WO2014156681A1 - Etching method - Google Patents

Etching method Download PDF

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Publication number
WO2014156681A1
WO2014156681A1 PCT/JP2014/056664 JP2014056664W WO2014156681A1 WO 2014156681 A1 WO2014156681 A1 WO 2014156681A1 JP 2014056664 W JP2014056664 W JP 2014056664W WO 2014156681 A1 WO2014156681 A1 WO 2014156681A1
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Prior art keywords
gas
etching
chamber
film
ozone
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PCT/JP2014/056664
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French (fr)
Japanese (ja)
Inventor
守谷　修司
武彦 妹尾
吉野　裕
相田　敏広
誠 堀口
智也 枇榔
Original Assignee
東京エレクトロン株式会社
岩谷産業株式会社
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Publication of WO2014156681A1 publication Critical patent/WO2014156681A1/en

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    • 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
    • H01L21/31105—Etching inorganic layers
    • H01L21/31111—Etching inorganic layers by chemical means
    • H01L21/31116—Etching inorganic layers by chemical means by dry-etching

Definitions

  • the present invention relates to an etching method for etching a film of a predetermined material formed on a substrate.
  • COR is a technique for etching an oxide, but recently, etching of not only an oxide such as silicon oxide (SiO 2 ) but also a silicon nitride (SiN) film has been studied.
  • etching gas for etching the SiN film by non-plasma HF gas + F 2 gas has been studied (for example, Patent Document 3).
  • the SiN film is often adjacent to Si such as a polysilicon (poly-Si) film or Si substrate, or an SiO 2 film.
  • the SiN film is converted into HF gas and F 2 gas.
  • the SiO 2 film is etched by NH 3 gas and HF gas generated as reaction products at low temperatures, and poly-Si is etched at high temperatures.
  • an object of the present invention is to provide an etching method capable of etching a silicon nitride film with a high selectivity relative to a silicon oxide film and / or a polysilicon film.
  • a substrate to be processed having a silicon nitride film on the surface and having a polysilicon film and / or a silicon oxide film provided adjacent to the silicon nitride film is placed in the chamber. Disposing and supplying NO gas or / and ozone gas and HF gas into the chamber, whereby the silicon nitride film is selectively etched with respect to the polysilicon film and / or the silicon oxide film. An etching method is provided.
  • ozone gas or oxygen plasma may be supplied to the substrate to be processed to modify the surface of the substrate to be processed.
  • the volume ratio of NO gas and HF gas is preferably in the range of 1: 0.1 to 1:30. Further, when ozone gas and HF gas are supplied as the etching gas, the volume ratio of ozone gas to HF gas is preferably in the range of 1: 1 to 1: 7.
  • the temperature of the mounting table on which the substrate to be processed is placed in the chamber is preferably in the range of 70 to 200 ° C., and the pressure in the chamber is 1.6 to 80 kPa. It is preferable to be in the range.
  • a storage medium that operates on a computer and stores a program for controlling an etching apparatus, and the program has a silicon nitride film on a surface when executed.
  • a substrate to be processed having a polysilicon film and / or a silicon oxide film provided adjacent to the silicon nitride film is disposed in the chamber, and NO gas or / and ozone gas and HF gas are disposed in the chamber.
  • NO gas or / and ozone gas and HF gas are disposed in the chamber.
  • the silicon nitride film on the surface of the substrate to be processed can be etched at a high etching rate, and the silicon nitride film
  • the silicon nitride film can be etched with a high selectivity with respect to the silicon oxide film and / or the polysilicon film provided adjacent to each other.
  • FIG. 1 shows schematic structure of the 1st example of the etching apparatus mounted in the processing system of FIG.
  • sectional drawing which shows schematic structure of the 2nd example of the etching apparatus mounted in the processing system of FIG.
  • sectional drawing shows schematic structure of the 3rd example of the etching apparatus mounted in the processing system of FIG.
  • sectional drawing which shows schematic structure of the 4th example of the etching apparatus mounted in the processing system of FIG.
  • FIG. 1 is a schematic configuration diagram showing a processing system equipped with an etching apparatus according to an embodiment of the present invention.
  • the processing system 1 includes a loading / unloading section 2 for loading / unloading a semiconductor wafer (hereinafter simply referred to as a wafer) W, and two load lock chambers (L / L) 3 provided adjacent to the loading / unloading section 2. And an etching apparatus 5 that is provided adjacent to each load lock chamber 3 and performs non-plasma etching on the wafer W.
  • the loading / unloading unit 2 has a transfer chamber (L / M) 12 in which a first wafer transfer mechanism 11 for transferring the wafer W is provided.
  • the first wafer transfer mechanism 11 has two transfer arms 11a and 11b that hold the wafer W substantially horizontally.
  • a mounting table 13 is provided on the side of the transfer chamber 12 in the longitudinal direction. For example, three carriers C capable of accommodating a plurality of wafers W arranged side by side can be connected to the mounting table 13. .
  • an orienter 14 is installed adjacent to the transfer chamber 12 to rotate the wafer W and optically determine the amount of eccentricity.
  • the wafer W is held by the transfer arms 11 a and 11 b, and is moved to a desired position by moving straight and moving up and down substantially in a horizontal plane by driving the first wafer transfer mechanism 11.
  • the transfer arms 11a and 11b are moved forward and backward with respect to the carrier C, the orienter 14 and the load lock chamber 3 on the mounting table 13, respectively.
  • Each load lock chamber 3 is connected to the transfer chamber 12 with a gate valve 16 interposed between the load lock chamber 3 and the transfer chamber 12, respectively.
  • a second wafer transfer mechanism 17 for transferring the wafer W is provided in each load lock chamber 3.
  • the load lock chamber 3 is configured to be evacuated to a predetermined degree of vacuum.
  • the second wafer transfer mechanism 17 has a pick that holds the wafer W substantially horizontally. In the wafer transfer mechanism 17, it is possible to move the pick between the load lock chamber 3 and the etching apparatus 5, thereby transferring the wafer W between the load lock chamber 3 and the etching apparatus 5. It is possible to do.
  • the processing system 1 has a control unit 90.
  • the control unit 90 includes a process controller 91 including a microprocessor (computer) that controls each component of the processing system 1.
  • a user interface 92 Connected to the process controller 91 is a user interface 92 having a keyboard for an operator to input commands and the like for managing the processing system 1 and a display for visualizing and displaying the operating status of the processing system 1.
  • the process controller 91 also includes a control program and a process for realizing various processes executed by the processing system 1, for example, supply of process gas in the etching apparatus 5 described later, exhaust in the chamber, and the like by controlling the process controller.
  • a processing unit that is a control program for causing each component of the processing system 1 to execute a predetermined process according to conditions, and a storage unit 93 that stores various databases and the like are connected.
  • the recipe is stored in an appropriate storage medium (not shown) in the storage unit 93. If necessary, an arbitrary recipe is called from the storage unit 93 and is executed by the process controller 91, whereby a desired process in the processing system 1 is performed under the control of the process controller 91.
  • a wafer W having an SiN film to be etched on the surface and at least one of a SiO 2 film and a poly-Si film formed adjacent thereto is used.
  • a plurality of wafers W are stored in the carrier C and transferred to the processing system 1.
  • a single wafer W is loaded from the carrier C of the loading / unloading unit 2 by one of the transfer arms 11 a and 11 b of the first wafer transfer mechanism 11 with the atmosphere side gate valve 16 opened.
  • the gate valve 16 on the atmosphere side is closed and the load lock chamber 3 is evacuated, then the gate valve 54 is opened, the pick is extended to the etching apparatus 5, and the wafer W is transferred to the etching apparatus 5.
  • the pick is returned to the load lock chamber 3, the gate valve 54 is closed, and an etching process is performed in the etching apparatus 5.
  • the gate valve 54 is opened, and the wafer W after the etching process on the mounting table 42 is retracted to the load lock chamber 3 by the pick of the second wafer transfer mechanism 17 to transfer the first wafer.
  • the carrier 11 is returned to the carrier C by one of the transport arms 11 a and 11 b of the mechanism 11. Thereby, processing of one wafer is completed. Such processing is performed on a plurality of wafers in the carrier C.
  • FIG. 2 is a cross-sectional view showing a first example of the etching apparatus 5.
  • the etching apparatus 5 of the first example includes a chamber 40 having a sealed structure, and a mounting table 42 on which the wafer W is mounted in a substantially horizontal state is placed inside the chamber 40. Is provided.
  • the etching apparatus 5 also includes a gas supply mechanism 43 that supplies HF gas, NO gas, and the like to the chamber 40 and an exhaust mechanism 44 that exhausts the inside of the chamber 40.
  • the chamber 40 includes a chamber body 51 and a lid 52.
  • the chamber body 51 has a substantially cylindrical side wall portion 51 a and a bottom portion 51 b, and an upper portion is an opening, and the opening is closed by a lid portion 52.
  • the side wall 51a and the lid 52 are sealed by a sealing member (not shown), and the airtightness in the chamber 40 is ensured.
  • a first gas introduction nozzle 61 and a second gas introduction nozzle 62 are inserted into the chamber 40 from above on the top wall of the lid portion 52.
  • a loading / unloading port 53 for loading / unloading the wafer W into / from the load lock chamber 3 is provided in the side wall 51a, and the loading / unloading port 53 can be opened and closed by a gate valve 54.
  • the mounting table 42 has a substantially circular shape in plan view, and is fixed to the bottom 51 b of the chamber 40.
  • a temperature controller 55 that adjusts the temperature of the mounting table 42 is provided inside the mounting table 42.
  • the temperature controller 55 includes, for example, a pipe line through which a temperature adjusting medium (for example, water) circulates, and heat exchange is performed with the temperature adjusting medium flowing in the pipe line, thereby the mounting table 42.
  • the temperature of the wafer W on the mounting table 42 is controlled.
  • the gas supply mechanism 43 has a first gas supply pipe 63 and a second gas supply pipe 64 connected to the first gas introduction nozzle 61 and the second gas introduction nozzle 62, respectively.
  • An HF gas supply source 65 is connected to the first gas supply pipe 63.
  • a NO gas supply source 66 is connected to the second gas supply pipe 64.
  • a third gas supply pipe 67 is connected to the first gas supply pipe 63, and an Ar gas supply source 68 that supplies Ar gas is connected to the third gas supply pipe 67. Further, a fourth gas supply pipe 69 is connected to the second gas supply pipe 64, and an N 2 gas supply source 70 is connected to the fourth gas supply pipe 69.
  • a fifth gas supply pipe 71 is further connected to the second gas supply pipe 64, and an O 2 gas supply source 72 and an ozone generator 73 are provided in the fifth gas supply pipe 71. . Then, O 2 gas sent from the O 2 gas supply source 72 is adapted to be ozonized by ozone generator 73.
  • the first to fifth gas supply pipes 63, 64, 67, 69 and 71 are provided with a flow rate controller 80 for opening and closing the flow path and controlling the flow rate.
  • the flow rate controller 80 is constituted by, for example, an on-off valve and a mass flow controller.
  • HF gas and Ar gas are introduced into the chamber 40 through the first gas supply pipe 63 and the first gas introduction nozzle 61, and NO gas, N 2 gas, and ozone gas are introduced into the second gas supply pipe 64. Then, the gas is introduced into the chamber 40 through the second gas introduction nozzle 62.
  • HF gas and NO gas are used as a processing gas for etching
  • ozone gas is used as a gas for a modification process before etching
  • Ar gas and N 2 gas are used as a dilution gas or a purge gas.
  • Any one of Ar gas and N 2 gas used as the purge gas may be used, or another inert gas may be used.
  • the exhaust mechanism 44 has an exhaust pipe 82 connected to an exhaust port 81 formed in the bottom 51 b of the chamber 40, and further, an automatic pressure provided in the exhaust pipe 82 for controlling the pressure in the chamber 40.
  • a control valve (APC) 83 and a vacuum pump 84 for evacuating the chamber 40 are provided.
  • Two capacitance manometers 86a and 86b as pressure gauges for measuring the pressure in the chamber 40 are provided from the side wall of the chamber 40 into the chamber 40.
  • the capacitance manometer 86a is for high pressure
  • the capacitance manometer 86b is for low pressure.
  • a temperature sensor (not shown) for detecting the temperature of the wafer W is provided in the vicinity of the wafer W mounted on the mounting table 42.
  • Al is used as the material of various components such as the chamber 40 and the mounting table 42 that constitute the etching apparatus 5.
  • the Al material constituting the chamber 40 may be a solid material, or may be an inner surface (such as the inner surface of the chamber body 51) subjected to an anodizing treatment.
  • the surface of Al constituting the mounting table 42 is required to have wear resistance, it is preferable to perform anodization to form an oxide film (Al 2 O 3 ) having high wear resistance on the surface.
  • the wafer W having the above-described configuration is loaded into the chamber 40 from the loading / unloading port 53 by the pick of the second wafer transfer mechanism 17 in the load lock chamber 3, and placed on the mounting table 42. Place.
  • reforming treatment with ozone gas is performed as necessary.
  • the reforming process is generated by adjusting the temperature of the mounting table 42 to a predetermined temperature by the temperature controller 55 and ozonizing the O 2 gas from the O 2 gas supply source 72 of the gas supply mechanism 43 by the ozone generator 73.
  • the ozone gas is introduced into the chamber 40 from the second gas supply pipe 64 and the second gas introduction nozzle 62.
  • This reforming treatment with ozone gas forms SiO 2 on the surface of the polysilicon film to protect it from etching, and facilitates etching by oxidizing the surface of the SiN film (forming SiNO).
  • the etching rate of the SiN film and the etching selectivity with respect to the poly-Si film and / or the SiO 2 film can be further increased in the next etching process.
  • the pressure in the chamber 40 is preferably in the range of 80 to 150 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C.
  • this modification treatment may be performed in a separate chamber instead of the chamber 40 of the etching apparatus 5. Further, this reforming treatment is not essential. When the reforming process is performed in a separate chamber or when the reforming process is not performed, the fifth gas supply pipe 71, the O 2 gas supply source 72, and the ozone generator 73 are unnecessary.
  • the SiN film is selectively etched by supplying NO gas and HF gas into the chamber 40.
  • the temperature controller 55 adjusts the temperature of the mounting table 42 to a predetermined range, and the pressure in the chamber 40 is adjusted to a predetermined range, so that NO gas is supplied from the NO gas supply source 66 of the gas supply mechanism 43.
  • NO gas is supplied from the NO gas supply source 66 of the gas supply mechanism 43.
  • HF gas is supplied from the HF gas supply source 65 to the first gas supply pipe 63 and the first gas introduction nozzle. It is introduced into the chamber 40 through 61.
  • both or one of Ar gas and N 2 gas may be supplied as a dilution gas.
  • the etching rate of the poly-Si film and the SiO 2 film by the NO gas and HF gas is low, and the SiN film can be etched with a high selectivity with respect to these films.
  • HF gas when HF gas is used alone, ammonia is generated when the SiN film is etched, and the SiO 2 film existing as a base is damaged, such as roughening.
  • NO gas is added to the HF gas. Thus, damage to the SiO 2 film can be suppressed.
  • the pressure in the chamber 40 is preferably in the range of 1.6 to 80 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C.
  • the volume ratio of NO gas to HF gas is preferably in the range of 1: 0.1 to 1:30. Further, the etching process is preferably performed at the same temperature as the modification process.
  • the etching rate can be 10 nm / min or more and the etching selectivity with respect to the poly-Si film and the SiO 2 film can be 50 or more.
  • the gate valve 54 is opened, and the wafer W after the etching process on the mounting table 42 is unloaded from the chamber 40 by the pick of the second wafer transfer mechanism 17. Etching by 5 is completed.
  • ozone gas is used as a processing gas for etching instead of the NO gas in the first example. That is, HF gas and ozone gas are used as a processing gas for etching.
  • FIG. 3 is a cross-sectional view showing a second example of the etching apparatus 5.
  • the etching apparatus 5 of the second example has no NO gas supply source, and an O 2 gas supply source 72 and an ozone generator 73 are provided in the second gas supply pipe 64. .
  • the wafer W is loaded into the chamber 40 and placed on the mounting table 42, and then, as necessary, as in the first example. Then, the reforming process using ozone gas is performed, and then the SiN film is selectively etched by supplying ozone gas and HF gas into the chamber 40.
  • the temperature of the mounting table 42 is adjusted to a predetermined range by the temperature controller 55, and the pressure in the chamber 40 is adjusted to the predetermined range, so that the O 2 gas supply source 72 of the gas supply mechanism 43
  • the O 2 gas is ozonized by the ozone generator 73, and the generated ozone gas is introduced into the chamber 40 from the second gas supply pipe 64 and the second gas introduction nozzle 62, and the HF gas is supplied from the HF gas supply source 65.
  • the gas is introduced into the chamber 40 through the first gas supply pipe 63 and the first gas introduction nozzle 61. At this time, both or one of Ar gas and N 2 gas may be supplied as a dilution gas.
  • ozone gas and HF gas act on the SiN film, and the SiN film can be etched at a high etching rate.
  • the etching rate of the poly-Si film and the SiO 2 film by ozone gas and HF gas is low, and the SiN film can be etched with a high selectivity with respect to these films.
  • the pressure in the chamber 40 is preferably in the range of 1.6 to 80 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C.
  • the volume ratio of ozone gas to HF gas is preferably in the range of 1: 1 to 1: 7. Further, the etching process is preferably performed at the same temperature as the modification process.
  • the etching rate can be 10 nm / min or more, and the etching selectivity with respect to the poly-Si film and the SiO 2 film can be 50 or more.
  • the gas mixed with the HF gas is NO gas or ozone gas, but both NO gas and ozone gas may be used. In that case, both the NO gas and the ozone gas can be supplied during the etching process using the etching apparatus shown in FIG.
  • FIG. 4 is a cross-sectional view showing a third example of the etching apparatus 5.
  • a remote plasma source 74 is provided in place of the ozone generator 73 of the apparatus of FIG. 2, and oxygen plasma (O 2 plasma) can be introduced into the chamber 40 instead of ozone gas.
  • the modification process is performed by oxygen plasma.
  • modification treatment the temperature of the stage 42 mounting the temperature controller 55 is adjusted to a predetermined temperature, the plasma of O 2 gas from the O 2 gas supply source 72 for the gas supply mechanism 43 at a remote plasma source 74
  • the oxygen plasma thus generated is introduced into the chamber 40 from the second gas supply pipe 64 and the second gas introduction nozzle 62.
  • SiO 2 is formed on the surface of the polysilicon film to protect it from etching, and the surface of the SiN film is oxidized (SiNO is formed) for easy etching.
  • SiNO is formed
  • the pressure in the chamber 40 is preferably in the range of 80 to 150 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C.
  • the etching process after the reforming process can be performed in the same manner as in the first example using HF gas and NO gas.
  • the SiN film can be formed at a high etching rate and with a poly- Etching can be performed with a high selectivity with respect to the Si film and the SiO 2 film.
  • FIG. 5 is a sectional view showing a fourth example of the etching apparatus 5.
  • an ozone generator 73 is provided as in the apparatus of FIG. 3, but a remote plasma source 74 is further provided, and an O 2 gas from an O 2 gas supply source 72 is switched by a switching valve 75 to generate an ozone generator.
  • 73 and the remote plasma source 74 can be selectively supplied, and ozone gas and oxygen plasma (O 2 plasma) can be introduced into the chamber 40.
  • Ozone gas generated by the ozone generator 73 is guided to the second gas supply pipe 64, and oxygen plasma generated by the remote plasma source 74 is guided to the second gas supply pipe 64 via the fifth gas supply pipe 71.
  • the modification process is performed by oxygen plasma, as in the third example.
  • modification treatment the temperature of the stage 42 mounting the temperature controller 55 is adjusted to a predetermined temperature, leading to O 2 gas from the O 2 gas supply source 72 for the gas supply mechanism 43 to the remote plasma source 74 In this manner, the oxygen plasma generated and introduced into the chamber 40 is introduced from the second gas supply pipe 64 and the second gas introduction nozzle 62 into the chamber 40 in the same manner as in the third example.
  • the SiN film can be etched at a high etching rate and with a high selectivity with respect to the poly-Si film and the SiO 2 film.
  • the SiN film existing on the surface of the wafer W is etched by the etching apparatus 5 in a non-plasma manner using NO gas or / and ozone gas and HF gas.
  • Etching can be performed at a high etching rate and with a high selectivity with respect to the SiO 2 film and / or poly-Si film.
  • the etching rate and selectivity of the SiN film can be further increased by performing the modification treatment with ozone gas or oxygen plasma (O 2 plasma) prior to the etching treatment.
  • Example A a sample (sample A) in which a SiN film was formed on a silicon substrate using dichlorosilane (DCS; SiCl 2 H 2 ) as a raw material on a SiO 2 film, and hexachlorodisilane (HCD; Si 2
  • sample B a sample in which a SiN film was formed using Cl 6
  • sample C a sample in which a poly-Si film was formed on a SiO 2 film
  • a thermal oxide film was formed on a silicon substrate
  • Samples (sample D) and five types of samples (sample E) in which a SiN film was formed on a SiO 2 film were subjected to ozone treatment at 200 ° C., ozone treatment at 70 ° C., and ozone + HF treatment at 200 ° C. 2 minutes at a time.
  • the present invention can be variously modified without being limited to the above embodiment.
  • the apparatus of the above embodiment is merely an example, and the etching method of the present invention can be carried out by apparatuses having various configurations.
  • the case where a semiconductor wafer is used as the substrate to be processed has been described.
  • the substrate is not limited to the semiconductor wafer, and other substrates such as an FPD (flat panel display) substrate represented by an LCD (liquid crystal display) substrate and a ceramic substrate. It may be.

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Abstract

A substrate to be treated (W) is disposed in a chamber (40), said substrate to be treated having a silicon nitride film on the surface, and also having a polysilicon film and/or a silicon oxide film that is provided adjacent to the silicon nitride film, and NO gas and/or ozone gas, and HF gas are supplied to the inside of the chamber (40), thereby selectively etching the silicon nitride film.

Description

エッチング方法Etching method
　本発明は、基板に形成された所定の材料の膜をエッチングするエッチング方法に関する。 The present invention relates to an etching method for etching a film of a predetermined material formed on a substrate.
　近時、半導体デバイスの製造過程で、ドライエッチングやウエットエッチングに代わる微細化エッチングが可能な方法として、化学的酸化物除去処理（Ｃｈｅｍｉｃａｌ　Ｏｘｉｄｅ　Ｒｅｍｏｖａｌ；ＣＯＲ）と呼ばれるノンプラズマドライエッチング技術が注目されている（例えば特許文献１、２）。酸化物として酸化シリコン（ＳｉＯ２）をエッチングする場合には、フッ化水素（ＨＦ）ガス単独、またはＨＦガスとアンモニア（ＮＨ３）ガスとの混合ガスが用いられている。 Recently, a non-plasma dry etching technique called “Chemical Oxide Removal (COR)” has been attracting attention as a method capable of performing fine etching instead of dry etching or wet etching in the manufacturing process of semiconductor devices. (For example, Patent Documents 1 and 2). When etching silicon oxide (SiO 2 ) as an oxide, hydrogen fluoride (HF) gas alone or a mixed gas of HF gas and ammonia (NH 3 ) gas is used.
　ところで、ＣＯＲは、酸化物をエッチングする技術であるが、最近では、酸化シリコン（ＳｉＯ２）のような酸化物のみならず、窒化シリコン（ＳｉＮ）膜をエッチングすることも検討されている。ノンプラズマでＳｉＮ膜をエッチングする場合のエッチングガスとしてはＨＦガス＋Ｆ２ガスが検討されている（例えば特許文献３）。 Incidentally, COR is a technique for etching an oxide, but recently, etching of not only an oxide such as silicon oxide (SiO 2 ) but also a silicon nitride (SiN) film has been studied. As an etching gas for etching the SiN film by non-plasma, HF gas + F 2 gas has been studied (for example, Patent Document 3).
特開２００５－３９１８５号公報JP 2005-39185 A 特開２００８－１６００００号公報JP 2008-160000 A 特開２０１０－１８２７３０号公報JP 2010-182730 A
　半導体ウエハにおいて、ＳｉＮ膜は、ポリシリコン（ｐｏｌｙ－Ｓｉ）膜やＳｉ基板等のＳｉや、ＳｉＯ２膜と隣接していることが多く、このような状態でＳｉＮ膜をＨＦガスおよびＦ２ガスでエッチングする場合、低温においては反応生成物として生成するＮＨ３ガスとＨＦガスによりＳｉＯ２膜がエッチングされてしまい、高温においてはｐｏｌｙ－Ｓｉがエッチングされてしまう。このように、ＳｉＮ膜をＳｉＯ２膜およびｐｏｌｙ－Ｓｉ膜に対して高選択比でエッチングし難いという問題がある。 In a semiconductor wafer, the SiN film is often adjacent to Si such as a polysilicon (poly-Si) film or Si substrate, or an SiO 2 film. In such a state, the SiN film is converted into HF gas and F 2 gas. When etching at a low temperature, the SiO 2 film is etched by NH 3 gas and HF gas generated as reaction products at low temperatures, and poly-Si is etched at high temperatures. Thus, there is a problem that it is difficult to etch the SiN film with a high selection ratio with respect to the SiO 2 film and the poly-Si film.
　したがって、本発明の目的は、窒化シリコン膜を酸化シリコン膜および／またはポリシリコン膜に対して高選択比でエッチングすることができるエッチング方法を提供することにある。 Therefore, an object of the present invention is to provide an etching method capable of etching a silicon nitride film with a high selectivity relative to a silicon oxide film and / or a polysilicon film.
　すなわち、本発明の一つの観点によれば、表面に窒化シリコン膜を有し、前記窒化シリコン膜に隣接して設けられたポリシリコン膜および／または酸化シリコン膜を有する被処理基板をチャンバー内に配置することと、前記チャンバー内にＮＯガスまたは／およびオゾンガスと、ＨＦガスとを供給し、これにより前記窒化シリコン膜を前記ポリシリコン膜および／または前記酸化シリコン膜に対して選択的にエッチングすることとを有するエッチング方法が提供される。 That is, according to one aspect of the present invention, a substrate to be processed having a silicon nitride film on the surface and having a polysilicon film and / or a silicon oxide film provided adjacent to the silicon nitride film is placed in the chamber. Disposing and supplying NO gas or / and ozone gas and HF gas into the chamber, whereby the silicon nitride film is selectively etched with respect to the polysilicon film and / or the silicon oxide film. An etching method is provided.
　前記エッチングに先だって、前記被処理基板にオゾンガスまたは酸素プラズマを供給して前記被処理基板の表面の改質処理を行ってもよい。 Prior to the etching, ozone gas or oxygen plasma may be supplied to the substrate to be processed to modify the surface of the substrate to be processed.
　前記エッチングのガスとしてＮＯガスとＨＦガスとを供給する場合に、ＮＯガスとＨＦガスとの体積比率を、１：０．１～１：３０の範囲とすることが好ましい。また、前記エッチングのガスとしてオゾンガスとＨＦガスとを供給する場合に、オゾンガスとＨＦガスとの体積比率を、１：１～１：７の範囲とすることが好ましい。 When supplying NO gas and HF gas as the etching gas, the volume ratio of NO gas and HF gas is preferably in the range of 1: 0.1 to 1:30. Further, when ozone gas and HF gas are supplied as the etching gas, the volume ratio of ozone gas to HF gas is preferably in the range of 1: 1 to 1: 7.
　前記エッチングを行う際に、前記チャンバー内で前記被処理基板を載置する載置台の温度を７０～２００℃の範囲とすることが好ましく、また、前記チャンバー内の圧力を１．６～８０ｋＰａの範囲とすることが好ましい。 When performing the etching, the temperature of the mounting table on which the substrate to be processed is placed in the chamber is preferably in the range of 70 to 200 ° C., and the pressure in the chamber is 1.6 to 80 kPa. It is preferable to be in the range.
　また、本発明の他の観点によれば、コンピュータ上で動作し、エッチング装置を制御するためのプログラムが記憶された記憶媒体であって、前記プログラムは、実行時に、表面に窒化シリコン膜を有し、前記窒化シリコン膜に隣接して設けられたポリシリコン膜および／または酸化シリコン膜を有する被処理基板をチャンバー内に配置することと、前記チャンバー内にＮＯガスまたは／およびオゾンガスと、ＨＦガスとを供給し、これにより前記窒化シリコン膜を前記ポリシリコン膜および／または前記酸化シリコン膜に対して選択的にエッチングすることとを有するエッチング方法が行われるように、コンピュータに前記エッチング装置を制御させる記憶媒体が提供される。 According to another aspect of the present invention, there is provided a storage medium that operates on a computer and stores a program for controlling an etching apparatus, and the program has a silicon nitride film on a surface when executed. A substrate to be processed having a polysilicon film and / or a silicon oxide film provided adjacent to the silicon nitride film is disposed in the chamber, and NO gas or / and ozone gas and HF gas are disposed in the chamber. Thereby controlling the etching apparatus in a computer so that an etching method is performed which includes selectively etching the silicon nitride film with respect to the polysilicon film and / or the silicon oxide film. A storage medium is provided.
　本発明によれば、チャンバー内にＮＯガスまたは／およびオゾンガスと、ＨＦガスとを供給することにより、被処理基板の表面の窒化シリコン膜を高いエッチングレートでエッチングすることができ、かつ窒化シリコン膜に隣接して設けられた酸化シリコン膜および／またはポリシリコン膜に対して窒化シリコン膜を高選択比でエッチングすることができる。 According to the present invention, by supplying NO gas or / and ozone gas and HF gas into the chamber, the silicon nitride film on the surface of the substrate to be processed can be etched at a high etching rate, and the silicon nitride film The silicon nitride film can be etched with a high selectivity with respect to the silicon oxide film and / or the polysilicon film provided adjacent to each other.
本発明の実施形態に係るエッチング方法を実施するために用いられるエッチング装置を搭載した処理システムを示す概略構成図である。It is a schematic block diagram which shows the processing system carrying the etching apparatus used in order to implement the etching method which concerns on embodiment of this invention. 図１の処理システムに搭載されたエッチング装置の第１の例の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the 1st example of the etching apparatus mounted in the processing system of FIG. 図１の処理システムに搭載されたエッチング装置の第２の例の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the 2nd example of the etching apparatus mounted in the processing system of FIG. 図１の処理システムに搭載されたエッチング装置の第３の例の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the 3rd example of the etching apparatus mounted in the processing system of FIG. 図１の処理システムに搭載されたエッチング装置の第４の例の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the 4th example of the etching apparatus mounted in the processing system of FIG.
　以下、図面を参照しながら、本発明の実施の形態について説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　＜本発明の実施形態に用いる処理システム＞
　図１は、本発明の一実施形態に係るエッチング装置を搭載した処理システムを示す概略構成図である。この処理システム１は、半導体ウエハ（以下、単にウエハと記す）Ｗを搬入出する搬入出部２と、搬入出部２に隣接させて設けられた２つのロードロック室（Ｌ／Ｌ）３と、各ロードロック室３にそれぞれ隣接して設けられた、ウエハＷに対してノンプラズマエッチングを行うエッチング装置５とを備えている。 <Processing system used in the embodiment of the present invention>
FIG. 1 is a schematic configuration diagram showing a processing system equipped with an etching apparatus according to an embodiment of the present invention. The processing system 1 includes a loading / unloading section 2 for loading / unloading a semiconductor wafer (hereinafter simply referred to as a wafer) W, and two load lock chambers (L / L) 3 provided adjacent to the loading / unloading section 2. And an etching apparatus 5 that is provided adjacent to each load lock chamber 3 and performs non-plasma etching on the wafer W.
　搬入出部２は、ウエハＷを搬送する第１ウエハ搬送機構１１が内部に設けられた搬送室（Ｌ／Ｍ）１２を有している。第１ウエハ搬送機構１１は、ウエハＷを略水平に保持する２つの搬送アーム１１ａ，１１ｂを有している。搬送室１２の長手方向の側部には、載置台１３が設けられており、この載置台１３には、ウエハＷを複数枚並べて収容可能なキャリアＣが例えば３つ接続できるようになっている。また、搬送室１２に隣接して、ウエハＷを回転させて偏心量を光学的に求めて位置合わせを行なうオリエンタ１４が設置されている。 The loading / unloading unit 2 has a transfer chamber (L / M) 12 in which a first wafer transfer mechanism 11 for transferring the wafer W is provided. The first wafer transfer mechanism 11 has two transfer arms 11a and 11b that hold the wafer W substantially horizontally. A mounting table 13 is provided on the side of the transfer chamber 12 in the longitudinal direction. For example, three carriers C capable of accommodating a plurality of wafers W arranged side by side can be connected to the mounting table 13. . In addition, an orienter 14 is installed adjacent to the transfer chamber 12 to rotate the wafer W and optically determine the amount of eccentricity.
　搬入出部２において、ウエハＷは、搬送アーム１１ａ，１１ｂによって保持され、第１ウエハ搬送機構１１の駆動により略水平面内で直進移動、また昇降させられることにより、所望の位置に搬送させられる。そして、載置台１３上のキャリアＣ、オリエンタ１４、ロードロック室３に対してそれぞれ搬送アーム１１ａ，１１ｂが進退することにより、搬入出させられるようになっている。 In the loading / unloading unit 2, the wafer W is held by the transfer arms 11 a and 11 b, and is moved to a desired position by moving straight and moving up and down substantially in a horizontal plane by driving the first wafer transfer mechanism 11. The transfer arms 11a and 11b are moved forward and backward with respect to the carrier C, the orienter 14 and the load lock chamber 3 on the mounting table 13, respectively.
　各ロードロック室３は、搬送室１２との間にそれぞれゲートバルブ１６が介在された状態で、搬送室１２にそれぞれ連結されている。各ロードロック室３内には、ウエハＷを搬送する第２ウエハ搬送機構１７が設けられている。また、ロードロック室３は、所定の真空度まで真空引き可能に構成されている。 Each load lock chamber 3 is connected to the transfer chamber 12 with a gate valve 16 interposed between the load lock chamber 3 and the transfer chamber 12, respectively. In each load lock chamber 3, a second wafer transfer mechanism 17 for transferring the wafer W is provided. The load lock chamber 3 is configured to be evacuated to a predetermined degree of vacuum.
　第２ウエハ搬送機構１７は、ウエハＷを略水平に保持するピックを有している。このウエハ搬送機構１７においては、ピックをロードロック室３とエッチング装置５との間で移動させることが可能となっており、これによりウエハＷをロードロック室３とエッチング装置５との間で搬送することが可能となっている。 The second wafer transfer mechanism 17 has a pick that holds the wafer W substantially horizontally. In the wafer transfer mechanism 17, it is possible to move the pick between the load lock chamber 3 and the etching apparatus 5, thereby transferring the wafer W between the load lock chamber 3 and the etching apparatus 5. It is possible to do.
　処理システム１は制御部９０を有している。制御部９０は、処理システム１の各構成部を制御するマイクロプロセッサ（コンピュータ）を備えたプロセスコントローラ９１を有している。プロセスコントローラ９１には、オペレータが処理システム１を管理するためにコマンドの入力操作等を行うキーボードや、処理システム１の稼働状況を可視化して表示するディスプレイ等を有するユーザーインターフェース９２が接続されている。また、プロセスコントローラ９１には、処理システム１で実行される各種処理、例えば後述するエッチング装置５における処理ガスの供給やチャンバー内の排気などをプロセスコントローラの制御にて実現するための制御プログラムや処理条件に応じて処理システム１の各構成部に所定の処理を実行させるための制御プログラムである処理レシピや、各種データベース等が格納された記憶部９３が接続されている。レシピは記憶部９３の中の適宜の記憶媒体（図示せず）に記憶されている。そして、必要に応じて、任意のレシピを記憶部９３から呼び出してプロセスコントローラ９１に実行させることで、プロセスコントローラ９１の制御下で、処理システム１での所望の処理が行われる。 The processing system 1 has a control unit 90. The control unit 90 includes a process controller 91 including a microprocessor (computer) that controls each component of the processing system 1. Connected to the process controller 91 is a user interface 92 having a keyboard for an operator to input commands and the like for managing the processing system 1 and a display for visualizing and displaying the operating status of the processing system 1. . The process controller 91 also includes a control program and a process for realizing various processes executed by the processing system 1, for example, supply of process gas in the etching apparatus 5 described later, exhaust in the chamber, and the like by controlling the process controller. A processing unit that is a control program for causing each component of the processing system 1 to execute a predetermined process according to conditions, and a storage unit 93 that stores various databases and the like are connected. The recipe is stored in an appropriate storage medium (not shown) in the storage unit 93. If necessary, an arbitrary recipe is called from the storage unit 93 and is executed by the process controller 91, whereby a desired process in the processing system 1 is performed under the control of the process controller 91.
　このような処理システム１では、ウエハＷとして、表面にエッチング対象であるＳｉＮ膜を有し、それと隣接してＳｉＯ２膜およびｐｏｌｙ－Ｓｉ膜の少なくとも一方が形成されたものを用い、そのようなウエハＷを複数枚キャリアＣ内に収納して処理システム１に搬送する。処理システム１においては、大気側のゲートバルブ１６を開いた状態で搬入出部２のキャリアＣから第１ウエハ搬送機構１１の搬送アーム１１ａ、１１ｂのいずれかによりウエハＷを１枚ロードロック室３に搬送し、ロードロック室３内の第２ウエハ搬送機構１７のピックに受け渡す。 In such a processing system 1, a wafer W having an SiN film to be etched on the surface and at least one of a SiO 2 film and a poly-Si film formed adjacent thereto is used. A plurality of wafers W are stored in the carrier C and transferred to the processing system 1. In the processing system 1, a single wafer W is loaded from the carrier C of the loading / unloading unit 2 by one of the transfer arms 11 a and 11 b of the first wafer transfer mechanism 11 with the atmosphere side gate valve 16 opened. To the pick of the second wafer transfer mechanism 17 in the load lock chamber 3.
　その後、大気側のゲートバルブ１６を閉じてロードロック室３内を真空排気し、次いでゲートバルブ５４を開いて、ピックをエッチング装置５まで伸ばしてウエハＷをエッチング装置５へ搬送する。 Thereafter, the gate valve 16 on the atmosphere side is closed and the load lock chamber 3 is evacuated, then the gate valve 54 is opened, the pick is extended to the etching apparatus 5, and the wafer W is transferred to the etching apparatus 5.
　その後、ピックをロードロック室３に戻し、ゲートバルブ５４を閉じ、エッチング装置５においてエッチング処理が行われる。 Thereafter, the pick is returned to the load lock chamber 3, the gate valve 54 is closed, and an etching process is performed in the etching apparatus 5.
　エッチング装置５におけるエッチング処理が終了した後、ゲートバルブ５４を開き、第２ウエハ搬送機構１７のピックにより載置台４２上のエッチング処理後のウエハＷをロードロック室３に退避させ、第１ウエハ搬送機構１１の搬送アーム１１ａ、１１ｂのいずれかによりキャリアＣに戻す。これにより、一枚のウエハの処理が完了する。このような処理をキャリアＣ内の複数枚のウエハに対して行う。 After the etching process in the etching apparatus 5 is completed, the gate valve 54 is opened, and the wafer W after the etching process on the mounting table 42 is retracted to the load lock chamber 3 by the pick of the second wafer transfer mechanism 17 to transfer the first wafer. The carrier 11 is returned to the carrier C by one of the transport arms 11 a and 11 b of the mechanism 11. Thereby, processing of one wafer is completed. Such processing is performed on a plurality of wafers in the carrier C.
　＜エッチング装置の第１の例およびそれによるエッチング方法＞
　次に、エッチング装置５の第１の例について説明する。
　図２はエッチング装置５の第１の例を示す断面図である。図２に示すように、第１の例のエッチング装置５は、密閉構造のチャンバー４０を備えており、チャンバー４０の内部には、ウエハＷを略水平にした状態で載置させる載置台４２が設けられている。また、エッチング装置５は、チャンバー４０にＨＦガスおよびＮＯガス等を供給するガス供給機構４３、チャンバー４０内を排気する排気機構４４を備えている。 <First Example of Etching Apparatus and Etching Method Using It>
Next, a first example of the etching apparatus 5 will be described.
FIG. 2 is a cross-sectional view showing a first example of the etching apparatus 5. As shown in FIG. 2, the etching apparatus 5 of the first example includes a chamber 40 having a sealed structure, and a mounting table 42 on which the wafer W is mounted in a substantially horizontal state is placed inside the chamber 40. Is provided. The etching apparatus 5 also includes a gas supply mechanism 43 that supplies HF gas, NO gas, and the like to the chamber 40 and an exhaust mechanism 44 that exhausts the inside of the chamber 40.
　チャンバー４０は、チャンバー本体５１と蓋部５２とによって構成されている。チャンバー本体５１は、略円筒形状の側壁部５１ａと底部５１ｂとを有し、上部は開口となっており、この開口が蓋部５２で閉止される。側壁部５１ａと蓋部５２とは、シール部材（図示せず）により封止されて、チャンバー４０内の気密性が確保される。蓋部５２の天壁には上方からチャンバー４０内に第１のガス導入ノズル６１および第２のガス導入ノズル６２が挿入されている。 The chamber 40 includes a chamber body 51 and a lid 52. The chamber body 51 has a substantially cylindrical side wall portion 51 a and a bottom portion 51 b, and an upper portion is an opening, and the opening is closed by a lid portion 52. The side wall 51a and the lid 52 are sealed by a sealing member (not shown), and the airtightness in the chamber 40 is ensured. A first gas introduction nozzle 61 and a second gas introduction nozzle 62 are inserted into the chamber 40 from above on the top wall of the lid portion 52.
　側壁部５１ａには、ロードロック室３に対してウエハＷを搬入出する搬入出口５３が設けられており、この搬入出口５３はゲートバルブ５４により開閉可能となっている。 A loading / unloading port 53 for loading / unloading the wafer W into / from the load lock chamber 3 is provided in the side wall 51a, and the loading / unloading port 53 can be opened and closed by a gate valve 54.
　載置台４２は、平面視略円形をなしており、チャンバー４０の底部５１ｂに固定されている。載置台４２の内部には、載置台４２の温度を調節する温度調節器５５が設けられている。温度調節器５５は、例えば温度調節用媒体（例えば水など）が循環する管路を備えており、このような管路内を流れる温度調節用媒体と熱交換が行なわれることにより、載置台４２の温度が調節され、載置台４２上のウエハＷの温度制御がなされる。 The mounting table 42 has a substantially circular shape in plan view, and is fixed to the bottom 51 b of the chamber 40. A temperature controller 55 that adjusts the temperature of the mounting table 42 is provided inside the mounting table 42. The temperature controller 55 includes, for example, a pipe line through which a temperature adjusting medium (for example, water) circulates, and heat exchange is performed with the temperature adjusting medium flowing in the pipe line, thereby the mounting table 42. The temperature of the wafer W on the mounting table 42 is controlled.
　ガス供給機構４３は、上述した第１のガス導入ノズル６１および第２のガス導入ノズル６２にそれぞれ接続された第１のガス供給配管６３および第２のガス供給配管６４を有している。第１のガス供給配管６３にはＨＦガス供給源６５が接続されている。また、第２のガス供給配管６４にはＮＯガス供給源６６が接続されている。 The gas supply mechanism 43 has a first gas supply pipe 63 and a second gas supply pipe 64 connected to the first gas introduction nozzle 61 and the second gas introduction nozzle 62, respectively. An HF gas supply source 65 is connected to the first gas supply pipe 63. A NO gas supply source 66 is connected to the second gas supply pipe 64.
　第１のガス供給配管６３には第３のガス供給配管６７が接続されていて、第３のガス供給配管６７には、Ａｒガスを供給するＡｒガス供給源６８が接続されている。また、第２のガス供給配管６４には第４のガス供給配管６９が接続されていて、第４のガス供給配管６９にはＮ２ガス供給源７０が接続されている。第２のガス供給配管６４には、さらに第５のガス供給配管７１が接続されており、第５のガス供給配管７１には、Ｏ２ガス供給源７２およびオゾン発生器７３が設けられている。そして、Ｏ２ガス供給源７２から送出されたＯ２ガスがオゾン発生器７３によりオゾン化されるようになっている。 A third gas supply pipe 67 is connected to the first gas supply pipe 63, and an Ar gas supply source 68 that supplies Ar gas is connected to the third gas supply pipe 67. Further, a fourth gas supply pipe 69 is connected to the second gas supply pipe 64, and an N 2 gas supply source 70 is connected to the fourth gas supply pipe 69. A fifth gas supply pipe 71 is further connected to the second gas supply pipe 64, and an O 2 gas supply source 72 and an ozone generator 73 are provided in the fifth gas supply pipe 71. . Then, O 2 gas sent from the O 2 gas supply source 72 is adapted to be ozonized by ozone generator 73.
　第１～第５のガス供給配管６３、６４、６７、６９、７１には流路の開閉動作および流量制御を行う流量制御器８０が設けられている。流量制御器８０は例えば開閉弁およびマスフローコントローラにより構成されている。 The first to fifth gas supply pipes 63, 64, 67, 69 and 71 are provided with a flow rate controller 80 for opening and closing the flow path and controlling the flow rate. The flow rate controller 80 is constituted by, for example, an on-off valve and a mass flow controller.
　ＨＦガスおよびＡｒガスは、第１のガス供給配管６３および第１のガス導入ノズル６１を介してチャンバー４０内へ導入され、ＮＯガス、Ｎ２ガス、およびオゾンガスは、第２のガス供給配管６４および第２のガス導入ノズル６２を介してチャンバー４０内へ導入される。 HF gas and Ar gas are introduced into the chamber 40 through the first gas supply pipe 63 and the first gas introduction nozzle 61, and NO gas, N 2 gas, and ozone gas are introduced into the second gas supply pipe 64. Then, the gas is introduced into the chamber 40 through the second gas introduction nozzle 62.
　これらガスのうち、ＨＦガスおよびＮＯガスはエッチングのための処理ガスとして用いられ、オゾンガスはエッチング前の改質処理のためのガスとして用いられ、ＡｒガスおよびＮ２ガスは、希釈ガスまたはパージガスとして用いられる。パージガスとして用いられるＡｒガスおよびＮ２ガスは、いずれか一種のみであってもよく、また、他の不活性ガスを用いてもよい。 Of these gases, HF gas and NO gas are used as a processing gas for etching, ozone gas is used as a gas for a modification process before etching, and Ar gas and N 2 gas are used as a dilution gas or a purge gas. Used. Any one of Ar gas and N 2 gas used as the purge gas may be used, or another inert gas may be used.
　排気機構４４は、チャンバー４０の底部５１ｂに形成された排気口８１に繋がる排気配管８２を有しており、さらに、排気配管８２に設けられた、チャンバー４０内の圧力を制御するための自動圧力制御弁（ＡＰＣ）８３およびチャンバー４０内を排気するための真空ポンプ８４を有している。 The exhaust mechanism 44 has an exhaust pipe 82 connected to an exhaust port 81 formed in the bottom 51 b of the chamber 40, and further, an automatic pressure provided in the exhaust pipe 82 for controlling the pressure in the chamber 40. A control valve (APC) 83 and a vacuum pump 84 for evacuating the chamber 40 are provided.
　チャンバー４０の側壁からチャンバー４０内に、チャンバー４０内の圧力を計測するための圧力計としての２つのキャパシタンスマノメータ８６ａ，８６ｂが設けられている。キャパシタンスマノメータ８６ａは高圧力用、キャパシタンスマノメータ８６ｂは低圧力用となっている。載置台４２に載置されたウエハＷの近傍には、ウエハＷの温度を検出する温度センサ（図示せず）が設けられている。 Two capacitance manometers 86a and 86b as pressure gauges for measuring the pressure in the chamber 40 are provided from the side wall of the chamber 40 into the chamber 40. The capacitance manometer 86a is for high pressure, and the capacitance manometer 86b is for low pressure. A temperature sensor (not shown) for detecting the temperature of the wafer W is provided in the vicinity of the wafer W mounted on the mounting table 42.
　エッチング装置５を構成するチャンバー４０、載置台４２等の各種構成部品の材質としては、Ａｌが用いられている。チャンバー４０を構成するＡｌ材は無垢のものであってもよいし、内面（チャンバー本体５１の内面など）に陽極酸化処理を施したものであってもよい。一方、載置台４２を構成するＡｌの表面は耐摩耗性が要求されるので、陽極酸化処理を行って表面に耐摩耗性の高い酸化被膜（Ａｌ２Ｏ３）を形成することが好ましい。 Al is used as the material of various components such as the chamber 40 and the mounting table 42 that constitute the etching apparatus 5. The Al material constituting the chamber 40 may be a solid material, or may be an inner surface (such as the inner surface of the chamber body 51) subjected to an anodizing treatment. On the other hand, since the surface of Al constituting the mounting table 42 is required to have wear resistance, it is preferable to perform anodization to form an oxide film (Al 2 O 3 ) having high wear resistance on the surface.
　次に、このような第１の例のエッチング装置によるエッチング方法について説明する。
　本例では、ゲートバルブ５４を開放した状態で、ロードロック室３内の第２ウエハ搬送機構１７のピックにより上述した構成のウエハＷを搬入出口５３からチャンバー４０内に搬入し、載置台４２に載置する。 Next, an etching method using the etching apparatus of the first example will be described.
In this example, with the gate valve 54 opened, the wafer W having the above-described configuration is loaded into the chamber 40 from the loading / unloading port 53 by the pick of the second wafer transfer mechanism 17 in the load lock chamber 3, and placed on the mounting table 42. Place.
　その後、ピックをロードロック室３に戻し、ゲートバルブ５４を閉じ、チャンバー４０内を密閉状態する。 Thereafter, the pick is returned to the load lock chamber 3, the gate valve 54 is closed, and the inside of the chamber 40 is sealed.
　この状態で、最初に必要に応じてオゾンガスによる改質処理を行う。改質処理は、温度調節器５５によって載置台４２の温度を所定の温度に調節し、ガス供給機構４３のＯ２ガス供給源７２からのＯ２ガスをオゾン発生器７３でオゾン化し、生成されたオゾンガスを第２のガス供給配管６４および第２のガス導入ノズル６２からチャンバー４０内へ導入することにより行われる。 In this state, first, reforming treatment with ozone gas is performed as necessary. The reforming process is generated by adjusting the temperature of the mounting table 42 to a predetermined temperature by the temperature controller 55 and ozonizing the O 2 gas from the O 2 gas supply source 72 of the gas supply mechanism 43 by the ozone generator 73. The ozone gas is introduced into the chamber 40 from the second gas supply pipe 64 and the second gas introduction nozzle 62.
　このオゾンガスによる改質処理は、ポリシリコン膜の表面にＳｉＯ２を形成してエッチングから保護するとともに、ＳｉＮ膜の表面を酸化（ＳｉＮＯを形成）することでエッチングしやすくするものである。この改質処理によりウエハＷの表面が改質されることにより、次のエッチング処理において、ＳｉＮ膜のエッチングレートおよびｐｏｌｙ－Ｓｉ膜および／またはＳｉＯ２膜に対するエッチング選択比をより高めることができる。 This reforming treatment with ozone gas forms SiO 2 on the surface of the polysilicon film to protect it from etching, and facilitates etching by oxidizing the surface of the SiN film (forming SiNO). By modifying the surface of the wafer W by this modification process, the etching rate of the SiN film and the etching selectivity with respect to the poly-Si film and / or the SiO 2 film can be further increased in the next etching process.
　このときのチャンバー４０内の圧力は８０～１５０ｋＰａの範囲が好ましく、載置台４２の温度は７０～２００℃の範囲が好ましい。 At this time, the pressure in the chamber 40 is preferably in the range of 80 to 150 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C.
　なお、この改質処理は、エッチング装置５のチャンバー４０ではなく、別個のチャンバーで行ってもよい。また、この改質処理は必須ではない。改質処理を別個のチャンバーで行う場合、または改質処理を行わない場合には、第５のガス供給配管７１、Ｏ２ガス供給源７２、オゾン発生器７３は不要である。 Note that this modification treatment may be performed in a separate chamber instead of the chamber 40 of the etching apparatus 5. Further, this reforming treatment is not essential. When the reforming process is performed in a separate chamber or when the reforming process is not performed, the fifth gas supply pipe 71, the O 2 gas supply source 72, and the ozone generator 73 are unnecessary.
　必要に応じて改質処理を行った後、チャンバー４０内に、ＮＯガスおよびＨＦガスを供給してＳｉＮ膜を選択的にエッチングする。具体的には、温度調節器５５によって載置台４２の温度を所定の範囲に調節し、チャンバー４０内の圧力を所定の範囲に調節して、ガス供給機構４３のＮＯガス供給源６６からＮＯガスを第２のガス供給配管６４および第２のガス導入ノズル６２を介してチャンバー４０内に導入するとともに、ＨＦガス供給源６５からＨＦガスを第１のガス供給配管６３および第１のガス導入ノズル６１を介してチャンバー４０内へ導入する。このとき、ＡｒガスおよびＮ２ガスの両方または一方を希釈ガスとして供給してもよい。 After performing the modification treatment as necessary, the SiN film is selectively etched by supplying NO gas and HF gas into the chamber 40. Specifically, the temperature controller 55 adjusts the temperature of the mounting table 42 to a predetermined range, and the pressure in the chamber 40 is adjusted to a predetermined range, so that NO gas is supplied from the NO gas supply source 66 of the gas supply mechanism 43. Is introduced into the chamber 40 through the second gas supply pipe 64 and the second gas introduction nozzle 62, and HF gas is supplied from the HF gas supply source 65 to the first gas supply pipe 63 and the first gas introduction nozzle. It is introduced into the chamber 40 through 61. At this time, both or one of Ar gas and N 2 gas may be supplied as a dilution gas.
　このようにしてエッチング処理を行うことにより、ＮＯガスおよびＨＦガスがＳｉＮ膜に作用して、ＳｉＮ膜を高エッチングレートでエッチングすることができる。 By performing the etching process in this way, NO gas and HF gas act on the SiN film, and the SiN film can be etched at a high etching rate.
　このとき、ＮＯガスおよびＨＦガスによるｐｏｌｙ－Ｓｉ膜およびＳｉＯ２膜のエッチングレートは低く、これら膜に対してＳｉＮ膜を高選択比でエッチングすることができる。また、ＨＦガスを単独で用いた場合には、ＳｉＮ膜をエッチングした際にアンモニアが生成され、下地として存在するＳｉＯ２膜に荒れ等のダメージを与えるが、ＨＦガスにＮＯガスを添加することで、ＳｉＯ２膜のダメージを抑えることができる。 At this time, the etching rate of the poly-Si film and the SiO 2 film by the NO gas and HF gas is low, and the SiN film can be etched with a high selectivity with respect to these films. In addition, when HF gas is used alone, ammonia is generated when the SiN film is etched, and the SiO 2 film existing as a base is damaged, such as roughening. However, NO gas is added to the HF gas. Thus, damage to the SiO 2 film can be suppressed.
　このエッチング処理におけるチャンバー４０内の圧力は１．６～８０ｋＰａの範囲が好ましく、載置台４２の温度は７０～２００℃の範囲が好ましい。また、ＮＯガスとＨＦガスとの体積比率は、１：０．１～１：３０の範囲であることが好ましい。また、エッチング処理は改質処理と同じ温度で行うことが好ましい。 In this etching process, the pressure in the chamber 40 is preferably in the range of 1.6 to 80 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C. The volume ratio of NO gas to HF gas is preferably in the range of 1: 0.1 to 1:30. Further, the etching process is preferably performed at the same temperature as the modification process.
　ＨＦガスおよびＮＯガスを用いてエッチング処理を行うことにより、エッチングレートを１０ｎｍ／ｍｉｎ以上、ｐｏｌｙ－Ｓｉ膜およびＳｉＯ２膜に対するエッチング選択比を５０以上とすることができる。 By performing the etching process using HF gas and NO gas, the etching rate can be 10 nm / min or more and the etching selectivity with respect to the poly-Si film and the SiO 2 film can be 50 or more.
　このように、エッチング装置５におけるエッチング処理が終了した後、ゲートバルブ５４を開き、第２ウエハ搬送機構１７のピックにより載置台４２上のエッチング処理後のウエハＷをチャンバー４０から搬出し、エッチング装置５によるエッチングが終了する。 As described above, after the etching process in the etching apparatus 5 is completed, the gate valve 54 is opened, and the wafer W after the etching process on the mounting table 42 is unloaded from the chamber 40 by the pick of the second wafer transfer mechanism 17. Etching by 5 is completed.
　＜エッチング装置の第２の例およびそれによるエッチング方法＞
　次に、エッチング装置５の第２の例について説明する。
　この例では、エッチングのための処理ガスとして第１の例のＮＯガスの代わりにオゾンガスを用いる。すなわち、エッチングのための処理ガスとしてＨＦガスとオゾンガスとを用いる。 <Second Example of Etching Apparatus and Etching Method Using It>
Next, a second example of the etching apparatus 5 will be described.
In this example, ozone gas is used as a processing gas for etching instead of the NO gas in the first example. That is, HF gas and ozone gas are used as a processing gas for etching.
　図３は、エッチング装置５の第２の例を示す断面図である。図３に示すように、第２の例のエッチング装置５は、ＮＯガス供給源が存在せず、第２のガス供給配管６４にＯ２ガス供給源７２およびオゾン発生器７３が設けられている。 FIG. 3 is a cross-sectional view showing a second example of the etching apparatus 5. As shown in FIG. 3, the etching apparatus 5 of the second example has no NO gas supply source, and an O 2 gas supply source 72 and an ozone generator 73 are provided in the second gas supply pipe 64. .
　このような第２の例のエッチング装置によりエッチング処理を行う場合には、チャンバー４０内にウエハＷを搬入して、載置台４２に載置した後、第１の例と同様に、必要に応じてオゾンガスによる改質処理を行い、その後、チャンバー４０内に、オゾンガスおよびＨＦガスを供給してＳｉＮ膜を選択的にエッチングする。具体的には、温度調節器５５によって載置台４２の温度を所定の範囲に調節し、チャンバー４０内の圧力を所定の範囲に調節して、ガス供給機構４３のＯ２ガス供給源７２からのＯ２ガスをオゾン発生器７３でオゾン化し、生成されたオゾンガスを第２のガス供給配管６４および第２のガス導入ノズル６２からチャンバー４０内へ導入するとともに、ＨＦガス供給源６５からＨＦガスを第１のガス供給配管６３および第１のガス導入ノズル６１を介してチャンバー４０内へ導入する。このとき、ＡｒガスおよびＮ２ガスの両方または一方を希釈ガスとして供給してもよい。 In the case where the etching process is performed by the etching apparatus of the second example as described above, the wafer W is loaded into the chamber 40 and placed on the mounting table 42, and then, as necessary, as in the first example. Then, the reforming process using ozone gas is performed, and then the SiN film is selectively etched by supplying ozone gas and HF gas into the chamber 40. Specifically, the temperature of the mounting table 42 is adjusted to a predetermined range by the temperature controller 55, and the pressure in the chamber 40 is adjusted to the predetermined range, so that the O 2 gas supply source 72 of the gas supply mechanism 43 The O 2 gas is ozonized by the ozone generator 73, and the generated ozone gas is introduced into the chamber 40 from the second gas supply pipe 64 and the second gas introduction nozzle 62, and the HF gas is supplied from the HF gas supply source 65. The gas is introduced into the chamber 40 through the first gas supply pipe 63 and the first gas introduction nozzle 61. At this time, both or one of Ar gas and N 2 gas may be supplied as a dilution gas.
　このようにしてエッチング処理を行うことにより、オゾンガスおよびＨＦガスがＳｉＮ膜に作用して、ＳｉＮ膜を高エッチングレートでエッチングすることができる。 By performing the etching process in this manner, ozone gas and HF gas act on the SiN film, and the SiN film can be etched at a high etching rate.
　このとき、オゾンガスおよびＨＦガスによるｐｏｌｙ－Ｓｉ膜およびＳｉＯ２膜のエッチングレートは低く、これら膜に対してＳｉＮ膜を高選択比でエッチングすることができる。 At this time, the etching rate of the poly-Si film and the SiO 2 film by ozone gas and HF gas is low, and the SiN film can be etched with a high selectivity with respect to these films.
　このエッチング処理におけるチャンバー４０内の圧力は１．６～８０ｋＰａの範囲が好ましく、載置台４２の温度は７０～２００℃の範囲が好ましい。また、オゾンガスとＨＦガスとの体積比率は、１：１～１：７の範囲であることが好ましい。また、エッチング処理は改質処理と同じ温度で行うことが好ましい。 In this etching process, the pressure in the chamber 40 is preferably in the range of 1.6 to 80 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C. The volume ratio of ozone gas to HF gas is preferably in the range of 1: 1 to 1: 7. Further, the etching process is preferably performed at the same temperature as the modification process.
　オゾンガスおよびＨＦガスを用いてエッチング処理を行うことにより、エッチングレートを１０ｎｍ／ｍｉｎ以上、ｐｏｌｙ－Ｓｉ膜およびＳｉＯ２膜に対するエッチング選択比を５０以上とすることができる。 By performing the etching process using ozone gas and HF gas, the etching rate can be 10 nm / min or more, and the etching selectivity with respect to the poly-Si film and the SiO 2 film can be 50 or more.
　以上の第１の例、第２の例では、ＨＦガスに混合するガスをＮＯガスまたはオゾンガスとしているが、ＮＯガスおよびオゾンガスの両方を用いてもよい。その場合には、図２に示すエッチング装置を用いて、エッチング処理の際に、ＮＯガスおよびオゾンガスの両方を供給できるようにする。 In the above first and second examples, the gas mixed with the HF gas is NO gas or ozone gas, but both NO gas and ozone gas may be used. In that case, both the NO gas and the ozone gas can be supplied during the etching process using the etching apparatus shown in FIG.
　＜エッチング装置の第３の例およびそれによるエッチング方法＞
　次に、エッチング装置５の第３の例について説明する。
　図４はエッチング装置５の第３の例を示す断面図である。この例では、図２の装置のオゾン発生器７３に代えてリモートプラズマ源７４を設け、オゾンガスの代わりに酸素プラズマ（Ｏ２プラズマ）をチャンバー４０内に導入できるようになっている。 <Third example of etching apparatus and etching method using the same>
Next, a third example of the etching apparatus 5 will be described.
FIG. 4 is a cross-sectional view showing a third example of the etching apparatus 5. In this example, a remote plasma source 74 is provided in place of the ozone generator 73 of the apparatus of FIG. 2, and oxygen plasma (O 2 plasma) can be introduced into the chamber 40 instead of ozone gas.
　このエッチング装置５の第３の例では、改質処理を酸素プラズマにより行う。この例では、改質処理は、温度調節器５５によって載置台４２の温度を所定の温度に調節し、ガス供給機構４３のＯ２ガス供給源７２からのＯ２ガスをリモートプラズマ源７４でプラズマ化し、生成された酸素プラズマを第２のガス供給配管６４および第２のガス導入ノズル６２からチャンバー４０内へ導入することにより行われる。 In the third example of the etching apparatus 5, the modification process is performed by oxygen plasma. In this example, modification treatment, the temperature of the stage 42 mounting the temperature controller 55 is adjusted to a predetermined temperature, the plasma of O 2 gas from the O 2 gas supply source 72 for the gas supply mechanism 43 at a remote plasma source 74 The oxygen plasma thus generated is introduced into the chamber 40 from the second gas supply pipe 64 and the second gas introduction nozzle 62.
　この酸素プラズマによる改質処理は、オゾンガスの場合と同様、ポリシリコン膜の表面にＳｉＯ２を形成してエッチングから保護するとともに、ＳｉＮ膜の表面を酸化（ＳｉＮＯを形成）することでエッチングしやすくするものである。酸素プラズマによる改質処理によってウエハＷの表面が改質されることにより、次のエッチング処理において、ＳｉＮ膜のｐｏｌｙ－Ｓｉ膜および／またはＳｉＯ２膜に対するエッチング選択比をより高めることができる。 In the modification process using oxygen plasma, as in the case of ozone gas, SiO 2 is formed on the surface of the polysilicon film to protect it from etching, and the surface of the SiN film is oxidized (SiNO is formed) for easy etching. To do. By modifying the surface of the wafer W by the modification process using oxygen plasma, the etching selectivity of the SiN film to the poly-Si film and / or the SiO 2 film can be further increased in the next etching process.
　このときのチャンバー４０内の圧力は８０～１５０ｋＰａの範囲が好ましく、載置台４２の温度は７０～２００℃の範囲が好ましい。 At this time, the pressure in the chamber 40 is preferably in the range of 80 to 150 kPa, and the temperature of the mounting table 42 is preferably in the range of 70 to 200 ° C.
　このように改質処理を行った後のエッチング処理は、ＨＦガスおよびＮＯガスを用いて、第１の例と同様に行うことができ、同様に、ＳｉＮ膜を高エッチングレートで、かつｐｏｌｙ－Ｓｉ膜およびＳｉＯ２膜に対して高選択比でエッチングすることができる。 The etching process after the reforming process can be performed in the same manner as in the first example using HF gas and NO gas. Similarly, the SiN film can be formed at a high etching rate and with a poly- Etching can be performed with a high selectivity with respect to the Si film and the SiO 2 film.
　＜エッチング装置の第４の例およびそれによるエッチング方法＞
　次に、エッチング装置５の第４の例について説明する。
　図５はエッチング装置５の第４の例を示す断面図である。この例では、図３の装置と同様、オゾン発生器７３を有しているが、さらにリモートプラズマ源７４を設け、Ｏ２ガス供給源７２からのＯ２ガスを切り替えバルブ７５により、オゾン発生器７３およびリモートプラズマ源７４に選択的に供給できるようにし、オゾンガスおよび酸素プラズマ（Ｏ２プラズマ）をチャンバー４０内に導入できるようになっている。オゾン発生器７３で発生したオゾンガスは第２のガス供給配管６４に導かれ、リモートプラズマ源７４で発生した酸素プラズマは第５のガス供給配管７１を経て第２のガス供給管６４に導かれる。 <Fourth Example of Etching Apparatus and Etching Method Using It>
Next, a fourth example of the etching apparatus 5 will be described.
FIG. 5 is a sectional view showing a fourth example of the etching apparatus 5. In this example, an ozone generator 73 is provided as in the apparatus of FIG. 3, but a remote plasma source 74 is further provided, and an O 2 gas from an O 2 gas supply source 72 is switched by a switching valve 75 to generate an ozone generator. 73 and the remote plasma source 74 can be selectively supplied, and ozone gas and oxygen plasma (O 2 plasma) can be introduced into the chamber 40. Ozone gas generated by the ozone generator 73 is guided to the second gas supply pipe 64, and oxygen plasma generated by the remote plasma source 74 is guided to the second gas supply pipe 64 via the fifth gas supply pipe 71.
　このエッチング装置５の第４の例においても、第３の例と同様、改質処理を酸素プラズマにより行う。この例では、改質処理は、温度調節器５５によって載置台４２の温度を所定の温度に調節し、ガス供給機構４３のＯ２ガス供給源７２からのＯ２ガスをリモートプラズマ源７４に導いてプラズマ化し、生成された酸素プラズマを第２のガス供給配管６４および第２のガス導入ノズル６２からチャンバー４０内へ導入することにより、第３の例と同様に行われる。 Also in the fourth example of the etching apparatus 5, the modification process is performed by oxygen plasma, as in the third example. In this example, modification treatment, the temperature of the stage 42 mounting the temperature controller 55 is adjusted to a predetermined temperature, leading to O 2 gas from the O 2 gas supply source 72 for the gas supply mechanism 43 to the remote plasma source 74 In this manner, the oxygen plasma generated and introduced into the chamber 40 is introduced from the second gas supply pipe 64 and the second gas introduction nozzle 62 into the chamber 40 in the same manner as in the third example.
　このように改質処理を行った後のエッチング処理は、切り替えバルブ７５によりＯ２ガス供給源７２からのＯ２ガスをオゾン発生器７３に導くようにし、ＨＦガスおよびオゾンガスを用いて、第２の例と同様に行うことができ、同様に、ＳｉＮ膜を高エッチングレートで、かつｐｏｌｙ－Ｓｉ膜およびＳｉＯ２膜に対して高選択比でエッチングすることができる。 The etching process after the modification treatment in this manner, the O 2 gas from the O 2 gas supply source 72 to guide the ozone generator 73 by the switching valve 75, with a HF gas and ozone, the second Similarly, the SiN film can be etched at a high etching rate and with a high selectivity with respect to the poly-Si film and the SiO 2 film.
　以上のように、本実施形態によれば、エッチング装置５によりウエハＷの表面に存在するＳｉＮ膜を、ＮＯガスまたは／およびオゾンガスと、ＨＦガスとによりノンプラズマでエッチングすることにより、ＳｉＮ膜を高エッチングレートで、かつＳｉＯ２膜および／またはｐｏｌｙ－Ｓｉ膜に対して高選択比でエッチングすることができる。また、エッチング処理に先立って、オゾンガスまたは酸素プラズマ（Ｏ２プラズマ）で改質処理を行うことにより、ＳｉＮ膜のエッチングレートおよび選択比を一層高めることができる。 As described above, according to the present embodiment, the SiN film existing on the surface of the wafer W is etched by the etching apparatus 5 in a non-plasma manner using NO gas or / and ozone gas and HF gas. Etching can be performed at a high etching rate and with a high selectivity with respect to the SiO 2 film and / or poly-Si film. In addition, the etching rate and selectivity of the SiN film can be further increased by performing the modification treatment with ozone gas or oxygen plasma (O 2 plasma) prior to the etching treatment.
　＜実験例＞
　次に、実験例について説明する。
　本実験例においては、ＳｉＯ２膜の上に、シリコン基板上にジクロロシラン（ＤＣＳ；ＳｉＣｌ２Ｈ２）を原料としてＳｉＮ膜を成膜したサンプル（サンプルＡ）と、ヘキサクロロジシラン（ＨＣＤ；Ｓｉ２Ｃｌ６）を原料としてＳｉＮ膜を成膜したサンプル（サンプルＢ）、および、ＳｉＯ２膜の上にｐｏｌｙ－Ｓｉ膜を成膜したサンプル（サンプルＣ）、シリコン基板上に熱酸化膜を形成したサンプル（サンプルＤ）、ＳｉＯ２膜上にＳｉＮ膜を形成したサンプル（サンプルＥ）の５種類のサンプルについて、２００℃でのオゾン処理、７０℃でのオゾン処理、２００℃でのオゾン＋ＨＦ処理を２ｍｉｎずつ行った。 <Experimental example>
Next, experimental examples will be described.
In this experimental example, a sample (sample A) in which a SiN film was formed on a silicon substrate using dichlorosilane (DCS; SiCl 2 H 2 ) as a raw material on a SiO 2 film, and hexachlorodisilane (HCD; Si 2 A sample (sample B) in which a SiN film was formed using Cl 6 ) as a raw material, a sample (sample C) in which a poly-Si film was formed on a SiO 2 film, and a thermal oxide film was formed on a silicon substrate Samples (sample D) and five types of samples (sample E) in which a SiN film was formed on a SiO 2 film were subjected to ozone treatment at 200 ° C., ozone treatment at 70 ° C., and ozone + HF treatment at 200 ° C. 2 minutes at a time.
　その結果、２００℃でのオゾン＋ＨＦ処理を２ｍｉｎ行うことにより、サンプルＡ、Ｂ、ＥのＳｉＮ膜は１０～２０ｎｍエッチングされていることが確認された。これに対し、ＳｉＯ２膜、ｐｏｌｙ－Ｓｉ膜はオゾン＋ＨＦ処理を２ｍｉｎ行ってもほとんどエッチングされないことが確認された。また、いずれのサンプルもオゾンガスのみでは、ほとんどエッチングされないことが確認された。 As a result, it was confirmed that the SiN films of Samples A, B, and E were etched by 10 to 20 nm by performing ozone + HF treatment at 200 ° C. for 2 minutes. On the other hand, it was confirmed that the SiO 2 film and the poly-Si film were hardly etched even when ozone + HF treatment was performed for 2 minutes. Moreover, it was confirmed that any sample was hardly etched only by ozone gas.
　＜本発明の他の適用＞
　なお、本発明は上記実施形態に限定されることなく種々変形可能である。例えば、上記実施形態の装置は一例に過ぎず、種々の構成の装置により本発明のエッチング方法を実施することができる。また、被処理基板として半導体ウエハを用いた場合について示したが、半導体ウエハに限らず、ＬＣＤ（液晶ディスプレイ）用基板に代表されるＦＰＤ（フラットパネルディスプレイ）基板や、セラミックス基板等の他の基板であってもよい。 <Other applications of the present invention>
The present invention can be variously modified without being limited to the above embodiment. For example, the apparatus of the above embodiment is merely an example, and the etching method of the present invention can be carried out by apparatuses having various configurations. In addition, the case where a semiconductor wafer is used as the substrate to be processed has been described. However, the substrate is not limited to the semiconductor wafer, and other substrates such as an FPD (flat panel display) substrate represented by an LCD (liquid crystal display) substrate and a ceramic substrate. It may be.
　１；処理システム
　２；搬入出部
　３；ロードロック室
　５；エッチング装置
１１；第１ウエハ搬送機構
１７；第２ウエハ搬送機構
４０；チャンバー
４３；ガス供給機構
４４；排気機構
６１；第１のガス導入ノズル
６２；第２のガス導入ノズル
６５；ＨＦガス供給源
６６；ＮＯガス供給源
７２；Ｏ２ガス供給源
７３；オゾン発生器
７４；リモートプラズマ源
９０；制御部
Ｗ；半導体ウエハ DESCRIPTION OF SYMBOLS 1; Processing system 2; Loading / unloading part 3; Load lock chamber 5; Etching apparatus 11; First wafer conveyance mechanism 17; Second wafer conveyance mechanism 40; Chamber 43; Gas supply mechanism 44; Introduction nozzle 62; second gas introduction nozzle 65; HF gas supply source 66; NO gas supply source 72; O 2 gas supply source 73; ozone generator 74; remote plasma source 90;

Claims (7)

  1. 　表面に窒化シリコン膜を有し、前記窒化シリコン膜に隣接して設けられたポリシリコン膜および／または酸化シリコン膜を有する被処理基板をチャンバー内に配置することと、
    　前記チャンバー内にＮＯガスまたは／およびオゾンガスと、ＨＦガスとを供給し、これにより前記窒化シリコン膜を前記ポリシリコン膜および／または前記酸化シリコン膜に対して選択的にエッチングすることと
    を有するエッチング方法。     A substrate to be processed having a silicon nitride film on the surface and having a polysilicon film and / or a silicon oxide film provided adjacent to the silicon nitride film;
    Etching comprising supplying NO gas or / and ozone gas and HF gas into the chamber, thereby selectively etching the silicon nitride film with respect to the polysilicon film and / or the silicon oxide film Method.
  2. 　前記エッチングに先だって、前記被処理基板にオゾンガスまたは酸素プラズマを供給して前記被処理基板の表面の改質処理を行うことをさらに有する請求項１に記載のエッチング方法。 The etching method according to claim 1, further comprising supplying ozone gas or oxygen plasma to the substrate to be processed to modify the surface of the substrate to be processed prior to the etching.
  3. 　前記エッチングのガスとしてＮＯガスとＨＦガスとを供給する場合に、ＮＯガスとＨＦガスとの体積比率を、１：０．１～１：３０の範囲とする、請求項１に記載のエッチング方法。 2. The etching method according to claim 1, wherein when NO gas and HF gas are supplied as the etching gas, a volume ratio of NO gas and HF gas is set to a range of 1: 0.1 to 1:30. .
  4. 　前記エッチングのガスとしてオゾンガスとＨＦガスとを供給する場合に、オゾンガスとＨＦガスとの体積比率を、１：１～１：７の範囲とする請求項１に記載のエッチング方法。 2. The etching method according to claim 1, wherein when ozone gas and HF gas are supplied as the etching gas, the volume ratio of ozone gas to HF gas is in the range of 1: 1 to 1: 7.
  5. 　前記エッチングを行う際に、前記チャンバー内で前記被処理基板を載置する載置台の温度を７０～２００℃の範囲とする請求項１に記載のエッチング方法。 2. The etching method according to claim 1, wherein, when performing the etching, the temperature of the mounting table on which the substrate to be processed is mounted in the chamber is in the range of 70 to 200 ° C.
  6. 　前記エッチングを行う際に、前記チャンバー内の圧力を１．６～８０ｋＰａの範囲とする請求項１に記載のエッチング方法。 The etching method according to claim 1, wherein the pressure in the chamber is set in the range of 1.6 to 80 kPa when performing the etching.
  7. 　コンピュータ上で動作し、エッチング装置を制御するためのプログラムが記憶された記憶媒体であって、前記プログラムは、実行時に、表面に窒化シリコン膜を有し、前記窒化シリコン膜に隣接して設けられたポリシリコン膜および／または酸化シリコン膜を有する被処理基板をチャンバー内に配置することと、前記チャンバー内にＮＯガスまたは／およびオゾンガスと、ＨＦガスとを供給し、これにより前記窒化シリコン膜を前記ポリシリコン膜および／または前記酸化シリコン膜に対して選択的にエッチングすることとを有するエッチング方法が行われるように、コンピュータに前記エッチング装置を制御させる記憶媒体。 A storage medium that operates on a computer and stores a program for controlling an etching apparatus, and the program has a silicon nitride film on a surface and is provided adjacent to the silicon nitride film at the time of execution. A substrate to be processed having a polysilicon film and / or a silicon oxide film is disposed in the chamber, and NO gas or / and ozone gas and HF gas are supplied into the chamber, whereby the silicon nitride film is formed. A storage medium that causes a computer to control the etching apparatus such that an etching method including selectively etching the polysilicon film and / or the silicon oxide film is performed.
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