TW201029065A - Selective etching and formation of xenon difluoride - Google Patents

Abstract

This invention relates to a process for selective removal of materials, such as: silicon, molybdenum, tungsten, titanium, zirconium, hafnium, vanadium, tantalum, niobium, boron, phosphorus, germanium, arsenic, and mixtures thereof, from silicon dioxide, silicon nitride, nickel, aluminum, TiNi alloy, photoresist, phosphosilicate glass, boron phosphosilicate glass, polyimides, gold, copper, platinum, chromium, aluminum oxide, silicon carbide and mixtures thereof. The process is related to the important applications in the cleaning or etching process for semiconductor deposition chambers and semiconductor tools, devices in a micro electro mechanical system (MEMS), and ion implantation systems. Methods of forming XeF2 by reacting Xe with a fluorine containing chemical are also provided, where the fluorine containing chemical is selected from the group consisting of F2, NF3, C2F6, CF4, C3F8, SF6, a plasma containing F atoms generated from an upstream plasma generator and mixtures thereof.

Description

201029065 VI. INSTRUCTIONS: CROSS-REFERENCE TO RELATED APPLICATIONS This application is incorporated herein by reference in its entirety, the entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire content BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to selective etching and formation of antimony difluoride. [Prior Art] Various deposition techniques have been developed in the electronics industry in which selected materials are deposited on a target substrate to produce electrons. An element such as a semiconductor. One deposition method is chemical vapor deposition (CVD) in which a gaseous reactant is introduced into a heated processing chamber to obtain a film deposited on a desired substrate. A subtype of CVD is Called plasma enhanced CVD (PECVD), in which plasma is built up in a CVD processing chamber. Typically, all deposition methods cause the film and particulate material to accumulate on surfaces other than the target substrate, ie, the deposited material also accumulates Walls, tool surfaces, susceptors, and other equipment used in deposition methods. Any gathering on walls, tool surfaces, foundations Materials, membranes, etc. on other equipment are considered contaminants and may cause defects in electronic product components. It is generally accepted that deposition chambers, tools, and equipment must be periodically cleaned to remove unwanted contaminating deposition materials. A preferred method of cleaning the deposition chamber, 201029065 - tools and equipment includes the use of perfluorinated compounds (pFC) such as < c2F6, cf4, c3F8, SF6 and NF3 as etchant cleaners. In these cleaning operations Normally, the chemically active fluorine species carried by the process gas convert unwanted unwanted residues into volatile products. The 'volatile products are then purged out of the reactor by process gases. The ions are used in integrated circuit manufacturing. To accurately introduce a controlled amount of dopant impurities into a semiconductor wafer, and it is an important method in microelectronic/semiconductor production. In an ideal situation, all raw material molecules are ionized and extracted, but actually However, a certain amount of decomposition of the raw material occurs, which causes a component on the surface in the ion source region or the ion implantation tool, such as Deposition and contamination on pressure insulators and high voltage components. Known pollution annihilation, boron, phosphorus, antimony or arsenic. An important advance in the field of ion implantation is to provide efficient, selective removal in implantation. The process is deposited in situ throughout the implanter, particularly in the ion source region, without residue residue. This in-situ cleaning enhances worker safety and contributes to stable, continuous operation of the injection equipment. Introducing a gas phase reactive halide composition, such as XeF2, NF3, F2, XeF6, SF6, C2f6, IFs or IF7, into the contaminated component for at least partial time and under sufficient conditions to at least partially remove from the 7G piece The residue is carried out in such a manner that the residue is selectively removed with respect to the material of the element constructing the ion implanter. In a micro electromechanical system (MEMS), a mixture of a sacrificial layer (usually having an amorphous germanium) and a protective layer is formed, thereby forming a device structure layer. Selective removal of the sacrificial material is a critical step in the method of structural release etching, where isotropic removal of a few microns of sacrificial 5 201029065 material without damaging other structures. It is understood that the etching method is a selective etching method that does not etch the protective layer. Typical sacrificial materials used in MEMS are: tantalum, molybdenum, tungsten, titanium, niobium, tantalum, vanadium, niobium, tantalum. The curved protective material is nickel, aluminum, photoresist, tantalum oxide, tantalum nitride. In order to effectively remove the sacrificial material, the release etch uses an etchant gas that is capable of performing a spontaneous chemical etch of the sacrificial layer, preferably an isotropic etch that removes the sacrificial layer. Since the isotropic etching effect of antimony difluoride is strong, xeF2 is used as a silver engraving agent for the hteM etching process. However, bismuth difluoride is expensive and is a difficult material to handle. The difluorinated gas is unstable in contact with air, light or water vapor (moisture). All barium fluoride must be protected from moisture, light and air to avoid the formation of antimony trioxide and hydrogen fluoride. Antimony trioxide is a dangerous, explosive, colorless, non-volatile solid. Hydrogen fluoride is not only dangerous but also reduces etching efficiency. In addition, the monofluorinated gas has a low vapor|solids, which makes it difficult to transport the antimony difluoride to the processing chamber. The following references illustrate methods for film deposition in semiconductor fabrication, as well as cleaning of deposition chambers, tools and equipment, and etching of substrates, etching of sacrificial layers of MEMS towels, and microelectronic device fabrication. Cleaning of the ion source region in an ion implantation system used: US 5,421,957 discloses a method for cryogenic cleaning of a cold wall cvd cavity. The method is carried out in situ without the (four) material. Cleaning of various materials such as worms, polycrystalline granules, nitriding stones, oxidized stone ceremonies and refractory metals, qinghe and its lithographs to make (iv) engraving gases such as nitrogen trifluoride three 201029065 - liquefied gas, six It is achieved by sulfur fluoride and carbon tetrafluoride. ' us 6,051,052 discloses an anisotropic etch of a germanium material using fluorine compounds such as NF3 and CZF6 as etchants in ion-enhanced plasmas. The etchant consists of a fluorochemical and a rare gas selected from the group consisting of He, Ar, Xe and Kr. The test substrate includes an integrated circuit that is connected to the substrate. In one embodiment, the titanium layer is formed on the insulating layer and is in contact with a tungsten plug. Then, an aluminum-copper alloy layer is formed on the titanium layer _, and a titanium nitride layer is formed thereon. US 2003/0047691 discloses the use of electron beam processing to etch or deposit material or to repair defects in a lith〇graphy mask. In one embodiment, the ruthenium difluoride is activated by an electron beam to etch the crane and nitride groups. GB 2,183,204 A discloses the use of NF3 for in situ cleaning of CVD deposition hardware, boats, tubes and quartz vessels, as well as semiconductor wafers. The NF3 is introduced into the heated reactor over 350 °C for a sufficient time to remove tantalum nitride, polycrystalline germanium, titanium telluride, tungsten antimonide, refractory metal and telluride.

Holt, JR et al, Comparison of the Interactions of XeF2 and F2 with Si (100) (2X1), J. Phys. Chem. B 2002, 106, 83 99-8406 discloses XeF2 and Si(100) at 2K (2Xl) The interaction 'and provides a comparison with F2. XeF2 was found to react rapidly and isotropically with Si at room temperature.

Chang, F. I., Gas-Phase Silicon Micromachining With

Xenon Difluoride, SPIE Vol. 2641/117-127 discloses the use

XeF2 acts as a gas phase, room temperature, isotropic cerium etchant and indicates that its 201029065 has high selectivity for many materials used in microelectromechanical systems such as aluminum, photoresists and dioxin. It is also indicated on page 119 that when forming a pattern on the substrate, XeF2 has a selectivity to dioxo and copper, gold, chin-chain alloys and acrylics greater than 10:00:1.

Isaac, W.C.#, Gas Phase Pulse Etching 〇f Silicon For MEMS With Xenon Difluoride, 1999 IEEE, 1637-1642 discloses the use of XeF2 as an isotropic vapor phase etchant for ruthenium. XeF2 is reported to have high selectivity for many metals, dielectrics, and polymers in the fabrication of integrated circuits. The author also states on page 1637 that XeF2 does not etch aluminum chromium, titanium nitride, tungsten, germanium dioxide, and tantalum carbide. Significant etchings for molybdenum: tantalum; and titanium: tantalum were also observed.

Winters et al, The Etching 〇f Silicon with XeF2 Vap〇r, Appl. Phys. Lett. 34(1) January 1, 1979, 70_73 discloses the use of CF4 fluorocarbon plasma to induce F atoms and CF3 groups generated during dissociation. The solid ruthenium is etched to produce volatile Sib species. The paper appeals to the use of XeF2 to etch ruthenium at 300 x at 1.4 x 1 Torr. Other experiments have shown that χπ2 also rapidly etches molybdenum, titanium and perhaps tungsten. The etching of Si〇2, S"N4 and Sic is not effective using XeF2, but etching is effective in the presence of electron or ion bombardment. Therefore, the authors conclude that the etching of these materials requires not only F atoms but also radiation or high temperature. US 6870654 Both US Pat. No. 7,078,293 discloses a structure release etching method which uses a etchant having a fluorine group or a gas group instead of a difluorinated gas, thereby avoiding the difficulty caused by the use of antimony difluoride. However, etching The effect is not as effective as the use of antimony difluoride. Therefore, us 687 〇 654 and 2010 29 065 i US 7078293 disclose a special structure for promoting the structure release etching method so that the processing time and the like are equivalent to those of germanium difluoride. 20060086376 discloses the use in the manufacture of microelectronic devices

XeF2 is used to clean the residue (boron boron, phosphonium or arsenic) from the components of the ion implanter. In particular, US 20060086370 relates to the in situ removal of residues from a vacuum chamber and a crucible contained therein by contacting the vacuum chamber and/or element with a gas phase reactive tooth composition, such as XeF2, for a sufficient period of time and The residue is at least partially removed from the element under the condition of a squeegee and is carried out in such a manner that the residue is selectively removed with respect to the material of the element constructing the ion implanter. An industrial objective is to find new etchants that can be used to remove hard-to-remove titanium nitride (TiN) films from the surface coated with cerium oxide (SiO 2 ) and cerium nitride (SiN). Such surfaces are found in semiconductor deposition chambers, particularly quartz chambers and in the walls of quartz vessels, semiconductor tools and equipment. Many conventional fluorine-based etchants that attack the Νι film also attack the μ% and siN surfaces, and thus are not acceptable for removing TiN deposition products from semiconductor deposition chambers and equipment. Another industrial purpose is to provide a method for selecting a S-dream from the surface of a cerium oxide (quartz). The surface is such as those commonly found in semiconductor deposition chambers and semiconductor tools and MEMS devices. The purpose of the industry is to provide a method for producing or forming antimony difluoride on site (as needed to reduce the cost of the owner). SUMMARY OF THE INVENTION 201029065 The present invention relates to an improved method for use from a ceria (quartz) surface such as a surface commonly found on semiconductor deposition chambers and semiconductor tools, and a tantalum nitride (SiN) surface commonly found in semiconductor tool components and the like. The titanium nitride (ΤιΝ) film and the deposited product are selectively removed. In a basic method of removing undesirable components of a contaminated surface, an etchant is contacted with the undesired component at the contact zone and the undesired component is converted to a volatile species. The volatile species is then removed from the contacting zone. An improvement in the basic method for removing undesired TiN deposition material from the surface of the contact zone selected from the group consisting of ruthenium and iridium is to use xenon difluoride (XeF2) as an etchant. The conditions are controlled such that the 2 and the surface of the SiN is not converted to a volatile component. In terms of selective etching, it is difficult to remove the film and deposition material from the semiconductor deposition chamber (sometimes referred to as the reaction chamber), tool parts and equipment, etc. Significant advantages include: the ability to selectively remove TiN films from the quartz-coated Si〇2/ and (iv) coated surfaces seen in the cleaning of the deposition chamber; the ability to remove the film from the quartz surface at moderate temperatures; The fluorescing agent in the remote piasma removes the TiN film from the surface of (10) and SiN without the adverse effects caused by the attack of fluorine atoms in the remote electropolymerization under normal conditions. The present invention also discloses a method for selectively patterning a first material relative to a second material, comprising: providing a structure comprising a first material and a second material in a chamber; providing a chamber comprising the crucible (5), inert An etchant gas with a fluorochemical; 201029065 contacting the structure with the etchant gas and selectively converting the first material to a volatile species; and removing the volatilization from the chamber a first species selected from the group consisting of ruthenium, molybdenum, tungsten, titanium, zirconium, hafnium, vanadium, niobium, tantalum, boron, phosphorus, lanthanum, arsenic, and mixtures thereof; and the first material is selected from the group consisting of: Cerium Oxide, Cerium Nitride, Nickel, Aluminum, TiNi Alloy, Photoresist, Phosphate Glass, Boron Phosphate Glass, Polyimide, Gold, Copper, Nickel, Aluminium, Tantalum Carbide And a mixture thereof. The invention also discloses a method of forming ruthenium difluoride in a chamber, comprising: providing said chamber with a composition selected from the group consisting of nf3, c2F6, cf4, c3f8, SF6, produced from an upstream plasma generator a fluorochemical of a plasma of F atoms and a mixture thereof; and bismuth difluoride formed by reacting hydrazine with the fluorochemical in the chamber.

[Embodiment] The deposition of titanium nitride (TiN) is generally practiced in the electronics industry for manufacturing integrated circuits, electrical components, and the like. In the deposition method, some are deposited on a surface i' different from the surface of the target substrate, for example, on walls and surfaces in the deposition chamber. XeF2 has been found to be effective as a selective squeegee for the surface of the oxidized and nitriding iN) contaminated with TiN. Based on this finding, one can use xenon difluoride (XeF2) as an etchant to remove unwanted Tm films and surfaces contaminated by deposited materials, such as those found to be coated or lined with dioxin (quartz). Or one of the facet semiconductor reactors or deposition chambers 11 201029065 chambers, tools, equipment, components, and wafers. - when removing unwanted TiN residues from surfaces in Si〇2 and SiN surfaces, such as deposition chambers, 'in the contact zone for converting TiN to volatile TiF4 and then removing the volatile species from the contact zone XeF2 is brought into contact with the surface under the conditions. Often, XeF2 and inert gases, for example,

Ar, and He are added together. The method t 'XeF2 for removing the TiN deposition material from the surface of SiN and Si〇2 may be preformed prior to introduction into the contact region, or for the purposes of the present invention' and as defined herein, XeF2 may be formed by two methods. In an embodiment in which XeF2 is formed in situ, xenon (Xe) is added to the fluorochemical and loaded into a remote plasma generator. Here, Xe reacts with the F atoms present in the resulting far-end plasma to form xep2. In another embodiment, a variation of the in situ embodiment, a fluorochemical is added to the remote plasma generator, and then Xe and the far plasma containing the F atom are added to the remote plasma. a chamber downstream of the generator. At this point, 'Xe reacts with the F atom to form XeF2 in the chamber. The chamber can be any type of chamber such as, but not limited to, a processing chamber, a deposition chamber, a cleaning chamber, a reactor, and a plasma generator. Examples of the fluorochemical used to form XeF2 include &, Nf3, perfluorocarbons such as CJ6, CF4, C3FS 'sulfur derivatives such as Sf6, and F atoms containing remote electricity generated from upstream plasma generators. Pulp. In a preferred embodiment, NF3 is used as the fluorochemical for forming XeF2. The fluorochemical can be produced in situ. For example, a halogen generator is used to generate F2 in situ, and then the & is introduced to the method. This will be a possible means of mitigating the risks associated with fluorine operations. • A wide range of Xe to fluorinated chemical ratios can be used in in situ methods of forming XeF2. The molar ratio of Xe to fluorochemical depends on the amount of xeF2 formed compared to the concentration of F atoms in the distal plasma. Without being bound by theory, it is believed that the far-end plasma acts as a source of fluorochemicals that are introduced as a source of fluorine for excitation and dissociation. The fluoro group then reacts with Xe present in the zone immediately after the plasma generation zone. In addition to the energy used to excite the fluorine-containing species and Xe, the path length of the segment is also considered to be an important parameter in the balance of XeF2 and xeF4 reduction. Furthermore, it is believed that if Xe is introduced into the space immediately behind the plasma excitation section, XeF4 formation can be further reduced since Xe has not been excited. It is well known that 氙 has a very low metastable energy state. The formation of this metastable state can result in an additional collision reaction between the XeF2 molecules formed within the segment. These collisions can cause XeF2 to dissociate into XeF and F groups. Then © these species can cause further reaction with other XeF2 molecules to form XeF4° so that by introducing Xe after plasma excitation, no metastable state is formed. Therefore, the formation of XeF4 is lowered. This is disclosed in a second embodiment, a variation of the in-situ embodiment, in which Xe is added to a remote plasma containing F atoms that is generated upstream of the plasma generator.

The preferred molar ratio of Xe to fluorochemical is ι: 1 〇 to 1 〇: 1. Optionally, an inert gas such as argon may be included in the far-end plasma generation of XeFz as a means of adjusting the selectivity of etching TiN relative to Si〇2, etching SiN or Si relative to si〇2 and siN. 13 201029065 The pressure suitable for removing TiN from the surface of Si〇2 and SiN is 〇 5 to 5 Torr, preferably 1 to 10 Torr. The temperature at which the TiN film is selectively etched from the ceria surface (quartz) and SiN surface is mainly determined by the method of carrying out the method. Thus, this means that if Xeh is formed in advance and added directly to the contact zone, the temperature should be raised to at least 100t, for example 1 〇〇 to 80 (rc, preferably 150 to 500. 〇. The pressure for XeF2 should be at least 〇 For example, 0, 1 to 20 Torr, preferably 0.2 to 10 Torr. Contrary to prior art methods in which the etch rate (Si etch) decreases with increasing temperature, where the etch rate increases with temperature quotient. The increase increases the specific enthalpy of the TiN residue because TiF4 is volatile under these conditions and is easily removed from the surface of 〇2 and SiN. The lower temperature causes TiF4 species to remain near the surface of Si〇2 and siN. Blocking the attack of XeF2. In the in-situ method of forming XeF2, cleaning or etching is performed in the presence of the far-end plasma. The temperature may be ambient temperature to 5 °C in the presence of the far-end plasma 'preferably ambient temperature Up to 300 ° C. The disclosed method of forming XeF 2 provides a significant advancement in the in-situ cleaning process because they not only provide a means of manufacturing XeF 2 at low cost, they also provide effective selectivity without residue. At the same time, no major downtime is required, which in turn reduces maintenance costs. In addition, the disclosed method uses a high vapor pressure emulsion instead of a low vapor pressure solid. This improves productivity due to higher gas flow, and thus can be made higher. Etch rate of etch. A further benefit stemming from the use of the disclosed method of forming Xei 2 , is that in addition to XeFz, there are some free fluorine radicals that may be helpful in facilitating the removal of residues that may not react when only in contact with XeF 2 . This is advantageous for all 14 201029065. Selective cleaning/button applications, such as cleaning and coating of components and semiconductor tools on which Si〇2, which does not require residue, is deposited; Etching of the layers, as well as residue cleaning in the ion source region of the ion implantation system used in the fabrication of microelectronic devices. The following examples are provided to illustrate various embodiments of the invention and are not intended to limit the scope thereof.效力 Efficacy of XeF2 in etching of deposited materials at various temperatures and pressures In this example, XeF2 is used as a remnant, in various The squeezing rate for TiN, SiO 2 and SiN was determined under temperature and pressure. The test samples were prepared from ruthenium wafers coated with TiN, Si 〇 2 and SiN films. The etch rate was exposed at the initial film thickness and timing by the film thickness. The change between the film thicknesses after etching or processing conditions is calculated. © In order to implement the surname, a large amount of XeF2 gas is introduced from the cylinder into the reactor chamber via an unused remote plasma generator. The XeF2 gas The pressure in the reactor chamber is kept constant by closing the gas flow from the cylinder as soon as the desired pressure is reached. The test specimen is placed on the surface of a pedestal heater used to maintain the temperature of the different substrates. on. The results are shown in Table 1 below. 15 201029065 Table i Etching rate for various materials using XeF2 Material temperature (°C) Pressure (Torr) Γ — Residual rate (nm/min) TiN 25 1 0 ------- TiN 100 1 0 TiN 150 1 —------ 8 TiN 200 1 13 TiN 300 0.5 20 Si02 300 0.5 0 SiN 100 1 0 SiN 150 1 0 SiN 300 1 0 The above results indicate that the pressure is 0.5 to 1 Torr. XeF2 is effective for etching TiN films at elevated temperatures of 150 to 300 C, and is ineffective at room temperature of 25 °C. Surprisingly, XeF2 does not etch the Si〇2 or SiN surface at any of the temperatures and pressures employed, but etches the TiN film at these temperatures. Since XeF2 cannot etch the Si〇2 and SiN surfaces at these elevated temperatures, but the TiN film remains, it is concluded that XeF2 can be used as a reagent for selectively etching TiN films and particles from the si〇2 and sm surfaces. Example 2 Selective Etching of 矽 Relative to Si〇2 In this example, the MKS Astron remote plasma generator was mounted at the top of the reactor chamber at 201029065. The distance between the outlet of the Astron generator and the sample sample is approximately six inches. Turn on the remote power generator' but turn off the pedestal heater in the reactor chamber. The chamber was kept at room temperature. The rate of money engraving for both Si and Si〇2 substrates in the case of remote plasma was measured. The process gas for the remote plasma is NF3 and it is mixed with various amounts of the second gas stream. The second gas stream comprises χβ, argon (Ar), or a combination thereof. The total gas flow rate to the reactor chamber was fixed at 40 〇 sccm and the Nf3 flow rate was fixed at 8 〇 sccm. While maintaining the total flow rate of the second gas stream at 32 〇sccm, the ratio of the Xe flow rate to the total flow rate of the second gas stream (Xe/(Ar+Xe)) is at 〇 (Ar only as the additional The process gas) and helium (Xe only as the additional process gas) vary. The results of etching the si substrate are shown in the table! The results of etching the Si〇2 substrate are shown in Table 2. As shown in Figure 1, Xe is added to the process gas NF3, increasing the si etch rate. Surprisingly, the addition of 6 to the remote plasmonics generator along with the NFs produces a plasma that enhances the Si etch. Figure 2 shows that the addition of Xe to NFS/argon plasma suppresses the Si〇2 substrate etch rate, which is surprising. Exist in the remote plasma? Atoms usually attack SiO2-based substrates. In conjunction with the analysis of Figure 1, it is speculated that the addition of Xe to the plasma results in an increase in the etching of the § substrate, but as in the embodiment! It is pointed out that the si〇2 substrate characterization is reduced or suppressed. Figure 3 is provided to compare the effect of adding Xe to the process gas for etch selectivity relative to si 〇 2 . As can be seen by comparing the results of 17 201029065 in Figures 1 and 2, Figure 3 shows that the etch selectivity of Si relative to Si 〇 2 increases as the amount of Xe in the process gas increases. In particular, the selectivity follows

Xe increases from 〇% to 100% in the gas stream and from 3〇 to 250 (> 8 times). The curved sacrificial materials in MEMS are: bismuth, molybdenum, tungsten, titanium, erbium, niobium, vanadium, niobium, niobium. The curved protective material is nickel, aluminum, photoresist, oxidized stone, and nitrided. Example 3 选择性 ϋ (Mo) selective etching with respect to Si〇2 A large cylindrical SS etching chamber with a length of 2.5 m and a diameter of 25 cm was used to determine another common sacrificial material in MEMS applications: etching of molybdenum (M〇) rate. The remote power was generated using a water cooled MKS Astron AX 7670 6 slpm unit. The plasma source was connected to the chamber through a 10 cm long inner diameter 4 cin delivery tube. Place the sample 2 feet from the loading/unloading end of the tube. Mo Mo etch rate = 1" micron / min at 2.75 Torr, NF3 flow 275sccm and Xe or Ar flow 600sccm. The etching rate of si〇2 was 82 nm/min for the NF3/Ar gas mixture and 26 nm/min for the NF3/Xe mixture. Thus the selectivity of the 'Xe/NF3 mixture is at least 3 times greater than the selectivity of the Ar/NF3 mixture. Please note that the Mo money engraving rate is limited by surface oxides. The etching rate of 'M〇' can be increased to > 2.7 μm/min in the case where the surface preparation treatment is used to destroy its intrinsic oxide. 18 201029065. Example 4 Formation of XeF2 in situ via reaction of Xe and NF3 The procedure of Example 2 was followed in this example. An Applied Materials P5000 DxZ2 PECVD chamber equipped with a 6slpm MKS Astron eX remote paddle generator was used for Fourier Transform Infrared Spectroscopy (FTIR) studies. FTIR measurements were taken downstream of the chamber pump at ambient pressure. A chamber having a path length of 5.6 m at 150 ° C was used. The instrument resolution is 2 cm·1. 4 shows the FTIR spectrum collected under the same conditions as in Example 2: a pressure of 4 Torr, a total gas flow rate of 400 sccm, an NF3 flow rate of 80 sccm, and a total flow rate of Xe and Ar of 320 sccm. A clearly significant peak was observed in the range of SOOdOOcnr1 in the Xe/NF3 spectrum, while the Ar/NF3 spectrum showed no peak in this region. Two main fronts at 551.5 cm_1 and 570.3 cm_1 were identified as XeF2 peaks. The control spectra from the XeF3 manufacturer showed peaks at 550.8 and 566.4 cm·1. Figure 5 shows that in the presence of Xe and NF3, three distinct peaks were observed at 551, 570 and φ 590 (^^1. XeF2 was identified by the peak at 55146701^1, while XeF4 was at 580, 590 (?111" was detected. Thus the peak at 567 cm-1 is a combination of 567 and 580 cm-1 peaks. So both XeF2 and XeF4 are formed in the Xe/NF3 mixture. No XeF6 was found from the FTIR spectrum or Evidence for XeOF4 formation. Table II shows several conditions in which the pressure changes from 0.5 to 5 Torr, the Xe flow rate varies from 200 to 1000 sccm, and the NF3. flow rate changes from 50 to 500 sccm. In all cases, XeF2 is detected. Peak. The peak is recorded here. 19 201029065 Table II Pressure (Torr) 0.5 4 5 2.75 5 2 NF3 (seem) 50 80 200 275 50 500 Xe (seem) 200 320 500 600 1000 1000 Peak (530.1 cm·1) 0.06 0.07 0.16 0.22 0.09 0.33 Peak (570.3 cm·1) 1.01 1.18 1.35 1.35 1.36 1.42 Peak (590 cm·1) 0.43 0.43 1.63 1.42 0.18 1.58 Peak (603.1 cm·1) 0.07 0.07 0.44 0.27 0.04 0.31 Ο The peak is in some It is easy to saturate under conditions, so the XeF2 peak at 520.1 cm·1 is also analyzed. The trailing edge of the XeF4 peak at and between 603.1 cm·1. The XeF2/XeF4 ratio is defined as the ratio of the peak heights at 530 cm_1 and 603 CHCT1. The experimental results using response surface regression are summarized in Table III below.

Table III Peak still 530.1 551.5 592 603.1 Ratio 603.1/530.1 Meaning Front edge XeF2 signal XeF2 Maximum value XeF4 Maximum value Trailing edge XeF4 Signal XeF2/XeF4 Xe Weak, weak, strong (strong up) nf3 Strong, strong, strong and strong (strong - Down) P weak medium strong strong down (strong down) 20 201029065 Please note: under all conditions here, the flow of Xe > NF3 flow, so NF3 is a stronger factor. Higher NF3 flux increases both XeF2 and XeF4 peaks, and Xe has a weak effect on the peak (due to the excess Xe). The pressure has a weak influence on the XeF2 peak and a strong influence on the XeF4 peak. Astron's working pressure is typically 1-10 Torr. Therefore, pressure is a key parameter in controlling the formation of XeF4. XeF4 can be hydrolyzed to produce Xe03, an explosive and impact sensitive compound. Under current test conditions, the XeF2/XeF4 ratio can be maximized at high Xe, low NF3 and low pressure conditions. For example, the flow rate of Xe is 1000 seem, the flow rate of NF3 is 50 sccm, and the pressure is 〇·5 Torr. Figure 6 shows that the unit of peak height of XeF2 FTIR and XeF4 FTIR peak height as a function of Xe/(Xe+Ar) is arbitrary. As the Xe flow fraction increases, the manufactured XeF2 increases and the XeF4 fraction decreases. High Xe flow is expected to maximize the formation of XeF2 relative to XeF4. Figure 7 shows the ratio of XeF2/XeF4 FTIR peak height as a function of Xe/NF3 flow rate ratio. It is clear that a high ratio of Xe/NF3 is expected to maximize the formation of XeF2 relative to XeF*. Figure 8 shows the XeF2 FTIR peak height (right gamma_axis) and the etch selectivity (left Y-axis) of Si/Si〇2 as a function of Xe/(Xe+Ar). The etching selectivity of Si/Si〇2 is clearly related to the in-situ formation of XeF<2. The use of plasma excitation to make XeF2 can also be used to produce XeF2 for use as an etchant in processes not directly related to its manufacturing location. The data shows the presence of the following conditions' which significantly contribute to the production of XeF2 and minimize the production of XeF4. Since XeF4 reacts to form the explosiveness of χe03 afterwards, 21 201029065, it is highly desirable to minimize XeF4 production. Since XeI?2 is formed in the reaction zone after the plasma generator, it can be removed from the zone by using cryogenic trapping to condense the material on the cold surface. The solid XeI?2 can then be lifted from the processing chamber and refilled into a transfer cylinder for use in the etching process. Since the introduction of excess hydrazine reduces XeF* formation, it is very helpful to recycle the hydrazine or recycle hydrazine into the process to ensure the productive use of all hydrazine required for XeFz production.

Example 5 Effect of Far End Plasma and Temperature on the Etching Rate of TiN and SiCh In this embodiment, except that the remote plasma generator and pedestal heater are both turned on to allow remote use at various substrate temperatures The procedure of Example 2 was followed by plasma to determine the etch rate of both si and 2. ❹ In the first set of experiments, the surname rates of TiN and Si〇2 were measured using a mixture of nf3 and Xe as process gases. The flow rate of xe is fixed at 32 〇 SCCm. The temperature varies from 1 〇〇 to 15 〇 (): the results of these experiments are shown as square points for TiN and Si〇2 in Figures 9 and 1〇. In the second set of experiments, The etch rate of TiN and si〇2 is measured using a mixture of NF3 and argon (Ar) as the process gas. The flow rate is fixed at 32 〇 Sccm. The temperature varies from 1 〇〇 to 15 〇. The results are shown as diamond points for TiN and Si〇2, respectively, in Figures 4 and 5. As shown in Figure 9, the addition of Xe to the process gas increases the TiN etch rate at temperatures generally above i3 〇 <>c. Figure 1A shows that compared to 9Ar added to NF3, Xe addition to NFs inhibited etch rate at 研究2 etch rate 22 201029065 at all study temperatures. The effect of Xe addition to process gas on etch selectivity was compared by comparing Figures 9 and 10. The results are visible. Figure 11 shows the etch selectivity of ΤιΝ relative to Si〇2, and the graph shows that when Xe is added to the process gas of 1' to 173, the selectivity is at a temperature above about ii〇. Starts increasing at °c and increases rapidly above 120〇c. In summary, Example 1 shows that when When carried out at elevated temperatures, XeF2 is a @selective etchant for TiN臈 relative to the ceria and tantalum nitride substrates. Examples 2 and 3 show the addition of Xe to the far end plasma generator The NF3 process gas in the middle (or reactor or chamber) can be compared to the etch selectivity when only Nf3 is used as the process gas, which can increase the etch selectivity of Si or M 〇 relative to Si 〇 2. Example 4 shows In-situ formation of XeF2 is observed when helium and a fluorine-containing gas such as NI?3 are introduced into the plasma generator (or reactor or chamber). Combination © 氙 with a fluorine-containing gas such as NF3 without using XeFz directly The cleaning method has an economic advantage (ie, a lower cost to the owner). A further benefit derived from the use of the disclosed method of forming XeFz is that in addition to XeF2 they also provide some free fluorine radicals, said free fluorine The free radicals help to promote the removal of residues that may not be reactive when only in contact with XeF2. Example 5 shows that Xe is added to the far-end plasma as compared to the selective selectivity of NF3 alone as a process gas. NFS process gas can be high (liter Increasing the etch selectivity of TiN relative to si% at elevated temperatures. The increased selectivity of TiN relative to Si〇2 is important in quartz tube furnace applications and coating 23 201029065 with Si〇 with TiN deposition thereon The components and semiconductor tools of 2 are important. The method can facilitate the cleaning of the deposition reactor between deposition cycles by connecting the remote downstream plasma unit to the process reactor and introducing process gas. N& does not have the economic advantage of using XeF2 for this cleaning method (ie, the lower cost of the owner). The cleaning methods described in the examples can also be used in off-line process reactors, the sole purpose of which is to clean the process reactor components before they are reused. Here, the distal downstream plasma reactor is connected to an off-line process reactor in which components (from the components of the deposition reaction) are placed. Subsequently, the helium and fluorine-containing gases, such as NF3, are introduced into the remote downstream unit before the process gas is introduced into the chamber containing the component to be cleaned. The increased selectivity of Si, Mo or TiN relative to Si〇2, And the disclosed methods of forming XeF2 are important in many applications, such as cleaning components and semiconductor tools coated with SiO2 having unwanted Si, Mo or TiN deposition thereon; etching of sacrificial layers in MEMS; and fabrication of microelectronic devices The residual fishing in the ion source region of the ion implantation system used in the cleaning is clean. The application can be extended to from Si3N4, Al, Al2〇3, Au, Ga,

Ni, Pt, Cu, Cr, TiNi alloy, SiC, photoresist, photosilicate glass, borophosphonite glass, polyimine, gold, copper, platinum, chromium, aluminum oxide, tantalum carbide and their The combination of other unwanted materials such as: tungsten, titanium, zirconium, hafnium, vanadium 'niobium, tantalum, boron, phosphorus, antimony, arsenic and mixtures. [Simple description of the figure] 24 201029065 Figure 1 is a plot of the etch rate of the tantalum substrate as a function of the concentration of Xe in the far-end plasma compared to Ar. Figure 2 is a graph of the etch rate of Si 〇 2 as a function of the concentration of Xe versus Ar in the Nf3 far end plasma. Figure 3 is a comparison of the etch selectivity of ruthenium relative to ruthenium dioxide as a function of the concentration of Xe in the far end plasma of NF3 compared to Ar. Figure 4 is a Fourier transform infrared (FTIR) spectrum of Αγ/νι?3 and Xe/NF3 from the far end plasma of NF3. Figure 5 is a Fourier transform infrared (FTIR) spectrum of Xe/NF3 from the far-end plasma of NF3, Fig. 6疋XeF2 and XeF4 Fourier transform infrared spectroscopy (FTIR) peak heights as NF3 remotes A graph of the function of Xe/(xe+Ar). Figure 7 is a plot of XeF2 and XeF4 Fourier Transform Infrared Spectroscopy (pTIR) peak height as a function of Xe/NF3 flow ratio in NF3 distal plasma. Figure 8 is a graph of the XeFz Fourier Transform Infrared Spectroscopy (FTIR) peak height and the etch selectivity of ruthenium relative to ruthenium dioxide as a function of Xe/(Xe+Ar) in the NF3 far end plasma. Figure 9 is an etch rate of TiN as Μ. The temperature and Xe in the far-end plasma are compared to the Ar concentration, a function graph. Figure 10 is a graph of etch rate of cerium oxide as a function of temperature in NFS remote plasma and concentration of Xe compared to Ar. Figure 11 is a graph comparing the etch selectivity of TiN to cerium oxide as NF; the concentration of Xe in the far-end electropolymer compared to Ar. 25

Claims (1)

201029065 VII. Patent application scope: The second material selectively etches the first material of the first material for use in relation to the first method 'including: providing a structure containing the first material and the second material in the cavity to the middle; providing the cavity to the inclusion a gas (Xe), an inert gas, and a gas-containing chemical-like gas; nB contacting the structure with the money engraving agent and selectively converting the first material into a volatile species; Removing the selective species from the chamber; wherein the first material is selected from the group consisting of hair, turn, crane, chin, wrong, give, hungry, say, butterfly, code, error, stone, and mixtures thereof And the material is selected from the group consisting of oxidized seconds, nitriding dream, chain, Ming, TiNi alloy, photoresist, dish salt surface, (four) (four) salt glass, polyimine, gold, copper, Ming, road, oxidation Ming, carbonized and their mixture. The method of claim 1, wherein the fluorine-containing chemical mouth is selected from the group consisting of F2, NF3, c2F6, cf4, C3F8, Sp6, and F-containing electropolymer produced from an upstream electropolymer generator And a mixture of them. 3. The method of claim 2, wherein the fluorine-containing chemical is a plasma containing F atoms generated from an upstream plasma generator. 4. The method of claim 3, wherein the inert gas is selected from the group consisting of Xe, Ar, He, and mixtures thereof. 26 201029065 There is a far-reaching method 'where the cavity' 6_ as in the method of the patent application of the third item, the temperature is from ambient temperature to 500. (: 7. The waste force of the method as claimed in the third paragraph of the patent application 〇1 to 10杷. where 'the chamber is in the chamber 8. The method of claim 1 of the patent scope has a molar ratio of fluorochemicals of 1:10 to 1 :1. Wherein Xe is relative to a method comprising a semiconductor device or a semiconductor processing chamber as claimed in claim 1. Wherein the structure疋 Wherein the structure, wherein the structure is as described in the third paragraph of the patent application, is a microelectromechanical device. u. The method of claim 1 is an ion implanter tool in an ion implantation system. 12. A method of forming a difluorination in a chamber to provide Xe gas to the chamber; a method comprising: 27 201029065 providing the chamber with a source selected from the group consisting of NF3, c2F6, CF4, c3F8, SF6, from upstream What does the pulp generator produce? Fluorine chemicals of atoms and their cations; and bismuth difluoride formed by reacting gas with the fluorochemical in the chamber. The method of claim 12, wherein the fluorochemical is an F-containing electric rim produced from an upstream plasma generator. 14. The method of claim 12, wherein the molar ratio of xe to fluorochemical is from 1:10 to 1 〇:1. The method of claim 12, wherein the chamber contains a plasma generator. G. The method of claim 15 wherein the plasma generator is a remote plasma generator K. The method of claim 12, wherein the temperature in the chamber is from ambient temperature to 500 ° C. 18. As claimed in claim 12, 7/3⁄4' (U to 1 Torr. Cavity to 28 201029065 n A method for selectively etching yttrium, molybdenum or molybdenum with respect to cerium oxide, tantalum nitride or cerium oxide and tantalum nitride, including: Providing a structure containing ruthenium, molybdenum or ruthenium and molybdenum, and ruthenium dioxide, ruthenium nitride or ruthenium dioxide and ruthenium nitride; providing the chamber with ruthenium (Xe), an inert gas, and a fluorine-containing chemistry An etchant gas; contacting the structure with the etchant gas and selectively converting the cerium, molybdenum or cerium with molybdenum into a volatile species; and removing the volatile species from the chamber. © 2〇. The method of claim 19, wherein The catalyzed chemical is selected from the group consisting of F2, NFi, r*F nx: ^ 2F6 'CF4, C3F8, SF6, the plasma containing the ''children from the upstream plasma generator and mixtures thereof. ❹ η• as claimed The method of claim 19, wherein the defeated product is an electric device containing F atoms generated from an upstream plasma generator. The method of claim 19 is the method of claim 19, wherein the inert gas is selected From Xe, Ar, He, and mixtures thereof. 23. The method of claim 4, wherein the chamber contains a remote plasma generator. The structure 24 is as claimed in claim 19 The method of claim 19, wherein the structure is an ion implanter tool in an ion implantation system. The method of claim 19, wherein the structure is an ion implantation machine tool in an ion implantation system.