WO2012148370A1 - Dispositifs et procédés de traitement par plasma sensiblement non oxydant - Google Patents

Dispositifs et procédés de traitement par plasma sensiblement non oxydant Download PDF

Info

Publication number
WO2012148370A1
WO2012148370A1 PCT/US2011/000733 US2011000733W WO2012148370A1 WO 2012148370 A1 WO2012148370 A1 WO 2012148370A1 US 2011000733 W US2011000733 W US 2011000733W WO 2012148370 A1 WO2012148370 A1 WO 2012148370A1
Authority
WO
WIPO (PCT)
Prior art keywords
plasma
treatment device
plasma treatment
copper
process chamber
Prior art date
Application number
PCT/US2011/000733
Other languages
English (en)
Inventor
Carlo Waldfried
Phillip Geissbuhler
Ivan Berry
Shijian Luo
Armin HUSEUNOVIC
Original Assignee
Axcelis Technologies, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Axcelis Technologies, Inc. filed Critical Axcelis Technologies, Inc.
Priority to PCT/US2011/000733 priority Critical patent/WO2012148370A1/fr
Publication of WO2012148370A1 publication Critical patent/WO2012148370A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/3105—After-treatment
    • H01L21/311—Etching the insulating layers by chemical or physical means
    • H01L21/31127—Etching organic layers
    • H01L21/31133—Etching organic layers by chemical means
    • H01L21/31138—Etching organic layers by chemical means by dry-etching
    • 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
    • H01J37/32357—Generation remote from the workpiece, e.g. down-stream
    • 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
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32458—Vessel
    • H01J37/32477—Vessel characterised by the means for protecting vessels or internal parts, e.g. coatings
    • 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
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32458—Vessel
    • H01J37/32477—Vessel characterised by the means for protecting vessels or internal parts, e.g. coatings
    • H01J37/32504—Means for preventing sputtering of the vessel
    • 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
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32798—Further details of plasma apparatus not provided for in groups H01J37/3244 - H01J37/32788; special provisions for cleaning or maintenance of the apparatus
    • H01J37/32816—Pressure
    • H01J37/32834—Exhausting
    • H01J37/32844—Treating effluent gases
    • 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
    • H01J37/32917—Plasma diagnostics
    • H01J37/32935—Monitoring and controlling tubes by information coming from the object and/or discharge
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/30—Capture or disposal of greenhouse gases of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present disclosure relates to semiconductor apparatuses and processes, and more particularly, to substantially non-oxidizing plasma mediated processes and plasma treatment devices suitable for treating a semiconductor workpiece.
  • high-k dielectrics With metal gates to enable scaling of devices. As integrated devices become smaller, scaling of the gate dielectric causes increased leakage due to electron tunneling through the thin dielectric layer.
  • a solution to this problem is to implement a gate dielectric with higher dielectric constant (also referred to as "high k").
  • high k generally refers to a dielectric constant greater than silicon dioxide.
  • the use of high k dielectric layers as gate insulator layers allow thicker layers to be used, with the thicker high k dielectric layer supplying capacitances equal to thinner silicon oxide layers, or with the high k dielectric layer having an equivalent oxide thickness, equal to the thinner silicon dioxide counterpart layer.
  • high k dielectric layers for gate insulator layer, will offer reduced leakage when compared to the thicker silicon dioxide gate insulator counterparts. Additionally, most high-k implementations utilize a metal gate electrode to control the threshold voltage and reduce gate electron carrier depletion.
  • gate dielectric or gate metal are sensitive to oxidation or oxidizing environments, which can change the stoichiometry of the oxide, consumption of the metal gate, changes to the gate stack work function, changes in the leakage current, and the like.
  • Gate First scheme the metal gate and high-k dielectric can be exposed to photoresist strip and wafer clean processes at the source-drain and source-drain extension ion implantation steps.
  • Gate Last integration scheme the metal gate and high-k dielectric can be exposed to the photoresist strip and clean processes at the contact etch steps.
  • the photoresist strip and wafer clean processes that occur subsequent to the high-k/metal gate deposition must take care not to oxidize either the gate materials, change the stoichiometry of the gate dielectric, and/or oxidize the channel underneath the gate dielectric.
  • Ashing refers to a plasma mediated stripping process by which photoresist and post etch residues are stripped or removed from a substrate upon exposure to the plasma.
  • the ashing process generally occurs after an etching or implant process has been performed in which a photoresist material is used as a mask for etching a pattern into the underlying substrate or for selectively implanting ions into the exposed areas of the substrate.
  • the remaining photoresist and any post etch or post implant residues on the wafer after the etch process or implant process is complete must be removed prior to further processing for numerous reasons generally known to those skilled in the art.
  • the ashing step is typically followed by a wet chemical treatment to remove traces of the ashing residue, which can cause device opens or shorts or lead to an increase in device leakage.
  • oxidizing plasma discharges are known to convert metal gate electrodes from the as deposited TiN, for example, into Ti0 2 .
  • oxidizing plasma discharges can oxidize the silicon conduction channel under the high-k dielectric since most high-k dielectrics are poor diffusion barriers to the oxidizing plasma chemistry and the oxidizing plasmas can change the oxygen content or oxidation state of the high-k dielectric itself. All cases result in degraded transistor performance.
  • the ashing plasma processes should not affect the high-k/metal gate stack or affect the underlying silicon conduction channel and preferentially removes only the photoresist material.
  • substantially non-oxidizing plasma processes have been developed.
  • One such process includes generating plasma from a gas mixture comprising hydrogen and another non-oxidizing gas such as nitrogen, or helium.
  • the mechanism of removal for these less aggressive plasma discharges is significantly different from oxidizing plasmas.
  • the substantially non-oxidizing plasma such as the plasma formed from nitrogen and hydrogen, does not ash the photoresist in the traditional sense. Rather, it is believed that the hydrogen in the plasma fragments the organic based polymer in the photoresist formulation.
  • the buildup of these ashing materials can lead to short mean-time- between-clean (MTBC) times and frequent rebuild/replacement of vacuum hardware resulting in loss of throughput and increased costs of ownership.
  • deposits of the fragmented photoresist material and ashing byproducts within the process chamber that are located above the plane of the substrate can lead to particulate contamination on the substrate, thereby further affecting device yields.
  • An additional problem with non-oxidizing plasma discharges is the non-uniformity of the plasma exposure especially for prior art apparatuses that have been optimized for oxidizing plasmas.
  • These prior art apparatuses typically include a baffle plate arrangement of some sort (e.g., a dual baffle plate configuration) for uniformly distributing the plasma to the outer edges of the underlying substrate. It has been found that the less aggressive substantially non-oxidizing plasma discharges have fewer reactive species and the dispersal from the center point of the baffle plate to its outer edge can result in hot spots on the wafer, i.e., areas of non-uniformity.
  • the excited state species (e.g., H + , H * , H 2 * ) in these substantially non-oxidizing plasmas also can possess relatively short lifetimes and have high recombination rates. While not wanting to be bound by theory, it is believed that the reduction in activity of hydrogen radicals as these species flow to the outer edges of the baffle plate is due to shorter lifetimes of hydrogen radicals than can be supported by the radial distance these species have to travel from the center-fed axial plasma flow to the outer edges of the plenum. Once the hydrogen radicals have recombined into molecular hydrogen or the like, the neutral gas can no longer react with the photoresist.
  • CuH copper hydride
  • the copper present can react with the substantially non-oxidizing plasma and be transported in the form of the intermediate CuH to the semiconductor workpiece by the plasma, thereby contaminating the semiconductor workpiece with copper.
  • a plasma treatment device for treating a substrate comprises a gas inlet in fluid communication with a plasma generating component and configured to receive a substantially non-oxidizing gas source, wherein the plasma generating component is configured to generate plasma from the substantially non-oxidizing gas source during operation of the plasma treatment device; a process chamber in fluid communication with the plasma generating component and configured to receive the plasma, wherein the process chamber is formed of a material containing less than 0.15% copper by weight; and an exhaust conduit fluidly connected to the process chamber.
  • a plasma treatment device for treating a substrate comprises a gas inlet in fluid communication with a plasma generating component and configured to receive a substantially non-oxidizing gas source, wherein the plasma generating component is configured to generate plasma from the gas source during operation of the plasma treatment device; a process chamber in fluid communication with the plasma generating component and configured to receive the plasma, wherein one or more interior surfaces of the plasma treatment device comprise a non-copper containing material provided on the interior walls with a thickness effective to prevent formation of a copper hydride species upon exposure to the plasma; and an exhaust conduit fluidly connected to the process chamber.
  • a plasma treatment device for treating a semiconductor workpiece comprises a gas inlet in fluid communication with a plasma generating component and configured to receive a substantially non-oxidizing gas source, wherein the plasma generating component is configured to generate plasma from the substantially non-oxidizing gas source during operation of the plasma treatment device; and a process chamber in fluid communication with the plasma generating component and configured to receive the plasma, wherein interior surfaces of the plasma treatment device are configured to be heated to a sufficient temperature to prevent photoresist and reaction byproduct buildup on the interior surfaces.
  • a substantially non-oxidizing plasma process for removing photoresist from a substrate within a process chamber comprises exciting a gas mixture comprising a substantially non-oxidizing gas to form reactive plasma species wherein the substantially non-oxidizing gas comprises at least one gas selected from the group consisting of H 2 , NH 3 , N 2 H 4 , H 2 S, CH 4 , C 2 H 6 , C 3 H 8 , HF, H 2 0, HC1, HBr, HCN, CO, N 2 0, and combinations thereof; exposing the substrate to the reactive plasma species, wherein the process chamber is formed of an aluminum metal alloy having a copper content to less than or equal to 0.15%; by weight so as to inhibit formation of copper hydride from interior surfaces of the process chamber exposed to the reactive plasma species; and selectively reacting photoresist on a semiconductor workpiece with the reactive plasma species to remove the photoresist from the substrate and form volatile photoresist and reaction byproducts.
  • the substantially non-oxidizing gas comprises at least one gas selected from the group consisting of H
  • a substantially non-oxidizirig plasma process for removing photoresist from a substrate within a process chamber comprises exciting a gas mixture comprising a substantially non-oxidizing gas to form reactive plasma species wherein the substantially non-oxidizing gas comprises at least one gas selected from the group consisting of H 2 , NH 3 , 3 ⁇ 4S, C3 ⁇ 4, C 2 H 6 , C 3 H 8 , HF, H 2 0, HC1, HBr, HCN,
  • FIG. 1 is a cross sectional view of a plasma ashing apparatus that includes a wide area plasma source for generating a substantially non-oxidizing plasma and an oxygen plasma abatement system located downstream of the plasma processing chamber;
  • FIG. 2 is an exploded view of an exemplary wide area plasma source
  • FIG. 3 is a cross sectional view of a downstream plasma ashing apparatus that includes a narrow area plasma source for generating a substantially non-oxidizing plasma and an oxygen plasma abatement system located downstream of the plasma processing chamber;
  • FIG. 4 is a cross sectional view of a process chamber configured to receive plasma from a narrow area plasma source in accordance with an embodiment of the invention
  • FIG. 5 graphically illustrates vapor pressure of copper hydride as a function of temperature
  • FIG. 6 graphically illustrates pressure of oxygen in a process chamber at a pressure of 1 torr as a function of process gas flow into the process chamber when oxygen is injected into an oxygen plasma abatement system located downstream of the process chamber;
  • FIG. 7 schematically represents gas flow configuration in accordance with one embodiment of the present invention that is suitable for use with a substantially non- oxidizing plasma apparatus;
  • FIG. 8 graphically illustrates detected copper levels on silicon substrates processed in various process chambers with a hydrogen-containing substantially non- oxidizing plasma, wherein the interior surfaces are coated and/or formed of different materials;
  • FIG. 9 graphically illustrates the amount of oxidation of TiN as a function of oxygen contained in an 0 2 /NH 3 plasma gas mixture, wherein the TiN was exposed to plasma generated from the plasma gas mixture.
  • FIG. 10 graphically illustrates the amount of TiN loss as a result of oxidation as a function of the amount of oxygen contained in a hydrogen bearing plasma gas mixture, wherein the TiN was exposed to plasma generated from the plasma gas mixture.
  • Disclosed herein are processes and plasma treatment devices (i.e., apparatuses) for substantially non-oxidizing plasma processing a semiconductor workpiece so as to remove organic matter therefrom, e.g., photoresist, photoresist ashing byproducts, post etch residues, and the like.
  • plasma treatment devices i.e., apparatuses
  • organic matter therefrom e.g., photoresist, photoresist ashing byproducts, post etch residues, and the like.
  • the processes and devices described herein can effectively prevent or eliminate hydrocarbon buildup within the process chamber as well as in the exhaust gas lines that may occur as a function of the substantially non-oxidizing plasma to remove the photoresist material. Moreover, the devices and processes provide improved plasma uniformity and a reduction in copper contamination.
  • the substantially non-oxidizing plasma processes are generally optimized to oxidize exposed materials to less than about 0.3 nanometers (nm) in depth during the photoresist ashing process.
  • the substantially non-oxidizing plasmas for ashing photoresist are typically hydrogen-containing gas mixtures but other non-hydrogen-containing gases have been shown to also be substantially non-oxidizing, including but not limited to N 2 0 and CO.
  • Exemplary substantially non-oxidizing plasmas are disclosed in U.S. Patent Publication No. 2009/0277871A1 entitled, Plasma Mediated Ashing Processes That Include Formation of a Protection Layer Before and/or During the Plasma Mediated Ashing Process, and in U.S Patent Application Serial No. 12/275,394 entitled. Front End of Line Plasma Mediated Ashing Processes and Apparatus, both of which are incorporated herein by reference in their entireties.
  • the particular components of the plasma gas mixture are selected by their ability to form a gas and plasma at plasma forming conditions.
  • the gas mixture selected is substantially free from components that generate reactive oxygen species in excess of non-oxidizing reactive species at plasma forming conditions.
  • the gas mixture may include reactive gases such as a hydrogen- bearing gas, a nitrogen-bearing gas, a fluorine-bearing gas, a chlorine-bearing gas, a bromine-bearing gas, and mixtures thereof.
  • the gas mixture may further comprise an inert gas such as argon, helium, neon, and the like.
  • substantially non-oxidizing plasma gas mixture is a mixture of NH 3 and 0 2 , wherein the volumetric concentration of 0 2 is less than 30%.
  • substantially non-oxidizing plasma chemistries are very sensitive to the amount of background oxygen present.
  • the substantially non-oxidizing plasma chemistry is forming gas (e.g., a mixture of 5% by volume hydrogen gas (H 2 ) in nitrogen gas (N 2 )) and silicon oxidation is of concern.
  • H 2 hydrogen gas
  • N 2 nitrogen gas
  • small vacuum leaks within the device can introduce sufficient amounts of oxygen to render the process oxidizing.
  • Spectral emission lines for excited state O can be monitored and the process terminated or a warning signal provided should the intensity of these emission lines exceed or drop below a pre-determined value or range.
  • molecular emission lines from OH (307nm) or CO (293nm, 303nm, 314nm, 484nm, and/or 520nm) can be monitored.
  • the device may include a feedback loop to provide the process termination and/or warning signals, which is well within the skill of those in the art. In this manner, an optical detector coupled to the process chamber can be used to detect vacuum leaks and the like.
  • Hydrogen-bearing gases suitable for use in the substantially non-oxidizing plasma process include those compounds that contain hydrogen.
  • the hydrogen-bearing gases include hydrocarbons, hydrofluorocarbons, hydrogen gas, ammonia, hydrides, or mixtures thereof.
  • Preferred hydrogen-bearing gases exist in a gaseous state at plasma forming conditions and release hydrogen to form reactive hydrogen such as atomic hydrogen and excited state molecular hydrogen species under plasma forming conditions.
  • the hydrocarbons or hydrofluorocarbons are generally unsubstituted or may be partially substituted with a halogen such as bromine, chlorine or fluorine.
  • Examples of hydrogen- bearing hydrocarbon gases include methane, ethane and propane.
  • Hydrogen-bearing gases may be composed of mixtures of a hydrogen gas and a noble gas or nitrogen.
  • noble gases suitable for use in the process include a gas in Group VIII of the periodic table such as argon, neon, helium, nitrogen, and the like.
  • Particularly preferable for use in the present invention is a gas mixture that includes a hydrogen bearing gas and a nitrogen bearing gas.
  • Halogen-bearing compounds in the plasma are less than about 10 percent of the total volume of the plasma gas mixture to maximize selectivity. It has been found that when the fluorine compounds, for example, are greater than about 10 percent by volume, polymerization of the photoresist byproducts can occur making the polymerized photoresist more difficult to remove.
  • Preferred halogen compounds include those compounds that generate halogen reactive species when excited by the plasma.
  • the halogen compound is a gas at plasma forming conditions and is selected from the group consisting of a compound having the general formula C x H y A z , wherein A represents a halogen such as F, CI, Br or I, x ranges from 1 to 4, y ranges from 0 to 9 and z ranges from 1 to 10, HF, F 2 HC1, HBr, Cl 2 , Br 2 , and SF 6 .
  • the halogen-bearing compound is CF 4 , C 2 F 6 , CHF 3 , CH 2 F 2 , CH 3 F or mixtures thereof.
  • a reduction suppression gas containing a nitrogen bearing gas may be added to the substantially non- oxidizing gas or gas mixture.
  • the nitrogen bearing gas is N 2 , NH 3 , NO, N0 2 , and/or N 2 0.
  • this can also function as the source for both the nitrogen bearing gas and the hydrogen bearing substantially non-oxidizing gas.
  • FIG. 1 there is shown a plasma apparatus 10 (i.e., plasma treatment device) configured for substantially non-oxidizing plasma processing organic based materials such as photoresist, sidewall deposits, post etch residues, and the like for removal thereof from substrates 1 1 (i.e., semiconductor workpieces) that include high- k dielectric materials, metal gate materials or other materials sensitive to oxidation.
  • the plasma apparatus 10 generally comprises a substantially non-oxidizing gas delivery component 12, a plasma-generating component 14, a processing chamber 16, and an exhaust assembly 18. It is to be understood that the plasma apparatus has been simplified to illustrate only those components that are relevant to an understanding of the present disclosure. Those of ordinary skill in the art will recognize that other components may be required to produce an operational plasma ashing apparatus 10.
  • the apparatus 10 overcomes many of the problems noted in the prior art as it relates to processing substrates with substantially non-oxidizing plasma discharges, and in particular, plasma uniformity, hydrocarbon condensation, and copper metal contamination, among others.
  • the gas delivery component 12 provides the above mentioned gas mixture to the plasma generating component 14, which in the present figure is configured as a wide area plasma source.
  • the plasma source can be either a narrow area plasma source or a wide area plasma source.
  • the term "wide area” generally defines a plasma generating component that is configured to generate plasma over relatively large area that is about the size of the underlying semiconductor workpiece.
  • the wide area plasma source uniformly distributes the reactive species over the entire semiconductor workpiece without the need for a plasma and/or gas distribution component, thereby minimizing recombination of the excited species.
  • Suitable wide area plasma sources include, without limitation, wide area radio frequency plasma sources, inductively coupled plasma sources, capacitively coupled plasma sources, electron cyclotron resonance sources, and the like.
  • An exemplary wide area plasma source apparatus is disclosed in U.S. Patent Publication No. 2008/0138992A1 , incorporated herein by reference in its entirety.
  • a "narrow area" plasma source is generally defined as a plasma generating component configured to generate plasma over an area less than a width of the substrate being processed.
  • narrow plasma area plasma sources further employ a plasma and/or gas distribution component such as a baffle plate assembly to uniformly distribute plasma onto the entire surface of the substrate.
  • FIG. 1 A more detailed schematic of the exemplary wide area plasma source 14 shown in FIG. 1 is a wide area radiofrequency plasma source 20 as depicted in FIG. 2, which can be coupled to an opening 38 in a top wall 34 of the process chamber 16.
  • the exemplary wide area plasma source 20 generally includes a top wall 22, and sidewalls 24 extending from the top wall 22.
  • One or more gas inlets 26 are in fluid communication with an interior region of the plasma source 20 and are positioned to inject gases above an underlying antenna array system 28.
  • the gas inlets 26 can be in the sidewall as shown or top wall (not shown) as may be desired for different apparatus configurations.
  • the antenna array system 28 includes a planar array of single antenna conductors 32 coupled together and in electrical communication with a power source (not shown). Each conductor 32 is substantially parallel to an adjacent conductor. The particular configuration of the various conductors that define the antenna array is not intended to be limited.
  • the illustrated antenna array system 28 in the present example extends from one sidewall to an opposing sidewall to form a grating and is positioned intermediate the gas inlets 26 and the underlying wafer pedestal 30.
  • the antenna array system 28 provides excitation energy over a wide area for plasma generation of gases flowing through the gas inlets 26 within the process chamber 16.
  • the wide area plasma source may include a baffle plate (not shown) configured to remove charged species from the plasma prior to plasma exposure of the semiconductor workpiece.
  • FIG 3. depicts a plasma apparatus 100 that includes a plasma generating component generally designated by reference numeral 1 14 that is a narrow area plasma source.
  • the narrow area plasma generating component includes a plasma tube 1 18 (i.e., a plasma containment device) coupled to an energy source (not shown) such as microwave energy and/or radiofrequency energy for exciting gases flowing therethrough.
  • the plasma tube 1 18 may be actively temperature controlled such as by flowing fluid in a space defined by the plasma tube and an outer envelope (not shown) circumscribing the plasma tube.
  • Exemplary plasma apparatuses including the narrow area plasma generating component include axial flow downstream plasma ashers such as those described in US Patent Nos. 7,449,416, and 6,897,615, incorporated herein by reference in their entireties.
  • the process chamber 16 is typically installed within the plasma ashing apparatuses 10, 100 intermediate the exhaust assembly 18 (below) and the plasma-generating component 14, 1 14 (above) as is generally shown in FIGS. 1 and 3.
  • the process chamber 16 includes a bottom wall 35, a top wall 34 and sidewalls 36 extending from the bottom wall 35 to the top wall 34.
  • the top wall 34 includes an opening 38 for introduction of the plasma or gases for forming the plasma into process chamber 16.
  • the opening 38 can be relatively small (see FIG. 3) to accommodate narrow area plasma sources such as is commonly employed in downstream plasma generators or relatively large (see FIG. 1) to accommodate seating and/or integration of wide area plasma generators.
  • Openings may also be disposed in the various walls that define the process chamber 16 and/or the plasma generating component 14 such as, for example, an optical port for monitoring endpoint detection in an in situ chamber cleaning process, a mass spectrometer inlet for analyzing gaseous species evolved during processing, or the like.
  • the process chamber 16 includes an exhaust opening 40.
  • the exhaust opening 40 may be centrally disposed in the bottom wall 35.
  • the exhaust opening 40 is coaxial with an opening 38 of the plasma tube 118 such as is commonly employed in narrow area plasma sources.
  • the process chamber 16 is configured to have a domed top wall 1 18 and a single baffle plate 120 as shown in FIG. 4.
  • the domed top wall 1 18 is dimensioned such that the reactive species travel about the same path length from the plasma tube opening 122 to all points on the workpiece surface 124.
  • the slight differences in path length can be compensated for by use of the single baffle plate 120, which is configured to have an aperture density at the outer regions 126 to be greater than those in the inner regions 128.
  • the inner region 128 of single baffle plate 120 is configured to have a substantially apertureless central portion 130 having a single aperture 131 at the centermost point of the baffle plate, wherein the substantially apertureless central portion 130 is at about the same diameter as the plasma tube opening 122.
  • the centermost aperture 131 is configured to allow sufficient flow of the active species to reach the central region of the workpiece.
  • the substantially-apertureless central portion 130 has the function of eliminating the high axial gas velocity exiting the plasma generating component and accelerating the gas/plasma species in a radial direction in order to achieve proper operation of the plenum formed between the baffle plate 120 and the domed wall 118 (i.e., lid) of the process chamber.
  • the plasma is then distributed into the process chamber cavity via apertures in the baffle plate.
  • the combination of the domed wall 1 18 and the single baffle plate 120 provide uniform distribution of the reactive species generated in the substantially non-oxidizing plasma.
  • the single baffle plate 120 including the substantially-apertureless central portion 130 can be fabricated from optically opaque materials such that any ultraviolet light created in the plasma generation region of source 1 14 does not travel directly to the corresponding central region of the underlying semiconductor workpiece, thereby preventing interface trapped charges that can deleteriously harm the manufactured device within the exposed region.
  • increased uniformity of ashing can be achieved distally from the centerpoint of the baffle plate to the outer edges by increasing the aperture density of the baffle plate. For example, by increasing the aperture density from the centermost point to the outer edges or by increasing the size of the apertures from the centermost point of the baffle plate to the outer edges, by including the substantially-apertureless portion as described above, or by a combination of one or more of the foregoing baffle plate configurations, can increase reactivity and improve plasma uniformity at the substrate.
  • the process chamber 16 configured for use with the narrow area plasma generating component is free of a baffle plate and domed top wall, wherein the semiconductor workpiece is seated on a moveable stage in the x-y directions. In this manner, the plasma source is scanned across the workpiece surface in the x and y directions.
  • the process chamber 16 further includes a wafer pedestal 30 (as shown in FIG. 1), e.g., chuck, which can function as a heated platen for heating the semiconductor workpiece during plasma processing.
  • the semiconductor workpiece 1 1 can be heated using a lamp array 33 underlying the substrate as shown in FIG. 1.
  • the operating pressures within the process chamber 16 are preferably about 100 millitorr to about 10 torr, with about 200 millitorr to about 2 torr more preferred, and with about 500 millitorr to about 1.5 torr even more preferred.
  • the process chamber walls e.g., bottom wall 35, top wall 34, and sidewalls 36, can be heated during substantially non-oxidizing plasma processing.
  • the process chamber walls are heated to greater than 60°C to substantially prevent hydrocarbon buildup, and in other embodiments, the process chamber walls are heated to greater than 100°C. At chamber wall temperatures greater than 100°C, hydrocarbon buildup within the interior of the process chamber 16 was found to be completely eliminated.
  • Heating of the process chamber walls can be caused by resistive heating, lamp heating, induction heating, or the like, the manner of which is well within the skill of those in the art.
  • the process chamber walls may be thermally insulated to minimize heat loss and increase thermal uniformity of the chamber's internal walls. Insulating the walls of the process chamber 16 can increase thermal uniformity of the chamber's internal walls, provide protection of sensitive components, and increase efficiency by lowering power usage, among others.
  • the vacuum lines, e.g., exhaust conduit 50 are heated in a similar manner.
  • the portion of the exhaust conduit 50 in fluid communication with the process chamber and immediately prior to the afterburner assembly 60 is preferentially heated.
  • the process chamber may be cooled in the event the process chamber surfaces are too hot for a given process.
  • the process chamber may further include an active temperature control system for regulating temperature of the process chamber walls.
  • the process chamber may be configured with fluid passages, and the like.
  • Prior art process chambers including the wafer support i.e., chuck are typically fabricated from an aluminum alloy, such as type 6061, which includes copper in an amount greater than 0.15% by weight of the alloy.
  • an aluminum alloy such as type 6061, which includes copper in an amount greater than 0.15% by weight of the alloy.
  • hydrogen-containing non-oxidizing plasmas can react during plasma processing with any exposed copper source within the process chamber to form copper hydride.
  • the copper within the copper hydride can then be transported within the plasma to the semiconductor workpiece, thereby contaminating semiconductor workpiece and likely affecting the electrical properties associated of any integrated circuit formed from the contaminated semiconductor workpiece.
  • an aluminum alloy having a copper content less than 0.
  • the aluminum alloy has a copper content less than 0.10% by weight of the alloy, and in still other embodiments, the aluminum alloy is selected to have a copper content of less than 0.07% by weight of the alloy.
  • Type 5083 aluminum alloy can be used to fabricate the process chamber 16 or wafer pedestal 30, which has a copper content less than 0.1% by weight depending on the manufacturer source. The use of aluminum alloys having the lower copper content substantially reduces formation of copper hydride during plasma processing as less copper is available.
  • the temperature within the process chamber 16 affects the reaction of the reactive species generated from the substantially non-oxidizing plasma process with any copper present the aluminum alloy.
  • the vapor pressure of CuH is strongly dependent on temperature.
  • the use of an aluminum alloy having a copper content less than 0.15 % by weight effectively and substantially prevents formation of copper hydride during non-oxidizing plasma processing.
  • copper hydride formation can occur with higher vapor pressures depending on the temperature and deleteriously contaminate the semiconductor workpiece during plasma processing in the manner as previously described.
  • the aluminum alloy can be coated with a non-copper containing material.
  • the aluminum alloy is subjected to an anodization process to form an anodized surface, which has been found to reduce the copper concentration at the surface.
  • Anodization substantially reduces copper hydride formation at plasma processing temperatures of 50°C to 200°C.
  • a suitable anodization process is MIL-A-8625, Type III, Class I, incorporated herein by reference in its entirety, which uses no dyes and no sealants. Typical anodization thickness using this process is about 0.0020 to about 0.0025 inches.
  • the aluminum alloy surfaces can be coated with a non- copper containing material to provide protection at temperatures greater than 100°C.
  • the aluminum alloy can be anodized prior to deposition of the non-copper containing coating.
  • Suitable materials include, without limitation, silicon carbide (SiC), silicon oxynitride (SiON), tantalum (Ta), tantalum nitride (TaN), titanium nitride (TiN), silicon oxycarbide (SiOC), aluminum oxide (A1 2 0 3 ), pure aluminum, silicon nitride, and the like.
  • Table I provides the thickness required for various materials to keep the surface copper concentration at 1/1000 th of the copper concentration in the aluminum alloy after 1 year at the given temperature.
  • diffusion of copper in aluminum is relatively high as evidenced by the relatively large coating thickness whereas minimal diffusion, which translates to smaller coating thicknesses, was observed with materials such as SiC, SiON, Ta, TaN, and Ti.
  • materials such as SiC, SiON, Ta, TaN, and Ti.
  • the manner in which the non-copper coating material is deposited can affect copper diffusivity. For example, thermally grown silicon oxide is much more effective at lowering copper diffusivity than silicon oxide deposited by a plasma enhanced chemical vapor deposition process (PECVD).
  • PECVD plasma enhanced chemical vapor deposition process
  • the non-copper containing material is SiON having a thickness of 6 microns or greater, which would maintain the surface copper concentration of 1/1000 th of the copper concentration in the aluminum alloy after more than 1 year at 300°C.
  • the non-copper containing coating material is A1 2 0 3 having a thickness of about 2 microns or greater.
  • the non-copper containing coating material is SiC having a thickness of about 1 micron or greater. Table I.
  • a sleeve can be formed of a non-copper containing material such as those described above.
  • the sleeve can be configured to the contour of the chamber sidewalls 24 such that the non-copper containing sleeve is exposed to the plasma instead of the aluminum alloy sidewalls.
  • trace gases can be added to the gas mixture to substantially prevent or prevent copper hydride formation.
  • Table II below provides the bond strength data for various copper compounds relative to copper hydride at 275°C and 300°C. Inhibition of CuH formation can be expected by addition of gaseous species that form bond strengths at about the bond strength for CuH or higher.
  • these compounds with copper may be beneficial to form these compounds with copper by addition of gases such as, without limitation, 0 2 , N 2 0, NH 3 , CH 4 , CF 4 , C 2 F 6 , SF 6 , H 2 S, Cl 2 , F 2 , CHF 3 , CH 2 F 2 , CH 3 F, HF, HC1, CO, C0 2 , HCN, C 2 H 6 , C 3 H 8 , mixtures thereof, and the like into the plasma and in an amount effective to form the respective higher bond strength copper compound.
  • gases such as, without limitation, 0 2 , N 2 0, NH 3 , CH 4 , CF 4 , C 2 F 6 , SF 6 , H 2 S, Cl 2 , F 2 , CHF 3 , CH 2 F 2 , CH 3 F, HF, HC1, CO, C0 2 , HCN, C 2 H 6 , C 3 H 8 , mixtures thereof, and the like into the plasma and in an amount effective to form the respective higher bond
  • the surfaces exposed to the substantially non-oxidizing plasma contain a copper content sufficiently low to prevent copper contamination of the semiconductor workpiece to a level of less than or equal to 2x10 10 copper atoms per cm 2 .
  • the exhaust assembly component 18 is coupled to the process chamber 16 and includes the exhaust conduit 50 in fluid communication with an interior region of the process chamber 16. It should be noted that the plasma generating component 14 or 1 14 is independent of the exhaust assembly component 18. That is, the exhaust assembly component as described below is applicable to any type of plasma generating component.
  • the exhaust conduit 50 is fluidly attached to opening 40 in the bottom plate 35 of the process chamber 16. In one embodiment, the exhaust conduit 50 is fabricated from quartz or sapphire coated quartz, aluminum or stainless steel.
  • the minimum diameter of the exhaust conduit 50 (and opening 40) is preferably at least about 2 inches but not greater than about 6 inches for a 300 mm ashing apparatus (about a 1.5 inch diameter but not greater than 5 inches greater is preferred for a 200 mm plasma ashing apparatus).
  • the exhaust conduit further includes an afterburner assembly 60.
  • the inside diameter of the exhaust conduit is configured to be large enough to maintain the operating pressure in the process chamber 16 and a pressure differential effective to prevent oxygen injected into the afterburner assembly 60 from diffusing back into the process chamber 16 via conduit 50.
  • the outlet 52 of the exhaust conduit 50 is preferably connected to vacuum system 54.
  • An afterburner assembly 60 is in operative communication with the exhaust conduit 50.
  • a gas inlet 62 and gas source 64 are in fluid communication with the exhaust conduit 50 and are positioned upstream from the afterburner assembly 60.
  • the afterburner assembly 60 is employed to generate a plasma discharge within the exhaust conduit 50 so as to volatilize any photoresist material and plasma ashing byproducts discharged from the process chamber 16 before such photoresist and byproducts deposit on downstream vacuum components.
  • the gas source 64 is preferably a reactant gas such as oxygen or a combination of gases including oxygen containing gases or halogen containing gases or combinations thereof.
  • a reactant gas such as oxygen or a combination of gases including oxygen containing gases or halogen containing gases or combinations thereof.
  • the reactant gas source e.g., oxygen
  • a plasma is formed within the exhaust conduit from the mixture by the afterburner assembly 60, the manner of which is described below.
  • the reactant gas is introduced to the afterburner assembly immediately above the assembly and is downstream from the exhaust opening 40 of the process chamber 16. Entry of the reactant gas into the process chamber 16 can deleteriously affect the gate stack in the manner previously described.
  • the hardware and process for generating plasma in the exhaust conduit is preferably adapted to prevent the reactant gas from traveling upstream, i.e., back into the process chamber.
  • FIG. 6 graphically depicts the gas flow necessary at a process chamber pressure of 1 torr to prevent of the reactant gas source (0 2 in this example) from back streaming into the process chamber. The data indicates that a flow greater than 1 standard liters per minute (SLM) must be employed to maintain the reactant gas pressure in the process chamber at background levels.
  • SLM standard liters per minute
  • the afterburner assembly 60 preferably comprises an RF coil 66 wrapped about an exterior of an insulated exhaust pipe connected to the exhaust conduit 50 to inductively excite a gas mixture flowing through the exhaust conduit.
  • the portion of the exhaust conduit 50 coupled to the afterburner RF coil 66 can be formed of quartz or a non-conductive dielectric material that has a low loss when immersed in the RF field whereas the remaining sections of the exhaust conduit 50 can be formed of a metal.
  • inductively coupling the gas mixture with RF power to form the plasma other means could be employed in an effective manner such as by capacitive excitation or the like. Additionally, other frequencies in the ISM band including microwaves may be used to excite the afterburner plasma.
  • the reactant gas is preferably introduced at inlet 62 upstream from the afterburner assembly 60.
  • a throttle valve 68, foreline valve (not shown), vacuum pump 54, and other vacuum processing lines are disposed downstream from the afterburner assembly 60.
  • the RF coils 66 are connected to a suitable RF generator or power supply 70.
  • the power supply frequency may vary, typically ranging from 400 KHz to the preferred value of 13.56 MHz at less than 1,000 watts (W), but may also be at higher frequencies and higher power. More preferably, an RF power of about 300 W to about 600 W is employed to inductively couple reactive species containing plasma in the exhaust conduit 50, which causes the organic matter contained therein to combust. As a result, deposition of photoresist material and other organic byproducts downstream from the process chamber is prevented and/or removed.
  • the RF connections are typically made through an RF matchbox 72 and the coils 66.
  • the afterburner assembly 60 including these components is energized using power source 70 at the beginning of the plasma ashing process.
  • the reactant containing gas admixture passing through the coupled RF field produces a plasma discharge that effectively and efficiently combusts organic matter passing therethrough.
  • the afterburner assembly 60 is configured to simultaneously operate during plasma ashing processing of a semiconductor workpiece 1 1 seated on the wafer pedestal 30 in the process chamber 16.
  • the portion of the exhaust conduit 50 intermediate the process chamber opening 40 and the afterburner assembly 60 is heated during processing so as to prevent hydrocarbon buildup on surfaces between the process chamber 16 and the afterburner assembly 60, or other effluent management system (not shown).
  • the exhaust conduit 50 may include an optical detection system 80.
  • the optical detection system 80 optically detects emission peaks from the plasma generated by the afterburner assembly that have particular wavelength ranges that correspond to the reaction byproducts (or reactants) of the reactions between the plasma and the photoresist.
  • the technique relies on detecting the change in the emission intensities of characteristic optical radiation from the reactants and/or byproducts in the plasma, wherein the magnitude of change can signal an end of the plasma ashing process.
  • Excited atoms or molecules in the plasma emit light when electrons relax from a higher energy state to a lower energy state. Atoms and molecules of different chemical compounds emit a series of unique spectral lines.
  • the emission intensity for each chemical compound within the plasma depends on the relative concentration of the chemical compound in the plasma.
  • the optical detection system 80 generally includes a collection optics 82 arranged outside the exhaust conduit 50 to collect the emission spectra thus passed. Since the exhaust conduit 50 is preferably fabricated from an optically transparent material such as quartz or sapphire, an optical port or window is not necessary. In the event that an optically non-transparent dielectric material is employed for the fabrication of the exhaust conduit, an optical port of quartz or sapphire may be formed in the exhaust conduit.
  • a spectrometer or monochromator 84 is arranged to receive light from the collection optics 82.
  • Plasma apparatuses including the afterburner assembly 60 and optical detection system 80 can be configured with a control system that shuts off the plasma flow in the afterburner assembly 60 and/or the plasma source 14, 1 14 when it measures spectral line intensities that exceed (or drop below depending on how the apparatus is configured) a predetermined value or range or a combination of predetermined values/ranges for different spectral lines. For example, upon determining ashing endpoint has occurred from data collected by the optical detector 82 in the exhaust conduit, the plasma ashing process can be immediately discontinued via a feedback loop.
  • the particular optical detector is not intended to be limited and it is well within the skill of those in the art to choose a suitable optical detector. An exemplary optical detector is described in U.S Patent Application No.
  • a residual gas analyzer may be included in order to obtain relevant information on reactants, byproducts, and/or end of process.
  • the substantially non-oxidizing plasma exposes a dielectric material such as quartz, alumina, zirconia, or other ceramic material
  • degradation and/or devitrification of the dielectric material can occur.
  • the dielectric material must be cooled sufficiently to prevent the substantially non-oxidizing plasma from causing the degradation and/or devitrification. It has been found that if the substantially non-oxidizing plasma exposed dielectric surfaces are cooled to a temperature of 700°C or lower degradation and/or devitrification is substantially reduced.
  • a semiconductor wafer e.g., workpiece 1 1 in FIG. 1 or workpiece 124 shown in FIG. 4 with photoresist, ion implanted photoresist residues and/or post etch residues thereon (and an oxidation sensitive material such as a high-k dielectric, metal gate or the like) is placed into the process chamber 16 on the wafer pedestal.
  • the workpiece is preferably heated such by infrared lamps 33 as shown in FIG. 1 or a thermally heated chuck to accelerate the reaction of the photoresist and/or post etch residues with the plasma.
  • the pressure within the process chamber 16 is then reduced.
  • the pressure within the process chamber 16 is maintained between about 0.1 torr to about 5 torr.
  • An excitable substantially non-oxidizing plasma gas mixture is then fed into the plasma-generating component 14.
  • the charged particles may be selectively removed before the plasma enters the process chamber 16.
  • the excited or energetic atoms of the gas are then fed into the process chamber 15 and uniformly expose the workpiece where, for example, atomic hydrogen species react with the photoresist and/or post etch residues, which causes removal of the photoresist material and also forms somewhat volatile byproducts.
  • the photoresist material and volatile byproducts are continuously swept away from the workpiece surface to the exhaust conduit assembly 18.
  • a reactant gas is fed into the afterburner assembly 60 in the exhaust conduit 50, which is downstream from the process chamber 16. None of the injected reactant gas enters the process chamber 16 due to the "plug-flow" condition imposed by the much larger process gas flow rate from the process chamber into the exhaust conduit 50.
  • the afterburner assembly 60 is then energized to form high-density plasma within the exhaust conduit 50.
  • a signal is then sent to a control unit (not shown) and the various plasma sources (14 or 144, and 60) can be turned off.
  • the vacuum is then released and the processed workpieces may be removed from the process chamber.
  • An optional water, rinse can be used to remove any remaining residue on the stripped wafer.
  • any suitable semiconductor workpiece can be processed by the substantially non-oxidizing plasma generated by the apparatuses 10, 100.
  • the semiconductor workpiece includes an oxidation sensitive material such as a high-k dielectric or a metal gate.
  • High-k dielectric materials are hereinafter defined as a metal oxide, a metal nitride, or a combination of metal oxides or metal nitrides suitable for use in the manufacture of integrated circuits or the like having a dielectric constant greater than about 4, with a dielectric constant greater than about 10 more preferred.
  • high-k dielectric materials examples include Hf0 2 , HfSi0 4 , A120 3 , HfA10 3 , Gd 2 0 3 , LaA10 3 , Sc20 3 , Y 2 0 3 , Dy 2 0 3 , GdSc0 3 , DySc0 3 , ⁇ 2 , BaZr0 3 , Ta 2 0 5 , Nb 2 0 5 , HfTi0 4 , Ti0 2 , SrTi0 3 or combinations thereof.
  • the oxygen sensitive metal gate materials include: Ru, Mo, Ti, Ta, W, TiN, TaN, WN, Hf , Mo 2 N, HfSiN, TaSiN, MoSiN, TiSiN, HfSi x , TaSi x , NiSi x , and MoSi x or combinations thereof, where x is an integer from 1 to 8.
  • x is an integer from 1 to 8.
  • gases and mass flow controllers can be employed as may be desired for different applications.
  • the gases include at least a substantially non-oxidizing gas source 801 such as one of the hydrogen bearing gases discussed above.
  • the substantially non-oxidizing gas 801 may be combined with one or more gases to provide additional advantages.
  • the substantially non-oxidizing gas 801 can be combined with a nitrogen bearing gas 802 so as to mitigate hydrogen reduction of metal nitrides or metal silicides and/or a gas 803 to mitigate CuH production, and/or a halogen bearing gas 804, and/or a diluent gas 805.
  • a nitrogen bearing gas 802 so as to mitigate hydrogen reduction of metal nitrides or metal silicides and/or a gas 803 to mitigate CuH production
  • a halogen bearing gas 804 and/or a diluent gas 805.
  • the particular combinations are not intended to be limited.
  • Each of the gases is connected to individual mass flow controllers and mixed with the substantially non-oxidizing process gas prior to entering the plasma generating component 12.
  • the plasma source 12 can be fluidly connected to a heated process chamber 16 that is fluidly connected to an exhaust assembly 18 that includes an afterburner abatement system 60.
  • a reactant gas 820 e.g., an oxidizer
  • the effluent of the afterburner assembly 60 is directed into vacuum pump 830, which is fluidly connected to an exhaust 840.
  • bare silicon wafers were exposed to plasma generated from forming gas in a RapidStrip320 plasma ashing tool commercially available from Axcelis Technologies, Inc., Beverly, MA. Different processing chamber configurations of different materials were employed. Copper metal contamination levels of the bare silicon wafers was determined after plasma processing by vapor phase decomposition with inductively coupled plasma mass spectrometer analysis (VDP ICP-MS). The plasma chemistry was formed by flowing forming gas (5% Hydrogen in Nitrogen) at 7 standard liters per minute (slm) into the plasma ashing tool at a pressure of 1 Torr, a wafer temperature of 275°C, and a power setting of 3500 Watts.
  • VDP ICP-MS inductively coupled plasma mass spectrometer analysis
  • FIG. 8 graphically illustrates the results for both the absolute copper amount (atms/cm 2 ) and the relative copper amount (detected copper atoms/total atoms of 1 1 probed metals in %).
  • the process chamber configured with a chuck formed of an aluminum alloy demonstrated the highest amounts of copper contamination. In contrast, copper contamination was minimized by use of a chuck having an anodized surface.
  • the process chamber configuration with the lowest levels of detected copper levels had all anodized or quartz surfaces with no exposed aluminum alloy surface.
  • a substrate having a TiN coating deposited thereon was exposed to plasmas formed from a gas mixture containing varying amounts of oxygen and NH 3 and a gas mixture that contained varying amounts of oxygen and a 5% by volume hydrogen gas/helium gas mixture without any nitrogen present in the mixture.
  • the results are shown in FIGS. 9 and 10.
  • FIG. 9 graphically illustrates the amount of oxidation of a TiN material exposed to a plasma gas mixture of NH 3 and 0 2 for 3 minutes, with chuck temperature at 240°C. For 0 2 concentrations of ⁇ about 25%, the results showed that TiN oxidation is ⁇ 0.1 nm for the exposure conditions. Thus, these results demonstrate the plasma was substantially non-oxidizing when the TiN material was exposed to plasma generated from a gas mixture containing less than 25% by volume.
  • FIG. 10 graphically illustrates the amount of TiN loss as a result of oxidation as a function of the amount of oxygen contained in the mixture of 02 and the hydrogen gas mixture (5% by volume hydrogen/helium gas mixture), wherein the TiN was exposed to plasma generated from the plasma gas mixture. Without the presence of nitrogen in the gas mixture for forming the plasma, the exposed TiN was reduced to Ti as represented by the negative oxidation loss when the plasma gas mixture contained less than a few percent of oxygen to no oxygen. In FIG. 9, this behavior was not observed and is believed to be due to the presence of nitrogen in the NH 3 gas.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Plasma & Fusion (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Drying Of Semiconductors (AREA)

Abstract

La présente invention concerne des dispositifs de traitement par plasma non oxydant permettant de traiter une pièce semi-conductrice. Ces dispositifs comprennent généralement : une source gazeuse sensiblement non oxydante; un composant de génération de plasma, en communication fluidique avec la source gazeuse non oxydante; une chambre de traitement, en communication fluidique avec le composant de génération de plasma; et un conduit d'échappement, positionné au centre d'une paroi inférieure de la chambre de traitement. Dans un mode de réalisation, la chambre de traitement est formée d'un alliage d'aluminium contenant moins de 0,15 % en poids de cuivre. Dans d'autres modes de réalisation, la chambre de traitement comprend un revêtement d'un matériau ne contenant pas de cuivre afin d'empêcher la formation d'un hydrure de cuivre durant le traitement avec du plasma sensiblement non oxydant. Dans d'autres modes de réalisation encore, les parois de la chambre de traitement sont configurées pour être chauffées durant le traitement par plasma. L'invention concerne également des procédés par plasma non oxydant.
PCT/US2011/000733 2011-04-27 2011-04-27 Dispositifs et procédés de traitement par plasma sensiblement non oxydant WO2012148370A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2011/000733 WO2012148370A1 (fr) 2011-04-27 2011-04-27 Dispositifs et procédés de traitement par plasma sensiblement non oxydant

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2011/000733 WO2012148370A1 (fr) 2011-04-27 2011-04-27 Dispositifs et procédés de traitement par plasma sensiblement non oxydant

Publications (1)

Publication Number Publication Date
WO2012148370A1 true WO2012148370A1 (fr) 2012-11-01

Family

ID=47072616

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2011/000733 WO2012148370A1 (fr) 2011-04-27 2011-04-27 Dispositifs et procédés de traitement par plasma sensiblement non oxydant

Country Status (1)

Country Link
WO (1) WO2012148370A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109545645A (zh) * 2019-01-17 2019-03-29 中国科学技术大学 一种等离子体刻蚀装置及其扩散装置
CN110716399A (zh) * 2018-07-12 2020-01-21 台湾积体电路制造股份有限公司 光刻胶去除方法

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6408786B1 (en) * 1999-09-23 2002-06-25 Lam Research Corporation Semiconductor processing equipment having tiled ceramic liner
WO2002053794A1 (fr) * 2000-12-29 2002-07-11 Lam Research Corporation Element d'equipement de traitement de semi-conducteurs revetu de carbonitrure et procede de fabrication de celui-ci
US20040023812A1 (en) 2000-09-21 2004-02-05 Schlumberger Technology Corporation Hydraulic Fracturing Method
US20040235299A1 (en) * 2003-05-22 2004-11-25 Axcelis Technologies, Inc. Plasma ashing apparatus and endpoint detection process
US6897615B2 (en) 2001-11-01 2005-05-24 Axcelis Technologies, Inc. Plasma process and apparatus
US20080138992A1 (en) 2006-12-06 2008-06-12 Divergilio William F Wide area radio frequency plasma apparatus for processing multiple substrates
US20080241517A1 (en) * 2007-03-29 2008-10-02 Lam Research Corporation Aluminum-plated components of semiconductor material processing apparatuses and methods of manufacturing the components
US7449416B2 (en) 2004-09-01 2008-11-11 Axcelis Technologies, Inc. Apparatus and plasma ashing process for increasing photoresist removal rate
US20090050485A1 (en) * 2007-08-22 2009-02-26 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Anodized aluminum alloy material having both durability and low polluting property
US20090277871A1 (en) 2008-03-05 2009-11-12 Axcelis Technologies, Inc. Plasma mediated ashing processes that include formation of a protective layer before and/or during the plasma mediated ashing process
WO2010080069A2 (fr) * 2009-01-06 2010-07-15 Frontken (Singapore) Pte Ltd Techniques de maintenance d'un système de traitement de substrat
US20110136346A1 (en) * 2009-12-04 2011-06-09 Axcelis Technologies, Inc. Substantially Non-Oxidizing Plasma Treatment Devices and Processes

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6408786B1 (en) * 1999-09-23 2002-06-25 Lam Research Corporation Semiconductor processing equipment having tiled ceramic liner
US20040023812A1 (en) 2000-09-21 2004-02-05 Schlumberger Technology Corporation Hydraulic Fracturing Method
WO2002053794A1 (fr) * 2000-12-29 2002-07-11 Lam Research Corporation Element d'equipement de traitement de semi-conducteurs revetu de carbonitrure et procede de fabrication de celui-ci
US6897615B2 (en) 2001-11-01 2005-05-24 Axcelis Technologies, Inc. Plasma process and apparatus
US20040235299A1 (en) * 2003-05-22 2004-11-25 Axcelis Technologies, Inc. Plasma ashing apparatus and endpoint detection process
US7449416B2 (en) 2004-09-01 2008-11-11 Axcelis Technologies, Inc. Apparatus and plasma ashing process for increasing photoresist removal rate
WO2008070002A1 (fr) * 2006-12-06 2008-06-12 Axcelis Technologies, Inc. Appareil à plasma à fréquence radio à aire large pour traiter des substrats multiples
US20080138992A1 (en) 2006-12-06 2008-06-12 Divergilio William F Wide area radio frequency plasma apparatus for processing multiple substrates
US20080241517A1 (en) * 2007-03-29 2008-10-02 Lam Research Corporation Aluminum-plated components of semiconductor material processing apparatuses and methods of manufacturing the components
US20090050485A1 (en) * 2007-08-22 2009-02-26 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Anodized aluminum alloy material having both durability and low polluting property
US20090277871A1 (en) 2008-03-05 2009-11-12 Axcelis Technologies, Inc. Plasma mediated ashing processes that include formation of a protective layer before and/or during the plasma mediated ashing process
WO2010080069A2 (fr) * 2009-01-06 2010-07-15 Frontken (Singapore) Pte Ltd Techniques de maintenance d'un système de traitement de substrat
US20110136346A1 (en) * 2009-12-04 2011-06-09 Axcelis Technologies, Inc. Substantially Non-Oxidizing Plasma Treatment Devices and Processes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110716399A (zh) * 2018-07-12 2020-01-21 台湾积体电路制造股份有限公司 光刻胶去除方法
CN110716399B (zh) * 2018-07-12 2023-04-07 台湾积体电路制造股份有限公司 光刻胶去除方法
CN109545645A (zh) * 2019-01-17 2019-03-29 中国科学技术大学 一种等离子体刻蚀装置及其扩散装置

Similar Documents

Publication Publication Date Title
US20130248113A1 (en) Substantially non-oxidizing plasma treatment devices and processes
US8268181B2 (en) Plasma ashing apparatus and endpoint detection process
EP2278608B1 (fr) Dispositif à plasma, ensemble de distribution de gaz pour dispositif à plasma et procédés correspondants
KR100738699B1 (ko) 도핑에 독립적인 폴리실리콘용 자기세정 에칭 방법
KR100271694B1 (ko) 기판 처리 장치로부터의 과플루오르 화합물 가스 방출을 감소시키기 위한 방법 및 장치
KR100743374B1 (ko) 프로세싱 챔버용 원격 플라즈마 클리닝 방법
EP1098189B1 (fr) Méthode de détection du point d'achèvement d'un traitement par plasma en l'absence d'oxygène
US20100130017A1 (en) Front end of line plasma mediated ashing processes and apparatus
US7479457B2 (en) Gas mixture for removing photoresist and post etch residue from low-k dielectric material and method of use thereof
KR102192281B1 (ko) 순수 환원성 플라즈마에서 높은 종횡비 포토레지스트 제거를 위한 방법
WO2011149638A2 (fr) Gravure sélective pour des films de silicium
CN107924839B (zh) 可调的远程分解
US20110180097A1 (en) Thermal isolation assemblies for wafer transport apparatus and methods of use thereof
WO2012148370A1 (fr) Dispositifs et procédés de traitement par plasma sensiblement non oxydant
JP2013048127A (ja) アッシュ後の側壁の回復
Ramos et al. On the interest of carbon-coated plasma reactor for advanced gate stack etching processes
KR102345853B1 (ko) 가스 성분의 모니터 방법 및 그 장치 그리고 그것을 이용한 처리 장치
US20220189764A1 (en) Radiation of Substrates During Processing and Systems Thereof
KR101384590B1 (ko) 반도체 디바이스 제조 방법 및 반도체 디바이스 제조 장치
TW201246332A (en) Substantially non-oxidizing plasma treatment devices and processes
KR20130022433A (ko) 애쉬-후 측벽 힐링
JP2004296548A (ja) 表面処理装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11726966

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11726966

Country of ref document: EP

Kind code of ref document: A1