Catalytic formation of boron and carbon films

Abstract

An exemplary method for semiconductor processing can include providing a boron-containing precursor to a processing region of a semiconductor processing chamber. A substrate can be disposed within the processing region of the semiconductor processing chamber. The method can include providing a carbon-containing precursor to the processing region of the semiconductor processing chamber. The carbon-containing precursor can be characterized by a carbon-carbon double bond or a carbon-carbon triple bond. The method can include thermally reacting the boron-containing precursor and the carbon-containing precursor at a temperature less than about 650° C. The method can include forming a boron-carbon-containing layer on the substrate.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 994,949, filed March 26, 2020, the contents of which are incorporated by reference in their entirety into this specification for all purposes.

[0002]

[0002] The present technology relates to semiconductor processing methods and components. More particularly, the present technology relates to systems and methods for fabricating masks or patterned films for semiconductor structures. [Background technology]

[0003]

[0003] Integrated circuits are made possible by methods for fabricating intricately patterned layers of material on a substrate surface. Fabricating patterned materials on a substrate requires controlled methods for forming and removing materials. As device sizes continue to shrink, the aspect ratios of features can become large, and maintaining the dimensions of these features during removal operations can be difficult. To facilitate the patterning of materials on a substrate, mask materials can be used. As the number of material layers being patterned increases, mask selectivity to multiple materials, along with maintaining the properties of the mask material, is becoming a greater challenge.

[0004]

[0004] Therefore, there is a need for improved systems and methods that can be used to manufacture high quality devices and structures. These and other needs are addressed by the present technology. Summary of the Invention

[0005] An exemplary method for semiconductor processing can include providing a boron-containing precursor to a processing region of a semiconductor processing chamber. A substrate can be disposed within the processing region of the semiconductor processing chamber. The method can include providing a carbon-containing precursor to the processing region of the semiconductor processing chamber. The carbon-containing precursor can be characterized by a carbon-carbon double bond or a carbon-carbon triple bond. The method can include thermally reacting the boron-containing precursor and the carbon-containing precursor at a temperature less than about 650° C. The method can include forming a boron-carbon-containing layer on the substrate.

[0006] In some embodiments, a processing region of a semiconductor processing chamber can be maintained plasma-free while forming a boron-carbon-containing layer on a substrate. The boron-carbon-containing layer can include or consist essentially of boron, carbon, and hydrogen. The substrate can be characterized by one or more features, and the boron-carbon-containing layer can be formed around the one or more features with a conformality of about 95% or greater. Thermally reacting the boron-containing precursor and the carbon-containing precursor can be performed at a temperature of about 500°C or less. The boron-carbon-containing layer can be characterized by a boron concentration of about 40% or greater, and the boron-carbon-containing layer can be characterized by a root-mean-square roughness of about 1.8 nm or less. The boron-carbon-containing layer can be characterized by a Young's modulus of about 80 GPa or greater. The method can include forming a plasma of a hydrogen-containing or oxygen-containing precursor in the processing region of the semiconductor processing chamber. The method can also include removing the boron-carbon-containing layer from the substrate. The plasma can be maintained halogen-free while removing the boron-carbon-containing layer from the substrate. The carbon-containing precursor can be characterized by a carbon to hydrogen ratio of about 1:3 or greater.

[0007] Some embodiments of the present technology may include a semiconductor processing method. The method may include providing a boron-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be disposed within the processing region of the semiconductor processing chamber. The method may include providing a hydrocarbon to the processing region of the semiconductor processing chamber. The hydrocarbon may be characterized by a carbon-carbon double bond or a carbon-carbon triple bond. The method may include thermally reacting the boron-containing precursor and the hydrocarbon at a temperature between about 75° C. and about 500° C. The method may include forming a boron-carbon-containing layer on the substrate.

[0008] In some embodiments, a processing region of a semiconductor processing chamber can be maintained plasma-free during a semiconductor processing method. The boron-carbon-containing layer can be characterized by a carbon concentration of about 40% or greater. The method can include exposing the boron-carbon-containing layer to a wet etchant comprising a hydroxide. The method can include removing the boron-carbon-containing layer from the substrate. The boron-carbon-containing layer can be characterized by an extinction coefficient at 633 nm of about 0.01 or greater. The boron-carbon-containing layer can be characterized by hydrogen incorporation of about 50% or less. The substrate can be characterized by one or more features, and the boron-carbon-containing layer can be formed around the one or more features with conformality of about 95% or greater.

[0009] Some embodiments of the present technology may include a semiconductor processing method. The method may include providing a boron-hydrogen-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be disposed within the processing region of the semiconductor processing chamber. The method may include providing a carbon-containing precursor to the processing region of the semiconductor processing chamber. The carbon-containing precursor may be characterized by a carbon-carbon double bond or a carbon-carbon triple bond. The method may include thermally reacting the boron-hydrogen-containing precursor and the carbon-containing precursor at a temperature less than about 600° C. The method may include forming a boron-carbon-containing layer on the substrate. The boron-carbon-containing layer may comprise or consist essentially of boron, carbon, and hydrogen.

[0010] In some embodiments, a processing region of a semiconductor processing chamber can be maintained plasma-free during formation of a boron-carbon containing layer on a substrate, the boron-carbon containing layer being characterized by a conformal thickness of about 95% or greater.

[0011] Such a technique may offer many advantages over conventional systems and techniques. For example, embodiments of the present technique can produce conformal materials that can be applied to numerous substrate features. Furthermore, the present technique can produce boron and carbon films with highly tunable film properties. These and other embodiments, along with many of their advantages and features, are described in more detail in conjunction with the following description and accompanying figures.

[0012] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remaining portions of the specification and drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 shows a schematic cross-sectional view of an exemplary plasma system in accordance with some embodiments of the present technique. [Figure 2]

[0014] 1 illustrates operations in a semiconductor processing method according to some embodiments of the present technique. [Figure 3]

[0015] 1 illustrates an exemplary liner manufactured in accordance with some embodiments of the present technique. [Figure 4A-4B]

[0016] 4A and 4B show exemplary spacer structures fabricated in accordance with some embodiments of the present technique. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0017] Some of the figures are included as schematic diagrams. It is understood that these figures are for illustrative purposes and should not be considered to be to scale unless specifically stated to be so. Furthermore, as schematic diagrams, the figures are provided to aid in understanding and may not include all aspects or information compared to realistic representations and may include exaggerated material for illustrative purposes.

[0015]

[0018] In the accompanying figures, similar components or features may have the same reference label. Furthermore, various components of the same type may be distinguished by tracing the reference numbers with a letter that distinguishes between the similar components. When only a first reference number is used herein, the description is applicable to any one of the similar components having the same first reference number, regardless of the letter.

[0016]

[0019] Hard masks, liner, and spacer films are utilized in many processing operations, including forming patterns through multiple layers of various materials. Increasing the etch selectivity of these materials relative to structural materials allows for tighter control of critical dimensions, especially as feature sizes continue to shrink. Carbon films are often used as hard masks, but the selectivity of these films is becoming more challenging for more complex memory and logic structures, which may have multiple different films on a substrate and may require patterning into high-aspect-ratio features. Therefore, newer films may incorporate metallic and non-metallic materials within the film to enhance etch selectivity. As a non-limiting example of a non-metallic material, boron can be incorporated into carbon films to enhance selectivity relative to many oxide and nitride materials. However, increased boron incorporation within the film can present a number of problems.

[0017]

[0020] Additional precursors used in addition to the carbon precursor for film formation can include boron and other non-metallic or metal-containing materials. The precursors can be mixed in the processing region and deposited using a plasma-enhanced chemical vapor deposition process. During plasma deposition, the material may be deposited in a blanket formation and may not provide conformal coverage. Therefore, even if a smooth layer is produced, it may be difficult to accommodate the substrate's features, resulting in pinch-off and other common problems that limit the film's effectiveness as a protective layer. Thermal deposition of carbon films is more difficult because many hydrocarbons may require very high thermal decomposition temperatures. Conventional techniques can overcome this problem by incorporating additional precursors, such as halogen-containing precursors, to lower the decomposition temperature of the carbon precursor to perform a thermal-based process. However, this can reduce the film's adhesion and cause undercutting upon subsequent removal, potentially leading to film delamination and device failure, as well as altering other material properties of the formed film.

[0018]

[0021] The present technique overcomes these problems by performing thermal-based boron and carbon deposition, which does not require the use of additional halogen gases during the deposition process. By performing a catalytic reaction between specific carbon-containing precursors and boron precursors, the present technique can enable lower temperature chemical vapor deposition to be performed, which can provide conformal or non-conformal growth on any number of semiconductor structures. The process performed allows for improved tailoring of the films produced, resulting in films characterized by a variety of material properties for various applications.

[0019]

[0022] While the remainder of the disclosure will routinely identify a particular deposition process utilizing the disclosed technology and describe one type of semiconductor processing chamber, it will be readily understood that the described method can be performed with any number of semiconductor processing chambers. Accordingly, the present technology should not be considered limited for use with only these particular deposition processes or chambers. Before describing methods for producing boron and carbon films, this disclosure will describe one possible chamber that can be used to perform methods according to embodiments of the present technology.

[0020]

[0023] FIG. 1 illustrates a cross-sectional view of an exemplary processing chamber 100 in accordance with some embodiments of the present technique. The diagram may provide an overview of a system that may incorporate one or more aspects of the present technique and / or be specifically configured to perform one or more operations in accordance with embodiments of the present technique. Additional details of the chamber 100 or the methods implemented therein may be further described below. While the chamber 100 may be utilized to form a film layer in accordance with some embodiments of the present technique, it should be understood that the methods may similarly be performed in any chamber in which film formation may occur. The processing chamber 100 may include a chamber body 102, a substrate support 104 disposed within the chamber body 102, and a lid assembly 106 coupled to the chamber body 102 and enclosing the substrate support 104 within a processing region 120. A substrate 103 may be provided in the processing region 120 through an opening 126, which may be sealed in a conventional manner for processing using a slit valve or door. The substrate 103 may be seated on a surface 105 of the substrate support during processing. The substrate support 104 can be rotatable along an axis 147, as indicated by arrow 145, where the shaft 144 of the substrate support 104 can be positioned. Alternatively, the substrate support 104 can be raised and rotated as needed during the deposition process.

[0021]

[0024] A plasma profile modulator 111 may be positioned within the processing chamber 100 to control plasma distribution across a substrate 103 disposed on a substrate support 104. The plasma profile modulator 111 may include a first electrode 108, which may be positioned 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, such as a ring electrode. The first electrode 108 may be a continuous loop around the circumference of the processing chamber 100 surrounding the processing region 120, or may be discontinuous at selected locations as needed. 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.

[0022]

[0025] One or more isolators 110 a, 110 b, which may be a dielectric material such as a ceramic or a metal oxide, e.g., aluminum oxide and / or aluminum nitride, may contact the first electrode 108 and electrically and thermally isolate the first electrode 108 from the gas distributor 112 and the chamber body 102. The gas distributor 112 may define an aperture 118 for distributing process precursors to the processing region 120. The gas distributor 112 may be coupled to a first 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 capable of being coupled to a processing chamber. In some embodiments, the first power source 142 may be an RF power source.

[0023]

[0026] The gas distributor 112 can be a conductive gas distributor or a non-conductive gas distributor. The gas distributor 112 can also be formed from conductive and non-conductive components. For example, the body of the gas distributor 112 can be conductive, while the faceplate of the gas distributor 112 can be non-conductive. The gas distributor 112 can be powered, for example, by a first power source 142 as shown in FIG. 1, or the gas distributor 112 can be coupled to ground in some embodiments.

[0024]

[0027] The first electrode 108 can be coupled to a first conditioning circuit 128 that can control the ground path of the processing chamber 100. The first conditioning circuit 128 can include a first electronic sensor 130 and a first electronic controller 134. The first electronic controller 134 can be or include a variable capacitor or other circuit element. The first conditioning circuit 128 can be or include one or more inductors 132. The first conditioning circuit 128 can be any circuit that allows for a variable or controllable impedance under plasma conditions present in the processing region 120 during processing. In some illustrated embodiments, the first conditioning circuit 128 can include a first circuit leg and a second circuit leg coupled in parallel between ground and the first electronic sensor 130. The first circuit leg can include a first inductor 132A. The second circuit leg can include a second inductor 132B coupled in series with the first electronic controller 134. A second inductor 132B can be disposed between the first electronic controller 134 and a node connecting both the first and second circuit legs to the first electronic sensor 130. The first electronic sensor 130 can be a voltage or current sensor and can be coupled to the first electronic controller 134, which can allow for some degree of closed-loop control of the plasma conditions in the processing region 120.

[0025]

[0028] The second electrode 122 can be coupled to the substrate support 104. The second electrode 122 can be embedded within the substrate support 104 or coupled to a surface of the substrate support 104. The second electrode 122 can be a plate, a perforated plate, a mesh, a wire screen, or any other distributed arrangement of conductive elements. The second electrode 122 can be a conditioning electrode and can be coupled to a second conditioning circuit 136 by a conduit 146, such as a cable having a selected resistance, e.g., 50 ohms, disposed on a shaft 144 of the substrate support 104. The second conditioning circuit 136 can include a second electronic sensor 138 and a second electronic controller 140, which can be a second variable capacitor. The second electronic sensor 138 can be a voltage or current sensor and can be coupled to the second electronic controller 140 to further control the plasma conditions in the processing region 120.

[0026]

[0029] A third electrode 124, which may be a bias electrode and / or an electrostatic chucking electrode, may be coupled to the substrate support 104. The third electrode may be coupled to a second power source 150 through a filter 148, which may be an impedance matching circuit. The second power source 150 may be DC power, pulsed DC power, RF bias power, a pulsed RF source, or bias power, or a combination of these or other power sources. In some embodiments, the second power source 150 may be RF bias power. The substrate support 104 may also include one or more heating elements configured to heat the substrate to a processing temperature between about 25° C. and about 800° C. or higher.

[0027]

[0030] The lid assembly 106 and substrate support 104 of FIG. 1 can be used with any processing chamber for plasma or thermal processing. During operation, the processing chamber 100 can provide real-time control of plasma conditions within the processing region 120. A substrate 103 can be placed on the substrate support 104, and process gases can flow through the lid assembly 106 using the inlet 114 according to any desired flow plan. The gases can exit the processing chamber 100 through the outlet 152. Power can be coupled with the gas distributor 112 to establish a plasma within the processing region 120. In some embodiments, the substrate can be subjected to an electrical bias using a third electrode 124.

[0028]

[0031] Upon energizing the plasma in the processing region 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. Electronic controllers 134, 140 may then be used to adjust the flow characteristics of the ground paths represented by the two adjustment circuits 128 and 136. Set points may be provided to the first adjustment circuit 128 and the second adjustment circuit 136 to provide independent control of the deposition rate and center-to-edge plasma density uniformity. In embodiments in which both electronic controllers may be variable capacitors, electronic sensors may adjust the variable capacitors to maximize the deposition rate and independently minimize thickness non-uniformity.

[0029]

[0032] Each of the conditioning circuits 128, 136 can have a variable impedance that can be adjusted using the respective electronic controllers 134, 140. If 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 can be selected to provide a range of impedances. This range can depend on the frequency and voltage characteristics of the plasma, and the capacitance range of each variable capacitor can be minimized. Thus, when the capacitance of the first electronic controller 134 is minimum or maximum, the impedance of the first conditioning circuit 128 can be high, resulting in a plasma shape with minimal aerial or lateral reach on the substrate support. When the capacitance of the first electronic controller 134 approaches a value that minimizes the impedance of the first conditioning circuit 128, the aerial reach of the plasma is maximized, 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 walls and the air coverage of the substrate support may decrease. The second electronic controller 140 may have a similar effect, increasing and decreasing the air coverage of the plasma above the substrate support as the capacitance of the second electronic controller 140 may be changed.

[0030]

[0033] Electronic sensors 130, 138 can be used to regulate the respective circuits 128, 136 in a closed loop. Depending on the sensor type used, a current or voltage setpoint can be attached to each sensor, which may include control software that determines adjustments to the respective electronic controllers 134, 140 to minimize deviations from the setpoint. As a result, the plasma shape can be selected and dynamically controlled during processing. While the preceding discussion is based on the electronic controllers 134, 140 being variable capacitors, it should be understood that any electronic component with adjustable characteristics can be used to provide adjustable impedance to the regulation circuits 128 and 136.

[0031]

[0034] As mentioned above, while a plasma processing chamber can be used for one or more aspects of film processing, some embodiments may not utilize a plasma-enhanced process for forming the boron and carbon films, which may limit the conformality of the films produced. In some embodiments, the present technique can form films without at least plasma generation. FIG. 2 illustrates exemplary operations in a processing method 200 in accordance with some embodiments of the present technique. The method may be performed in various processing chambers, including the processing chamber 100 described above, as well as any other chamber, including non-plasma chambers, in which operations may be performed. Method 200 may include several optional operations that may or may not be specifically associated with some embodiments of the method in accordance with the present technique. For example, many of the operations are described to provide a broader range of structure formation, but are not critical to the technique or may be performed by alternative methodologies, as will be readily understood. Method 200 may include a processing method that may include several operations for developing boron-carbon-containing films that may include a tunable ratio of boron and carbon within the film. As further described below, varying the ratio of boron to carbon can result in numerous properties that facilitate device processing of many structures.

[0032]

[0035] In operation 205, the method may include providing a boron-containing precursor to a processing region of a semiconductor processing chamber in which a substrate may be housed. In operation 210, which may occur simultaneously with operation 205, or before or after operation 205, a carbon-containing precursor may be provided to the processing region of the semiconductor processing chamber. In operation 215, the boron-containing precursor and the carbon-containing precursor may be thermally reacted in the processing region of the semiconductor processing chamber, and in operation 220, a boron-carbon-containing layer may be formed on the substrate. In some embodiments, the semiconductor processing chamber, pedestal, or substrate for carrying out the reaction can be maintained at a temperature of 650° C. or less, and in some embodiments, can be maintained at a temperature of about 600° C. or less, about 550° C. or less, about 500° C. or less, about 475° C. or less, about 450° C. or less, about 425° C. or less, about 400° C. or less, about 375° C. or less, about 350° C. or less, about 325° C. or less, about 300° C. or less, about 275° C. or less, about 250° C. or less, about 225° C. or less, about 200° C. or less, about 175° C. or less, about 150° C. or less, about 125° C., about 100° C. or less, about 75° C. or less, or less.

[0033]

[0036] As previously mentioned, some or all of the formation operations can be performed while the substrate processing region is maintained plasma-free. By performing thermal chemical vapor deposition, more conformal materials can be formed. Many hydrocarbon precursors are characterized by high thermal decomposition temperatures, which pose problems for the thermal deposition of carbon-containing materials. The present technology can provide deposition operations performed at lower temperatures by utilizing precursors that promote catalytic reactions between boron and carbon precursors. While any number of boron-containing and carbon-containing precursors can be used, in some embodiments, precursors can be selected to promote catalytic reactions. For example, in some embodiments, the boron-containing precursor can include or consist of boron and hydrogen and be represented by the formula B x H ywhere x and y are any numbers. Exemplary boron-containing precursors may include borane, diborane, tetraborane, pentaborane, hexaborane, decaborane, or any other boron-containing precursor.

[0034]

[0037] The carbon-containing precursor can be or include any number of carbon-containing precursors. For example, the carbon-containing precursor can be or include any hydrocarbon, or any material containing or consisting of carbon and hydrogen. In some embodiments, to facilitate the catalytic reaction between the carbon precursor and the boron precursor, the carbon-containing precursor can be characterized by one or more carbon-carbon double bonds and / or one or more carbon-carbon triple bonds. Thus, in some embodiments, the carbon-containing precursor can be or include an alkene or alkyne, or any other carbon-containing material. While the precursor can include a carbon-hydrogen-containing precursor that can contain any amount of carbon and hydrogen bonds, along with any other elemental bonds, in some embodiments, the carbon-containing precursor can be composed of carbon-carbon and carbon-hydrogen bonds.

[0035]

[0038] Many factors can affect the concentration of carbon and boron in the film. For example, in some embodiments, the film produced may be limited to or consist essentially of boron, carbon, and hydrogen, along with any traces that may, for example, be contaminants. In some embodiments, the boron concentration may be about 50% or greater, about 55% or greater, about 60% or greater, about 65% or greater, about 70% or greater, about 75% or greater, about 80% or greater, about 85% or greater, about 90% or greater, about 95% or greater, about 97% or greater, or about 99% or greater, and the film may be essentially a boron film. Similarly, the carbon concentration may be about 5% or greater, about 10% or greater, about 15% or greater, about 20% or greater, about 25% or greater, about 30% or greater, about 35% or greater, about 40% or greater, about 45% or greater, about 50% or greater, about 55% or greater, about 60% or greater, about 65% or greater, about 70% or greater, about 75% or greater, or greater. The present technology can adjust the boron and / or carbon concentration based on the flow rate; for example, the flow rate can be adjusted to a ratio of boron precursor to carbon precursor of about 0.002:1 up to about 60:1.

[0036]

[0039] In some embodiments, the carbon flow rate can result in a carbon concentration up to a threshold, such as less than 50%. However, the present technique can further increase the carbon concentration in the produced film by utilizing precursors characterized by higher carbon concentrations. As previously described, the process can include a hydroboration reaction between the precursors. If the carbon-containing precursor contains additional carbon atoms, the produced film may have an even greater carbon concentration. For example, some carbon-containing precursors may contain one or more benzene or other carbon-containing moieties on the precursor. In some embodiments, catalytic reactions may not occur on the ring structure, which may allow additional carbon from the benzene to be incorporated into the formed film. This can result in higher carbon concentrations compared to conventional techniques.

[0037]

[0040] As previously mentioned, hydrogen incorporation into a film can affect one or more material properties as well as the quality of the film produced. While the carbon-containing precursor and / or the boron-containing precursor may contain hydrogen, in some embodiments, no additional hydrogen source may be provided. While an inert precursor or carrier gas may be provided with the boron-containing precursor and the carbon-containing precursor, in some embodiments, no other chemically reactive precursor may be provided with the precursor. By limiting the provided hydrogen to that contained in the carbon-containing precursor and the boron-containing precursor, the atomic ratio of hydrogen in the film produced may be lower than if hydrogen gas were also provided.

[0038]

[0041] For example, the atomic ratio of hydrogen to boron in the provided precursor may be about 20:1 or less in embodiments, and may be about 18:1 or less, about 15:1 or less, about 14:1 or less, about 13:1 or less, about 12:1 or less, about 12:1 or less, about 11:1 or less, about 10:1 or less, about 9:1 or less, about 8:1 or less, about 7:1 or less, about 6:1 or less, about 5:1 or less, about 4:1 or less, about 3:1 or less, or less. Similarly, carbon-containing precursors may be characterized by a carbon-to-hydrogen ratio of about 1:3 or greater, and may be characterized by a carbon-to-hydrogen ratio of about 1:2 or greater, about 1:1 or greater, about 2:1 or greater, about 3:1 or greater, or greater. This can produce films characterized by hydrogen concentrations of about 50% or less, and can produce films characterized by hydrogen incorporation of about 45% or less, about 40% or less, about 35% or less, about 30% or less, about 25% or less, about 20% or less, about 15% or less, about 15% or less, about 10% or less, about 5% or less, or less. Increasing hydrogen incorporation can increase the extinction coefficient of the produced film, such as providing an extinction coefficient at 633 nm of about 0.010 or greater, and can provide an extinction coefficient of about 0.012 or greater, about 0.014 or greater, about 0.016 or greater, about 0.018 or greater, about 0.020 or greater, about 0.025 or greater, about 0.05 or greater, about 0.10 or greater, or greater. Therefore, reducing hydrogen incorporation within the produced film can improve subsequent lithography or processing operations.

[0039]

[0042] This limiting of hydrogen uptake can improve many properties of the film, which can improve the film for use in various applications. Films produced by this technique can be characterized by many material properties that can be affected by the concentration of boron and / or carbon in the film. For example, adjusting processing conditions can further affect the film produced.

[0040]

[0043] The boron-carbon containing material formed is characterized by a Young's modulus of about 50 GPa or greater, and may be characterized by a modulus of about 80 GPa or greater, about 90 GPa or greater, about 100 GPa or greater, about 110 GPa or greater, about 120 GPa or greater, about 130 GPa or greater, about 140 GPa or greater, about 150 GPa or greater, or greater. The modulus may increase as the boron concentration in the film increases. The roughness of the film may also be affected by the boron concentration in the film, with increasing boron concentration increasing the roughness. Roughness may be affected by the thickness of the film produced, and in some embodiments, roughness characteristics may be for any film thickness, including deposition thicknesses of about 1,000 nm or less, and may be characteristic of films deposited to thicknesses of 500 nm or less, about 250 nm or less, about 100 nm or less, about 50 nm or less, about 10 nm or less, about 5 nm or less, or less. For example, the root mean square roughness of the deposited film can be about 3.0 nm or less, about 2.5 nm or less, about 2.0 nm or less, about 1.9 nm or less, about 1.8 nm or less, about 1.7 nm or less, about 1.6 nm or less, about 1.5 nm or less, about 1.4 nm or less, about 1.3 nm or less, about 1.2 nm or less, about 1.1 nm or less, about 1.0 nm or less, about 0.5 nm or less, about 0.1 nm or less, about 0.05 nm or less, about 0.01 nm or less, or less.

[0041]

[0044] While both modulus and roughness may increase with increasing boron concentration, in some embodiments, deposition temperature may improve both modulus and roughness, increasing modulus and decreasing roughness. For example, if the deposition temperature is increased to about 450°C or above, about 480°C or above, the roughness of the film may be lower than the roughness of a corresponding film deposited at 400°C or below. Thus, in some embodiments, depending on the desired film properties, deposition can be performed at a temperature between about 450°C and about 500°C. As one non-limiting example, when deposited within this range, deposition of a film characterized by 80% boron incorporation can yield a film characterized by a modulus of about 150 GPa or above, while maintaining roughness at about 1.5 nm or below.

[0042]

[0045] The boron-carbon materials produced by this technique can be used in many structures, such as masks, liners, or spacers, and can be removed after subsequent processing is performed. Based on the composition of the material being produced, in some embodiments, the film can be removed without the need for a halogen-containing plasma, which can affect etch selectivity relative to the underlying material, and in some embodiments, plasma removal may not be necessary at all. For example, in some embodiments, after formation of the boron-carbon material and subsequent material processing, the boron-carbon material may be removed in optional operation 225. In some embodiments, an in-situ plasma can be formed from a hydrogen-containing or oxygen-containing precursor in the processing region of the chamber, such as utilizing oxygen, water, or any other oxygen-containing material, which can provide ashing of the boron-carbon material while preserving or substantially preserving the underlying material. Additionally, in some embodiments, wet etching can be performed. For example, in some embodiments, an oxidizing material can be applied to the boron-carbon material, which can remove the material. If the carbon incorporation exceeds a threshold value, such as about 30% or more, about 35% or more, about 40% or more, a hydroxide solution, such as mixed with an acid such as sulfuric acid, can be applied to the substrate, which can remove the boron-carbon material.

[0043]

[0046] As previously described, in some embodiments, thermal-based material formation can provide a more conformal film, which can function as a liner, spacer, hard mask, or other material used during semiconductor processing. Figure 3 illustrates an exemplary liner fabricated in accordance with some embodiments of the present technology. The boron-carbon film according to the present technology can be used in many applications. In one non-limiting application of 3D NAND structures, a boron-carbon film can be used to protect a stack structure 300 to reduce or limit critical dimension blowout during stack etching. For example, a substrate 305 can form a stack 310, which can be or include alternating oxide and spacer material layers. During memory hole formation, multiple high-aspect ratio holes can be etched through the structure. In some embodiments of the present technology, after a partial stack etch is performed, a boron-carbon film 315 can be applied over the structure as shown. It should be understood that these examples are not intended to be limiting, as the present technology can be utilized in any number of processing operations, which may include cutting word lines, forming memory contacts, or other etching processes. The film can be formed based on the above-mentioned method.

[0044] The aspect ratio of the feature, or the ratio of the feature's depth to the feature's width or diameter formed during etching, can be about 10:1 or greater, and can be about 15:1 or greater, about 20:1 or greater, about 25:1 or greater, about 30:1 or greater, about 35:1 or greater, about 40:1 or greater, about 45:1 or greater, about 50:1 or greater, or even greater. The plasma-deposited layer may not be able to access deeper within the trench, and pinch-off may occur at the top of the feature. However, boron-carbon films produced by the techniques of the present invention can be characterized by complete coverage of the entire structure, as shown. For example, the thickness of the film along the sidewall near the top of the structure is substantially the same as the thickness of the film along the sidewall near the bottom of the structure, and the film produced is substantially conformal. Thus, in some embodiments, the deposited film can be characterized by the conformality or similarity of the thickness formed between any two regions along the sidewall of the feature, or along at least about 90% of the formed film. In some embodiments, conformality may be about 93% or greater, about 95% or greater, about 96% or greater, about 97% or greater, about 98% or greater, about 99% or greater, or higher. While this technique can provide a highly conformal film, the process can be tailored to produce less conformal coverage. For example, some embodiments can include forming a first amount of coverage along some exposed surfaces while limiting coverage on other surfaces. As a non-limiting example, the process can provide coverage along the sidewalls of a trench or feature while limiting or reducing coverage along the bottom or surface near the bottom of the trench or feature. Thus, the present technique can provide non-conformal coverage in some embodiments.

[0045]

[0048] 4A-4B illustrate an exemplary spacer structure 400 fabricated utilizing a boron-carbon film in accordance with some embodiments of the present technique. For example, as shown in FIG. 4A, during a pattern transfer operation to reduce the linewidth of a layer 410 overlying a substrate 405, mandrels 415 can be formed and a boron-carbon material 420 can be deposited thereon. The boron-carbon material can be formed according to the methods described above. Forming a conformal film, which can be characterized by any of the conformal percentages described above, can provide more accurate pattern transfer. While FIG. 4B illustrates a relatively thin layer, it should be understood that the features can be characterized by any thickness capable of producing any of the aspect ratios described above. If the remaining line structures are characterized by a limited thickness, such as about 20 nm or less, about 15 nm or less, or less, the hardness of the material can affect the verticality of the fabricated features.

[0046]

[0049] For example, conventional films, which can be characterized by reduced modulus or hardness, can bend, tilt, and even collapse as their length increases. By utilizing films according to embodiments of the present technology, improved hardness can be achieved while limiting film roughness, which can affect pattern transfer. While some plasma-enhanced depositions can provide materials characterized by increased hardness due to ion bombardment, the deposition process may not provide conformality, preventing the use of materials where pitchwalking or incomplete transfer may occur. By utilizing boron-carbon materials according to embodiments of the present technology, conformal films can be produced without plasma formation, and the produced films can also be characterized by improved material properties.

[0047]

[0050] In the foregoing description, for purposes of explanation, numerous details are 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 particular embodiments may be practiced without some of these details, or with additional details.

[0048]

[0051] While several embodiments have been disclosed, 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. Moreover, in order to avoid unnecessarily obscuring the technology of the present invention, many well-known processes and elements have not been described. Therefore, the above description should not be construed as limiting the scope of the technology.

[0049]

[0052] Where a range of values ​​is presented, unless the context clearly dictates otherwise, it is understood that each intervening value between the upper and lower limits of that range is also specifically disclosed, to the smallest unit of the unit of the lower limit. Any narrower range between any stated or unstated intervening value in a stated range, and any other stated or intervening value in that stated range, is also encompassed. The upper and lower limits of these smaller ranges may be individually included or excluded in the range, and each range in which either, neither, or both limits are included in the narrower range is also encompassed within the technology, subject to the specifically excluded limit in the stated range. When a stated range includes one or both of the limits, ranges excluding either or both of the included limits are also included.

[0050]

[0053] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "a precursor" includes a reference to a plurality of such precursors, a reference to "a layer" includes a reference to one or more layers and equivalents thereof known to those skilled in the art, and so forth.

[0051]

[0054] Additionally, the terms "comprise(s)", "comprising", "contain(s)", "containing", "include(s)", and "including", when used in this specification and claims, are intended to specify the presence of stated features, integers, components, or steps, but do not exclude the presence or addition of one or more other features, integers, components, steps, operations, or groups.

Claims

1. providing a boron-containing precursor to a processing region of a semiconductor processing chamber, wherein a substrate is disposed within the processing region of the semiconductor processing chamber; providing the boron-containing precursor to the processing region of the semiconductor processing chamber; providing a carbon-containing precursor characterized by a carbon-carbon double bond or a carbon-carbon triple bond to the processing region of the semiconductor processing chamber; thermally reacting the boron-containing precursor and the carbon-containing precursor at a temperature less than about 650°C; forming a boron-carbon containing layer on the substrate; Including, The semiconductor processing method, wherein the boron-carbon containing layer is characterized by an extinction coefficient at 633 nm of about 0.01 or greater.

2. 10. The semiconductor processing method of claim 1, wherein the processing region of the semiconductor processing chamber is maintained plasma-free during formation of the boron-carbon containing layer on the substrate.

3. 2. The semiconductor processing method of claim 1, wherein said boron-carbon containing layer consists essentially of boron, carbon, and hydrogen.

4. 10. The semiconductor processing method of claim 1, wherein the substrate is characterized by one or more features, and the boron-carbon containing layer is formed around the one or more features with a conformality of about 95% or greater.

5. 10. The semiconductor processing method of claim 1, wherein thermally reacting the boron-containing precursor and the carbon-containing precursor is carried out at a temperature of about 500[deg.] C. or less.

6. 10. The semiconductor processing method of claim 1, wherein the boron-carbon containing layer is characterized by a boron concentration of about 40% or greater, and wherein the boron-carbon containing layer is characterized by a root mean square roughness of about 1.8 nm or less.

7. 7. The semiconductor processing method of claim 6, wherein the boron-carbon containing layer is characterized by a Young's modulus of about 80 Gpa or greater.

8. forming a plasma of a hydrogen-containing precursor or an oxygen-containing precursor in the processing region of the semiconductor processing chamber; and removing the boron-carbon containing layer from the substrate; 10. The semiconductor processing method of claim 1, further comprising:

9. 9. The semiconductor processing method of claim 8, wherein the plasma is maintained halogen-free during removal of the boron-carbon containing layer from the substrate.

10. 10. The semiconductor processing method of claim 1, wherein the carbon-containing precursor is characterized by a carbon to hydrogen ratio of about 1:3 or greater.

11. providing a boron-containing precursor to a processing region of a semiconductor processing chamber, wherein a substrate is disposed within the processing region of the semiconductor processing chamber; providing the boron-containing precursor to the processing region of the semiconductor processing chamber; providing a hydrocarbon characterized by a carbon-carbon double bond or a carbon-carbon triple bond to the processing region of the semiconductor processing chamber; thermally reacting the boron-containing precursor with the hydrocarbon at a temperature between about 75°C and about 500°C; forming a boron-carbon containing layer on the substrate; Including, The semiconductor processing method, wherein the boron-carbon containing layer is characterized by an extinction coefficient at 633 nm of about 0.01 or greater.

12. 12. The semiconductor processing method of claim 11, wherein the processing region of the semiconductor processing chamber is maintained plasma-free during the semiconductor processing method.

13. 12. The semiconductor processing method of claim 11, wherein the boron-carbon containing layer is characterized by a carbon concentration of about 40% or greater.

14. exposing the boron-carbon containing layer to a wet etchant comprising hydroxide; and removing the boron-carbon containing layer from the substrate; 14. The semiconductor processing method of claim 13, further comprising:

15. 12. The semiconductor processing method of claim 11, wherein the boron-carbon containing layer is characterized by hydrogen uptake of about 50% or less.

16. 12. The semiconductor processing method of claim 11, wherein the substrate is characterized by one or more features and the boron-carbon containing layer is formed around the one or more features with a conformality of about 95% or greater.

17. providing a boron-hydrogen containing precursor to a processing region of a semiconductor processing chamber, wherein a substrate is disposed within the processing region of the semiconductor processing chamber; providing the boron-hydrogen containing precursor to the processing region of the semiconductor processing chamber; providing a carbon-containing precursor characterized by a carbon-carbon double bond or a carbon-carbon triple bond to the processing region of the semiconductor processing chamber; thermally reacting the boron-hydrogen containing precursor and the carbon containing precursor at a temperature less than about 600°C; forming a boron-carbon containing layer on the substrate consisting essentially of boron, carbon, and hydrogen; Including, The semiconductor processing method, wherein the boron-carbon containing layer is characterized by an extinction coefficient at 633 nm of about 0.01 or greater.

18. 20. The semiconductor processing method of claim 17, wherein the processing region of the semiconductor processing chamber is maintained plasma-free while forming the boron-carbon containing layer on the substrate.

19. 20. The semiconductor processing method of claim 17, wherein the boron-carbon containing layer is characterized by a conformal thickness of about 95% or greater.

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