In-situ processing of molybdenum oxyhalide byproducts in semiconductor processing apparatus

Abstract

A method is provided for improving atomic layer deposition efficiency of molybdenum metal by in-situ cleaning and purging a molybdenum oxyhalide precursor transfer line leading to a deposition chamber. The cleaning treatment may be performed by pretreating the transfer line with at least one surface passivating agent and / or by periodically treating the transfer line with at least one corrosion inhibitor. Methods of removing oxides from deposited molybdenum films are also provided.

Description

Incorporated by Reference

[0001] The PCT application form is filed concurrently with this specification as a part of this application. Each application identified in the concurrently filed Application Data Sheet to which this application claims the benefit or priority is incorporated herein by reference in its entirety and for all purposes. Background Art

[0002] Many semiconductor device manufacturing processes involve the deposition of metals such as molybdenum to form conductive films. During the deposition process, contaminants, precursor impurities, or precursor byproducts produced by the decomposition of the precursors can clog the pipes or pipelines that deliver the precursors to the deposition chamber. Due to the blockage, the flow of gas in the pipeline can be obstructed or completely blocked. In order to remove the contaminants, the deposition must be stopped and the device disassembled so that the pipelines can be regularly replaced and / or removed for cleaning. Such traditional methods of contaminant removal are inefficient because they interrupt the continuous operation of the deposition process. Therefore, it is necessary to use in situ techniques to remove and / or prevent undesirable contaminants from the delivery pipes during the deposition process without the need to shut down for inefficient maintenance to remove molybdenum oxyhalide precursor contaminants.

[0003] The background description provided here is for the purpose of generally presenting the background of the present disclosure. The work of the currently designated inventors within the scope described in this background section and aspects of the specification that could not be determined as prior art at the time of filing the application are neither explicitly nor implicitly admitted to be prior art against the present disclosure. Summary of the invention

[0004] The present invention provides a method for improving the efficiency of atomic layer deposition of molybdenum metal by in-situ cleaning of precursor delivery lines. The cleaning process can be performed by pre-treating the delivery line with a surface passivating agent and / or by periodically treating the delivery line with a corrosion inhibitor.

[0005] Thus, in a first aspect, the present disclosure encompasses a method for depositing molybdenum metal. In some embodiments, the method comprises introducing a molybdenum oxyhalide precursor into a deposition chamber containing a semiconductor substrate via one or more precursor delivery lines; supplying a periodic flow of at least one corrosion inhibitor to the precursor delivery lines; and reacting the molybdenum oxyhalide precursor with at least one reactant to form a molybdenum-containing layer on the semiconductor substrate.

[0006] In some embodiments, at least one corrosion inhibitor is a chemical etchant.

[0007] In some embodiments, the chemical etchant is a tungsten halide or a molybdenum halide.

[0008] In some embodiments, the at least one corrosion inhibitor is chlorine, oxygen, fluorine, hydrogen chloride, hydrogen fluoride, chlorine trifluoride, nitrogen trifluoride, or a combination thereof.

[0009] In some embodiments, the at least one corrosion inhibitor is oxygen and chlorine.

[0010] In some embodiments, oxygen and chlorine are supplied to the precursor delivery line sequentially or simultaneously.

[0011] In some embodiments, the at least one corrosion inhibitor is oxygen and fluorine.

[0012] In some embodiments, oxygen and fluorine are supplied to the precursor delivery line sequentially or simultaneously.

[0013] In some embodiments, the corrosion inhibitor is one of tungsten hexafluoride (WF6), molybdenum pentachloride (MoCl5), and water (H2O).

[0014] In some embodiments, the molybdenum oxyhalide precursor is Mo q O n Y m , wherein Y is halogen; n is 1 or 2; q is 1, 2 or 4; and m is 1, 2 or 11.

[0015] In some embodiments, the molybdenum oxyhalide precursor is MoOF4, Mo4O 11 I, MoO2I, MoO2Br2, MoO2Cl2, MoOC l4 or a combination thereof.

[0016] In some embodiments, at least one reactant is hydrogen, ammonia, diborane, water, hydrogen sulfide, thiols, alcohols, amines, hydrazine, silane, disilane, or combinations thereof.

[0017] In a second aspect, the present disclosure covers a method for depositing molybdenum metal, comprising: providing a deposition chamber having one or more molybdenum oxyhalide precursor delivery lines; pretreating the one or more molybdenum oxyhalide precursor delivery lines with at least one surface passivating agent to form one or more treated molybdenum oxyhalide precursor delivery lines; introducing one or more semiconductor substrates into the deposition chamber; introducing a molybdenum oxyhalide precursor into the deposition chamber via the one or more treated molybdenum oxyhalide precursor delivery lines; and reacting the molybdenum oxyhalide precursor with at least one reactant to form a molybdenum-containing layer on the semiconductor substrate.

[0018] In some embodiments, one or more of the molybdenum oxyhalide precursor delivery lines are stainless steel or a nickel alloy.

[0019] In some embodiments, the molybdenum oxyhalide precursor is Mo q O n Y m , wherein Y is halogen; n is 1 or 2; q is 1, 2 or 4; and m is 1, 2 or 11.

[0020] In some embodiments, the molybdenum oxyhalide precursor is MoOF4, Mo4O 11 I, MoO2I, MoO2Br2, MoO2Cl2, MoOCl4 or a combination thereof.

[0021] In some embodiments, at least one reactant is hydrogen, ammonia, diborane, water, hydrogen sulfide, thiols, alcohols, amines, hydrazine, silane, disilane, or combinations thereof.

[0022] In some embodiments, at least one surface passivating agent is fluorine.

[0023] In a third aspect, the present disclosure encompasses a method for atomic layer deposition of molybdenum metal, comprising: providing a deposition chamber having one or more molybdenum oxyhalide precursor delivery lines; pretreating the molybdenum oxyhalide precursor delivery lines with at least one surface passivating agent to form one or more treated molybdenum oxyhalide precursor delivery lines; introducing one or more semiconductor substrates into the deposition chamber;

[0024] A molybdenum oxyhalide precursor is introduced into a deposition chamber via one or more treated molybdenum oxyhalide precursor delivery lines; the molybdenum oxyhalide precursor is reacted with at least one reactant to deposit a molybdenum-containing layer on a semiconductor substrate; and a periodic flow of at least one corrosion inhibitor is supplied to the molybdenum oxyhalide precursor delivery line.

[0025] In some implementations, one or more semiconductor substrates are dummy wafers.

[0026] In some embodiments, one or more of the molybdenum oxyhalide precursor delivery lines are stainless steel or a nickel alloy.

[0027] In some embodiments, the molybdenum oxyhalide precursor is Mo q O n Y m , wherein Y is halogen; n is 1 or 2; q is 1, 2 or 4; and m is 1, 2 or 11.

[0028] In some embodiments, the molybdenum oxyhalide precursor is MoOF4, Mo4O 11 I, MoO2I, MoO2Br2, MoO2Cl2, MoOCl4 or a combination thereof.

[0029] In some embodiments, at least one corrosion inhibitor is a chemical etchant.

[0030] In some embodiments, the chemical etchant is a tungsten halide or a molybdenum halide.

[0031] In some embodiments, the at least one corrosion inhibitor is chlorine, oxygen, fluorine, hydrogen chloride, hydrogen fluoride, chlorine trifluoride, nitrogen trifluoride, or a combination thereof.

[0032] In some embodiments, the at least one corrosion inhibitor is one of tungsten hexafluoride (WF6), molybdenum pentachloride (MoCl5), and water (H2O).

[0033] In some embodiments, the at least one corrosion inhibitor is oxygen and chlorine.

[0034] In some embodiments, oxygen and chlorine are supplied sequentially or simultaneously to one or more molybdenum oxyhalide precursor delivery lines.

[0035] In some embodiments, the at least one corrosion inhibitor is oxygen and fluorine.

[0036] In some embodiments, oxygen and fluorine are supplied sequentially or simultaneously to one or more molybdenum oxyhalide precursor delivery lines.

[0037] In a fourth aspect, the present disclosure encompasses a method comprising providing a semiconductor processing chamber having one or more molybdenum oxyhalide precursor delivery lines; and supplying at least one corrosion inhibitor to the one or more molybdenum oxyhalide precursor delivery lines after processing one or more semiconductor substrates using the molybdenum oxyhalide precursor.

[0038] In a fifth aspect, the present disclosure encompasses a method comprising providing a semiconductor processing chamber having one or more molybdenum oxyhalide precursor delivery lines; and pretreating the one or more molybdenum oxyhalide precursor delivery lines with at least one surface passivating agent before treating one or more semiconductor substrates with the molybdenum oxyhalide.

[0039] In a sixth aspect, the present disclosure encompasses a method comprising providing a semiconductor processing chamber having one or more molybdenum oxyhalide precursor delivery lines; and pretreating the one or more molybdenum oxyhalide precursor delivery lines with at least one surface passivator before treating one or more semiconductor substrates with the molybdenum oxyhalide precursor; and supplying at least one corrosion inhibitor to the one or more molybdenum oxyhalide precursor delivery lines after treating the one or more semiconductor substrates with the molybdenum oxyhalide precursor.

[0040] In a seventh aspect, the present disclosure encompasses a method comprising depositing platinum in a feature to fill the feature; and after filling the feature, exposing the deposited platinum to a chemical etchant to remove oxide from the deposited platinum. In some embodiments, the chemical etchant is a tungsten halide or a molybdenum halide. In some embodiments, depositing the platinum comprises sequentially introducing the molybdenum halide and a hydrogen co-reactant into a chamber containing a substrate. In some embodiments, the hydrogen co-reactant is a plasma generated by hydrogen (H2) or other hydrogen-containing gases.

[0041] These and other aspects will be further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a process flow diagram depicting the operations of a method for deposition of molybdenum metal in conjunction with the periodic use of a corrosion inhibitor according to certain disclosed embodiments.

[0043] Figure 2 is a process flow diagram depicting operations of a method for deposition of molybdenum metal in conjunction with pretreatment of the precursor delivery line with a surface passivating agent according to certain disclosed embodiments.

[0044] Figure 3 is a process flow diagram depicting the operation of a method for deposition of molybdenum metal in conjunction with pretreatment of the precursor delivery line with a surface passivating agent and periodic application of a corrosion inhibitor in accordance with certain disclosed embodiments.

[0045] Figure 4 Examples of apparatus that may be used to perform the methods described herein are shown, according to certain disclosed embodiments.

[0046] Figure 5 An example of a feature filled with molybdenum (Mo) is shown.

[0047] Figure 6 is a process flow diagram depicting the operations of a method for depositing molybdenum metal. DETAILED DESCRIPTION

[0048] In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments presented. The disclosed embodiments may be implemented without some or all of these specific details. In other respects, well-known processing operations are not described in detail in order not to unnecessarily obscure the disclosed embodiments. Although the disclosed embodiments will be described in conjunction with specific embodiments, it should be understood that they are not intended to limit the disclosed embodiments.

[0049] The embodiments disclosed below describe deposition materials on substrates, such as wafers, substrates or other workpieces. Workpieces can be of various shapes, sizes and materials. In this application, the terms "semiconductor wafer", "wafer", "substrate", "wafer substrate" and "partially manufactured integrated circuit" can be used interchangeably. It will be understood by those of ordinary skill in the art that the term "partially manufactured integrated circuit" can refer to any of the many stages of manufacturing integrated circuits on silicon wafers. The diameter of the wafers or substrates used in the semiconductor equipment industry is typically 200mm, or 300mm or 450mm. Unless otherwise specified, the processing details described herein (such as flow rates, power levels, etc.) are applicable to processing substrates of 300mm diameter, or are applicable to processing chambers configured to process substrates of 300mm diameter, and can be adjusted as needed for substrates or chambers of other sizes. In addition to semiconductor wafers, other workpieces that can be used for the implementation scheme disclosed herein include various items, such as printed circuit boards, etc. These processes and devices can be used to manufacture semiconductor devices, displays, light emitting diodes, photovoltaic panels, etc.

[0050] Halide refers to an anion of F, Cl, Br or I.

[0051] Unless otherwise specified, the term "about" as used herein refers to a difference of + / - 10% from any stated value. As used herein, this term modifies any recited value, range of values, or endpoints of one or more ranges.

[0052] As used herein, the terms "top", "bottom", "upper", "lower", "above", and "below" are used to indicate the relative relationships between structures. The use of these terms does not indicate or require that a particular structure must be located in a particular position in a device.

[0053] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean at least one of A, at least one of B, and at least one of C.

[0054] By "atomic layer deposition" (ALD) is meant a vapor deposition process in which a deposition cycle (preferably a plurality of consecutive deposition cycles) is performed in a process chamber (i.e., a deposition chamber). Typically during each cycle, a precursor chemical is adsorbed to a deposition surface (i.e., a substrate assembly surface or a previously deposited underlying surface, such as material from a previous ALD cycle) to form a monolayer or sub-monolayer that is not susceptible to reaction with additional precursors (i.e., a self-limiting reaction). Thereafter, if necessary, a reactant (i.e., another precursor or a reactive gas) may be introduced into the process chamber for use in converting the chemically adsorbed precursor to the desired material on the deposition surface. Typically, such a reactant is capable of reacting with the already chemically adsorbed precursor. In addition, during each cycle, a sweep step may also be utilized to remove excess precursor from the process chamber and / or to remove excess reactant and / or reaction byproducts from the process chamber after conversion of the chemically adsorbed precursor.

[0055] "Deposition" or "vapor deposition" refers to a process of forming a metal layer on one or more surfaces of a substrate from a vaporized precursor composition comprising one or more metal-containing compounds. The metal-containing compounds are vaporized and directed toward and / or contacted with one or more surfaces of a substrate (i.e., a semiconductor substrate or semiconductor component) placed in a deposition chamber. Typically, the substrate is heated. These metal-containing compounds form a non-volatile, thin, and uniform metal-containing layer on the surface of the substrate. One operation of the method is a cycle, and the process can be repeated for multiple cycles if necessary to obtain the desired metal thickness.

[0056] By "chemical etchant" is meant any compound used to remove material, such as layers, byproducts, or contaminants, from a surface.

[0057] By "contaminant" is meant any compound that may be an impurity, decomposition product, or byproduct of the gas delivered to the deposition chamber.

[0058] A "delivery line" is any process equipment, such as a pipe, tube, or conduit, that can be used to transport or deliver gases (e.g., reactants and / or precursors). In semiconductor manufacturing processes, a precursor delivery line can be used to deliver precursors to a deposition chamber and can be made of stainless steel or nickel alloys.

[0059] The so-called "surface passivator" refers to a substance that can make a surface inert, and the surface does not change its properties when it interacts with other chemical substances (such as reactants and / or precursors).

[0060] As used herein, "platinum metal" or "metallic molybdenum" refers to a material composed mainly of molybdenum (Mo). A small amount of other elements (such as C, N or O) may be present in the platinum metal (for example, the total content is less than about 15 atomic %, or less than about 10%, wherein hydrogen is not included in the calculation). As used herein, "high purity platinum metal" means that the content of other elements contained in the platinum metal is less than about 5%, for example, less than about 1%, when hydrogen is not included in the calculation.

[0061] Figure 1 A non-limiting deposition process 100 for depositing platinum metal is schematically shown, which includes a cleaning mechanism in which a corrosion inhibitor is periodically passed through a platinum oxyhalide precursor delivery line. In some embodiments, the deposition process is atomic layer deposition. Atomic layer deposition (ALD) is a technique that utilizes a continuous self-limiting reaction to deposit a thin layer of material. The ALD process utilizes a surface-mediated deposition reaction to deposit a film in a layer-by-layer manner in a cycle. As an example, an ALD cycle may include the following operations: (i) delivering / adsorbing a precursor, (ii) sweeping a precursor from a chamber, (iii) delivering a second reactant and optionally igniting a plasma, and (iv) removing byproducts from the chamber. The reaction between the second reactant and the adsorbed precursor to form a film on the surface of the substrate affects film composition and properties, such as non-uniformity, stress, wet etching rate, dry etching rate, electrical properties (e.g., breakdown voltage and leakage current), etc. In ALD deposition of silicon oxide films, the reaction involves oxygen plasma reacting with carbon and nitrogen to form gaseous species; oxidizing silicon to silicon oxide; removing trace carbon, nitrogen, and hydrogen impurities; and improving film bonding and densification.

[0062] Unlike chemical vapor deposition (CVD) techniques, ALD processes use surface-mediated deposition reactions to deposit films on a layer-by-layer basis. In one example of an ALD process, a substrate surface having a population of surface active sites is exposed to a gas phase distribution of a first precursor, such as a silicon-containing precursor, which is provided in a certain dosage to a chamber containing the substrate. Molecules of the first precursor are adsorbed onto the substrate surface, including chemically adsorbed species and / or physically adsorbed molecules of the first precursor. It should be understood that when a compound is adsorbed onto the substrate surface as described herein, the adsorption layer may include the compound and derivatives of the compound. For example, the adsorption layer of a silicon-containing precursor may include a silicon-containing precursor and a derivative of the silicon-containing precursor. After the first precursor is dosed, the chamber is evacuated to remove most or all of the first precursor remaining in the gas phase, so that most or only the adsorbed species remain. In some implementations, the chamber may not be completely evacuated. For example, the reactor may be evacuated so that the partial pressure of the first precursor in the gas phase is low enough to slow down the reaction. A second reactant, such as an oxygen-containing gas, is introduced into the chamber so that some of these molecules react with the first precursor adsorbed on the surface. In some processes, the second reactant reacts immediately with the adsorbed first precursor. In other embodiments, the second reactant reacts only after a temporary application of an activation source. The chamber can then be evacuated again to remove unbound second reactant molecules. As described above, in some embodiments the chamber may not be completely evacuated. Additional ALD cycles may be used to build film thickness.

[0063] In some embodiments, the ALD method includes plasma activation. As described herein, the ALD methods and apparatus described herein may be conformal film deposition (CFD) methods generally described in U.S. Patent Application No. 13 / 084,399, filed on April 11, 2011, entitled “PLASMA ACTIVATED CONFORMAL FILM DEPOSITION” (now U.S. Patent No. 8,728,956), and described in U.S. Patent Application No. 13 / 084,305, filed on April 11, 2011, entitled “SILICONNITRIDE FILMS AND METHODS”, the entire contents of which are incorporated herein by reference.

[0064] Back to Figure 1 In operation 102, a molybdenum oxyhalide precursor is delivered to a deposition chamber via a delivery line. In some embodiments, the delivery line may be heated to a temperature of about 100° C. to about 300° C. In some embodiments, the delivery line is a high nickel alloy or electro-polished stainless steel.

[0065] Molybdenum oxyhalide precursors are of the chemical formula MoO y X zGiven, where X is a halogen (fluorine (F), chlorine (Cl), bromine (Br) or iodine (I)), and y and z are numbers greater than 0, such that MoO y X z Examples of molybdenum oxyhalides include molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxide tetrachloride (MoOCl4), molybdenum oxide tetrafluoride (MoOF4), molybdenum dioxide dibromide (MoO2Br2), and molybdenum iodide MoO2I and Mo4O 11 I. It should be understood that the term molybdenum oxyhalide precursor used herein may refer to the molybdenum oxyhalide precursor described above, or a molybdenum oxyhalide precursor containing molybdenum, oxygen, a halide, and one or more other elements. In some embodiments, the molybdenum oxyhalide or molybdenum oxyhalide containing may contain a variety of different halogens (e.g., F and Cl and / or I and / or Br, etc.).

[0066] The molybdenum halide or molybdenum oxyhalide precursor may also be a mixed halide precursor having two or more halogens.

[0067] exist Figure 1 In the embodiment of the present invention, operation 104 is an in-situ cleaning procedure used in some embodiments. As deposition proceeds, after a predetermined or preselected number of deposition cycles and / or a predetermined or preselected number of layers or thickness of layers, the flow of the molybdenum oxyhalide may be temporarily stopped or slowed to allow the corrosion inhibitor to flow through the delivery line to remove contaminants therein. In some embodiments, the corrosion inhibitor may flow into the system when objective indicators from monitoring equipment indicate that it is necessary. For example, an increase in temperature or pressure may indicate a blockage that requires treatment. In some embodiments, the corrosion inhibitor may flow into the delivery line simultaneously with the molybdenum oxyhalide precursor.

[0068] In some embodiments, the contaminants may be precursor impurities, precursor byproducts, or decomposition products. For example, when the precursor is molybdenum dioxide dichloride, the byproducts may include MoO3, MoO x Suboxide and / or MoO x Cl y Complex.

[0069] In some embodiments, the corrosion inhibitor is a chemical etchant capable of reducing the accumulation of contaminants, for example, a tungsten halide, such as tungsten fluoride (WF5) or tungsten hexafluoride (WF6), or a molybdenum halide, such as molybdenum chloride ([MoCl5]2), molybdenum tetrafluoride (MoF4), molybdenum pentafluoride (MoF5), molybdenum hexafluoride (MoF6), molybdenum bromide (MoBr2), molybdenum dichloride (MoCl2), molybdenum tribromide (MoBr3), molybdenum trichloride (MoCl3), molybdenum triiodide (MoI3), molybdenum tetrabromide (MoBr4) or molybdenum hexachloride (MoCl6).

[0070] In some embodiments, the chemical etchant is chlorine (Cl2), oxygen (O2), fluorine (F2), hydrogen chloride (HCl), hydrogen fluoride (HF), chlorine trifluoride (ClF3), nitrogen trifluoride (NF3), or a combination thereof. Examples of combinations include chlorine with oxygen and fluorine with oxygen. In some embodiments, a single corrosion inhibitor may be sufficiently effective. In some embodiments, a combination of more than one corrosion inhibitor may be used. If a combination of corrosive agents is used, they may flow through the transfer line together (simultaneously) or sequentially (one after the other).

[0071] In some embodiments, liquid water (H2O) can be used as a corrosion inhibitor as well as a chemical etchant. Liquid water can be injected into the transfer line. The water can then be scavenged by heating the transfer line to remove the water. Water helps remove metal contamination such as iron, nickel, or chromium. The formation of hydrates such as MoO2Cl2 hydrates can be reversed by scavenging.

[0072] In some embodiments, after the corrosion inhibitor flows through the delivery line, a molybdenum precursor may flow to passivate the line.

[0073] In operation 106, in order to deposit Figure 1 The molybdenum shown, the molybdenum precursor can react with a reactant. Examples of reactants include hydrogen (H2), silane (SiH4), diborane (B2H6), germane (GeH4), ammonia (NH3) and hydrazine (N2H4).

[0074] For example, in some embodiments, a molybdenum oxyhalide precursor may be used to fill a trench or via with molybdenum. The molybdenum may be filled into the feature by atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0075] ALD is a surface mediated deposition technique in which the precursors and reactants dosed are introduced sequentially into a deposition chamber. Platinum can be deposited using one or more cycles of sequential dosing of molybdenum precursors and reactants. MoO2Cl2 can be used as a precursor and H2 as a reducing agent. The dosed MoO2Cl2 and H2 are sequentially introduced into the deposition chamber, and a purge gas (e.g., argon) is flowed in between. For ALD, the temperature of the substrate and the pressure of the chamber can be controlled. For example, the substrate can be heated between 300°C and 800°C, for example, between 650°C and 750°C. In some embodiments, the chamber can be pressurized to between 10 Torr and 90 Torr, for example, between 30 Torr and 50 Torr. In some embodiments, temperature and / or pressure can be used to control the reaction rate. In some embodiments, temperature and / or pressure can be used to control selectivity.

[0076] In some embodiments, the platinum filling may involve CVD. In a CVD process, a platinum precursor and a reactant are in a vapor phase together in a deposition chamber. Generally speaking, a CVD process fills features faster than an ALD process. In one example, the precursor may be a molybdenum oxychloride (e.g., MoO2Cl2) and flows into the deposition chamber along with a reactant (e.g., H2). In this example, the wafer is exposed to the precursor and the reactant simultaneously, which react and fill the feature with platinum.

[0077] In some other embodiments, a pulsed CVD process may be used to fill the features. A pulsed CVD process allows reactants to flow continuously into the chamber while a precursor is pulsed into the chamber. For example, H2 gas may flow into the chamber and flow continuously into the chamber while a molybdenum-containing precursor flows into the chamber intermittently. During the CVD operation, the temperature of the substrate and the pressure in the chamber may be controlled.

[0078] Back to Figure 1 , operation 108 is the deposition (or treatment) of at least one molybdenum-containing layer. In operation 108, if the desired thickness is reached, the treatment can be terminated. If the desired thickness is not reached, the treatment operations 102 and 106 (including 104 if necessary) are repeated for a number of cycles sufficient to reach the desired metal thickness.

[0079] In some embodiments, operations 102, 106, and 108 may be repeatedly performed without performing the intermediate operation 104 to deposit a molybdenum-containing layer on multiple substrates. Operation 104 may be performed without a substrate in the deposition chamber, or only using a dummy wafer that does not contain part of the manufacturing equipment.

[0080] Figure 2 A non-limiting process 200 for depositing molybdenum metal is schematically illustrated and includes an in-situ cleaning mechanism that pre-treats the molybdenum oxyhalide precursor delivery line with a surface passivating agent to prevent contaminant buildup.

[0081] In operation 202, a deposition chamber is equipped with a molybdenum precursor delivery line. In some embodiments, the precursor is a molybdenum oxyhalide.

[0082] In operation 204, the precursor delivery line is treated with at least one surface passivating agent (prior to treatment) before the precursor is delivered to the deposition chamber via the delivery line in operation 206. In some embodiments, the surface passivating agent is fluorine. In some embodiments, the surface passivating agent is a fluorocarbon or a fluorochlorocarbon. In some embodiments, a combination of surface passivating agents may be used.

[0083] In some embodiments, a surface passivator is coated on the inside of the transfer line to prevent contaminant buildup.

[0084] In operation 208 , the precursors and reactants react to deposit a molybdenum-containing layer.

[0085] Figure 3 A non-limiting process 300 for depositing molybdenum metal is schematically shown, which includes a two-pronged in-situ cleaning mechanism. In a deposition chamber equipped with a precursor delivery line (operation 302), the molybdenum oxyhalide precursor delivery line is pretreated with a surface passivating agent in operation 304; then, in operation 308, a corrosion inhibitor is periodically passed through the delivery line as needed by the deposition cycle of the layer (represented as operations 306 and 310).

[0086] In some embodiments, the in-situ cleaning methods described herein may be used in conjunction with filters, moisture mitigation units, or other cleaning devices to ensure the robustness of semiconductor manufacturing systems.

[0087] As described above, etching and surface passivation operations can be performed in situ without the need for disassembly and replacement. Device

[0088] Figure 4 A schematic diagram of an embodiment of an ALD processing station 400 is depicted, having a process chamber 402 for maintaining a low pressure environment. In some embodiments, multiple ALD processing stations can be included in a common low pressure process tool environment. In some embodiments, one or more hardware parameters of the ALD processing station 400, including the parameters discussed in detail below, can be programmatically adjusted by one or more computer controllers 450. In some other embodiments, the process chamber can be a single station chamber.

[0089] The ALD processing station 400 is fluidly connected to a reactant delivery system 401 for delivering process gases to a distribution showerhead 406. The reactant delivery system 401 includes a mixing vessel 404 for mixing and / or conditioning process gases, such as a Mo-containing precursor gas, a hydrogen-containing gas, an argon gas or other carrier gas, or other reactant-containing gas, for delivery to the showerhead 406. One or more mixing vessel inlet valves 420 can control the introduction of process gases into the mixing vessel 404. In various embodiments, deposition of an initial molybdenum layer is performed in the processing station 400, and in some embodiments, other operations (such as in-situ cleaning or molybdenum gap filling) can be performed in the same or another station of the multi-station processing tool 400.

[0090] For example, Figure 4 Embodiments include a vaporization point 403 for vaporizing liquid reactants supplied to a mixing vessel 404. In some embodiments, the vaporization point 403 may be a heated evaporator. In some embodiments, a liquid precursor or liquid reactant may be vaporized at a liquid injector (not shown). For example, a liquid injector may inject a pulse of a liquid reactant into a carrier gas stream upstream of the mixing vessel 404. In one embodiment, a liquid injector may vaporize a reactant by flashing a liquid from a higher pressure to a lower pressure. In another example, a liquid injector may atomize a liquid into dispersed droplets that are then vaporized in a heated delivery pipe. Smaller droplets may vaporize faster than larger droplets, thereby reducing the delay between liquid injection and completion of vaporization. Faster vaporization may reduce the length of the pipeline downstream of the vaporization point 403. In one embodiment, a liquid injector may be mounted directly to the mixing vessel 404. In another embodiment, a liquid injector may be mounted directly to a spray head 406.

[0091] In some embodiments, a liquid flow controller (LFC) can be set upstream of the vaporization point 403 to control the mass flow rate of the liquid used for vaporization and delivered to the processing chamber 402. For example, the LFC can include a thermal mass flow meter (MFM) located downstream of the LFC. Then the plunger valve of the LFC can be adjusted in response to a feedback control signal provided by a proportional integral differential (PID) controller that is electrically communicated with the MFM. However, it can take one second or more to use feedback control to stabilize the liquid flow. This can extend the time of dosing liquid reactants. Therefore, in some embodiments, the LFC can be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, this can be performed by disabling the sensing pipeline and PID controller of the LFC.

[0092] Showerhead 406 distributes processing gas toward substrate 412. Figure 4In the illustrated embodiment, substrate 412 is positioned below showerhead 406 and is shown resting on pedestal 408. Showerhead 406 may have any suitable shape and may have any suitable number and arrangement of ports to distribute process gases to substrate 412.

[0093] In some embodiments, the pedestal 408 can be raised or lowered to expose the substrate 412 to the volume between the substrate 412 and the showerhead 406. In some embodiments, the pedestal 408 can be temperature controlled by a heater 410. The pedestal 408 can be set to any suitable temperature during operation for performing the various disclosed embodiments, such as a temperature between about 300° C. and about 500° C. It should be understood that in some embodiments, the pedestal height can be adjusted programmatically via a suitable computer controller 450. At the end of a processing phase, the pedestal 408 can be lowered during another substrate transfer phase to allow the substrate 412 to be removed from the pedestal 408.

[0094] In some embodiments, the position of the showerhead 406 can be adjusted relative to the pedestal 408 to change the volume between the substrate 412 and the showerhead 406. In addition, it should be understood that the vertical position of the pedestal 408 and / or the showerhead 406 can be changed by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 408 may include a rotation axis for rotating the orientation of the substrate 412. It should be understood that in some embodiments, one or more of these exemplary adjustments can be performed programmatically by one or more appropriate computer controllers 450. The computer controller 450 may include the following and Figure 4 Any features associated with controller 450.

[0095] In some embodiments as described above where plasma can be used, the showerhead 406 and the base 408 are electrically connected to a radio frequency (RF) power supply 414 and a matching network 416 to power the plasma. In some embodiments, the energy of the plasma can be controlled by controlling one or more of the processing station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power supply 414 and the matching network 416 can be operated at any suitable power to form a plasma with a component of a desired free radical substance. Similarly, the RF power supply 414 can provide RF power of any appropriate frequency. In some embodiments, the RF power supply 414 can be configured to control a high-frequency RF power supply and a low-frequency RF power supply that are independent of each other. Exemplary low-frequency RF frequencies can include, but are not limited to, frequencies between 0kHz and 900kHz. Exemplary high-frequency RF frequencies can include, but are not limited to, frequencies between 1.8MHz and 2.45GHz, or frequencies greater than about 13.56MHz, or greater than 27MHz, or greater than 80MHz, or greater than 60MHz. It will be appreciated that any suitable parameters may be adjusted discretely or continuously to provide plasma energy for surface reactions.

[0096] In some embodiments, the plasma can be monitored in situ by one or more plasma monitors. In one case, the plasma power can be monitored by one or more voltage, current sensors (e.g., VI probes). In another case, the plasma density and / or the process gas concentration can be measured by one or more optical emission spectroscopy sensors (OES). In some embodiments, one or more plasma parameters can be adjusted programmatically based on the measurement results from such an in-situ plasma monitor. For example, an OES sensor can be used in a feedback loop to provide programmatic control of the plasma power. It should be understood that in some embodiments, other monitors can be used to monitor plasma and other processing characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure sensors.

[0097] In some embodiments, instructions for controller 450 may be provided via input / output control (IOC) sequencing instructions. In one example, instructions for setting the conditions of the treatment phase may be included in the corresponding recipe phase of the treatment recipe. In some cases, the treatment recipe phase may be arranged in order so that all instructions for the treatment phase are executed simultaneously with the treatment phase. In some embodiments, instructions for setting one or more reactor parameters may be included in the recipe phase. For example, the first recipe phase may include instructions for setting the flow rate of an inert gas and / or a reactant gas (e.g., a Mo precursor), instructions for setting the flow rate of a carrier gas (e.g., argon), and time delay instructions for the first recipe phase. The subsequent second recipe phase may include instructions for adjusting or stopping the flow rate of an inert gas and / or a reactant gas, instructions for adjusting the flow rate of a carrier gas or a purge gas, and time delay instructions for the second recipe phase. The third recipe phase may include instructions for adjusting the flow rate of a second reactant gas (e.g., H2), instructions for adjusting the flow rate of a carrier gas or a purge gas, instructions for igniting plasma, and time delay instructions for the third recipe phase. A subsequent fourth recipe stage may include instructions for adjusting or stopping the flow rates of the inert gas and / or the reactant gas, and instructions for adjusting the flow rates of the carrier gas or the purge gas, and time delay instructions for the fourth recipe stage. It should be understood that within the scope of the present disclosure, these recipe stages may be further subdivided and / or repeated in any suitable manner.

[0098] Additionally, in some embodiments, pressure control for the processing station 400 may be provided by a butterfly valve 418. Figure 4 In the embodiment shown, butterfly valve 418 throttles the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of process station 400 can also be adjusted by changing the flow rate of one or more gases introduced into process station 400.

[0099] Figure 4 Also shown is a delivery line process gas source 430. The delivery line process gas source may include one or more corrosion inhibitor and / or surface passivation gas sources as described above. It is configured to provide a delivery line process gas to the process gas delivery line described above. The controller may include instructions for performing periodic in-situ etching and / or surface passivation. The instructions may include instructions for heating the delivery line as described above.

[0100] Another aspect of the present disclosure relates to the use of WF6 or other chemical etchants to remove molybdenum oxide after deposition on a substrate. Figure 5An example of a feature is shown that includes molybdenum 510 deposited to fill the feature. In some embodiments, molybdenum oxide may be present on the exposed surface 512 and in the seam 514, if present. Exposing the filled feature to a chemical etchant as described removes the oxide.

[0101] Figure 6 FIG. 6 is a flow chart according to some embodiments. In operation 605, the feature is filled with molybdenum. Figure 1 Operation 108 of describes filling the features with molybdenum. An example of a feature is a hole or via in a semiconductor substrate or a layer on a semiconductor substrate. For example, the feature can be formed at least partially in a dielectric layer. In some embodiments, the feature can have an aspect ratio of at least about 2:1, at least about 4:1, at least about 6:1, at least about 10:1, at least about 25:1, or more.

[0102] As described above, molybdenum can be filled into the features by atomic layer deposition (ALD) or chemical vapor deposition (CVD). Thermal ALD or plasma enhanced ALD (PEALD) can be used. Likewise, thermal CVD or plasma enhanced CVD (PECVD) can also be used.

[0103] For example, Mo2Cl2 or MoCl5 can be used as a precursor and H2 as a reducing agent. The dosed MoCl5 and H2 are introduced into the deposition chamber in sequence, and a purge gas (such as argon) is flowed in between. For ALD, the temperature of the substrate and the pressure of the chamber can be controlled. In the PEALD process, the Mo precursor can be used alternately with the plasma generated by H2 gas.

[0104] In some embodiments, the platinum filling may involve CVD. In a CVD process, a platinum precursor and a reactant are in a vapor phase in a deposition chamber. Generally speaking, a CVD process fills features faster than an ALD process. In one example, the precursor may be a molybdenum oxychloride (e.g., MoO2Cl) and flows into the chamber along with a reactant (e.g., H2). In this example, the wafer is exposed to the precursor and the reactant simultaneously, which react and fill the feature with platinum.

[0105] In some other embodiments, a pulsed CVD process may be used to fill the features. A pulsed CVD process allows a reactant to flow continuously into the chamber while a precursor is pulsed into the chamber. For example, H2 gas may flow into the chamber and flow continuously into the chamber, while a molybdenum-containing precursor flows into the chamber intermittently. During the CVD operation, the temperature of the substrate and the pressure in the chamber may be controlled. Any of the above processes may use any suitable reducing agent, including H2, silane (SiH4) and / or diborane (B2H6) or plasmas generated therefrom.

[0106] In some embodiments, particularly when deposition is performed at relatively low temperatures (e.g., plasma-based deposition), residual oxides may be present. This may be in the form of molybdenum oxide (MoO x ) and / or a hydrated molybdenum precursor (e.g., MoO2Cl2·H2O).

[0107] In operation 615, an optional sweep is performed. Then, in operation 625, WF6 or other chemical etchants described herein (e.g., MoCl5) are introduced into the chamber containing the substrate containing the filled features. This may be referred to as dosing or soaking, and the oxide is removed. These methods may be described above with reference to Figure 4 The method is performed in the device.

[0108] The foregoing describes implementations of the present invention as implemented in a single-chamber or multi-chamber semiconductor processing tool. The apparatus and processes described herein can be used in conjunction with lithography patterning tools or processes, for example, to prepare or manufacture semiconductor devices, displays, LEDs, photovoltaic panels, etc. Typically, although not necessarily, these tools / processes will be used or operated together in a common manufacturing facility. Photolithographic patterning of films typically includes some or all of the following steps, each of which enables multiple available tools: (1) coating a workpiece, i.e., a substrate, with photoresist using a spin coating or spray coating tool; (2) curing the photoresist using a hot plate or oven or a UV curing tool; (3) exposing the photoresist to visible light or UV light or X-rays using a tool such as a wafer stepper; (4) developing the resist to selectively remove the resist and thereby pattern it using a tool such as a wet cleaning station; (5) transferring the resist pattern to an underlying film or workpiece by using a dry or plasma assisted etching tool; and (6) removing the resist using a tool such as a radio frequency or microwave plasma resist stripper. in conclusion

[0109] Although the above embodiments have been described in some detail for the purpose of clear understanding, it is apparent that certain variations and modifications may be implemented within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and devices of the embodiments of the present invention. Therefore, the embodiments of the present invention should be considered illustrative rather than restrictive, and these embodiments are not limited to the details given herein.

Claims

1. A method for depositing molybdenum metal, comprising: introducing a molybdenum oxyhalide precursor into a deposition chamber containing a semiconductor substrate via one or more precursor delivery lines; supplying a periodic flow of at least one corrosion inhibitor to the precursor delivery line; and The molybdenum oxyhalide precursor is reacted with at least one reactant to form a molybdenum-containing layer on the semiconductor substrate.

2. The method of claim 1, wherein the at least one corrosion inhibitor comprises a chemical etchant.

3. The method of claim 2, wherein the chemical etchant comprises a tungsten halide or a molybdenum halide.

4. The method of claim 1, wherein the at least one corrosion inhibitor comprises chlorine, oxygen, fluorine, hydrogen chloride, hydrogen fluoride, chlorine trifluoride, nitrogen trifluoride, or a combination thereof.

5. The method of claim 4, wherein the at least one corrosion inhibitor comprises oxygen and chlorine. The method according to claim 5 , wherein the oxygen and chlorine are supplied to the precursor delivery line sequentially or simultaneously.

7. The method of claim 4, wherein the at least one corrosion inhibitor comprises oxygen and fluorine. The method according to claim 7 , wherein the oxygen and fluorine are supplied to the precursor delivery line sequentially or simultaneously.

9. The method according to claim 1, wherein the molybdenum oxyhalide precursor is Mo q O n Y m , wherein Y is halogen; n is 1 or 2; q is 1, 2 or 4; and m is 1, 2 or 11.

10. The method according to claim 9, wherein the molybdenum oxyhalide precursor comprises MoOF4, Mo4O 11 I, MoO2I, MoO2Br2, MoO2Cl2, MoOCl4 or a combination thereof and / or the at least one reactant comprises hydrogen, ammonia, diborane, water, hydrogen sulfide, thiol, alcohol, amine, hydrazine, silane, disilane or a combination thereof.

11. The method of claim 1, wherein the corrosion inhibitor is one of tungsten hexafluoride (WF6), molybdenum pentachloride (MoCl5), and water (H2O).

12. A method for depositing molybdenum metal, comprising: providing a deposition chamber having one or more molybdenum oxyhalide precursor delivery lines; pretreating the one or more molybdenum oxyhalide precursor delivery lines with at least one surface passivating agent to form one or more treated molybdenum oxyhalide precursor delivery lines; introducing one or more semiconductor substrates into the deposition chamber; introducing a molybdenum oxyhalide precursor into the deposition chamber via the one or more treated molybdenum oxyhalide precursor delivery lines; and The molybdenum oxyhalide precursor is reacted with at least one reactant to form a molybdenum-containing layer on the semiconductor substrate.

13. The method of claim 12, wherein the one or more molybdenum oxyhalide precursor delivery lines comprise stainless steel or a nickel alloy.

14. The method according to claim 12, wherein the molybdenum oxyhalide precursor is Mo q O n Y m , wherein Y is halogen; n is 1 or 2; q is 1, 2 or 4; and m is 1, 2 or 11.

15. The method according to claim 14, wherein the molybdenum oxyhalide precursor comprises MoOF4, Mo4O 11 I, MoO2I, MoO2Br2, MoO2Cl2, MoOCl4 or a combination thereof.

16. The method of claim 12, wherein the at least one reactant comprises hydrogen, ammonia, diborane, water, hydrogen sulfide, mercaptans, alcohols, amines, hydrazine, silane, disilane, or combinations thereof.

17. The method of claim 12, wherein the at least one surface passivating agent is fluorine.

18. A method for atomic layer deposition of molybdenum metal, comprising: providing a deposition chamber having one or more molybdenum oxyhalide precursor delivery lines; pretreating the molybdenum oxyhalide precursor delivery line with at least one surface passivating agent to form one or more treated molybdenum oxyhalide precursor delivery lines; introducing one or more semiconductor substrates into the deposition chamber; introducing a molybdenum oxyhalide precursor into the deposition chamber via the one or more treated molybdenum oxyhalide precursor delivery lines; reacting the molybdenum oxyhalide precursor with at least one reactant to deposit a molybdenum-containing layer on the semiconductor substrate; A periodic flow of at least one corrosion inhibitor is supplied to the molybdenum oxyhalide precursor delivery line.

19. The method of claim 18, wherein the one or more semiconductor substrates comprise a dummy wafer.

20. The method of claim 18, wherein the one or more molybdenum oxyhalide precursor delivery lines comprise stainless steel or a nickel alloy.

21. The method according to claim 18, wherein the molybdenum oxyhalide precursor is Mo q O n Y m , wherein Y is halogen; n is 1 or 2; q is 1, 2 or 4; and m is 1, 2 or 11.

22. The method of claim 21, wherein the molybdenum oxyhalide precursor comprises MoOF4, Mo4O 11 I, MoO2I, MoO2Br2, MoO2Cl2, MoOCl4 or a combination thereof.

23. The method of claim 18, wherein the at least one corrosion inhibitor comprises a chemical etchant.

24. The method of claim 23, wherein the chemical etchant comprises a tungsten halide or a molybdenum halide.

25. The method of claim 18, wherein the at least one corrosion inhibitor comprises chlorine, oxygen, fluorine, hydrogen chloride, hydrogen fluoride, chlorine trifluoride, nitrogen trifluoride, or a combination thereof.

26. The method of claim 25, wherein the at least one corrosion inhibitor comprises oxygen and chlorine.

27. The method of claim 26, wherein the oxygen and chlorine are supplied to the one or more molybdenum oxyhalide precursor delivery lines sequentially or simultaneously.

28. The method of claim 25, wherein the at least one corrosion inhibitor comprises oxygen and fluorine.

29. The method of claim 28, wherein the oxygen and fluorine are supplied to the one or more molybdenum oxyhalide precursor delivery lines sequentially or simultaneously.

30. A method comprising: providing a semiconductor processing chamber having one or more molybdenum oxyhalide precursor delivery lines; and After treating one or more semiconductor substrates with the molybdenum oxyhalide precursor, at least one corrosion inhibitor is supplied to the one or more molybdenum oxyhalide precursor delivery lines.

31. A method comprising: providing a semiconductor processing chamber having one or more molybdenum oxyhalide precursor delivery lines; and And pretreating the one or more molybdenum oxyhalide precursor delivery lines with at least one surface passivating agent prior to treating the one or more semiconductor substrates with the molybdenum oxyhalide.

32. A method comprising: Providing a semiconductor processing chamber having one or more molybdenum oxyhalide precursor delivery lines; and pretreating the one or more molybdenum oxyhalide precursor delivery lines with at least one surface passivating agent prior to treating the one or more semiconductor substrates with the molybdenum oxyhalide; and After treating one or more semiconductor substrates with the molybdenum oxyhalide precursor, at least one corrosion inhibitor is supplied to the one or more molybdenum oxyhalide precursor delivery lines.

33. A method comprising: depositing molybdenum in the feature to fill the feature; and After filling the features, the deposited molybdenum is exposed to a chemical etchant to remove oxide from the deposited molybdenum.

34. The method of claim 33, wherein the chemical etchant is a tungsten halide.

35. The method of claim 33, wherein the chemical etchant is a molybdenum halide.

36. The method of claim 33, wherein the oxide comprises molybdenum oxide and / or a hydrated molybdenum precursor.

37. The method of claim 33, wherein depositing molybdenum in the feature comprises a plasma enhanced ALD process.

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