Hydrogen Deposition Reduction Process

Abstract

An exemplary method of semiconductor processing may include treating a surface of a substrate with a hydrogen-containing precursor. The substrate may be disposed within a processing region of a semiconductor processing chamber. The method may include contacting the substrate with a tungsten-containing precursor. The method may include forming an initiation layer comprising tungsten on the substrate. The method may include treating the initiation layer with a hydrogen-containing precursor. The method may include forming a plasma of a tungsten-containing precursor and a carbon-containing precursor. The hydrogen in the plasma may be limited to hydrogen included in the carbon-containing precursor. The method may include forming a tungsten-containing hard mask layer on the initiation layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Patent Application No. 62 / 934,289, filed on November 12, 2019, the contents of which are incorporated herein by reference in their entirety for all purposes. Technical Field

[0003] The present technology relates to methods and components for semiconductor processing. More specifically, the present technology relates to systems and methods for producing hard mask films. Background Art

[0004] Integrated circuits are made possible by processes that produce complex patterned layers of material on a substrate surface. Producing patterned material on a substrate requires controlled methods for forming and removing materials. As component sizes continue to decrease, the aspect ratios of structures may increase, and maintaining the dimensions of these structures during removal operations may be challenging. To facilitate the patterning of materials on a substrate, a hard mask may be employed. As the number of material layers being patterned increases, hard mask selectivity for multiple materials is becoming a greater challenge.

[0005] Therefore, there is a need for improved systems and methods for producing high quality components and structures. These and other needs are addressed by the present technology. Summary of the invention

[0006] An exemplary method of semiconductor processing may include treating a surface of a substrate with a hydrogen-containing precursor. The substrate may be disposed within a processing region of a semiconductor processing chamber. The method may include contacting the substrate with a tungsten-containing precursor. The method may include forming an initiation layer comprising tungsten on the substrate. The method may include treating the initiation layer with a hydrogen-containing precursor. The method may include forming a plasma of a tungsten-containing precursor and a carbon-containing precursor. The hydrogen in the plasma may be limited to hydrogen included in the carbon-containing precursor. The method may include forming a tungsten-containing hard mask layer on the initiation layer.

[0007] In some embodiments, processing the surface of the substrate may include: forming a plasma containing a hydrogen precursor, and contacting the surface of the substrate with the effluent of the plasma to produce a hydrogen termination. When processing the surface of the substrate is being performed, a tungsten-containing precursor may be delivered for contact. When the tungsten-containing precursor is delivered, the flow rate of the tungsten-containing precursor may be increased. Processing the initiation layer may include: forming a plasma containing a hydrogen precursor, and contacting the initiation layer with the effluent of the plasma. The plasma may also include a nitrogen-containing precursor. The hydrogen-containing precursor may be or may include diatomic hydrogen, and the nitrogen-containing precursor may be or may include diatomic nitrogen. The tungsten-containing precursor may be or may include tungsten hexafluoride, and the carbon-containing precursor may be or may include propylene. When the plasma containing the tungsten precursor and the carbon-containing precursor is formed, the diatomic hydrogen may be removed from the semiconductor processing chamber. The method may include forming a seasoning layer including a silicon-containing material on an exposed surface of a processing region of the semiconductor processing chamber.

[0008] Some embodiments of the present technology may include methods of semiconductor processing. The method may include forming an adjustment layer on an exposed surface of a processing region of a semiconductor processing chamber. The method may include forming an initiation layer including tungsten on a substrate. The substrate may be disposed within the processing region of the semiconductor processing chamber. The method may include forming a plasma containing a tungsten precursor and a carbon-containing precursor. The atomic ratio of hydrogen in the precursor delivered to form the plasma to tungsten in the precursor delivered to form the plasma may be less than 8:1. The method may include forming a tungsten-containing hard mask layer on the initiation layer.

[0009] In some embodiments, the adjustment layer may be or may include silicon oxide and silicon nitride. The step of forming the initiation layer may include forming a plasma of a hydrogen-containing precursor. The step of forming the initiation layer may include contacting the surface of the substrate with an effluent of the plasma to produce a hydrogen termination. The step of forming the initiation layer may include flowing a tungsten-containing precursor into the processing region to contact the surface of the substrate. The tungsten-containing precursor may be unexcited when flowing to contact the surface of the substrate. The method may include: forming a plasma of a hydrogen-containing precursor, and contacting the initiation layer with the effluent of the plasma. The tungsten-containing precursor may be or may include tungsten hexafluoride, and the carbon-containing precursor may be or may include propylene. When the plasma of the tungsten-containing precursor and the carbon-containing precursor is formed, diatomic hydrogen may be excluded from the semiconductor processing chamber.

[0010] Some embodiments of the present technology may include methods of semiconductor processing. The method may include forming an adjustment layer on an exposed surface of a processing region of a semiconductor processing chamber. The method may include treating a surface of a substrate with a hydrogen-containing precursor. The substrate may be disposed within a processing region of the semiconductor processing chamber. The method may include contacting the substrate with a tungsten-containing precursor. The method may include forming an initiation layer comprising tungsten on the substrate. The method may include treating the initiation layer with a hydrogen-containing precursor. The method may include forming a plasma of a tungsten-containing precursor and a carbon-containing precursor. The hydrogen in the plasma may be limited to hydrogen included in the carbon-containing precursor. The method may include forming a tungsten-containing hard mask layer on the initiation layer.

[0011] In some embodiments, the method may include removing the substrate from the semiconductor processing chamber. The method may include performing a chamber cleaning process in a processing region of the semiconductor processing chamber. The method may include forming a plasma containing an oxygen precursor in a processing region of the semiconductor processing chamber.

[0012] This technology can provide numerous benefits over conventional systems and techniques. For example, embodiments of the present technology can produce hard mask films characterized by reduced grain size. In addition, the present technology can reduce peeling of the formed film. These and other embodiments and their many advantages and features are described in more detail in conjunction with the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remainder of the specification and the accompanying drawings.

[0014] Figure 1 A schematic cross-sectional view of an exemplary plasma system is shown in accordance with some embodiments of the present technology.

[0015] Figure 2A Operations in a semiconductor processing method according to some embodiments of the present technology are illustrated.

[0016] Figure 2B Operations in a semiconductor processing method according to some embodiments of the present technology are illustrated.

[0017] Some of the drawings are included as schematic diagrams. It should be understood that the drawings are for illustration purposes only and should not be considered to be to scale unless specifically noted as being to scale. Additionally, as schematic diagrams, the drawings are provided to aid understanding and may not include all aspects or information compared to realistic representations and may include exaggerated material for illustration purposes.

[0018] In the drawings, similar components and / or features may have the same reference numeral. In addition, various components of the same type may be distinguished by following the reference numeral with a letter that distinguishes the similar components. If only the first reference numeral is used in the specification, the description may apply to any of the similar components having the same first reference numeral, regardless of the letter. DETAILED DESCRIPTION

[0019] Hard masks are used in many processing operations that may include forming patterns through a variety of different material layers. Increasing the etch selectivity of these materials relative to the hard mask film provides tighter control over critical dimensions, especially as feature sizes continue to shrink. Amorphous silicon or carbon films are often used as hard masks, although the selectivity of these films is becoming a greater challenge for more complex memory and logic structures, which may have a variety of different films on a substrate and may need to be patterned into high aspect ratio features. Therefore, newer films may include the incorporation of metal materials into the film to increase the etch selectivity. As a non-limiting example, tungsten may be incorporated into a carbon film to increase selectivity relative to a variety of oxide and nitride materials. However, as the incorporation of tungsten into the film increases, many problems may develop.

[0020] Metal halide precursors can be used to deposit tungsten and other metal-containing materials. In the case of tungsten, tungsten hexafluoride can be used for deposition in a plasma enhanced chemical vapor deposition process. During plasma deposition, residual fluorine can be incorporated into the crystalline structure and can diffuse through the film to the hard mask interface with the substrate. This can reduce the adhesion of the film, which can cause undercuts during subsequent etching and can cause film peeling and component failure. To limit adhesion problems, many conventional techniques can utilize hydrogen during the deposition process, which can accept residual fluorine and extract it from the chamber as a volatile byproduct.

[0021] Incorporating hydrogen into the film may cause additional problems during processing. For example, the thermal stability of hydrogen incorporated into the film may be low, and outgassing may occur during subsequent processing. In addition, hydrogen may affect film stress, which may cause the film to become increasingly compressed, which may also cause film delamination. Finally, the amount of hydrogen in the plasma may affect the deposition process and may cause an increase in the grain size and crystallinity of the formed tungsten and carbon films. For example, conventional processes may be characterized by a grain size of 2nm or greater. As the critical dimension is reduced to 20nm or less, these grain sizes may increase surface roughness and may increase line edge roughness and line width roughness during etching operations. In addition, larger grain structures may cause effective distortion during the formation of higher aspect ratio features, which may affect subsequent operations by reducing critical dimension uniformity.

[0022] To improve the grain problem of the film, some conventional processes take remedial measures. For example, conventional techniques may reduce tungsten incorporation, perform multiple deposition operations, or incorporate boron doping. All of these changes may adversely affect processing. For example, as the tungsten percentage decreases, the etch selectivity of the film may also decrease. Multiple deposition operations may increase waiting time, and boron incorporation may reduce the film extinction coefficient.

[0023] The present technology overcomes these problems by performing tungsten deposition that may not utilize additional hydrogen during the deposition process. The present technology may improve adhesion by forming an initiation layer at the substrate surface. By removing hydrogen from the deposition process when forming the bulk of the hard mask film, a greater number of nucleation sites may be formed, which may reduce grain size as film growth proceeds. The present technology may also perform chamber cleaning, treatments, and conditioning to further improve deposition and reduce dropped particles.

[0024] Although the remaining disclosure will routinely identify specific deposition processes utilizing the disclosed techniques, it will be readily appreciated that the systems and methods are equally applicable to other deposition, etching, and cleaning chambers, and processes that may occur therein. Therefore, the techniques should not be considered limited to use with only these specific deposition processes or chambers. Prior to describing additional variations and adjustments to this system in accordance with embodiments of the present technology, the present disclosure will discuss one possible chamber that may be used to perform processes in accordance with embodiments of the present technology.

[0025] Figure 1 A cross-sectional view of an exemplary processing chamber 100 according to some embodiments of the present technology is shown. The figures may show an overview of a system incorporating one or more aspects of the present technology, and / or an overview of a system that may be specifically configured to perform one or more operations according to embodiments of the present technology. Additional details of the chamber 100 or the methods performed may be further described below. The chamber 100 may be used to form a film layer according to some embodiments of the present technology, although it should be understood that the method may be similarly performed in any chamber in which film formation may occur. The processing chamber 100 may include a chamber body 102, a substrate support 104, and a lid assembly 106, the substrate support 104 being disposed inside the chamber body 102, and the lid assembly 106 being coupled to the chamber body 102 and enclosing the substrate support 104 in a processing space 120. The substrate 103 may be provided to the processing space 120 via an opening 126, which may be conventionally sealed by a slit valve or door for processing. The substrate 103 may be seated on a surface 105 of the substrate support during processing. As indicated by arrow 145, the substrate support 104 may be rotated along an axis 147 where the shaft 144 of the substrate support 104 may be located. Alternatively, the substrate support 104 may be lifted for rotation as desired during the deposition process.

[0026] A plasma profile adjuster 111 may be disposed in the processing chamber 100 to control the plasma distribution across the substrate 103 disposed on the substrate support 104. The plasma profile adjuster 111 may include a first electrode 108, which may be disposed adjacent to the chamber body 102 and may separate the chamber body 102 from other components of the lid assembly 106. The first electrode 108 may be part of the lid assembly 106, or may be a separate sidewall electrode. The first electrode 108 may be an annular or ring-shaped member, and may be an annular electrode. The first electrode 108 may be a continuous ring around the circumference of the processing chamber 100 surrounding the processing volume 120, or may be discontinuous at selected locations if desired. The first electrode 108 may also be a perforated electrode, such as a perforated ring or mesh electrode, or may be a plate electrode, such as a secondary gas distributor, for example.

[0027] One or more isolators 110a, 110b may contact the first electrode 108 and electrically and thermally isolate the first electrode 108 from a gas distributor 112 and from the chamber body 102. The isolators 110a, 110b may be a dielectric material, such as a ceramic or a metal oxide, such as aluminum oxide and / or aluminum nitride. The gas distributor 112 may define holes 118 for distributing process precursors into the processing volume 120. The gas distributor 112 may be coupled to a first electrical power source 142, such as an RF generator, an RF power source, a DC power source, a pulsed DC power source, a pulsed RF power source, or any other power source that may be coupled to the processing chamber. In some embodiments, the first electrical power source 142 may be an RF power source.

[0028] The gas distributor 112 may be a conductive gas distributor or a non-conductive gas distributor. The gas distributor 112 may also be formed of conductive and non-conductive components. For example, the body of the gas distributor 112 may be conductive, while the panel of the gas distributor 112 may be non-conductive. The gas distributor 112 may be formed of conductive and non-conductive components. Figure 1 A first electrical power source 142 is shown supplying power, or in some embodiments the gas distributor 112 may be grounded.

[0029] The first electrode 108 may be coupled to a first tuning circuit 128, which may control a ground path for the processing chamber 100. The first tuning circuit 128 may include a first electronic sensor 130 and a first electronic controller 134. The first electronic controller 134 may be or may include a variable capacitor or other circuit element. The first tuning circuit 128 may be or may include one or more inductors 132. The first tuning circuit 128 may be any circuit that achieves a variable or controllable impedance under plasma conditions present in the processing space 120 during processing. In some embodiments shown, the first tuning circuit 128 may include a first circuit branch and a second circuit branch coupled in parallel between the ground and the first electronic sensor 130. The first circuit branch may include a first inductor 132A. The second circuit branch may include a second inductor 132B coupled in series with the first electronic controller 134. The second inductor 132B may be disposed between the first electronic controller 134 and a node connecting both the first circuit branch and the second circuit branch to the first electronic sensor 130. The first electronic sensor 130 may be a voltage or current sensor and may be coupled to a first electronic controller 134 , which may provide a degree of closed loop control of the plasma conditions within the processing volume 120 .

[0030] The second electrode 122 may be coupled to the substrate support 104. The second electrode 122 may be embedded within the substrate support 104 or coupled to a surface of the substrate support 104. The second electrode 122 may be a distributed arrangement of a plate, a perforated plate, a mesh, a wire mesh, or any other conductive element. The second electrode 122 may be a tuning electrode and may be coupled to the second tuning circuit 136 through a conduit 146, such as a cable having a selected resistance, such as 50 ohms, disposed in a rod 144 of the substrate support 104. The second tuning circuit 136 may have a second electronic sensor 138 and a second electronic controller 140, which may be a second variable capacitor. The second electronic sensor 138 may be a voltage or current sensor and may be coupled to the second electronic controller 140 to provide further control of the plasma conditions in the processing volume 120.

[0031] The third electrode 124 may be a bias electrode and / or an electrostatic adsorption electrode, and the third electrode 124 may be coupled to the substrate support 104. The third electrode may be coupled to the second electrical power source 150 via a filter 148, and the filter 148 may be an impedance matching circuit. The second electrical power source 150 may be DC power, pulsed DC power, RF bias power, pulsed RF source or bias power, or a combination of these or other power sources. In some embodiments, the second electrical power source 150 may be RF bias power.

[0032] Figure 1The lid assembly 106 and substrate support 104 of the processing chamber 100 can be used with any processing chamber for plasma or thermal processing. In operation, the processing chamber 100 can provide instant control of plasma conditions in the processing space 120. The substrate 103 can be disposed on the substrate support 104, and the process gas can be flowed through the lid assembly 106 using the inlet 114 according to any desired flow plan. The gas can leave the processing chamber 100 via the outlet 152. Electrical power can be coupled to the gas distributor 112 to establish a plasma in the processing space 120. In some embodiments, the substrate can be subjected to an electrical bias using the third electrode 124.

[0033] When a plasma is ignited in the processing space 120, a potential difference may be established between the plasma and the first electrode 108. A potential difference may also be established between the plasma and the second electrode 122. The electronic controllers 134, 140 may then be used to adjust the flow properties of the ground path represented by the two tuning circuits 128 and 136. The set point may be communicated to the first tuning circuit 128 and the second tuning circuit 136 to provide independent control of the deposition rate and the uniformity of the plasma density from the center to the edge. In embodiments where both electronic controllers may be variable capacitors, the electronic sensors may adjust the variable capacitors to independently maximize the deposition rate and minimize the thickness non-uniformity.

[0034] Each of the tuning circuits 128, 136 may have a variable impedance that can be adjusted using the respective electronic controllers 134, 140. When the electronic controllers 134, 140 are variable capacitors, the capacitance range of each variable capacitor and the inductance of the first inductor 132A and the second inductor 132B may be selected to provide an impedance range. This range may depend on the frequency and voltage characteristics of the plasma, which may have a minimum value in the capacitance range of each variable capacitor. Thus, when the capacitance of the first electronic controller 134 is at a minimum or maximum value, the impedance of the first tuning circuit 128 may be high, causing the plasma shape to have minimal aerial or lateral coverage above the substrate support. When the capacitance of the first electronic controller 134 approaches a value that minimizes the impedance of the first tuning circuit 128, the aerial coverage of the plasma may grow to a maximum value, effectively covering the entire working area of ​​the substrate support 104. As the capacitance of the first electronic controller 134 deviates from the minimum impedance setting, the plasma shape may shrink from the chamber wall and the aerial coverage of the substrate support may decrease. The second electronic controller 140 may have a similar effect, as the capacitance of the second electronic controller 140 may be varied to increase and decrease the aerial coverage of the plasma above the substrate support.

[0035] The electronic sensors 130, 138 may be used to tune the individual circuits 128, 136 in a closed loop. Depending on the type of sensor used, a set point for current or voltage may be installed in each sensor, and the sensors may be provided with control software that determines adjustments to each individual electronic controller 134, 140 to minimize deviations from the set point. Thus, the plasma shape may be selected and dynamically controlled during processing. It should be understood that while the foregoing discussion is based on electronic controllers 134, 140 that may be variable capacitors, any electronic component with an adjustable characteristic may be used to provide an adjustable impedance to the tuned circuits 128 and 136.

[0036] FIG. 2 illustrates exemplary operations in a processing method 200 according to some embodiments of the present technology. The method may be performed in various processing chambers including the processing chamber 100 described above. The method 200 may include a number of optional operations that may or may not be specifically related to some embodiments of the method according to the present technology. For example, many operations are described in order to provide a greater range of structure formation, but these operations are not critical to the technology or may be performed by alternative methods that will be readily understood.

[0037] Method 200 may include a processing method that may include a number of operations for preparing a chamber for processing and forming a hard mask film or other deposition operations. The method may include optional operations before the start of method 200, or the method may include additional operations. For example, method 200 may include operations performed in a different order than that shown. As will be explained, in some embodiments, at optional operation 205, multiple repetitions may be performed and the method may be performed after a previous chamber clean. Exemplary cleaning operations may utilize plasma-enhanced halogen-containing or other etchant precursors. Although advantageous for removing material, halogen materials may interact with aluminum chamber components as discussed above, and in one non-limiting example, utilizing a fluorine precursor may result in aluminum fluoride being formed and / or redeposited around the processing area of ​​the chamber.

[0038] In some embodiments, method 200 may include plasma treatment at optional operation 210, which may include a plasma enhanced precursor, which may be sent from a remote plasma unit or developed in situ in the processing region. The precursor may include a hydrogen-containing precursor, an oxygen-containing precursor, or any other precursor that may be used to or promote the conversion of aluminum fluoride back to aluminum or aluminum oxide. As a non-limiting example, nitrous oxide or some other oxygen-containing precursor (such as oxygen) may be delivered to the processing region and a plasma may be generated. The resulting oxygen-containing plasma effluent may convert aluminum fluoride to aluminum oxide, which may be more stably retained on the chamber surface. In addition, the precursor may remove aluminum fluoride material from the chamber.

[0039] A conditioning or treatment film may then be developed within the chamber at optional operation 215. For example, an oxide material, such as silicon oxide, may be formed over surfaces of a processing chamber, such as a region within a processing region, including exposed surfaces of the processing volume 120 described previously. The region may be an internal plasma region, which may be at least partially defined by a plurality of chamber components. For example, chamber sidewalls, showerheads or faceplates, and pedestals may all be included in or at least partially define aspects of the processing region. A plasma may be formed within the processing region, and a precursor for depositing silicon oxide may be introduced. A film of silicon oxide of a first thickness may be formed over the chamber surface, which may ensure complete coating of the surface.

[0040] After forming the silicon oxide surface, method 200 may include forming a nitride material, such as silicon nitride. A second thickness of silicon nitride may be formed on the silicon oxide. The components in the processing chamber may be aluminum or may include aluminum. Silicon nitride may not easily deposit or adhere to the aluminum surface. However, silicon nitride can provide a film that resists etching under processing conditions where certain film deposition may occur. For example, as will be further described below, tungsten and carbon films may be produced, and the tungsten-containing precursor may include a halogenated tungsten precursor. The in-situ plasma may dissociate the precursor to form a halogen effluent, which may react with unprotected aluminum. Silicon nitride may capture fluorine and may provide a better adhesion surface for tungsten and carbon films, which may reduce drop particles on the substrate. Silicon oxide may adhere better to aluminum, but may not provide sufficient adhesion for tungsten and carbon films, which may introduce additional drop particles to the substrate.

[0041] Because the first layer and the second layer provide different benefits, the thickness of the first layer of silicon oxide can be different from the thickness of the second layer of silicon nitride. For example, in some embodiments, the role of silicon oxide can be to provide complete coating across the chamber surface. Therefore, the first thickness can be limited to fully coat the chamber surface. Therefore, the first layer of oxide can be characterized by a first thickness of less than or about 50nm, and can be characterized by a first thickness of less than or about 40nm, less than or about 30nm, less than or about 20nm, less than or about 10nm, less than or about 9nm, less than or about 8nm, less than or about 7nm, less than or about 6nm, less than or about 5nm, less than or about 4nm or less. The first layer can be characterized by a thickness of greater than or about 1nm or more, which can ensure complete coverage of the internal surface. If gaps are formed in the cover layer, the silicon nitride may not adhere easily, and aluminum exposure may occur.

[0042] In some embodiments, the role of silicon nitride can be to provide a resistant coating during plasma processing. Thus, in some embodiments, the second thickness can be greater than the first thickness, which can provide improved resistance, gettering, and protection from plasma effluents. For example, the second layer of nitride can thus be characterized by a second thickness greater than or about 50 nm, and can be characterized by a thickness greater than or about 60 nm, greater than or about 70 nm, greater than or about 80 nm, greater than or about 90 nm, greater than or about 100 nm, greater than or about 120 nm, greater than or about 140 nm, greater than or about 160 nm, greater than or about 180 nm, greater than or about 200 nm, or greater.

[0043] After forming the coating or conditioning layer, the substrate may be placed in a processing region at optional operation 220. For example, a substrate support may be coated with oxides and nitrides during the method, and the substrate may be placed on a first layer and a second layer of material covering the substrate support. For example, the substrate may be located on a silicon nitride material formed above the substrate support. Exemplary substrates may include a variety of materials, including silicon, silicon germanium, and a variety of previously formed films including oxides, nitrides, or any other material that may be formed on a semiconductor substrate.

[0044] In some embodiments, the substrate may be or may include silicon, although other materials may be used. In operation 225, the surface of the substrate may be treated to facilitate initiation of subsequent deposition operations. Treatment of the substrate surface may be performed by one or more precursors, and may include, for example, a hydrogen-containing precursor, a nitrogen-containing precursor, and / or other precursors. A plasma may be formed from the precursors, which may produce hydrogen terminations on the surface of the substrate, which may facilitate incorporation of subsequent materials. The interaction of hydrogen radicals may produce dangling bonds or other ligand terminations at the surface, which may increase interaction with the precursors. In operation 230, a tungsten-containing precursor may be delivered to the processing area to contact the substrate. A tungsten-containing precursor (such as tungsten hexafluoride) may be delivered to interact with dangling bonds at the surface of the substrate. This may form a tungsten layer at the surface of the substrate, and in some embodiments, the thickness of the tungsten layer may be less than or about 100 Å.

[0045] In some embodiments, the tungsten-containing precursor may have a regulated delivery during formation. The tungsten-containing precursor may be delivered after the plasma used for treatment is terminated, and in some embodiments may be delivered as an unexcited precursor. Additionally, in some embodiments, the tungsten-containing precursor may be delivered during the treatment operation or at least partially during the treatment operation. For example, an initial flow rate of the tungsten-containing precursor may be provided during the treatment operation and may be slowly ramped up for a period of time before the plasma is extinguished. By slowly increasing the flow rate during plasma treatment, the generation of fluorine radicals may be reduced, which in some embodiments may limit the incorporation of fluorine into the starting layer.

[0046] At operation 235, subsequent processing operations may be performed on the initiation layer. The processing may include materials similar to or different from the processing performed at operation 225. For example, a hydrogen-containing precursor and / or a nitrogen-containing precursor may be delivered to the substrate processing region, and a plasma may be generated from the precursors. The plasma effluent may contact and / or bombard the tungsten-containing initiation layer. This interaction may incorporate nitrogen into the tungsten material, and may also generate nitrogen vacancies from additional bombardment. The resulting tungsten and nitrogen layer may serve as a barrier layer for subsequent deposition, and may provide nucleation sites for further deposition.

[0047] In some embodiments, the initiation layer formation may be repeated with the processing for any number of cycles. For example, the tungsten-containing precursor may be flowed again to the processing area to further build up the tungsten and nitrogen layers. Additionally, by repeating the process, fluorine and / or tungsten may be incorporated into vacancies within the structure. This may limit the subsequent diffusion of fluorine that is subsequently delivered during bulk film formation. After one or more cycles of building up the initiation layer, the method 200 may form a bulk layer of tungsten and carbon film.

[0048] At operation 240, a plasma may be formed from a tungsten-containing precursor and a hydrogen-containing precursor. The tungsten-containing precursor may be or may include tungsten hexafluoride, or any other tungsten-containing material, and the carbon-containing precursor may include a variety of carbon-containing precursors. For example, the carbon-containing precursor may be or may include any alkane, olefin, or any other carbon-containing material. The precursor may include a carbon- and hydrogen-containing precursor, which may include any amount of carbon and hydrogen bonds. In some embodiments, the carbon-containing precursor may consist of carbon-carbon and carbon-hydrogen bonds.

[0049] As previously noted, a bulk film or mask may be formed with limited introduction of hydrogen to promote grain size reduction of the film. Although the carbon-containing precursor may include hydrogen, in some embodiments, no additional source of hydrogen may be provided. For example, diatomic hydrogen may be excluded from the delivered precursor. Although an inert precursor or carrier gas may be provided with the tungsten-containing precursor and the carbon-containing precursor, in some embodiments no other chemically reactive precursor may be delivered with the precursor. By limiting the hydrogen provided in the plasma to hydrogen included in the carbon-containing precursor, the atomic ratio of hydrogen delivered to form the plasma may be lower than when hydrogen is additionally provided. For example, in an embodiment, the atomic ratio of hydrogen to tungsten in the delivered precursor may be less than or about 8:1, and may be less than or about 7:1, less than or about 6:1, less than or about 5:1, less than or about 4:1, less than or about 3:1, less than or about 2:1, or less. In one non-limiting example, the carbon-containing precursor may be propylene, and for the precursor delivered to form the plasma, the ratio of hydrogen to tungsten may be 6: 1. At operation 245, the plasma effluent may be deposited on a starting layer, such as a blanket substrate, and form a hard mask film, which may be or include a carbon-containing or tungsten-containing hard mask film.

[0050] Incorporating additional hydrogen into the delivered precursors that generate the plasma may affect the properties of the plasma. For example, hydrogen may often be the majority of the delivered precursors, which may generate a large number of hydrogen radicals within the plasma. Although the plasma may at least partially dissociate the tungsten-containing precursor, the hydrogen radicals may also increase chemical interactions with the tungsten material, such as chemically removing fluorine from the precursor. However, the amount of hydrogen may also reduce the deposition rate by blocking nucleation sites and removing deposited material.

[0051] In order to improve the reduced chemical interactions by removing hydrogen delivery, some embodiments of the present technology may increase the amount of tungsten-containing precursor delivered. For example, maintaining the tungsten delivery amount without providing hydrogen material can reduce the incorporation of tungsten into the resulting film because the reduced tungsten radicals and effluent amounts can be deposited or interacted at the substrate surface. In order to increase the amount of tungsten incorporated at the surface and maintain the tungsten percentage in the film, the tungsten flow rate can be maintained at greater than or about 100 sccm, and can be maintained at greater than or about 150 sccm, greater than or about 200 sccm, greater than or about 250 sccm, greater than or about 300 sccm or higher. In addition, in some embodiments, although the atomic flow rate of the carbon-containing precursor may be higher, in some embodiments, the tungsten-containing precursor flow rate may be maintained higher than the flow rate of the carbon-containing precursor. For example, for the exemplary precursors tungsten hexafluoride and propylene, the volume flow rate ratio of the tungsten-containing precursor to the carbon-containing precursor can be greater than or about 1:1, and can be greater than or about 1.05:1, greater than or about 1.10:1, greater than or about 1.15:1, greater than or about 1.20:1, greater than or about 1.25:1, greater than or about 1.30:1, greater than or about 1.35:1, greater than or about 1.40:1, or more.

[0052] This can maintain a tungsten percentage in the resulting film at greater than or about 10%, and can maintain a tungsten percentage in the resulting film at greater than or about 12%, greater than or about 13%, greater than or about 14%, greater than or about 15%, greater than or about 16%, greater than or about 17%, greater than or about 18%, greater than or about 19%, greater than or about 20%, greater than or about 21%, greater than or about 22%, greater than or about 23%, greater than or about 24%, greater than or about 25%, greater than or about 26%, greater than or about 27%, greater than or about 28%, greater than or about 29%, or more. In addition, by removing the transport of diatomic hydrogen, the deposition rate of the bulk film can be increased. For example, the present technology may provide deposition rates greater than or about 1.2 times faster, and may provide deposition rates greater than or about 1.4 times faster, greater than or about 1.6 times faster, greater than or about 1.8 times faster, greater than or 2.0 times faster, greater than or about 2.2 times faster, greater than or about 2.4 times faster, greater than or about 2.6 times faster, greater than or about 2.8 times faster, or more, as compared to films formed using diatomic hydrogen with deposition precursors.

[0053] Reducing the incorporation of hydrogen can provide additional nucleation sites for tungsten incorporation at the substrate. By increasing the number of nucleation sites, the general area of ​​each site can be reduced, which can reduce the area for grain growth of the film. By reducing or removing the hydrogen content in the plasma precursor, the average grain size of the formed film can be less than or about 2.5 nm, and in some embodiments can be less than or about 2.4 nm, less than or about 2.3 nm, less than or about 2.2 nm, less than or about 2.1 nm, less than or about 2.0 nm, less than or about 1.9 nm, less than or about 1.8 nm, less than or about 1.7 nm, less than or about 1.6 nm, less than or about 1.5 nm, less than or about 1.4 nm, less than or about 1.3 nm, less than or about 1.2 nm, or less. These smaller grain sizes can increase critical dimension uniformity during the formation of high aspect ratio features or features characterized by reduced critical dimensions.

[0054] After the deposition process is completed, such as by forming the bulk film to a desired thickness, the substrate may be removed from the processing area at optional operation 250. Residual carbon material or tungsten and carbon material from the process may have collected on the surface of the silicon nitride conditioning, or on exposed chamber surfaces. In other processes, alternative precursors may be provided on the surface protected by the silicon nitride. Therefore, in some embodiments, a chamber clean may be performed at optional operation 255, which may be similar or identical to the cleaning performed at operation 205 previously described. For example, performing a chamber clean at optional operation 255 may restart method 200 for another substrate in some embodiments. The chamber clean may utilize a halogen-containing precursor, which may be plasma enhanced within the processing area to facilitate the removal of residual material. In some embodiments, the cleaning process may remove some or all aspects of the residual tungsten and carbon materials, and may remove some or all of each layer of the conditioning material.

[0055] The process may then be repeated for subsequent substrates. In some embodiments, the entire method may not be repeated. For example, in some processing operations, the silicon nitride material may not be completely removed over the entire processing area, and therefore the silicon oxide material may remain intact. Therefore, in some embodiments, the method may include forming or reforming or repairing the silicon nitride film, such as by starting method 200 at some intermediate operation of the process. In some embodiments, the method may start with any of the described operations. By removing diatomic hydrogen and other hydrogen sources from the bulk deposition of the film, an improved grain structure can be provided that is superior to conventional techniques while maintaining or improving optical properties or other film properties. In order to accommodate fluorine diffusion and other aspects of the resulting film, a starting layer or barrier layer may be incorporated at the interface of the bulk film with the underlying substrate.

[0056] In the foregoing description, for the purpose of explanation, numerous details have been set forth in order to provide an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the art that certain embodiments may be practiced without some of these details or with additional details.

[0057] Several embodiments have been disclosed, and those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. In addition, in order to avoid unnecessarily obscuring the present technology, many known processes and elements are not described. Therefore, the above description should not be considered to limit the scope of the technology.

[0058] When providing a range of values, it is understood that unless the context clearly indicates otherwise, the minimum fraction of each intermediate value to the unit of the lower limit between the upper and lower limits of the range is also specifically disclosed. Any narrower range between any of the values ​​in the range or any other described or intermediate values ​​in the described range is covered. The upper and lower limits of these smaller ranges can be independently included in the range, or excluded from the range, and each range (wherein any one, none or both limits are included in the smaller range) is also covered in the technology, complying with any specifically excluded limits in the range. When the range includes one or both of the limits, then it also includes the range excluding any one or both of those included boundaries.

[0059] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a precursor" includes a plurality of such precursors and reference to "the layer" includes reference to one or more layers and equivalents of the layer known to those skilled in the art, and so forth.

[0060] Furthermore, when used in this specification and the appended claims, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”, “include(s)” and “including” are intended to specify the presence of stated features, integers, components or operations, but they do not exclude the presence or addition of one or more other features, integers, components, operations, actions or groups.

Claims

1. A semiconductor processing method, include: treating a surface of a substrate with a hydrogen-containing precursor, wherein the substrate is disposed within a processing region of a semiconductor processing chamber; contacting the substrate with a tungsten-containing precursor; forming a starting layer including tungsten on the substrate; treating the initiation layer with a hydrogen-containing precursor; forming a plasma of the tungsten-containing precursor and the carbon-containing precursor, wherein hydrogen in the plasma of the tungsten-containing precursor and the carbon-containing precursor is limited to hydrogen included in the carbon-containing precursor, and wherein an atomic ratio of hydrogen to tungsten in the tungsten-containing precursor and the carbon-containing precursor is less than 8:1; and A tungsten-containing hard mask layer is formed on the initiation layer.

2. The semiconductor processing method according to claim 1, wherein the step of processing the surface of the substrate include: forming a plasma of the hydrogen-containing precursor, and The surface of the substrate is contacted with effluent from the plasma to produce hydrogen terminations.

3. The semiconductor processing method of claim 1, wherein the tungsten-containing precursor is delivered to perform the contacting while processing the surface of the substrate is performed. 4 . The semiconductor processing method of claim 3 , wherein a flow rate of the tungsten-containing precursor is increased while delivering the tungsten-containing precursor.

5. The semiconductor processing method according to claim 1, wherein the processing of the starting layer include: forming a plasma of the hydrogen-containing precursor, and The initiation layer is contacted with effluent from the plasma.

6. The semiconductor processing method of claim 5, wherein the plasma further comprises a nitrogen-containing precursor.

7. The semiconductor processing method of claim 6 wherein the hydrogen-containing precursor comprises diatomic hydrogen, and wherein the nitrogen-containing precursor comprises diatomic nitrogen.

8. The semiconductor processing method of claim 1, wherein the tungsten-containing precursor comprises tungsten hexafluoride, and wherein the carbon-containing precursor comprises propylene.

9. The semiconductor processing method of claim 8, wherein diatomic hydrogen is purged from the semiconductor processing chamber while forming the plasma of the tungsten-containing precursor and the carbon-containing precursor.

10. The semiconductor processing method according to claim 1, further comprising: include: A conditioning layer including a silicon-containing material is formed on exposed surfaces of the processing region of the semiconductor processing chamber.

11. A semiconductor processing method, include: forming an adjustment layer on an exposed surface of a processing region of a semiconductor processing chamber; forming an initial layer including tungsten on a substrate, wherein the substrate is disposed within the processing region of the semiconductor processing chamber; forming a plasma containing a tungsten precursor and a carbon-containing precursor, wherein the atomic ratio of hydrogen to tungsten in the tungsten-containing precursor and the carbon-containing precursor is less than 8:1; and A tungsten-containing hard mask layer is formed on the initiation layer.

12. The semiconductor processing method of claim 11, wherein the adjustment layer comprises silicon oxide and silicon nitride.

13. The semiconductor processing method according to claim 11, wherein the starting layer is formed include: forming a plasma containing a hydrogen precursor, contacting a surface of the substrate with effluent from the plasma to produce hydrogen terminations, and A tungsten-containing precursor is flowed into the processing region to contact the surface of the substrate.

14. The semiconductor processing method of claim 13 wherein said tungsten-containing precursor is not excited when flowing to contact said surface of said substrate.

15. The semiconductor processing method according to claim 11, further comprising: include: forming a plasma containing a hydrogen precursor, The initiation layer is contacted with effluent from the plasma.

16. The semiconductor processing method of claim 11 wherein the tungsten-containing precursor comprises tungsten hexafluoride, and wherein the carbon-containing precursor comprises propylene.

17. The semiconductor processing method of claim 16, wherein diatomic hydrogen is purged from the semiconductor processing chamber while forming the plasma of the tungsten-containing precursor and the carbon-containing precursor.

18. A semiconductor processing method, include: forming an adjustment layer on an exposed surface of a processing region of a semiconductor processing chamber; treating a surface of a substrate with a hydrogen-containing precursor, wherein the substrate is disposed within the processing region of the semiconductor processing chamber; contacting the substrate with a tungsten-containing precursor; forming a starting layer including tungsten on the substrate; treating the initiation layer with a hydrogen-containing precursor; forming a plasma of the tungsten-containing precursor and the carbon-containing precursor, wherein hydrogen in the plasma of the tungsten-containing precursor and the carbon-containing precursor is limited to hydrogen included in the carbon-containing precursor, and wherein an atomic ratio of hydrogen to tungsten in the tungsten-containing precursor and the carbon-containing precursor is less than 8:1; and A tungsten-containing hard mask layer is formed on the initiation layer.

19. The semiconductor processing method according to claim 18, further comprising: include: removing the substrate from the semiconductor processing chamber; as well as A chamber cleaning process is performed in the processing region of the semiconductor processing chamber.

20. The semiconductor processing method according to claim 19, further comprising: include: A plasma containing an oxygen precursor is formed within the processing region of the semiconductor processing chamber.

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