~ Also enclosed are an Information Disclosure Statement, Form PTO/SB/08, and
`one cited reference.
`
`Page 2 of 472
`
`
`
`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 4 of 202
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`Page 3 of 3
`
`PETITION FOR EXTENSION. If any extension of time is necessary for the filing of this
`application, including any extension in parent Application No. 10/101,863, filed March 16, 2002,
`for the purpose of maintaining copendency betWeen the parent application and this application,
`and such extension has not otherwise been requested, such an extension is hereby requested, and
`the Commissioner is authorized to charge necessary fees for such an extension to our Deposit
`Account No. 06-0916. A duplicate copy of this paper is enclosed for use in charging the deposit
`account.
`
`FINNEGAN, HENDERSON, F ARABOW,
`GARRETT & D
`R, L.L.P.
`
`Dated: September 16, 2005
`
`FINNEGAN, HENDERSON, F ARABOW,
`GARRETT & DUNNER L.L.P.
`901 New York Avenue, N.W.
`Washington, D.C. 20001-4413
`(650) 849-6622
`
`EXPRESS MAIL LABEL NO.
`EV 708643040 US
`
`Page 3 of 472
`
`
`
`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 5 of 202
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`PATENT
`Customer Number 22,852
`Attorney Docket No. 9140.0016-02
`
`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`Commissioner for Patents
`P.O. Box 1450
`Alexandria, VA 22313-1450 ·
`
`Prior Application Art Unit: 2823
`
`Prior Application Examiner: ESTRADA, Michelle
`
`SIR: This is a request for filing a
`0 Continuation 0 Continuation-in-Part [2J Divisional Application under 37 C.F.R. § l .53(b)
`of pending prior Application No. 10/101,863 filed March 16, 2002, ofHongmei ZHANG,
`Mukundan NARASINHAN, Ravi B. MULLAPUDI, and Richard E. DEMARAY for BIASED
`PULSE DC REACTIVE SPUTTERING OF OXIDE FILMS.
`1.
`Enclosed is a complete copy of the prior application including the oath or
`Declaration and drawings, if any, as originally filed. I hereby verify that the
`attached papers are a true copy of prior Application No. 10/101,863 as originally
`filed on March 16, 2002, which is incorporated herein by reference.
`A Preliminary Amendment is enclosed.
`The filing fee is calculated on the basis of the claims existing in the prior
`application as amended in the Preliminary Amendment filed herewith.
`
`2.
`
`3.
`
`Page 4 of 472
`
`
`
`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 6 of 202
`
`Basic Utility Application Filing Fee
`Search Fee
`
`Examination Fee
`
`Page 2of3
`
`$300
`
`$500
`
`$200
`
`$ 300.00
`
`500.00
`
`200.00
`
`Number of Claims
`7 -
`2 -
`
`Basic
`
`Extra
`
`20
`
`3
`
`0 x $ 50
`
`0 x $200
`
`+$360
`If over 100 pages, add $250 for
`each additional 50 pages or
`fraction thereof.
`
`Total Claims
`Independent Claims
`LJ Presentation of Multiple Dep. Claim(s)
`Total Application Pages
`(specification, drawings, and printed
`sequence or computer listing)
`Subtotal
`Reduction by 1/2 if small entity
`TOTAL APPLICATION FILING FEE
`
`66
`
`0
`
`0
`
`0
`
`0
`
`$ 1,000.00
`- 0
`$ 1,000.00
`
`4. ~ The Commissioner is hereby authorized to charge the fee of$1,000.00 to Deposit
`Account No. 06-0916.
`
`5. ~ The Commissioner is hereby authorized to charge any fees which may be required
`including fees due under 37 C.F.R. § 1.16 and any other fees due under 37 C.F.R.
`§ 1.17, or credit any overpayment during the pend ency of this application to
`Deposit Account No. 06-0916.
`
`6.
`
`7.
`
`8.
`
`[2J
`
`[2J
`
`[g].
`
`The prior application is assigned ofrecord to: Symmorphix, Inc.
`The power of attorney in the prior application is to FINNEGAN, HENDERSON,
`FARABOW, GARRETT & DUNNER, L.L.P., Customer No. 22,852
`Since the power does not appear in the original declaration, a copy of the power in
`the prior application is enclosed.
`9. ~ Please address all correspondence to FINNEGAN, HENDERSON, FARABOW,
`GARRETT and DUNNER, L.L.P., Customer Number 22,852.
`10. ~ Also enclosed are an Information Disclosure Statement, Form PTO/SB/08, and
`one cited reference.
`
`Page 5 of 472
`
`
`
`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 7 of 202
`
`Page 3 of 3
`
`PETITION FOR EXTENSION. If any extension of time is necessary for the filing of this
`application, including any extension in parent Application No. 10/101,863, filed March 16, 2002,
`for the purpose of maintaining copendency betWeen the parent application and this application,
`and such extension has not otherwise been requested, such an extension is hereby requested, and
`the Commissioner is authorized to charge necessary fees for such an extension to our Deposit
`Account No. 06-0916. A duplicate copy of this paper is enclosed for use in charging the deposit
`account.
`
`FINNEGAN, HENDERSON, F ARABOW,
`GARRETT & D
`R, L.L.P.
`
`Dated: September 16, 2005
`
`FINNEGAN, HENDERSON, F ARABOW,
`GARRETT & DUNNER L.L.P.
`901 New York Avenue, N.W.
`Washington, D.C. 20001-4413
`(650) 849-6622
`
`EXPRESS MAIL LABEL NO.
`EV 708643040 US
`
`Page 6 of 472
`
`
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`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 8 of 202
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`M-12245 US
`852923 vi
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`Express Mail Label No.
`EL 941069152 US
`
`Biased Pulse DC Reactive Sputtering of Oxide Films
`
`Hongmei Zhang
`Mukundan Narasimhan
`Ravi Mullapudi
`Richard E. Demaray
`
`Background
`
`1. Field of the Invention
`
`[0001] The present invention relates to deposition of oxide and oxynitride films and, in
`particular, to deposition of oxide .and oxynitride films by pulsed DC reactive sputtering.
`
`2. Discussion of Related Art
`
`[0002]
`Deposition of insulating materials and especially optical materials is
`technologically important in several areas including production of optical devices and production
`of semiconductor devices. In semiconductor devices, doped alumina silicates can be utilized as
`· high dielectric insulators.
`
`[0003] The increasing prevalence of fiber optic communications systems has created an
`unprecedented demand for devices for processing optical signals. Planar devices such as optical
`waveguides, couplers, splitters, and amplifiers, fabricated on planar substrates, like those
`commonly used for integrated circuits, ~d configured to receive and process signals from
`optical fibers are highly desirable. Such devices hold promise for integrated optical and
`electronic signal processing on a single semiconductor-like substance.
`
`[0004] The basic design of planar optical waveguides and amplifiers is well known, as
`described, for example, in U, S. Patent Nos. 5,119,460 and 5,563,979 to Bruce et al., 5,613,995
`to Bhandarkar et al., 5,900,057 to Buchal et al., and 5,107,538 to Benton et al., to cite only a few.
`These devices, ver)r generally, include a core region, typically bar shaped, of a certain refractive
`index surrounded by a cladding region of a lower refractive index. In the case of an optical
`amplifier, the core region includes a certain concentration of a dopant, typically a rare earth ion
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`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 9 of 202
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`such as an erbium or praseodymium ion which, when pumped by a laser, fluoresces, for
`example, in the 1550 nm and 1300 nm wavelength ranges used for optical communication, to
`amplify the optical signal passing through the core.
`
`[0005] As described, for example in the patents by Bruce et al., Bhandarkar et al, and Buchal et
`al., planar optical devices may be fabricated by process sequences including forming a layer of
`cladding material on a substrate; forming a layer of core material on the layer of cladding mater;
`patterning the core layer using a photolighotgraphic mask and an etching process to form a core
`ridge; and covering the core ridge with an upper cladding layer.
`
`[0006] The performance of.these planar optical devices depends sensitively on the. value and
`uniformity of the refractive index of the core region and of the cladding region, and particularly
`on the diflerence in refractive index, ~n, between ~he regions. Particularly for passiye devices
`such as waveguides, couplers, and splitters, ~n should be carefully controlled, for example to
`values within about 1 %, and the refractive index of both core and cladding need to be highly
`uniform, for some applications at the fewer than parts per thousand level. In the case of doped
`materials forming the core region of planar optical amplifiers, it is important that the dopant be
`uniformly distributed so as to avoid non-radiative quenching or radiative quenching, for example
`by upconversion. The refractive index and other desirable properties of the core and cladding
`regions, such as physical and chemical uniformity, low stress, and high density, depend, of
`course, on the choice of materials for the devices and on the processes by which they are
`fabricated.
`
`[0007) Because of their optical properties, silica and refractory oxides s_uch as Ah03, are good
`candidate materials for planar optical devices. Further, these oxides serve as suitable hosts for
`,,
`rare earth dopants used in optical amplifiers. A common material choice is so-called low
`temperature glasses, doped with alkali metals, boron, or phosphorous, which have the advantage
`ofrequiring lower processing temperatures. In addition, dopants are used to modify the
`refractive index. Methods such as flame hydrolysis, ion exchange for introducing alkali ions in
`glasses, sputtering, and various chemical vapor deposition processes (CVD) have been used to
`form films of doped glasses. However, dopants such as phosphorous and boron are hygroscopic,
`and alkalis are undesirable for integration with electronic devices. Control of uniformity of
`doping in CVD processes can be difficult and CVD deposited films can have structural defects
`
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`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 10 of 202
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`leading to scattering losses when used to guide light. In addition, doped low temperature glasses
`may require further processing after deposition. A method for eliminating bubbles in thin films
`of sodium-boro-silicate glass by high temperature sintering is described, for example, in the '995
`patent to Bhandarkar et al.
`
`[0008] Typically, RF sputtering has been utilized for deposition of oxide dielectric films.
`However, RF sputtering utilizes ceramic targets which are typically formed of multiple smaller
`tiles. Since the tiles can not be made very large, there may be a large problem of arcing between
`tiles and therefore contamination of the deposited film due to this arcing. Further, the reactors
`required for RF sputtering tend to be rather complicated. In particular, the engineering of low
`capacitance efficient RF power distribution to the cathode is difficult in RF systems. Routing of
`low capacitance forward and return power into a vacuum vessel of the reaction chamber often
`exposes the power path in such a way that diffuse plasma discharge is allowed under some
`conditions of impedance tuning of the matching networks.
`
`[0009] Therefore, there is a need for new methods of depositing oxide and oxynitride films and
`for forming planar optical devices.
`
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`Summary
`
`[0010] In accordance with the.present invention, a sputtering reactor apparatus for depositing
`oxide and oxynitride films is presented. Further, methods for depositing oxide and oxynitride
`films for optical waveguide devices are also presented. A sputtering reactor according to the
`present invention includes a pulsed DC power supply coupled through a filter to a target and a
`substrate efoctrode coupled to an RF power supply. A substrate m~mnted on the substrate
`electrode is therefore supplied with a bias from the RF power supply.
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`[0011] The target can be a metallic target made of a material to be deposited on the substrate. In
`some embodiments, the metallic target is formed from Al, Si and ,various rare-earth ions. A
`target with an erbium concentration, for example, can be utilized to deposit a film that can be
`formed into a waveguide optical amplifier.
`
`[0012) A substrate can be any material and, in some embodiments, is a silicon wafer. In some
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`embodiments, RF power can be supplied to the wafer. In some embodiments, the wafer and the
`electrode can be separated by an insulating glass.
`
`[0013) In some embodiments, up to about 10 kW of pulsed DC power at a frequency of between
`about 40 kHz and 350 kHz and a reverse pulse time of up to about 5 µsis supplied to the target.
`The wafer can be biased with up to about several hundred watts of RF power. The temperature
`of the substrate can be controlled to within about 10° C and can vary from about -50° C to
`several hundred degrees C. Process gasses can be fed into the reaction chamber of the reactor
`apparatus. In some embodiments, the process gasses can include combinations of Ar, N1, 02,
`C2F6, C02, CO and other process gasses.
`
`[0014] Several material properties of the deposited layer can be modified by adjusting the
`composition of the target, the compo~ition and flow rate of the process gasses, the p~wer
`supplied to the target and the substrate, and the temperature of the substrate. For example, the
`index ofrefraction of the deposited layer depends on deposition parameters. Further, in some
`embodiments stress can be relieved on the substrate by depositing a thin film of material on a
`back side of the wafer. Films deposited according to the present invention can be utilized to
`form optical waveguide devices such as multiplexers and rare-earth doped amplifiers.
`
`[0015] These and other embodiments, along with examples of material layers deposited
`according to the present invention, are further described below with respect to the following
`figures.
`
`Brief Description of the Figures
`
`[0016] Figures IA and lB show a pulsed DC sputtering reactor according to the present
`invention .
`
`[0017) Figure 2 shows a planar view of target utilized in a reactor as shown in Figures IA and
`lB.
`
`[0018] Figure 3 shows a cross-section view of an example target utilized in a reactor as shown in
`Figures lA and lB.
`
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`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 12 of 202
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`M-12245 US
`· 852923 vi
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`[0019] Figure 4 shows a flow chart of an embodiment of a process for depositing a film on a
`substrate according to the present invention.
`
`[0020] Figure 5 shows a hysterises curve of target voltage versus oxygen flow rates for an
`example target in an embodiment of a reactor according to the present invention.
`
`(0021) Figure 6 shows a photo-luminescence and lifetimes of a film deposited in a process
`according to the presei:it invention as a function of after deposition anneal temperature.
`
`[0022] Figure 7 shows the relationship between the index of refraction of a film as a function of
`deposited oxide layers according to the present invention and due to oxide build-up on the target.
`
`[0023] Figure 8 shows a graph of the index of refraction of a film deposited according to the
`present invention as a fu:riction of the aluminum content in a composite Al/Si target..
`
`[0024] Figure 9 shows .a graph of typical indices of refraction of material layers deposited
`according to the present invention.
`
`[0025] Figur~ 10 shows a table of indices of refraction for a silica layer deposited according to
`the present invention as a function of different process parameters.
`
`[0026] Figure 11 shows the refractive indices as a function of 02/ Ar ratio utilized in an Alumina
`process according to the present invention.
`
`[0027] Figure 12 shows the refractive indices as a function of DC pulsed power.frequency for an
`Alumina layer deposited according to the present invention .
`
`[0028) Figure 13 shows variation .in the refractive index over time during repeated depositions
`from a single target.
`
`[0029) Figure 14 shows variation in refractive index over time for repeated depositions from a
`target of another material layer according to the present invention.
`
`[0030] Figure 15 shows the variation refractive index over time for repeated depositions from a
`target of another material layer according to the present invention.
`
`[0031] Figure 16A through 16D shows a TEM film deposited according to the present invention.
`
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`Case 6:20-cv-00636-ADA Document 70 Filed 03/10/21 Page 13 of 202
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`[0032] Figure 17 shows the transparency of a film deposited according to the present invention.
`
`[003~] Figure 18 shows an uppercladding layer deposited according to the present invention
`over a multiple-waveguide structure such that the deposited layer is substantially planarized.
`
`[0034) Figure 19 illustrates the deposition of a film over a waveguide structure.
`
`[0035) Figures 20 and 21 illustrate different etch and deposition rates for deposition of films as a
`function of the surface angle of the film.
`
`[0036] Figure 22 illustrates calcul~tion of the planarizati.on time for a particular deposition
`process.
`
`[0037] Figures 23 through 25 through illus.trate adjustment of process parameters in order to
`achieve planarization of a film deposited over a waveguide structure according to the present
`invention.
`
`[0038] Figure 26 shows the gain characteristics of an erbium doped waveguide amplifier formed
`of films depositions according to the present invention .
`
`[0039] Figures 27 shows gain, insertion loss of a waveguide with an active core deposited
`according to the present invention.
`
`[0040) Figure 28 shows up-conversion constants, and lifetimes of the active core layer of Figure
`27 deposited according to the present invention.
`
`.[0041] Figure 29 shows drift in the index ofrefraction with subsequent depositions for films
`deposited from a target according to the present invention.
`
`[0042] Figure 30 shows drift in the photoluminescence with subsequent depositions according to
`the present invention.
`
`[0043] Figure 31 shows drift in the excited state lifetime with subsequent depositions according
`to the present invention.
`
`[0044] Figure 32 shows stabilization of the index ofrefraction in subsequent depositions.
`
`[0045) Figure 33 shows the index of refraction of a film formed from a pure silicon target as a
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`852923 vi
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`function of the ratio of 0 2/N2 in the process gas.
`
`· [0046] In the figures, elements having the same designation have the same or similar function .
`
`Detailed Description
`
`(0047] Reactive DC magnetron sputtering of nitrides and carbides is a widely practiced
`technique, but the reactive ~c magnetron sputtering of nonconducting oxides is done rarely.
`Films such as aluminum oxide are almost impossible to deposit by conventional reactive DC
`magnetron sputtering due to rapid formation of insulating oxide layers on the target surface. The
`insulating surfaces charges up and result in arcing during process. This arcing can damage the
`power supply, produce particles and degrade the properties of deposited oxide films.
`
`[0048] RF sputtering of oxide films is discussed in Application Serial No. 091903,050 (the '050
`application) by Demaray etal., entitled "Planar Optical Devices and Methods for Their
`Manufacture," assigned to the same assignee as is the pres.ent invention, herein incorporated by
`reference in its entirety. Further, targets that can be utilized in a reactor according to the present
`invention are discussed in U.S. Application serial no. {Attorney Docket No. M-12247 US} (the
`'247 application), filed concurrently with the present disclosure, assigned to the same assignee as
`is the present invention, herein incorporated by reference in its entirety. A gain-flattened
`amplifier formed of films deposited according to the present invention are described in U.S.
`Application serial no. {Attorney Docke! No. M-12652 US} (the '652 application), filed
`concurrently with the present disclosure, assigned to the same assignee as is the present
`invention, herein incorporated by reference in its entirety. Further, a mode size converter formed
`with films deposited according to the present invention is described in U.S. Application serial no ..
`{Attorney Docket No. M-12138 US} (the '138 application), filed concurrently with the present
`disclosure, assigned to the same assignee as is the present invention, herein incorporated by
`reference in its entirety.
`
`[0049] Figure IA shows a schematic of a reactor apparatus 10 for sputtering of material from a
`target 12 according to the present invention. In some embodiments, apparatus 10 may, for
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`example, be adapted from an AKT-1600 PVD (400 X 500 mm substrate size) system from
`
`Applied Komatsu or an AKT-4300 (600 X 720 mm substrate size) system from Applied
`
`Komatsu, Santa Clara, CA. The AKT-1600 reactor, for example, has three deposition chambers
`connected by a vacui.lm transport chamber. These Komatsu reactors can be modified such that
`pulsed DC power is Supplied to the target arid RF power is supplied to the substrate during
`deposition of a material film.
`
`[0050) Apparatus I 0 includes a target 12 which is electrically coupled through a filter 15 to a
`pulsed DC power supply 14. In some embodiments, target 12 is a wide area sputter source
`target, which provides material to be deposited on substrate 16. Substrate 16 is positioned
`parallel to and opposite target 12. Target 12 functions as a cathode when power is applied to it
`artd is equivalently termed a cathode. Application of power to target 12 creates a plasma 53.
`Substrate 16 is capacitively coup~ed to an electrode 17 through an insulator 54. Electrode 17 can
`be coupled to an RF power supply 18. Magnet 20 is scanned across the top of target 12.
`
`[0051) For pulsed reactive de magnetron sputtering, as performed by apparatus 10, the polarity
`of the power supplied to target 12 by power supply 14 oscillates between negative and positive
`potentials. During the positive period, the insulating layer on the surface of target 12 is
`
`discharged and arcing is prevented. To .obtain arc free deposition, the pulsing frequency exceeds
`a critical frequency that depend on target material, cathode current and reverse time. High
`quality oxide films can be made using reactive pulse DC magnetron sputtering in apparatus 10.
`
`(0052] Pulsed DC power supply 14 can be any pulsed DC pow~r supply, for example an AE
`Pinnacle plus lOK by Advanced Energy, Inc. With this example supply, up to 10 kW of pulsed
`.
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`DC power can be supplied at a frequency of between 0 and 350 KHz. The reverse voltage is
`10% of the negative target voltage. Utilization of other power supplies will lead to different
`power characteristics, frequency characteristics and reverse voltage percentages. The reverse
`
`time on this embodiment of power supply 14 can be adjusted between 0 and 5 µs.
`
`[0053] Filter 15 prevents the bias power from power supply 18 from coupling into pulsed DC
`power supply 14. In some embodiments, power supply 18 is a 2 MHz RF power supply, for
`example can be a Nova-25 power supply made by ENI, Colorado Springs, Co.
`
`[0054] Therefore, filter 15 is a 2 MHz band rejection filter. In some embodiments, the band
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`width of the filter can be approximately 100 kHz. Filter 15, therefore, prevents the 2 MHz
`power from the bias to substrate 16 from damaging power supply 18.
`
`[0055] However, both RF and pulsed DC deposited films are not fully dense and most likely
`have columnar structures. These columnar structures are detrimental for optical wave guide
`applications due to the scattering loss caused by the structure. By applying a RF bias on wafer
`16 during deposition, the deposited film can be dandified by energetic ion bombardment and the
`columnar structure can be substantially eliminated.
`
`[0056} In the AKT-1600 based system, for example, target 12 can have an active size of about
`675.70 X 582.48 by 4 mm in order to deposit films on substrate 16 that have d.imension about
`400 X 500 mm. The temperature of substrate 16 can be held at between -SOC and 500C. The
`distance between target 12 and substrate 16 can be between about 3 and about 9 cm., Process gas
`can be inserted into the chamb.er· of apparatus 10 at a rate. up to about 200 seem while the
`pressure in the chamber of apparatus 10 can be held at between about . 7 and 6 millitorr. Magnet
`20 provides a magnetic field of strength between about 400 and about 600 Gauss directed in the
`plane of target 12 and is moved across target 12 at a rate ofless than about 20-30 sec/scan. In
`some embodiments utilizing the A.KT 1600 reactor, magnet 20 can be a race-track shaped
`magnet with dimension about 150 mm by 600 mm.
`
`[0057] A top down view of magnet 20 and wide area target 12 is shown in Figure 2. A film
`deposited on a substrate positioned on carrier sheet 17 directly opposed to region 52 of target 12
`has good thickness unifonnity. Region 52 is the region shown in Figure lB that is exposed to a
`uniform plasma condition. In some implementations, carrier 17 can be coextensive with region
`52. Region 24 shown in Figlire 2 indicates the area below which both physically and chemically
`uniform deposition can be achieved, where physical and chemical unifonnity provide refractive
`index uniformity, for example. Figure 2 indicates that region 52 of target 12 that provides
`thfokness uniformity is, in general, larger than region 24 of target 12 providing thickness and
`· chemical uniformity. In optimized processes, however, regions 52 and 24 may be coextensive.
`
`[0058) In some embodiments, magnet. 20 extends beyond area 52 in one direction, the Y
`direction in Figure 2, so that scanning is necessary in only one direction,.the X direction, to
`provide a time averaged uniform magnetic field. As shown in Figures IA and lB, magnet 20
`can be scanned over the entire extent of target 12, which is larger than region 52 of uniform
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`sputter erosion. Magnet 20 is moved in a plane parallel to the plane of target 12.
`
`[0059] The combination of a uniform target 12 with a target area 52 larger than the area of
`substrate 16 can provide films of highly uniform thickness. Further, the material properties of
`the film deposited can be highly uniform. The conditions of sputtering at the target surface, such
`as the uniformity of erosion, the average temperature of the plasma at the target surface and the
`equilibration of the target surface with the gas phase ambient of the process are uniform over a
`region which is greater than or equal to the region to be coated with a uniform film thickness. In
`addition, the region of uniform film thickness is greater than or equal to the region of the film
`which is to have highly uniform optical properties such as index of refraction, density,
`transmission or absorptivity:
`
`[0060] Target 12 can be formed of any materials, but is typically metallic materials ~uch as, for
`example, combinations of Al aIJ.d Si. Therefore, in some embodiments, target 12 includes a
`metallic target material formed. from intermetalic compounds of optical elements such as Si, Al,
`Er and Yb. Additionally, target 12 can be fom1ed, for example, from materials such as La, Yt,
`Ag, Au, and Eu. To form optically active films on substrate 16, target 12 can include rare-earth
`ions. In some embodiments of target 12 with rare earth ions, the rare earth ions can be pre(cid:173)
`alloyed with the metallic host components to form intermetalics. See the '247 application.
`
`[0061] In several embodiments of the invention, material tiles are formed. These tiles can be
`mounted on a backing plate to form a target for apparatus 10. Figure 3A shows an embodiment
`of target 12 formed with individual tiles 30mounted on a cooled backplate 25. In order to form
`a wide area target of an alloy target material, the cop.solidated material of individual tiles 30
`· should first be uniform to the grain size-of the powder from which it is formed. It also should be
`formed into a structural material capable of forming and :finishing to a tile shape having a surface
`roughness on the order of the powder size from which it is consolidated. A wide area sputter
`cathode target can be formed from a close packed array of smaller tiles. Target 12, therefore,
`may include any number of tiles 30, for example between 2 to 20 individual tile