High-elastic boron-based ceramics for semiconductors

Abstract

Various embodiments herein relate to methods, apparatus, and systems for depositing boron-based ceramic films on substrates. The boron-based ceramic films described herein advantageously can be formed at relatively low temperatures (e.g., about 600°C or less) while still achieving very high quality exhibiting good mechanical strength (e.g., high hardness and high Young's modulus), good etch selectivity, amorphous morphology, etc. The films herein also have low hydrogen content, low oxygen content, and low halide content. In many cases, the films can be formed by the reaction between a boron halide and a saturated or unsaturated hydrocarbon in the presence of a plasma.

Description

Technical Field

[0001] Incorporation by Reference: The PCT application form is submitted simultaneously with this specification as part of this application. Each application identified in the simultaneously submitted PCT application form and for which this application claims benefit or priority is incorporated by reference in its entirety herein for all purposes.

Background Art

[0002] In semiconductor processing, there are often trade - offs between the required material properties and constraints. For example, many high - quality materials could not be obtained without using very strict processing conditions. Due to the strict processing conditions, for example, the application range of such high - quality materials was limited because partially assembled semiconductor devices could not withstand the harsh processing conditions.

[0003] The description of the background provided herein is for the purpose of presenting the content of the present disclosure generally. The research of the currently named inventors, to the extent described in this background art section, whether explicitly or implicitly, is not admitted as prior art to the present disclosure, similar to aspects of the specification that may not qualify as prior art in another form at the time of filing.

Summary of the Invention

[0004] Various embodiments herein relate to a method, apparatus, and system for forming a boron - based ceramic film on a semiconductor substrate. The boron - based ceramic film is a high - quality film having high mechanical strength (e.g., high hardness and high Young's modulus) and other favorable qualities.

[0005] In one aspect of the disclosed embodiments, a method of forming a boron-based ceramic film on a substrate is provided. The method includes (a) accommodating the substrate in a reaction chamber, (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber, and (c) generating an inductively coupled plasma in the reaction chamber and reacting the first reactant with the second reactant at a temperature of about 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate.

[0006] In various embodiments, the boron-based ceramic film may have a hydrogen content of about 15 atomic % or less. In these or other embodiments, the boron-based ceramic film may have a halide content of about 1 atomic % or less. In these or other embodiments, the boron-based ceramic film may have a Young's modulus of about 175 GPa or more. In some embodiments, the boron-based ceramic film may have an oxygen content of about 1 atomic % or less. In these or other embodiments, the second reactant may include a saturated hydrocarbon or an unsaturated hydrocarbon. The saturated hydrocarbon or unsaturated hydrocarbon may be the only hydrogen-containing precursor supplied to the reaction chamber. In some embodiments, the reactants supplied to the reaction chamber do not include both boron and hydrogen. That is, the reactants supplied to the reaction chamber are not hydrogen-containing boron precursors. Specific examples of precursors that may be excluded include hydrogen boride and borane. In some embodiments, the first reactant includes BF3, the second reactant includes CH4, and the boron-based ceramic film includes boron carbide having a composition of B x C y (where 2 < x < 4.5 and y = 1). In some embodiments, the boron-based ceramic film includes B x A yIt may contain boron carbide or boron nitride having a composition of (where 1 < x < 4.5, y = 1, and A is carbon or nitrogen). In some embodiments, the boron-based ceramic film may further contain tungsten and / or silicon. In some embodiments, the boron-based ceramic film may contain at least one material selected from the group consisting of boron carbide, boron nitride, boron carbonitride, tungsten boride carbide, tungsten boron nitride, silicon boride carbide, silicon boron nitride, and tungsten silicon boride carbide.

[0007] In various embodiments, the boron-based ceramic film may have the specific properties described herein. For example, in some embodiments, the Young's modulus of the boron-based ceramic film may be between about 250 and 300 GPa. In these or other embodiments, the hardness of the boron-based ceramic film may be about 20 GPa or more, for example 25 GPa or more. In these or other embodiments, the hydrogen content of the boron-based ceramic film may be about 13 atomic % or less. In these or other embodiments, the halide content of the boron-based ceramic film may be about 0.75 atomic % or less. In these or other embodiments, the density of the boron-based ceramic film may be about 2 g / cc or more, for example 2.2 g / cc or more. In these or other embodiments, the boron-based ceramic film may have a boron content of about 50 atomic % or more. In some such embodiments, the boron content of the boron-based ceramic film may be about 60 atomic % or more. In these or other embodiments, the oxygen content of the boron-based ceramic film may be about 0.5 atomic % or less. In these or other embodiments, the boron-based ceramic film may be amorphous.

[0008] In some embodiments, certain reactants, and / or plasmas, and / or processing conditions may be used. For example, in some embodiments, the plasma may be a dielectrically coupled plasma. In these or other embodiments, the first reactant may include BF3. In these or other embodiments, the first reactant may include BCl3. In various cases, the first reactant may include BF3 and / or BCl3. In these or other embodiments, the first reactant may include BBr3. In these or other embodiments, the first reactant may include Bl3. In various cases, the first reactant may include BBr3 and / or Bl3. In these or other embodiments, the second reactant may include a reactant selected from the group consisting of methane (CH4), ethane (C2H6), propane (C3H8), ethene (C2H4), and propene (C3H6). In some such embodiments, the second reactant may include CH4. In these or other embodiments, the second reactant may include C2H6. In these or other embodiments, the second reactant may include C3H8. In these or other embodiments, the second reactant may include C2H4. In these or other embodiments, the second reactant may include C3H6.

[0009] In another aspect of the disclosed embodiments, an apparatus for forming a boron-based ceramic film on a substrate is provided. The apparatus includes (a) a reaction chamber, (b) a substrate support configured to support a substrate within the reaction chamber, (c) one or more inlets for introducing reactants into the reaction chamber, (d) one or more outlets for removing materials from the reaction chamber, and (e) a controller having at least one processor and a memory, the at least one processor and the memory being communicatively connected to each other, the memory storing computer-executable instructions for controlling the at least one processor to execute any of the methods described herein.

[0010] In another aspect of the disclosed embodiments, an apparatus for forming a boron-based ceramic film on a substrate is provided. The apparatus includes (a) a reaction chamber, (b) a substrate support configured to support a substrate within the reaction chamber, (c) one or more inlets for introducing reactants into the reaction chamber, (d) one or more outlets for removing materials from the reaction chamber, and (e) a controller having at least one processor and a memory, the at least one processor and the memory being communicatively connected to each other, the memory storing computer-executable instructions for controlling the at least one processor to expose the substrate to a capacitively coupled plasma to carry out a plasma-enhanced chemical vapor deposition reaction between boron halide and an additional reactant to form a boron-based ceramic film on the substrate at a temperature of about 600 °C or less.

[0011] In yet other aspects of the disclosed embodiments, an apparatus for forming a boron-based ceramic film on a substrate is provided. The apparatus includes (a) a reaction chamber, (b) a substrate support configured to support the substrate within the reaction chamber, (c) one or more inlets for introducing reactants into the reaction chamber, (d) one or more outlets for removing materials from the reaction chamber, (e) a plasma generator configured to generate a dielectrically coupled plasma within the reaction chamber, and (f) a controller having at least one processor and a memory, the at least one processor and the memory being communicatively connected to each other, the memory storing computer-executable instructions for controlling the at least one processor to (i) accommodate the substrate within the reaction chamber, (ii) flow a first reactant and a second reactant into the reaction chamber, (iii) generate the plasma within the reaction chamber, and react the first reactant and the second reactant at a temperature of about 600 °C or less to form the boron-based ceramic film on the substrate, the boron-based ceramic film having (1) a Young's modulus of about 175 GPa or more, (2) a hydrogen content of about 15 atomic % or less, and (3) a halide content of about 1 atomic % or less.

[0012] These and other aspects are described further below with reference to the drawings.

Brief Description of the Drawings

[0013] [Fig. 1] FIG. 1 is a flowchart illustrating a method of forming a boron-based ceramic material according to various embodiments.

[0014] [Fig. 2] FIG. 2 is a diagram showing a reaction chamber that can be used to deposit a boron-based ceramic material according to various embodiments.

[0015] [Fig. 3]Figure 3 is a diagram showing a multi-station tool that can be used to deposit boron-based ceramic materials according to various embodiments.

[0016] [Fig. 4] Figure 4 is a diagram showing a processing system having a plurality of reaction chambers each having a plurality of stations inside, which can be used to deposit boron-based ceramic materials according to various embodiments.

[0017] [Fig. 5] Figure 5 is a graph showing experimental results (FTIR) of examining the composition of a boron-based ceramic material deposited according to an embodiment of the present specification.

[0018] [Fig. 6A] Figure 6A is a graph showing experimental results (XPS) of examining the bonding states present in a boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 6B] Figure 6B is a graph showing experimental results (XPS) of examining the bonding states present in a boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 6C] Figure 6C is a graph showing experimental results (XPS) of examining the bonding states present in a boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 6D] Figure 6D is a graph showing experimental results (XPS) of examining the bonding states present in a boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 6E] Figure 6E is a graph showing experimental results (XPS) of examining the bonding states present in a boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 6F] Figure 6F is a graph showing experimental results (XPS) of examining the bonding states present in a boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 7A]Figure 7A is a graph showing the experimental results (XPS) of examining the bonding states present in the boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 7B] Figure 7B is a graph showing the experimental results (XPS) of examining the bonding states present in the boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 7C] Figure 7C is a graph showing the experimental results (XPS) of examining the bonding states present in the boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 7D] Figure 7D is a graph showing the experimental results (XPS) of examining the bonding states present in the boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 7E] Figure 7E is a graph showing the experimental results (XPS) of examining the bonding states present in the boron-based ceramic material deposited according to a specific embodiment of the present specification. [Fig. 7F] Figure 7F is a graph showing the experimental results (XPS) of examining the bonding states present in the boron-based ceramic material deposited according to a specific embodiment of the present specification.

Mode for Carrying Out the Invention

[0019] In the following description, many specific details are set forth in order to provide a thorough understanding of the presented embodiments. Each of the disclosed embodiments may be practiced without some or all of the above specific details. In other instances, detailed descriptions of well-known processing operations are not presented so as not to unnecessarily obscure the disclosed embodiments. The disclosed embodiments are described in conjunction with specific embodiments, but it will be understood that the disclosed embodiments are not intended to be limiting.

[0020] Conventional techniques for forming boron-based ceramic materials present several challenges that make it difficult to incorporate such techniques into semiconductor assembly schemes. For example, such conventional techniques are (1) carried out at very high temperatures and / or (2) result in materials of low quality and low mechanical strength. Exemplary high-temperature techniques can involve, for example, high-temperature furnace reactions, electron beam reactions, hot filament activation, combustion synthesis reactions, etc. These techniques have problems because many semiconductor assembly schemes have limited thermal budgets, i.e., the substrate / material can be damaged when exposed to excessive heating. Further, these high-temperature techniques generally result in highly crystalline ceramic materials and are thus not suitable for hard mask applications. Therefore, it is desirable to keep the processing temperature low. However, conventional low-temperature techniques for forming boron-based ceramics have resulted in low-quality materials that do not exhibit desired properties such as etching selectivity and mechanical strength.

[0021] Conventional low-temperature techniques utilize plasma-enhanced chemical vapor deposition (PECVD) to form boron-based ceramics (e.g., boron carbide or boron nitride) using diborane (B2H6) as a reactant. The processing temperature is typically less than 550 °C and is suitable for various semiconductor applications. However, because diborane having a significant hydrogen content is used, the degree of hydrogen incorporation into the film becomes high. Often, such films have more than 20% hydrogen. Unless otherwise stated, the film compositions described herein in percent are intended to represent atomic percent.

[0022] Furthermore, such conventional low-temperature films tend to be of low density and exhibit poor mechanical properties (e.g., hardness less than 20 GPa and Young's modulus less than 150 GPa), resulting in unacceptably low etching selectivity. Due to these poor properties, conventional low-temperature boron-based ceramic materials are undesirable or even inappropriate as hard masks or for other applications in integrated circuits that require high mechanical strength properties.

[0023] Surprisingly, the inventors have identified a new low-temperature deposition technique that can be used to form high-quality boron-based ceramic materials with excellent properties such as high etching selectivity, high mechanical strength, and stable thermal and optical properties. The resulting boron-based ceramic materials are particularly well-suited as hard mask materials, but can be used for a variety of semiconductor applications if desired. As used herein, low-temperature techniques are those that occur at about 600 °C or less.

[0024] Figure 1 is a flowchart illustrating a method 100 for depositing a boron-based ceramic material according to various embodiments of the present specification. Method 100 begins at operation 101 where a substrate is housed in a reaction chamber. The reaction chamber is a PECVD chamber configured to generate inductively coupled plasma. The substrate is typically mounted on a substrate holder within the reaction chamber. Next, at operation 103, reactants are flowed into the reaction chamber. In many cases, the reactants include (1) at least one boron halide, and (2) at least one saturated or unsaturated hydrocarbon. Examples of boron halides include, for example, boron trifluoride (BF3), boron trichloride (BCl3), boron tribromide (BBr3), and boron triiodide (BI3). Examples of saturated hydrocarbons include, for example, methane (CH4), ethane (C2H6), propane (C3H8), butane (C3H 10 ) etc. Examples of unsaturated hydrocarbons include, for example, ethene (C2H4), propene (C3H6), butene (C4H8), etc. Generally, the hydrocarbon reactants used herein are small hydrocarbon molecules similar to those listed above (e.g., C x H y) Using these reactants, ceramic films containing boron and carbon, such as BC, WBC, BCN, SiBC, SiWBC, etc., may be formed. When the ceramic film contains nitrogen, a nitrogen-containing reactant such as NH3 may be used. When the ceramic film contains tungsten, a tungsten-containing reactant may be used. When the ceramic film contains silicon, a silicon-containing reactant may be used. In another example, the ceramic film is BN, and the reactants used to form the ceramic film include boron halide and NH3.

[0025] In various embodiments, the reactant does not include diborane or any other boron and hydrogen-containing reactant. In other words, the reactant does not include a hydrogen-containing boron precursor. Specific examples of precursors that can be excluded include boron hydride and borane. In many cases, except for hydrocarbon reactants, there is no hydrogen-containing reactant supplied to the reaction chamber. By excluding such reactants, for example, the amount of hydrogen introduced into the reaction chamber can be minimized, and most of the hydrogen introduced into the reaction chamber is guaranteed to react and be removed from the chamber (e.g., as a gas-phase reactant) easily and efficiently before being incorporated into the growing film, so that the amount of hydrogen incorporated into the boron-based ceramic film can be minimized. Therefore, the obtained boron-based ceramic film has a significantly lower hydrogen content compared to conventional low-temperature boron-based ceramic films. For example, conventional low-temperature boron-based ceramic films formed from diborane always have a hydrogen content of over 20%, while the films manufactured according to the embodiments herein have a lower hydrogen content, such as less than 15%, less than 14%, or less than 13%. In one example presented below in the experimental section, the technology described herein is used to produce boron carbide with a hydrogen content of only 12.5%. The reduction in hydrogen content compared to conventional technologies / films results in significant improvement in film properties such as etching selectivity, hardness, and Young's modulus.

[0026] Returning to FIG. 1, the method proceeds to operation 105 where plasma is generated from the reactants within the reaction chamber and the substrate is exposed to the plasma. Boron trifluoride reacts with the hydrocarbon to form a boron-based ceramic material that deposits on the substrate. In operation 106, by-products and unreacted gases are pumped out of the reaction chamber. Operations 103, 105, and 106 may overlap in time, and the duration of each operation may be selected to produce a boron-based ceramic material of a desired thickness. By removing by-products from the reaction chamber in operation 106, formation of a boron-based ceramic material of a desired composition with, for example, a low amount of impurities as described herein is facilitated. After the boron-based ceramic material has been deposited on the substrate, the plasma is extinguished and the substrate is removed from the reaction chamber in operation 107. Thereafter, the method can be repeated on different substrates.

[0027] Numerous reaction examples are shown below, but the embodiments of this specification are not intended to be limited to the recited examples.

[0028] Reaction 1: 4BF3(g) + 3CH4(g) → B4C(s) + 8HF(g) + 2CH2F2(g)

[0029] Reaction 2: 4BCl3(g) + 3CH4(g) → B4C(s) + 8HCl(g) + 2CH2Cl2(g)

[0030] Reaction 3: 4BBr3(g) + 3CH4(g) → B4C(s) + 8HBr(g) + 2CH2Br2(g)

[0031] Reaction 4: 4BI3(g) + 3CH4(g) → B4C(s) + 8HI(g) + 2CH2I2(g)

[0032] Reactions 1-4 relate to specific embodiments where boron halide is reacted with methane to produce B4C, hydrogen halide, and dihalomethane, but the embodiments are not so limited. In various embodiments, other fluorocarbons may be produced (instead of, or in addition to, the products listed above). Such fluorocarbons have the formula CF x H4-x may have.

[0033] In another example, the ceramic film to be formed is BN. Examples of reactions that can be used are shown below.

[0034] Reaction 5: BX3 + NH3 + H2 → BN + NH4X + HX (where X is a halogen)

[0035] The stoichiometry may be appropriately balanced according to the desired use, for example, for producing a boron- and nitrogen-containing ceramic material having a specific composition. In some cases, alternative or additional reaction products may be produced.

[0036] In another example, the ceramic film to be formed is BCN. Examples of reactions that can be used are shown below.

[0037] Reaction 6: BX3 + CH4 + NH3 → BCN x N y+ + NH4X + CX x H 4-x + HX (where X is a halogen)

[0038] The stoichiometry may be appropriately balanced according to the desired use, for example, for producing BCN having a specific composition. In some cases, alternative or additional reaction products may be produced.

[0039] One advantage of the disclosed technology is that there is little reaction between the boron-based ceramic material and the by-products of the deposition process. As a result, the by-products can be cleanly removed from the reaction chamber before they can be trapped in the growing film. By cleanly removing the by-products in this way, a film with a low degree of impurities with respect to both hydrogen and the halogen introduced from the boron halide reactant is produced.

[0040] Another advantage of the disclosed technology is that the composition of the boron-based ceramic material can be precisely controlled by careful stoichiometric balance and control of the relative reactant flow rates. In many cases, the reactant flow rates are controlled to produce a boron-containing ceramic material having boron atoms that are 2 to 4 times that of other atoms. For example, when forming boron carbide, the flow of reactants may be controlled to produce boron carbide having boron atoms that are about 2 to 4 times that of carbon atoms.

[0041] It should be understood that the resulting ceramic material does not necessarily have a perfect stoichiometric balance. More generally, in some cases, the boron-containing materials produced herein have the formula B x A y (where 2 < x < 4.5, y = 1, and A is an element such as carbon or nitrogen). In some such cases, x may be at least about 2.25, at least about 2.5, at least about 2.75, at least about 3, at least about 3.25, at least about 3.5, or at least about 3.75. In these or other cases, x may be about 4.4 or less, about 4.3 or less, about 4.2 or less, or about 4.1 or less. Any of the minimum and maximum values described for x may be combined as desired for a particular application (e.g., 2.3 < x < 4.1, etc.). As described above, in some cases, the boron-containing ceramic material may include one or more additional elements such as tungsten and / or silicon in addition to carbon and / or nitrogen.

[0042] In various embodiments, the boron-containing ceramic material may be doped with nitrogen and / or phosphorus. The flow rate of each reactant may be controlled relative to each other to achieve the desired stoichiometry.

[0043] As described above, in many cases, the reactants for forming the boron-based ceramic material include (1) at least one boron halide and (2) at least one saturated or unsaturated hydrocarbon. These reactants are suitable for forming ceramic materials containing both boron and carbon. In embodiments where the boron-based ceramic material contains other elements such as nitrogen, tungsten, or silicon, the reactants supplied to the reaction chamber will also contain such elements. In certain embodiments where the boron-based ceramic material is BN, the saturated or unsaturated hydrocarbon may be replaced with a nitrogen-containing reactant such as NH3.

[0044] The boron-containing ceramic material having the disclosed composition and formed according to the embodiments herein exhibits highly desirable properties such as an amorphous form, low hydrogen content, low halide content, high etching selectivity, high density, high hardness, high Young's modulus, stable thermal and optical properties, etc. Due to these properties, the boron-containing ceramic material becomes useful as a hard mask.

[0045] Generally, in the use of a hard mask, an amorphous material is preferred over a crystalline material. The amorphous material exhibits smoother and less rough, better patterning. With a low hydrogen content, the etching selectivity is increased and the stability of the film is also increased. Regarding etching selectivity, it is desirable that the ceramic material is relatively resistant to the etching chemistry (e.g., fluorocarbon-based or chlorine-based etching chemistry) used for a particular application compared to other materials (e.g., dielectric materials) where etching is desired. The etching selectivity is also affected by the film density, and a higher density ceramic film tends to exhibit a lower etching rate and correspondingly higher etching selectivity while being used as a hard mask. For example, it is also desirable to have a low halide content to prevent the diffusion of halides to underlying or surrounding materials that may be damaged by the halides. Also, it is desirable that the boron-containing ceramic material has a high hardness along with a high mechanical strength exhibited by a high Young's modulus. The combination of these properties ensures a high-quality hard mask material.

[0046] As described above, the reactants and reactant flow rates may be selected such that a desired stoichiometric balance occurs in the resulting boron-containing ceramic material. Further, various other processing conditions may be controlled during deposition. In some embodiments, the pressure within the reaction chamber may be maintained between about 50 - 1000 mTorr (e.g., 6.5 - 135 Pa), or between about 50 - 200 mTorr (e.g., 6.5 - 27 Pa). In some cases, the RF power used to generate the plasma may be between about 500 - 2000 W. In some cases, dual-frequency RF may be used, for example, with a first frequency of about 13.5 MHz and a second frequency of about 400 kHz. Different RF power levels may be provided for each frequency. In a specific example, the plasma may be pulsed with a duty cycle between about 5 - 15%, for example, about 10%. The plasma may be pulsed at a frequency between about 200 - 800 Hz, for example, about 500 Hz. The substrate may be exposed to the plasma for a duration sufficient to form a boron-containing ceramic material of the desired thickness. An example of the thickness for hard mask applications may be between about 500 - 5000 angstroms, for example, between about 500 - 1000 angstroms. An example of the duration of plasma exposure may be a short time of several seconds or a long time of several minutes, depending on the deposition rate and the desired thickness. During deposition, the substrate may be supported on a substrate support that can be temperature-controlled. In a specific case, the substrate support may be maintained at a temperature between about 400 - 650 °C. By using plasma energy to facilitate the reaction between the reactants, the substrate can be kept at a relatively low temperature during processing. In many cases, the substrate temperature is maintained between about 200 - 600 °C. Thus, the heat load on the substrate is relatively low, especially compared to the high-temperature deposition techniques described above. In a specific embodiment, one or more precursors may be heated to ensure sufficient volatilization of the precursors.

[0047] In the technology described in this specification, the plasma used is inductively coupled plasma. Inductively coupled plasma is sufficiently high energy so as to be able to effectively and efficiently break down reactants into smaller, more favorable forms. In comparison, other types of plasma, such as capacitively coupled plasma, are not high energy enough to cause the desired reactant dissociation / reaction. In certain embodiments, in addition to inductively coupled plasma, capacitively coupled plasma or other types of plasma may also be used.

[0048] In some embodiments, the boron-based ceramic film may be deposited in separate steps occurring at various locations. For example, FIG. 3 (further described below) shows a multi-station processing tool 300. In some embodiments, the boron-based ceramic film is deposited at two or more stations, with a portion of the film being deposited at each station. This multi-station deposition method may be used to average out film non-uniformities, such as those resulting from deposition at a particular processing station.

[0049] Apparatus: FIG. 2 schematically shows one embodiment of a processing station 200 that can be used to deposit a boron-containing ceramic material using plasma enhanced chemical vapor deposition (PECVD) according to various embodiments of this specification. Processing station 200 may also be used for other purposes such as chemical vapor deposition and atomic layer deposition. For simplicity, processing station 200 is depicted as a stand-alone processing station having a processing chamber body 202 for maintaining a low pressure environment. However, it will be understood that multiple processing stations 200 may be included in a common processing tool environment. Further, it will be understood that in some embodiments, one or more hardware parameters of processing station 200, including those discussed in detail below, may be programmatically adjusted by one or more computer controllers.

[0050] The processing station 200 is in fluid communication with a reactant delivery system 201 for sending process gas to the distribution showerhead 206. In this example, the reactant delivery system 201 includes a mixing vessel 204 for mixing and / or conditioning the process gas for sending to the showerhead 206. One or more mixing vessel inlet valves 220 may control the introduction of the process gas into the mixing vessel 204. In other specific examples, the process gas may remain separated until being sent to the showerhead 206 or the processing chamber body 202. Similarly, a showerhead inlet valve 205 may control the introduction of the process gas into the showerhead 206. In various embodiments, a specific process gas may be sent from a cylinder containing a monolithic carbon adsorption pack (not shown). This delivery system may be particularly useful for safely delivering corrosive gases such as BF3.

[0051] Some reactants may be stored in liquid form prior to vaporization and subsequent delivery at the processing station. For example, the embodiment of FIG. 2 includes a vaporization point 203 for vaporizing the liquid reactant supplied to the mixing vessel 204. In some embodiments, the vaporization point 203 may be a heated vaporizer. The reactant vapor generated from such a vaporizer may condense in the downstream delivery piping. By exposing the condensed reactant to a non-affinity gas, small particles may be generated. These small particles may clog the piping, interfere with the operation of the valves, contaminate the substrate, etc. Some methods for addressing such problems involve flushing and / or evacuating the delivery piping to remove residual reactants. However, flushing the delivery piping can increase the cycle time of the processing station and reduce the throughput of the processing station. Accordingly, in some embodiments, the delivery piping downstream of the vaporization point 203 may be heat traced. In some examples, the mixing vessel 204 may also be heat traced. In one non-limiting example, the piping downstream of the vaporization point 203 has an increasing temperature profile in the range from about 100° C. to about 150° C. in the mixing vessel 204.

[0052] In some embodiments, the reactant liquid may be vaporized by a liquid injector. For example, the liquid injector may inject pulses of the liquid reactant into the carrier gas stream upstream of the mixing vessel. In one scenario, the liquid injector may vaporize the reactant by flowing the liquid vigorously from a higher pressure to a lower pressure. In another scenario, the liquid injector may atomize the liquid into tiny droplets and then vaporize them with a heated delivery pipe. It will be appreciated that smaller droplets vaporize faster than larger droplets, reducing the delay between liquid injection and complete vaporization. Faster vaporization may shorten the length of the pipe downstream from the vaporization point 203. In one scenario, the liquid injector may be directly attached to the mixing vessel 204. In another scenario, the liquid injector may be directly attached to the shower head 206.

[0053] In some embodiments, a liquid flow controller upstream of the vaporization point 203 may be provided to control the mass flow of the liquid for vaporization and delivery to the vaporization and processing station 200. For example, the liquid flow controller (LFC) may include a thermal mass flow meter (MFM) located downstream of the LFC. The plunger valve of the LFC may then be adjusted in response to a feedback control signal provided by a proportional-integral-derivative (PID) controller that is in electrical communication with the MFM. However, it may take more than one second to stabilize the liquid flow by feedback control. This may increase the time for administering the liquid reactant. Thus, in some embodiments, the LFC may be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, the LFC may be dynamically switched from the feedback control mode to the direct control mode by disabling the sense tubes of the LFC and the PID controller.

[0054] An inert gas may be co-introduced into the chamber together with one or more reactants. Examples of inert gases include He, Ar, H2, and N2. The inert gas may be flowed at a rate between about 500 and 10,000 sccm. The inert gas can be useful for many reasons, such as promoting uniform delivery of the reaction gas, maintaining the plasma, achieving uniform film growth across the substrate surface, promoting removal of by-products from the substrate surface, etc.

[0055] The showerhead 206 distributes process gas toward the substrate 212. The process gas may include any of the process gases described herein, including but not limited to boron halides, saturated and unsaturated hydrocarbons, silicon-containing reactants, tungsten-containing reactants, NH3 and other nitrogen-containing reactants, inert gases, etc. In the embodiment shown in FIG. 2, the substrate 212 is located under the showerhead 206 and is illustrated as being placed on the pedestal 208. It will be understood that the showerhead 206 may have any suitable shape and may have any suitable number and arrangement of ports for distributing process gas to the substrate 212.

[0056] In some embodiments, the microvolume portion 207 is located under the showerhead 206. By performing the deposition process within the microvolume portion rather than the overall volume of the processing station, it may be possible to shorten the exposure and scavenging times of the reactants, shorten the time for changing processing conditions (e.g., pressure, temperature, etc.), or limit the exposure of the robotics of the processing station to the process gas. Examples of the size of the microvolume portion include, but are not limited to, volumes between 0.1 liter and 2 liters. This microvolume portion also affects the productivity throughput. When the deposition rate per cycle decreases, the cycle time is simultaneously shortened. In certain cases, the latter effect is dramatic enough to improve the overall throughput of the module for a given target film thickness.

[0057] In some embodiments, the pedestal 208 may be raised or lowered to expose the substrate 212 to the microvolume portion 207 and / or to change the volume of the microvolume portion 207. For example, during the substrate transfer stage, the pedestal 208 may be lowered so that the substrate 212 can be mounted on the pedestal 208. During the deposition process stage, the pedestal 208 may be raised to position the substrate 212 within the microvolume portion 207. In some embodiments, the microvolume portion 207 may completely surround not only the substrate 212 but also a part of the pedestal 208 to form a high-flow impedance region during the deposition process.

[0058] Optionally, the pedestal 208 may be lowered and / or raised between portions of the deposition process to adjust, for example, the processing pressure and reactant concentration within the microvolume portion 207. In one scenario where the process chamber body 202 remains at a reference pressure during the deposition process, lowering the pedestal 208 may allow the microvolume portion 207 to be evacuated. Examples of the volume ratio of the microvolume portion to the volume of the process chamber include, but are not limited to, volume ratios between 1:200 and 1:10. It will be understood that in some embodiments, the height of the pedestal may be programmatically adjusted by a suitable computer controller.

[0059] In another scenario, by adjusting the height of the pedestal 208, the plasma density can be varied during the plasma activation and / or processing cycles included in the deposition process. At the end of the deposition process stage, the pedestal 208 may be lowered between another substrate transfer stage to remove the substrate 212 from the pedestal 208.

[0060] The modification examples of the micro-volume portion described in this specification describe a pedestal whose height can be adjusted. However, in some embodiments, it will be understood that the position of the shower head 206 may be adjusted relative to the pedestal 208 to change the volume of the micro-volume portion 207. Furthermore, it will be understood that the vertical positions of the pedestal 208 and / or the shower head 206 may be changed by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 208 may include a rotation axis for rotating the orientation of the substrate 212. In some embodiments, it will be understood that one or more of these adjustment examples may be programmatically executed by one or more suitable computer controllers.

[0061] Returning to the embodiment shown in FIG. 2, the shower head 206 and the pedestal 208 are in electrical communication with an RF power supply 214 and a matching network 216 to supply power to the plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of the process station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power supply 214 and the matching network 216 may be operated at any suitable power to form a plasma having radical species of a desired composition. Examples of suitable power are included above. Similarly, the RF power supply 214 may supply RF power at any suitable frequency. In some embodiments, the RF power supply 214 may be configured to control a high-frequency RF power supply and a low-frequency RF power supply independently of each other. Examples of low-frequency RF frequencies include, but are not limited to, frequencies between 50 kHz and 200 kHz. Examples of high-frequency RF frequencies include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz. It will be understood that any suitable parameters may be adjusted discretely or continuously to provide plasma energy for surface reactions. In one non-limiting example, the plasma power may be pulsed intermittently to reduce ion bombardment on the substrate surface compared to a plasma that is continuously powered.

[0062] In some embodiments, the plasma may be monitored in-situ by one or more plasma monitors. In one scenario, the plasma power may be monitored by one or more voltage, current sensors (e.g., VI probes). In another scenario, the plasma density and / or the process gas concentration may be measured by one or more optical emission spectroscopy sensors (OES). In some embodiments, one or more plasma parameters may be programmatically adjusted based on measurements from such in-situ plasma monitors. For example, an OES sensor may be used in a feedback loop for program control of the plasma power. It will be understood that in some embodiments, other monitors may be used to monitor the plasma and other process characteristics. Such monitors include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure transducers.

[0063] In some embodiments, the plasma may be controlled via input / output control (IOC) sequence instructions. In one example, instructions for setting plasma conditions for a plasma processing stage may be included in a corresponding plasma activation recipe stage of a deposition processing recipe. In some cases, the processing recipe stages may be arranged in sequence such that all instructions for a deposition processing stage are executed simultaneously with that processing stage. In some embodiments, instructions for setting one or more plasma parameters may be included in a recipe stage preceding the plasma processing stage. For example, a first recipe stage may include instructions for setting the flow rate of an inert gas and / or a reactive gas, instructions for setting a power set point of a plasma generator, and a time delay instruction for the first recipe stage. A subsequent second recipe stage may include an instruction for enabling the plasma generator and a time delay instruction for the second recipe stage. A third recipe stage may include an instruction for disabling the plasma generator and a time delay instruction for the third recipe stage. It will be understood that these recipe stages may be further subdivided and / or repeated in any suitable manner within the scope of the present disclosure.

[0064] In some deposition processes, the plasma strike continues for an order of several seconds or more. In certain implementations, much shorter plasma pulses may be used. These may be on the order of 10 ms to 1 second, typically about 20 - 80 ms, with 50 ms being an example. For such very short RF plasma pulses, it is necessary to stabilize the plasma extremely rapidly. To achieve this, the plasma generator may be configured to vary the frequency while presetting the impedance matching to a specific voltage. Conventionally, high-frequency plasma is generated at an RF frequency of about 13.56 MHz. In various embodiments disclosed herein, the frequency is variable to a value different from this standard value. By allowing the frequency to vary while fixing the impedance matching to a predetermined voltage, the plasma can be stabilized more rapidly. This result can be important when using very short plasma pulses associated with certain deposition cycles.

[0065] In some embodiments, pedestal 208 may be temperature controlled via heater 210. Further, in some embodiments, pressure control of deposition processing station 200 may be provided by butterfly valve 218. As shown in the embodiment of FIG. 2, butterfly valve 218 throttles the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of processing station 200 may be adjusted by varying the flow rate of one or more gases introduced into processing station 200.

[0066] FIG. 3 shows a schematic diagram of one embodiment of a multi-station processing tool 300 having an inbound load lock 302 and an outbound load lock 304, either or both of which may comprise a remote plasma source. An atmospheric pressure robot 306 is configured to move wafers from a cassette carried via pod 308 into inbound load lock 302 via atmospheric port 310. The wafer is placed on pedestal 312 within inbound load lock 302 by robot 306, atmospheric port 310 is closed, and the load lock is pumped down. If inbound load lock 302 comprises a remote plasma source, the wafer may be exposed to remote plasma processing within the load lock prior to being introduced into processing chamber 314. Further, the wafer may also be heated within inbound load lock 302, for example, to remove moisture and adsorbed gases. Next, chamber transfer port 316 to processing chamber 314 is opened and another robot (not shown) places the wafer into the reactor and positions it for processing on the pedestal of the first station shown within the reactor. The embodiment depicted in FIG. 3 includes load locks, but it will be understood that in some embodiments, wafers may be placed directly into the processing station.

[0067] The illustrated processing chamber 314 includes four processing stations numbered 1 through 4 in the embodiment shown in FIG. 3. Each station has a heated pedestal (shown as 318 for station 1) and a gas line inlet. It will be appreciated that in some embodiments, each processing station may have different or multiple purposes. Although the illustrated processing chamber 314 includes four stations, it will be understood that a processing chamber according to the present disclosure may have any suitable number of stations. For example, in some embodiments, the processing chamber may have five or more stations, and in other embodiments, the processing chamber may have three or fewer stations.

[0068] FIG. 3 also depicts an embodiment of a wafer handling system 390 for transporting wafers within the processing chamber 314. In some embodiments, the wafer handling system 390 may transport wafers between various processing stations and / or between a processing station and a load lock. It will be understood that any suitable wafer handling system may be employed. Non-limiting examples include a wafer carousel and a wafer handling robot. FIG. 3 also depicts an embodiment of a system controller 350 employed to control the processing conditions and hardware state of the processing tool 300. The system controller 350 may include one or more memory devices 356, one or more mass storage devices 354, and one or more processors 352. The processor 352 may include a CPU or computer, analog and / or digital input / output connections, a stepping motor controller board, and the like.

[0069] In some embodiments, the system controller 350 controls all activities of the processing tool 300. The system controller 350 executes system control software 358 that is stored in the mass storage device 354, loaded into the memory device 356, and executed on the processor 352. The system control software 358 may include instructions for controlling timing, gas mixing, chamber and / or station pressure, chamber and / or station temperature, purge conditions and timing, wafer temperature, RF power level, RF frequency, substrate, pedestal, chuck, and / or susceptor position, and other parameters of the particular processes performed by the processing tool 300. The system control software 358 may be configured in any suitable manner. For example, subroutines or control objects of various processing tool components may be described to control the operation of the processing tool components necessary to perform various processing tool processes according to the disclosed methods. The system control software 358 may be coded in any suitable computer-readable programming language.

[0070] In some embodiments, the system control software 358 may include input / output control (IOC) sequence instructions for controlling the various parameters described above. For example, each stage of the PECVD process may include one or more instructions executed by the system controller 350. Instructions for setting the processing conditions of the PECVD process stage may be included in the corresponding PECVD recipe stage. In some embodiments, the PECVD recipe stages may be arranged in sequence such that all instructions for the PECVD process stage are executed simultaneously with that process stage.

[0071] In some embodiments, other computer software and / or programs stored in the mass storage device 354 and / or the memory device 356 associated with the system controller 350 may be employed. Examples of programs or portions of programs for this purpose include a substrate positioning program, a process gas control program, a pressure control program, a heater control program, and a plasma control program.

[0072] The substrate positioning program may include program code for a processing tool component used to mount a substrate on the pedestal 318 and control the spacing between the substrate and other components of the processing tool 300.

[0073] The process gas control program may include code for controlling the gas composition and flow rate, and optionally for flowing gas into one or more processing stations prior to deposition, to stabilize the pressure within the processing station. The process gas control program may include code for controlling the gas composition and flow rate within any of the disclosed ranges. The pressure control program may include code for controlling the pressure within the processing station, for example, by adjusting a throttle valve in the exhaust system of the processing station, the gas flow into the processing station, etc. The pressure control program may include code for maintaining the pressure within the processing station within any of the disclosed pressure ranges.

[0074] The heater control program may include code for controlling the current to a heating unit used to heat the substrate. Alternatively, the heater control program may control the delivery of a heat transfer gas (such as helium) to the substrate. The heater control program may include instructions for maintaining the temperature of the substrate within any of the disclosed ranges.

[0075] The plasma control program may include code for setting the RF power level and frequency applied to the process electrode at one or more processing stations using, for example, any of the RF power levels disclosed herein. The plasma control program may also include code for controlling the duration of each plasma exposure.

[0076] In some embodiments, there may be a user interface associated with the system controller 350. The user interface may include a display screen, a graphical software display of the apparatus and / or processing conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0077] In some embodiments, the parameters adjusted by the system controller 350 may be related to the processing conditions. Non-limiting examples include process gas composition and absolute and relative flow rates, temperature, pressure, plasma conditions (such as RF power level, frequency, and exposure time), etc. These parameters may be provided to the user in the form of a recipe that can be input using the user interface.

[0078] Signals for monitoring the process may be provided by the analog and / or digital input connections of the system controller 350 from various process tool sensors. Signals for controlling the process may be output to the analog and digital output connections of the process tool 300. Non-limiting examples of process tool sensors that can be monitored include mass flow controllers, pressure sensors (such as pressure gauges), thermocouples, etc. Appropriate feedback and control algorithms programmed with the data from these sensors may be used to maintain the processing conditions.

[0079] Any suitable chamber may be used to implement the disclosed embodiments. Examples of deposition apparatuses include, but are not limited to, apparatuses of the VECTOR™ product family, SPEED™ product family, FLEX™ product family, and / or SEQUEL™ product family available from Lam Research Corporation, Fremont, California, respectively, or various other commercially available processing systems. Two or more stations may perform the same function. Similarly, two or more stations may perform different functions. Each station can be designed / configured to perform a specific function / method as desired.

[0080] FIG. 4 is a block diagram of a processing system suitable for performing a thin film deposition process according to a particular embodiment. System 400 includes a transfer module 403. The transfer module 403 provides a clean pressurized environment to minimize the risk of contamination as the substrate being processed moves between various reactor modules. Mounted on the transfer module 403 are two multi-station reactors 409 and 410, each capable of performing atomic layer deposition (ALD) and / or chemical vapor deposition (CVD) according to a particular embodiment. Reactors 409 and 410 may include a plurality of stations 411, 413, 415, and 417 that can execute operations sequentially or non-sequentially according to the disclosed embodiments. A station may include a heated pedestal or substrate support, one or more gas inlets or showerheads or distribution plates.

[0081] Also, one or more single or multi-station modules 407 capable of performing plasma or chemical (non-plasma) pre-cleaning or any other optional processes described in connection with the disclosed method may be mounted on the transfer module 403. In some cases, module 407 may be used for various processes for preparing a substrate for deposition, for example. Module 407 may also be designed / configured to perform various other processes such as etching or polishing. System 400 also includes one or more wafer source modules 401 where wafers are stored before and after processing. An atmospheric robot (not shown) in the atmospheric transfer chamber 419 may first remove the wafer from the source module 401 to the load lock 421. A wafer transfer device (usually a robot arm unit) in the transfer module 403 transfers the wafer from the load lock 421 to the modules mounted on the transfer module 403 and moves it between the modules.

[0082] In various embodiments, the system controller 429 is employed to control the processing conditions during deposition. The controller 429 will typically include one or more memory devices and one or more processors. The processor may include a CPU or computer, analog and / or digital input / output connections, a stepping motor controller board, etc.

[0083] The controller 429 may control all activities of the deposition apparatus. The system controller 429 executes system control software including a set of instructions for controlling timing, gas mixing, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power level, wafer chuck or pedestal position, and other parameters of a particular process. Other computer programs stored in the memory device associated with the controller 429 may be employed in some embodiments.

[0084] Typically, there will be a user interface associated with the controller 429. The user interface may include a display screen, a graphical software display of the device and / or processing conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0085] The system control logic may be configured in any suitable manner. Generally, this logic can be designed or configured within hardware and / or software. Instructions for controlling the drive electric circuit may be hard-coded or provided as software. The instructions may be provided by "programming". Such programming is understood to include any form of logic, including hard-coded logic in a digital signal processor, an application-specific integrated circuit, and other devices with specific algorithms implemented as hardware. Also, the programming is understood to include software or firmware instructions that can be executed on a general-purpose processor. The system control software may be coded in any suitable computer-readable programming language.

[0086] The computer program code for controlling the flow of reactants and other processes in the processing sequence can be described in any conventional computer-readable programming language, such as assembly language, C, C++, Pascal, Fortran, etc. The compiled object code or script is executed by the processor to perform the tasks specified within the program. Also, as described above, the program code may be hard-coded.

[0087] The controller parameters relate to process conditions such as, for example, process gas composition and flow rate, temperature, pressure, cooling gas pressure, substrate temperature, chamber wall temperature, etc. These parameters may be provided to the user in the form of a recipe and may be input using a user interface. Signals for monitoring the process may be provided by the analog and / or digital input connections of the system controller 429. Signals for controlling the process are output to the analog and digital output connections of the deposition apparatus 400.

[0088] The system software may be designed or configured in various ways. For example, various chamber component subroutines or control objects may be described to control the operation of the chamber components necessary to perform the deposition process (and, in some cases, other processes) according to the disclosed embodiments. Examples of programs or portions of programs for this purpose include substrate positioning code, process gas control code, pressure control code, and heater control code.

[0089] In some implementations, the controller 429 may be part of a system that may also be part of the example described above. Such a system may include semiconductor processing equipment such as one or more processing tools, one or more chambers, one or more processing platforms, and / or certain processing components (such as a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing a semiconductor wafer or substrate. This electronics may be referred to as a "controller" that can control various components or sub-components of one or more systems. Depending on the processing requirements and / or the type of system, the controller 429 may be programmed to control any of the processes disclosed herein, such as the supply of process gas, temperature setting (e.g., heating and / or cooling), pressure setting, vacuum setting, power setting, setting of radio frequency (RF) generators in some systems, setting of RF matching circuits, frequency setting, flow rate setting, fluid supply setting, position and operation setting, transfer of wafers in and out, such as connection or interface connection to tools and other transfer tools and / or load locks connected to a particular system.

[0090] Broadly speaking, the controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that, for example, receive commands, issue commands, control operations, enable cleaning operations, and enable endpoint measurement. The integrated circuits may include chips in the form of firmware that stores program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers (e.g., software) that execute program instructions. The program instructions are instructions transmitted to the controller in the form of various individual settings (or program files) that define operating parameters for performing specific processing on a semiconductor wafer or for a semiconductor wafer or for the system. The operating parameters may, in some embodiments, be part of a recipe defined by a process engineer to achieve one or more processing steps in the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer types.

[0091] In some implementations, the controller may be integrated with, coupled to, or network-connected to the system, or a combination thereof, and may be part of a computer or coupled to a computer. For example, the controller may be all or part of a host computer system within a "cloud" or a manufacturing plant that enables remote access to wafer processing. By enabling remote access to the system, this computer can monitor the current progress of the assembly operation, verify the history of past assembly operations, verify trends or performance metrics from multiple manufacturing operations, change the parameters of the current process, set the process steps following the current process, or initiate a new process. In some examples, a remote computer (e.g., a server) can provide a process recipe to the system through a network that can include a local network or the Internet. The remote computer may include a user interface that enables input or programming of parameters and / or settings, and the parameters and / or settings are then transmitted from the remote computer to the system. In some examples, the controller receives instructions in a data format that defines the parameters of each process step performed during one or more operations. It should be understood that this parameter may be specific to the type of process being performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by including one or more separate controllers that are network-connected to each other and operate towards a common purpose such as the processes and controls described herein. Examples of controllers distributed for such purposes include one or more integrated circuits on a chamber that are combined to communicate with one or more integrated circuits that are remotely located (e.g., at the platform level or as part of a remote computer) to control the processes on the chamber.

[0092] Although not limited, exemplary systems may include a plasma etching chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etching chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etching (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be related to or used in the assembly and / or manufacture of semiconductor wafers.

[0093] As described above, depending on one or more processing steps performed by a tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a main computer, other controllers, or one or more of the tools used for material transfer that transports the wafer container to and / or from tool positions and load ports within a semiconductor manufacturing factory.

[0094] Experiment: Figure 5 shows the experimental results of Fourier transform infrared spectroscopy (FTIR) of the boron-containing ceramic film deposited according to the embodiments of this specification. In this example, the boron-containing ceramic film is boron carbide. For clarity, the boron carbide film analyzed in relation to Figure 5 is referred to as "boron carbide film 1". The reactants used to form boron carbide film 1 include BF3 and CH4, as well as an inert gas. The flow rates of these reactants were carefully controlled to achieve a film with a specific B:C ratio, which will be further described below. When exposed to appropriate plasma conditions at a temperature of about 600 °C, BF3 and CH4 reacted with each other to form boron carbide according to Reaction 1 above. As shown in Reaction 1, gaseous HF and CH2F2 were also produced and efficiently removed from the reaction chamber through a vacuum connection. There may also have been other reaction products generated.

[0095] FTIR analysis reveals what types of bonds are present in boron carbide film 1 and their relative abundances. In the results of Figure 5, a substantial B-C bond is shown at a wavenumber of approximately 1200 (cm -1 ). This suggests a high degree of boron-carbon bonding in the analyzed film. Figure 5 also shows a small amount of B-H bond at a wavenumber of approximately 2600 (cm -1 ) and a very small amount of C-H bond at a wavenumber of approximately 2900 (cm -1 ). This suggests a small amount of boron-hydrogen bonding and a very small amount of carbon-hydrogen bonding within the analyzed film. Also, no B-O bond was observed. Since the B-C peak is much stronger than other combined peaks, it is clear that boron carbide film 1 is substantially composed of B-C bonds. From these results, it was estimated that the hydrogen content of the film is about 4% or less.

[0096] In addition, to more accurately characterize the composition of the film, Rutherford backscattering analysis (RBS) and hydrogen forward scattering spectroscopy (HFS) were performed on boron carbide film 1 analyzed in relation to Figure 5. The results are shown in Table 1 below.

Table 1

[0097] The results of RBS / HFS shown in Table 1 generally agree with the (less accurate) FTIR results described in connection with FIG. 5. The exact hydrogen content listed in Table 1 (e.g., 12.5% H) is higher than the approximate hydrogen content (e.g., 4% H) estimated from the data in FIG. 5, but it is understood that the exact hydrogen content is still quite low. Specifically, boron carbide film 1 has significantly less hydrogen compared to boron carbide films deposited according to conventional low-temperature techniques (e.g., using diborane as a reactant). Conventional diborane-based techniques typically produce films with at least about 20% hydrogen. As described above, the relatively high levels of hydrogen in conventional low-temperature boron-based ceramic films lead to poor quality such as high etching rates and corresponding low etching selectivity, low mechanical strength (e.g., low hardness and low Young's modulus), etc.

[0098] Also, Table 1 shows that boron carbide film 1 has a very low oxygen and fluorine content. A low oxygen content is desirable because it means that the film does not oxidize and is less likely to absorb moisture, thereby ensuring that the film remains stable over time. In this example, the FTIR cut-off time was 4 weeks. A low fluorine (or other halide) content is desirable because it reduces the risk of fluorine (or other halides) migrating to other parts of the device (e.g., the underlying or overlying layers) and causing damage there.

[0099] Furthermore, X-ray diffraction analysis (XRD) of boron carbide film 1 was performed, and it was found that the film is amorphous. No signs of crystallinity were observed. Additionally, this film had good adhesion to the underlying layer.

[0100] Figures 6A - 6F show the results of X-ray photoelectron spectroscopy (XPS) related to the boron carbide film 1 described in relation to FIG. 5 and Table 1. As described above, the boron carbide film 1 was deposited at a temperature of about 600°C. FIG. 6A shows a fluorine 1s scan, FIG. 6B shows a silicon 2p scan, FIG. 6C shows a boron 1s scan, FIG. 6D shows a carbon 1s scan, FIG. 6E shows a nitrogen 1s scan, and FIG. 6F shows an oxygen 1s scan.

[0101] Figures 7A - 7F show XPS results related to a boron carbide film deposited according to another embodiment of the present specification. For clarity, the film analyzed in relation to FIGS. 7A - 7F is referred to as the "boron carbide film 2". Compared with the boron carbide film 1 deposited at about 600°C, the boron carbide film 2 was deposited at a lower temperature of about 400°C. FIG. 7A shows a fluorine 1s scan, FIG. 7B shows a silicon 2p scan, FIG. 7C shows a boron 1s scan, FIG. 7D shows a carbon 1s scan, FIG. 7E shows a nitrogen 1s scan, and FIG. 7F shows an oxygen 1s scan.

[0102] The XPS results of FIGS. 6A - 6F and 7A - 7F generally agree with the FTIR / RBS / HFS results showing a significant amount of boron / carbon and much smaller amounts of other elements in the film, as described above. Generally speaking, the results of FIGS. 6A - 6F and 7A - 7F reveal a simple bond structure in the boron carbide film in which B - C bonds are dominant and B - H and B - O bonds are hardly or not at all observed. For example, boron and carbon each show a single-bond state, indicating that most are B - C bonds.

[0103] Table 2 shows the deposition temperatures of the two films described in this column and the hardness / Young's modulus obtained.

Table 2

[0104] The boron carbide film 2 deposited at a lower temperature showed a lower hardness and Young's modulus compared to the boron carbide film 1 at a higher temperature, but these properties were still within an acceptable range for various desired applications such as hard mask applications. In particular, the hardness and Young's modulus were still significantly higher for the boron carbide films deposited according to the embodiments of the present specification compared to similar films deposited using conventional low-temperature techniques that relied on the use of diborane.

[0105] Table 3 shows various properties of the boron carbide film 1 and a similar boron carbide film deposited according to a conventional low-temperature technique that relied on the use of diborane.

Table 3

[0106] The results in Table 3 indicate that the boron-based ceramic films formed according to the embodiments herein can have significantly improved properties compared to low-temperature boron-based ceramic films deposited by conventional methods using diborane or other hydrogen and boron-containing reactants. In various embodiments, the boron-based ceramic films deposited according to the embodiments herein may have any combination of the following properties: a hardness of about 20 GPa or more, such as about 25 GPa or more; a hardness of about 40 GPa or less, such as about 35 GPa or less, or about 30 GPa or less, or between about 25 - 30 GPa; a Young's modulus of about 175 GPa or more, such as about 200 GPa or more, or about 250 GPa or more; a Young's modulus of about 400 GPa or less, such as about 350 GPa or less, or about 300 GPa or less; a hydrogen content of about 15% or less, such as about 13% or less; a boron content of about 50% or more, such as about 60% or more; a fluorine (or other halide) content of about 1% or less, such as about 0.75% or less; an oxygen content of about 1% or less, such as about 0.5% or less; and a density of about 2 g / cc or more, such as about 2.2 g / cc or more. Further, the boron-based ceramic films formed according to the embodiments herein typically exhibit good adhesion to the underlying silicon layer and will show little or no water uptake even after a four-week waiting period. As shown in Table 3, these properties are generally not achievable with conventional low-temperature techniques. Additionally, as described above, high-temperature techniques for forming boron-based ceramic materials are often inappropriate for hard mask and similar semiconductor applications due to the limited thermal budget for such applications and the high crystallinity typically resulting from high-temperature processing. Thus, the techniques described herein provide excellent film properties that significantly improve upon the prior art.

[0107] Conclusion: Although the foregoing embodiments have been described in some detail for clarity of understanding, it will be apparent that certain changes and modifications may be made within the scope of the appended claims. Note that there are many alternative ways to implement the processes, systems, and apparatuses of this embodiment. Therefore, this embodiment is illustrative rather than restrictive, and this embodiment should be considered not to be limited to the details provided herein. Also, the present disclosure can be realized in the following forms. [Form 1] A method of forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of about 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. A method comprising the above steps. [Form 2] The method according to Form 1, wherein the boron-based ceramic film has a hydrogen content of about 15 (atomic) % or less. [Form 3] The method according to Form 2, wherein the boron-based ceramic film has a halide content of about 1 (atomic) % or less. [Form 4] The method according to Form 3, wherein the boron-based ceramic film has a Young's modulus of about 175 GPa or more. [Form 5] The method according to Form 4, wherein the boron-based ceramic film has an oxygen content of about 1 (atomic) % or less. [Form 6] The method according to Form 1, wherein the second reactant contains a saturated hydrocarbon or an unsaturated hydrocarbon, and the saturated hydrocarbon or the unsaturated hydrocarbon is the only hydrogen-containing precursor supplied to the reaction chamber. [Form 7] The method according to Form 1, wherein the first reactant contains BF 3 and the second reactant contains CH 4 , and the boron-based ceramic film contains boron carbide having a composition of B x C y (where 2 < x < 4.5 and y = 1). [Form 8] The method according to Form 1, wherein the boron-based ceramic film further contains tungsten and / or silicon. [Form 9] The method according to Form 1, wherein the Young's modulus of the boron-based ceramic film is between about 250 and 300 GPa. [Form 10] The method according to Form 1, wherein the hardness of the boron-based ceramic film is about 20 GPa or more. [Form 11] The method according to Form 1, wherein the hydrogen content of the boron-based ceramic film is about 13 (atomic) % or less. [Form 12] The method according to Form 1, wherein the halide content of the boron-based ceramic film is about 0.75 (atomic)% or less. [Form 13] The method according to Form 1, wherein the density of the boron-based ceramic film is about 2 g / cc or more. [Form 14] The method according to Form 1, wherein the boron-based ceramic film has a boron content of about 50 (atomic)% or more. [Form 15] The method according to Form 1, wherein the first reactant is BF 3 and / or BCl 3 . [Form 16] The method according to Form 1, wherein the first reactant is BBr 3 and / or Bl 3 . [Form 17] The method according to Form 1, wherein the second reactant comprises a reactant selected from the group consisting of methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ), ethene (C 2 H 4 ), and propene (C 3 H 6 ). [Form 18] The method according to Form 1, wherein the boron-based ceramic film is amorphous. [Form 19] An apparatus for substrate processing, comprising (a) a reaction chamber, (b) a substrate support configured to support a substrate within the reaction chamber, (c) one or more inlets for introducing reactants into the reaction chamber, (d) one or more outlets for removing materials from the reaction chamber, (e) a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected to each other, and the memory stores computer-executable instructions for controlling the at least one processor to (i) expose the substrate to a capacitively coupled plasma to carry out a plasma-excited chemical vapor deposition reaction between boron halide and an additional reactant to form a boron-based ceramic film on the substrate at a temperature of about 600 °C or less. [Form 20] An apparatus for forming a boron-based ceramic film on a substrate, comprising (a) a reaction chamber, (b) a substrate support configured to support the substrate within the reaction chamber, (c) one or more inlets for introducing reactants into the reaction chamber, (d) one or more outlets for removing materials from the reaction chamber, (e) a plasma generator configured to generate a capacitively coupled plasma within the reaction chamber (f) a controller having at least one processor and a memory, and wherein the at least one processor and the memory are communicably connected to each other, and the memory stores computer-executable instructions for controlling the at least one processor to (i) accommodate the substrate in the reaction chamber, (ii) introduce a first reactant and a second reactant into the reaction chamber, (iii) generate the plasma in the reaction chamber, and react the first reactant and the second reactant at a temperature of about 600° C. or lower to form the boron-based ceramic film on the substrate, wherein the boron-based ceramic film has (1) a Young's modulus of about 175 GPa or more, (2) a hydrogen content of about 15 (atomic)% or less, and (3) a halide content of about 1 (atomic)% or less, and the device.

Claims

1. A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. The method includes: the boron-based ceramic film having a hydrogen content of 15 atomic % or less. A method.

2. The method according to claim 1, wherein: the boron-based ceramic film has a halide content of 1 atomic % or less.

3. The method according to claim 2, wherein: the boron-based ceramic film has a Young's modulus of 175 GPa or more.

4. The method according to claim 3, wherein: the boron-based ceramic film has an oxygen content of 1 atomic % or less.

5. The method according to claim 1, wherein: the second reactant contains a saturated hydrocarbon or an unsaturated hydrocarbon, and the saturated hydrocarbon or the unsaturated hydrocarbon is the only hydrogen-containing precursor supplied to the reaction chamber.

6. A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. The method includes: wherein the first reactant contains BF 3 and the second reactant contains CH 4 and the boron-based ceramic film contains B x C y (where 2 < x < 4.5 and y = 1), a method comprising boron carbide having the composition of.

7. A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. The method includes: A method in which the boron-based ceramic film further contains tungsten and / or silicon. **Claim 8**: A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating an inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. The method includes: wherein the Young's modulus of the boron-based ceramic film is between 250 and 300 GPa. **Claim 9**: A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating an inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. The method includes: wherein the hardness of the boron-based ceramic film is 20 GPa or more. **Claim 10**: A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating an inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600 °C or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate. The method includes: wherein the hydrogen content of the boron-based ceramic film is 13 (atomic) % or less. **Claim 11**: A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600° C. or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate; comprising a method in which the halide content of the boron-based ceramic film is 0.75 (atomic) % or less.

12. A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600° C. or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate; comprising a method in which the density of the boron-based ceramic film is 2 g / cc or more.

13. A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600° C. or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate; comprising a method in which the boron-based ceramic film has a boron content of 50 (atomic) % or more.

14. The method according to claim 1, wherein the first reactant comprises BF 3 and / or BCl 3 A method comprising.

15. A method for forming a boron-based ceramic film on a substrate, comprising: (a) accommodating the substrate in a reaction chamber; (b) supplying a first reactant containing boron halide and a second reactant to the reaction chamber; The first reactant is BBr 3 and / or Bl 3 A method comprising. (c) generating inductively coupled plasma in the reaction chamber, and reacting the first reactant with the second reactant at a temperature of 600° C. or lower in a plasma-excited chemical vapor deposition reaction to form the boron-based ceramic film on the substrate; The second reactant is methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ), ethene (C 2 H 4 ), and propene (C 3 H 6 ), and a method comprising a reactant selected from the group consisting of comprising

16. The method according to claim 1,

17. The method according to claim 1, a method in which the boron-based ceramic film is amorphous.

18. An apparatus for substrate processing, (a) A reaction chamber, (b) A substrate support configured to support a substrate within the reaction chamber, (c) One or more inlets for introducing reactants into the reaction chamber, (d) One or more outlets for removing materials from the reaction chamber, (e) A controller having at least one processor and a memory comprising, the at least one processor and the memory being communicatively connected to each other, the memory controlling the at least one processor to, (i) Exposing the substrate to an inductively coupled plasma to carry out a plasma-excited chemical vapor deposition reaction between boron halide and an additional reactant to form a boron-based ceramic film on the substrate at a temperature of 600 °C or lower, storing computer-executable instructions therefor, the boron-based ceramic film having a halide content of 1 (atomic) % or less, an apparatus.

19. An apparatus for forming a boron-based ceramic film on a substrate, (a) A reaction chamber, (b) A substrate support configured to support the substrate within the reaction chamber, (c) One or more inlets for introducing reactants into the reaction chamber, (d) One or more outlets for removing materials from the reaction chamber, (e) A plasma generator configured to generate an inductively coupled plasma within the reaction chamber, (f) A controller having at least one processor and a memory comprising, the at least one processor and the memory being communicatively connected to each other, the memory controlling the at least one processor to, (i) Accommodate the substrate within the reaction chamber, (ii) Flow a first reactant and a second reactant into the reaction chamber, (iii) Generate the plasma within the reaction chamber and react the first reactant and the second reactant at a temperature of 600 °C or lower to form the boron-based ceramic film on the substrate, storing computer-executable instructions therefor, the boron-based ceramic film having (1) A Young's modulus of 175 GPa or more, (2) A hydrogen content of 15 (atomic) % or less, (3) A halide content of 1 (atomic) % or less, having, the first reactant comprising boron halide , an apparatus.

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