Layer forming method and apparatus

Abstract

To provide a method and a device for depositing a molybdenum-containing layer on a substrate.SOLUTION: There are provided a method and a device for depositing a molybdenum-containing layer on a substrate, by forming a molybdenum layer, by supplying a precursor containing molybdenum(VI) dichloride dioxide and a first reactant containing boron and hydrogen to a substrate in a chamber, to thereby generate a reaction. The first reactant containing boron and hydrogen is diborane.SELECTED DRAWING: Figure 1a

Description

[Technical field]

[0001] The present disclosure relates generally to methods and apparatus for forming a layer on a substrate. More specifically, the present disclosure relates to methods and apparatus for depositing a molybdenum-containing layer on a substrate in a reaction chamber.

[0002] The deposition method can include delivering a precursor comprising molybdenum dichloride dioxide and a first reactant to a substrate in a reaction chamber and reacting a portion of the precursor and the first reactant to form a molybdenum layer. The layer on the substrate can be used for the manufacture of a semiconductor device. [Background technology]

[0003] In atomic layer deposition (ALD) and chemical vapor deposition (CVD), a substrate is exposed to suitable precursors and first reactants that react into a desired layer on the substrate. A layer may be deposited in a gap created during the fabrication of a feature on the substrate to fill the gap.

[0004] In ALD, the substrate is exposed to a pulse of precursor, and a monolayer of the precursor may chemisorb to the substrate surface. The surface sites may be occupied by the precursor in whole or by its fragments. The precursor cannot adsorb or react with the portion of the precursor already adsorbed on the substrate surface, and the reaction may be chemically self-limiting. The excess precursor is then purged, for example, by supplying an inert gas and / or pumping it out of the reaction chamber. The substrate is then exposed to a pulse of the first reactant, which chemically reacts with the adsorbed precursor in whole or by its fragments until the reaction is complete, and the surface is covered with a monolayer of the reaction product.

[0005] It has been recognized that there may be a need to improve the quality of the deposition process of the molybdenum layer. Summary of the Invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are described in more detail below in the Detailed Description of exemplary embodiments of this disclosure. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0007] There may be a need for an improved method of forming a deposited molybdenum layer on a substrate. Thus, in an embodiment, a method of depositing a molybdenum-containing layer on a substrate in a reaction chamber may be provided. The method may include delivering a precursor including molybdenum (VI) dichloride dioxide (MoO2Cl2) to the substrate in the reaction chamber. The method may include delivering a first reactant to the substrate in the reaction chamber and reacting the precursor and a portion of the first reactant to form the molybdenum layer. The first reactant may include boron and hydrogen.

[0008] By having a first reactant that includes boron and hydrogen, the reactivity of the first reactant with a precursor that includes molybdenum (VI) dichloride dioxide (MoO2Cl2) may be improved. Thus, the deposition of the molybdenum layer may be improved. The quality of the overall layer may be improved and / or the rate of the deposition process may be improved.

[0009] In some other embodiments, a method of semiconductor processing is provided, the method including depositing a metal layer into a gap in a substrate, thereby filling the gap.

[0010] According to a further embodiment, there is provided a deposition apparatus for depositing a molybdenum-containing layer on a substrate, comprising: a reaction chamber including a substrate holder for holding a substrate; a heating system constructed and arranged to control the temperature of the substrate; a delivery system comprising a valve for providing a precursor and at least a first reactant into the reaction chamber; and a sequence controller operably connected to the valves and programmed to enable deposition of molybdenum on a substrate in a reaction chamber containing a precursor and a first reactant, the distribution system providing a precursor delivery device that delivers molybdenum (VI) dichloride dioxide (MoO2Cl2) vapor and a first reactant delivery system constructed and arranged to deliver vapor of a first reactant comprising boron and hydrogen.

[0011] While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present disclosure, the advantages of the presently disclosed embodiments may be more readily ascertained from the following description of certain specific examples of the presently disclosed embodiments when read in conjunction with the appended drawings. [Brief description of the drawings]

[0012] [Figure 1a] 1 shows a flow chart illustrating a method for depositing a layer, according to one embodiment. [Figure 1b] 1 shows a flow chart illustrating a method for depositing a layer, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Although certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, and obvious modifications and equivalents thereof, and therefore it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0014] The figures shown herein are not meant to be actual illustrations of any particular materials, structures or devices, but merely idealized representations used to describe embodiments of the present disclosure.

[0015] As used herein, the term "substrate" may refer to any underlying material or materials that may be used or upon which a device, circuit or film may be formed.

[0016] As used herein, the term "cyclic deposition" refers to the sequential introduction of one or more precursors (reactants) into a reaction chamber to deposit a film on a substrate, and includes deposition techniques such as atomic layer deposition and cyclic chemical vapor deposition.

[0017] As used herein, the term "cyclic chemical vapor deposition" can refer to any process in which a substrate is sequentially exposed to one or more volatile precursors that react and / or decompose on the substrate to produce a desired deposit.

[0018] The term "atomic layer deposition" (ALD) as used herein can refer to a vapor deposition process in which a deposition cycle, preferably multiple consecutive deposition cycles, are performed in a reaction chamber. Typically, during each cycle, a precursor is chemisorbed to the deposition surface (e.g., the surface of a substrate or a surface of a previously deposited underlayer, such as a material deposited using a previous ALD cycle) to form a monolayer or submonolayer that does not readily react with additional precursors (i.e., a self-limiting reaction). If necessary, a reactant (e.g., another precursor or reactant gas) can then be subsequently introduced into the process chamber for use in converting the chemisorbed precursor to the desired material on the deposition surface. Typically, this reactant can further react with the precursor. Additionally, a purging step can be utilized during each cycle to remove excess precursor from the process chamber after conversion of the chemisorbed precursor and / or to remove excess reactants and / or reaction by-products from the process chamber. Additionally, the term "atomic layer deposition" as used herein is also meant to include processes indicated by related terms, such as, for example, "chemical vapor deposition atomic layer deposition," "atomic layer epitaxy" (ALE), molecular beam epitaxy (MBE), gas source MBE, or metalorganic MBE, as well as chemical beam epitaxy when performed with alternating pulses of precursor compositions, reactive gases, and purge (e.g., inert carrier) gases.

[0019] As used herein, the term "layer" is intended to mean any continuous or non-continuous structure and material formed by the methods disclosed herein. For example, a "layer" can include 2D materials, nanolaminates, nanorods, nanotubes, or nanoparticles, or even partial or complete molecular layers, or partial or complete atomic layers, or clusters of atoms and / or molecules. A "layer" can include materials or layers that have pinholes, yet are at least partially continuous.

[0020] A molybdenum layer may be desired as a conductive layer in a semiconductor device. Thus, a method may be used to deposit a molybdenum-containing layer on a substrate in a reaction chamber. The method may include providing a precursor including molybdenum (VI) dichloride dioxide (MoO2Cl2) to a substrate in a reaction chamber. The precursor may include a molybdenum oxyhalide rather than molybdenum oxytetrachloride (MoOCl4). The precursor may include a molybdenum oxychloride rather than molybdenum oxytetrachloride (MoOCl4). The precursor may have Mo-O and Mo-Cl bonds rather than molybdenum oxytetrachloride (MoOCl4). The precursor may include a molybdenum oxyhalide having the same number of oxygens as chloride atoms bonded to the molybdenum. The precursor may include a molybdenum oxyhalide having two oxygen and two chloride atoms bonded to the molybdenum.

[0021] The method can further include providing a first reactant comprising boron and hydrogen onto the substrate in the reaction chamber and reacting a portion of the precursor and the first reactant to form a molybdenum layer on the substrate. The first reactant comprising boron and oxygen is represented by the formula B n H (n+x) where n is an integer from 1 to 10 and x is an even number.

[0022] The first reactant containing boron and hydrogen can be, for example, a compound represented by the formula B n H (n+4) The nido-borane may be selected from the group consisting of:

[0023] The first reactant containing boron and hydrogen can be, for example, a compound represented by the formula B n H (n+6) The arachno-boranes may be selected from the group consisting of:

[0024] The first reactant containing boron and hydrogen can be, for example, a compound represented by the formula B n H (n+8) The borane may be selected from the group consisting of the hypo-boranes.

[0025] The first reactant containing boron and hydrogen is, for example, B n H m In the above embodiment, n is an integer from 1 to 10, and m is an integer from 1 to 10 different from n.

[0026] The first reactant containing boron and hydrogen may be diborane (B2H6). Diborane may have a structure with four terminal and two bridging hydrogen atoms. The bond between the boron and the terminal hydrogen atoms is a conventional covalent bond. The bond between the boron atom and the bridging hydrogen atoms may be different since two electrons are used to bond to the terminal hydrogen atoms, and each boron atom has one valence electron for the additional bond. The bridging hydrogen atoms each donate one electron, so the boron atoms of diborane may be held together by four electrons. The length of the B-H bridging bond may be longer than the B-H terminal bond. The difference in the length of these bonds may reflect the difference in their strength. The B-H bridging bond of diborane may be relatively weak.

[0027] The reduction of molybdenum dichloride dioxide (MoO2Cl2) by diborane (B2H6) has the following reaction pathway: MoO2Cl2+1 / 2 B2H6→Mo(s)+BOCl+HCl+H2O The B-H bridge bond of diborane may need to be broken to cleave diborane in half for the reaction. Compared to the reaction pathway of MoO2Cl2+3H2→Mo(s)+2HCl+2H2O, fewer molecules with weaker hydrogen bonds may also be involved in facilitating the reaction of MoO2Cl2 with B2H6. The reduction of molybdenum oxytetrachloride (MoOCl4) by diborane (B2H6) follows MoOCl4+1 / 2 B2H6→Mo(s)+BOCl+3HCl, which may lead to a high concentration of etchant HCl in the reaction chamber, which may cause undesirable etching and / or deposition rates.

[0028] Diborane can be a highly reactive and versatile reactant. Diborane is used in the semiconductor industry, for example as a doping agent. Therefore, diborane can be easily adopted in the industry as a reactant for molybdenum (VI) dichloride dioxide (MoO2Cl2) for molybdenum deposition.

[0029] The surface on which molybdenum can be deposited may comprise any deposition material. Alternatively, the surface may comprise a different type of deposition material. The surface may comprise, for example, aluminum oxide and / or titanium nitride. For example, when a molybdenum conductive layer may be desired, it may be difficult to deposit molybdenum on a different material. The first layer, called the seed or nucleation layer, may be more difficult to deposit. Therefore, it may be preferable to provide molybdenum (VI) dichloride dioxide (MoO2Cl2) to the substrate in the reaction chamber, and to supply a first reactant comprising boron and hydrogen to the substrate in the reaction chamber, to react a portion of the precursor with the first reactant, and to form a molybdenum seed layer on the substrate.

[0030] Gaps created during the fabrication of features of integrated circuit devices may be filled with a metal layer, for example made of molybdenum. The gaps may have a high aspect ratio such that their depth is much greater than their width. The gaps may extend vertically into already fabricated layers with a substantially horizontal top surface. Vertical metal-filled gaps may be used, for example, for wordlines in dynamic random access memory (DRAM) type memory integrated circuits. Vertical metal-filled gaps may also be used, for example, in logic integrated circuits. For example, metal-filled gaps may be used as gate fills in P-type metal oxide semiconductor (PMOS) or complementary metal oxide semiconductor (CMOS) integrated circuits or source / drain trench contacts.

[0031] The gaps may be arranged horizontally in already fabricated layers. Again, the gaps may have a high aspect ratio, such that their depth in the horizontal direction is now much greater than their width. Horizontal, metal-filled gaps may be used, for example, for wordlines in 3D NAND type memory integrated circuits. Gaps may also be arranged in a combination of vertical and horizontal directions.

[0032] The surface of the gap may include one type of deposition material. Alternatively, the surface of the gap may include different types of deposition materials. The surface of the gap may include, for example, aluminum oxide and / or titanium nitride. For example, when a molybdenum conductive layer is desired in the gap, it may be difficult to deposit the molybdenum onto the different materials of the gap. It may be desirable for the molybdenum layer to cover the entire surface of the gap, filling the complete gap. Additionally, it may be desirable for the molybdenum layer to cover the entire surface of the gap that includes different types of materials.

[0033] To fill the complete gap, a molybdenum seed layer may be deposited in the gap and a molybdenum bulk layer may be deposited on the molybdenum seed layer. The seed layer may be formed by sequentially repeating pretreatment atomic layer deposition (ALD) cycles. Thus, it may be preferred to provide molybdenum (VI) dichloride dioxide (MoO2Cl2) to a substrate in a reaction chamber, supply a first reactant including boron and hydrogen to the substrate in the reaction chamber, react a portion of the precursor with the first reactant, and form a molybdenum seed layer in the gap on the substrate.

[0034] Alternatively, the seed layer may be formed by a chemical vapor deposition (CVD) process. The CVD process may be pulsed, where a first precursor is delivered onto the substrate in pulses, while a first reactant is delivered to the substrate continuously.

[0035] A bulk layer can be deposited over the seed layer by sequentially repeating the bulk ALD cycles. A bulk molybdenum layer can be provided over the molybdenum seed layer by supplying a precursor including molybdenum(VI) dichloride dioxide (MoO2Cl2) and a second reactant including hydrogen to a substrate in a reaction chamber, where a portion of the precursor and the second reactant react to form the bulk molybdenum layer. The second reactant can include hydrogen (H2). The second reactant can be free of boron. Hydrogen can be a relatively inexpensive and common reactant.

[0036] Alternatively, the bulk molybdenum layer may be deposited on the molybdenum seed layer by a CVD process that may be pulsed, where the second precursor is delivered to the substrate in pulses, while the second reactant is delivered to the substrate continuously.

[0037] 1a and 1b show a flow chart outlining a method for depositing a molybdenum layer, according to one embodiment.

[0038] The molybdenum layer may be deposited as a seed layer. The molybdenum layer may be deposited in the gap. A bulk molybdenum layer may be deposited on the seed layer.

[0039] A first ALD cycle 1 of the molybdenum seed layer can be shown in Figure 1a. A second ALD cycle 2 of the molybdenum bulk layer can be shown in Figure 1b.

[0040] A substrate having a gap may be provided in the reaction chamber in step 3. A first precursor including molybdenum (VI) dichloride dioxide (MoO2Cl2) may be supplied to the substrate for a first supply period T1 in step 5 (see FIG. 1a). Thereafter, additional supply of the first precursor to the substrate can be stopped, e.g., by purging a portion of the first precursor from the reaction chamber, e.g., during a first removal period R1 in step 7.

[0041] Further, the first cycle may include supplying 9 a first reactant to the substrate during a second supply period T2. The first reactant may include boron and hydrogen. The first reactant may include boron and hydrogen atoms in one molecule, for example, diborane (B2H6). Hydrogen gas may be added to the gas flow of the first reactant. A portion of the first precursor and the first reactant may react to form at least a portion of a molybdenum seed layer on the substrate. A small number of cycles (approximately 50) may be required before deposition of the seed layer begins. For example, additional supply of the first reactant to the substrate may be stopped during the second removal period R1 of step 10, for example, by purging a portion of the first reactant from the reaction chamber.

[0042] Optionally, the first reactant may be used to clean the substrate before the seed layer is deposited. The diborane reactant is highly reactive and can be effective at cleaning the surface of the substrate.

[0043] The first precursor and the first reactant can be selected to have suitable nucleation on the surface of the gap. The first ALD cycle 1 can be repeated N times to deposit a molybdenum seed layer, where N is selected between 100 and 1000, preferably between 200 and 800, and more preferably between 300 and 600. The seed layer can have a thickness of 1 to 20 nm, preferably between 2 to 10 nm, and more preferably between 3 to 7 nm.

[0044] After the first ALD cycle 1 has been repeated N times, a first precursor including molybdenum(VI) dichloride dioxide (MoO2Cl2) can be provided to the substrate in step 11 during a third delivery period T3 of bulk ALD cycle 2 (see FIG. 1b), which can be performed in the same reaction chamber as the first ALD cycle 1 of FIG. 1a or in a different reaction chamber.

[0045] When the temperature requirements for the first cycle are different, it may be advantageous to perform the bulk ALD cycle in a different reaction chamber than the first ALD cycle, and thus substrate transport may be required.

[0046] Thereafter, additional delivery of the first precursor to the substrate may be stopped and removed from the reaction chamber, which may be accomplished by purging a portion of the first precursor from the reaction chamber to the exhaust pump of the reaction chamber during a third removal period R3 of step 13.

[0047] The cycle may further include supplying 15 a second reactant to the substrate during a fourth supply period T4. A portion of the first precursor and the second reactant may react to form at least a portion of a bulk molybdenum layer on the substrate. For example, during a fourth removal period R4 of step 17, additional supply of the second reactant to the substrate may be stopped, for example, by purging a portion of the second reactant from the reaction chamber.

[0048] The first precursor and second reactant can be selected to have suitable electronic properties, for example, low electrical resistivity, and the molybdenum film can have an electrical resistivity of less than 3000 μΩ·cm, or less than 1000 μΩ·cm, or less than 500 μΩ·cm, or less than 200 μΩ·cm, or less than 100 μΩ·cm, or less than 50 μΩ·cm, or less than 25 μΩ·cm, or less than 15 μΩ·cm, or even less than 10 μΩ·cm.

[0049] The second ALD cycle 2 for the bulk layer can be repeated M times, where M is selected between 200 and 2000, preferably between 400 and 1200, more preferably between 600 and 1000. The bulk molybdenum layer can have a thickness between 1 and 100 nm, preferably between 5 and 50 nm, more preferably between 10 and 30 nm.

[0050] The process temperature of the reaction chamber during the first ALD cycle for the seed molybdenum layer may be between 300 and 800° C., preferably between 400 and 700° C., more preferably between 500 and 650° C. The vessel in which the first precursor is evaporated may be maintained at between 20 and 150° C., preferably between 30 and 120° C., more preferably between 40 and 110° C.

[0051] The process temperature of the reaction chamber during the second ALD cycle for the bulk molybdenum layer may be between 300 and 800° C., preferably between 400 and 700° C., more preferably between 500 and 650° C. The vessel in which the first precursor is evaporated may be maintained at between 20 and 150° C., preferably between 30 and 120° C., more preferably between 40 and 110° C.

[0052] Supplying the first precursor to the reaction chamber may take a duration T1, T3 selected from 0.1 to 10 seconds, preferably 0.5 to 5 seconds, more preferably 0.8 to 2 seconds. For example, T1 may be 1 second and T3 may be 1.3 seconds. The flow rate of the first or second precursor to the reaction chamber may be selected from 50 to 1000 sccm, preferably 100 to 500 sccm, more preferably 200 to 400 sccm. The pressure of the reaction chamber may be selected from 0.1 to 100 Torr, preferably 1 to 50 Torr, more preferably 4 to 20 Torr.

[0053] Supplying the first and / or second reactant to the reaction chamber for duration T2, T4 may take 0.5-50 seconds, preferably 1-10 seconds, more preferably 2-8 seconds. The flow rate of the first or second reactant to the reaction chamber may be selected from 50-50000 sccm, preferably 100-20000 sccm, more preferably 500-10000 sccm.

[0054] For the second reactant, we can consider silane. The general formula for silane is Si x H2 (x+2)where x is an integer 1, 2, 3, 4.... Silane (SiH4), disilane (Si2H6) or trisilane (Si3H8) can be suitable examples of second reactants bearing hydrogen atoms.

[0055] Purging a portion of at least one of the first precursor, the first reactant, and the second reactant from the reaction chamber for a duration R1, R2, R3, or R4 can be performed for a period of 0.5 to 50 seconds, preferably 1 to 10 seconds, and more preferably 2 to 8 seconds.

[0056] After delivering the first precursor to the substrate, after delivering the first reactant to the substrate, and after delivering the second reactant to the reaction chamber, purging can be used to remove a portion of at least one of the first precursor, the first reactant, and the second reactant from the reaction chamber for a duration R1, R2, R3, or R4. Purging can be accomplished by pumping and / or delivering a purge gas. The purge gas can be an inert gas, such as nitrogen.

[0057] The method can be used in single or batch wafer ALD equipment.

[0058] The method can include providing a substrate to a reaction chamber, and a first ALD cycle in the reaction chamber can include delivering a first precursor to the substrate in the reaction chamber, purging a portion of the first precursor from the reaction chamber, delivering a first reactant to the substrate in the reaction chamber, and purging a portion of the first reactant from the reaction chamber.

[0059] The method can further include providing a substrate to a reaction chamber, and the bulk ALD cycle in the reaction chamber can include delivering a second precursor to the substrate in the reaction chamber, purging a portion of the second precursor from the reaction chamber, delivering a second reactant to the substrate in the reaction chamber, and purging a portion of the second reactant from the reaction chamber.

[0060] Exemplary single-wafer reactors specifically designed for carrying out ALD processes are commercially available from ASM International NV (Almere, The Netherlands) under the trade names Pulsar®, Emerald®, Dragon®, Synergis® and Eagle®. The method can also be carried out in a batch wafer reactor (e.g., a vertical furnace). For example, the deposition process can also be carried out in an A400™ or A412™ vertical furnace available from ASM International NV. The furnace can have a process chamber capable of accommodating quantities of 100 or more semiconductor substrates, or wafers, having diameters of 200 mm or 300 mm.

[0061] The wafer reactor can have a controller and memory that can control the reactor. In accordance with embodiments of the present disclosure, the memory can be programmed with a program that, when executed by the controller, delivers precursors and reactants to the reaction chamber.

[0062] Gaps that may be filled with molybdenum using the methods of the present disclosure may have a high aspect ratio such that the vertical and / or horizontal depth is much greater than the width. For example, the aspect ratio of the gap (gap depth / gap width) may be greater than about 2, greater than about 5, greater than about 10, greater than about 20, greater than about 50, greater than about 75, and in some cases greater than about 100, or greater than about 150, or even greater than about 200. The aspect ratio may be less than 1000.

[0063] It may be difficult to determine the aspect ratio for a gap, but in this context it may be pointed out that the aspect ratio may be replaced by the surface enhancement effect ratio, which is the ratio of the total surface area of ​​the wafer or a portion of the wafer to the planar surface area of ​​the wafer or a portion of the wafer. The surface enhancement effect ratio of a gap (surface of the gap / surface of the wafer) may be greater than about 2, greater than about 5, greater than about 10, greater than about 20, greater than about 50, greater than about 75, and in some cases greater than about 100, or greater than about 150, or even greater than about 200. The surface enhancement ratio may be less than 1000.

[0064] The surface of the gap may include different types of deposited materials. The surface may include, for example, Al2O3 or TiN.

[0065] A conformal molybdenum metal layer may be deposited on the surfaces of the gap by depositing a seed layer by successively repeating a first ALD cycle with a first precursor and a first reactant, and a conformal molybdenum bulk layer may be deposited on the seed layer by successively repeating a second ALD cycle with the first precursor and a second reactant.

[0066] Details of the method used are shown in Figures 1 and 1b and the associated description. In some embodiments, the deposited films including Mo can have a step coverage of greater than about 50%, greater than about 80%, greater than about 90%, greater than about 95%, greater than about 98%, or greater than about 99%.

[0067] The method can be carried out in an atomic layer deposition apparatus. For example, a deposition apparatus for depositing a molybdenum-containing layer on a substrate can include a reaction chamber including a substrate holder for holding a substrate; a heating system constructed and arranged to control the temperature of the substrate; a delivery system comprising a valve for providing a precursor and at least a first reactant into the reaction chamber; and a sequence controller operatively connected to the valve and programmed to enable deposition of molybdenum on the substrate in the reaction chamber with the precursor and the first reactant.

[0068] The distribution system may include a precursor delivery device configured and arranged to deliver molybdenum (VI) dichloride dioxide (MoO2Cl2) vapor, and a first reactant delivery system configured and arranged to deliver a vapor of a first reactant including boron and hydrogen, e.g., diborane.

[0069] The first reactant may be diborane and may be delivered into the reaction chamber at a flow rate of 50 and 50000, e.g., 495 sccm, for a duration T2, T4 of 5 seconds. A nitrogen purge gas may be used for a duration R1, R2, R3 or R4 of 5 seconds after the delivery of the first precursor, after the delivery of the first reactant, and after the delivery of the first reactant.

[0070] During the pre-treatment and bulk ALD cycles, the process temperature can be, for example, about 550° C. and the pressure can be approximately 10 Torr. The vessel in which the first precursor can be vaporized can be about 70° C.

[0071] The method can also be used in spatial atomic layer deposition systems. In spatial ALD, precursors and reactants are continuously fed into different physical sections, and the substrate is moved between the sections. At least two sections can be provided in which half-reactions can occur in the presence of the substrate. When the substrate is present in such a half-reaction section, a monolayer can be formed from the first or second precursor. The substrate is then moved to a second half-reaction zone where an ALD cycle is completed with the first or second reactant to form one ALD monolayer. Alternatively, the substrate position can be fixed and the gas supply moved, or some combination of the two. To obtain thicker films, this sequence can be repeated.

[0072] According to an embodiment of a spatial ALD apparatus, a method includes: placing a substrate in a reaction chamber comprising a plurality of sections, each section separated from an adjacent section by a gas curtain; providing a first precursor, such as, for example, molybdenum (VI) dichloride dioxide, to a substrate within a first section of a reaction chamber; moving the substrate surface through the gas curtain relative to the reaction chamber (e.g., laterally) into a second section of the reaction chamber; delivering a first reactant including boron and hydrogen, such as diborane, to the substrate in a second section of the reaction chamber to form a molybdenum seed layer; moving the substrate surface (e.g., laterally) relative to the reaction chamber; and repeating the supplying of the first precursor and the reactant, including moving (e.g., laterally) the substrate relative to the reaction chamber, to form a molybdenum seed layer.

[0073] To form the bulk layer, the method further comprises: placing a substrate in a reaction chamber comprising a plurality of sections, each section separated from an adjacent section by a gas curtain; providing a first precursor, such as, for example, molybdenum (VI) dichloride dioxide, to a substrate within a first section of a reaction chamber; moving the substrate surface through the gas curtain relative to the reaction chamber (e.g., laterally) into a second section of the reaction chamber; supplying a second reactant, such as hydrogen (H2), to the substrate in a second section of the reaction chamber to form a molybdenum bulk layer; moving the substrate surface (e.g., laterally) relative to the reaction chamber; and repeating the supplying of the first precursor and the second reactant, including lateral movement of the substrate surface relative to the reaction chamber, to form a molybdenum bulk layer.

[0074] The first reactant may include hydrogen and boron, such as diborane, and the second reactant may be hydrogen (H2).

[0075] In additional embodiments, the seed or bulk molybdenum layer may include less than about 40 atomic percent, less than about 30 atomic percent, less than about 20 atomic percent, less than about 10 atomic percent, less than about 5 atomic percent, or even less than about 2 atomic percent% oxygen. In further embodiments, the seed or bulk layer may include less than about 30 atomic percent, less than about 20 atomic percent, less than about 10 atomic percent, less than about 5 atomic percent, or even less than about 2 atomic percent hydrogen.

[0076] In some embodiments, the seed or bulk molybdenum layer may include about 10 atomic percent, or less than about 5 atomic percent, or less than about 1 atomic percent, or even less than about 0.5 atomic percent halide or chloride. In still further embodiments, the seed or bulk molybdenum layer may include less than about 10 atomic percent, or less than about 5 atomic percent, or less than about 2 atomic percent, or less than about 1 atomic percent, or even less than about 0.5 atomic percent carbon. In the embodiments outlined herein, the atomic percentage (at.%) concentrations of elements may be determined utilizing Rutherford backscattering (RBS).

[0077] In some embodiments of the present disclosure, forming a semiconductor device structure, such as a semiconductor device structure, can include forming a gate electrode structure including a molybdenum film, the gate electrode structure having an effective work function greater than about 4.9 eV, or greater than about 5.0 eV, or greater than about 5.1 eV, or greater than about 5.2 eV, or greater than about 5.3 eV, or even greater than about 5.4 eV. In some embodiments, the above effective work function values ​​can be exhibited for electrode structures including a molybdenum layer having a thickness less than about 100 Angstroms, or less than 50 Angstroms, or less than about 40 Angstroms, or even less than 30 Angstroms.

[0078] Those skilled in the art will appreciate that various omissions, additions and modifications can be made to the processes and structures described above without departing from the scope of the invention. It is contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments can be made and still fall within the scope of the description. Various features and aspects of the disclosed embodiments can be combined in any order or substituted for one another. All such modifications and variations are intended to fall within the scope of the invention, as defined by the appended claims.

Claims

1. 1. A method for depositing a molybdenum-containing layer on a substrate in a reaction chamber, comprising: Molybdenum(VI) dichloride dioxide (MoO ２ C ２ providing a precursor comprising: delivering a first reactant to the substrate in the reaction chamber to react a portion of a precursor with the first reactant to form a molybdenum layer; the first reactant comprises boron and hydrogen; the molybdenum layer is a seed layer; supplying a precursor comprising the molybdenum (VI) dichloride dioxide (MoO2Cl2) to the substrate in the reaction chamber; providing a bulk molybdenum layer on the seed layer by sequentially repeating ALD cycles including: supplying a second reactant comprising hydrogen to the substrate in the reaction chamber such that a portion of the precursor reacts with the second reactant to form a bulk molybdenum layer.

2. The second reactant is hydrogen (H ２ 2. The method of claim 1 , comprising:

3. The method of claim 1, wherein the precursor is delivered to the reaction chamber in pulses, the pulses being from 0.1 to 10 seconds.

4. The method of claim 1, wherein the flow rate of the precursor into the reaction chamber is between 50 and 1000 sccm.

5. The method of claim 1, wherein the flow rate of the first reactant into the reaction chamber is between 50 and 50,000 sccm.

6. The method of claim 1, wherein the pressure in the reaction chamber is from 0.1 to 100 Torr.

7. The method according to claim 1, wherein the process temperature is from 300 to 800°C.

8. 10. The method of claim 1, wherein depositing the molybdenum layer comprises repeating an atomic layer deposition (ALD) cycle comprising sequentially delivering the precursor and the first reactant to the substrate.

9. The method of claim 8, wherein the substrate is purged for 0.5 to 50 seconds between delivering the precursor and the first reactant.

10. 10. The method of claim 9, wherein delivering the first reactant into the reaction chamber takes between 0.5 and 50 seconds.

11. The first reactant comprising boron and hydrogen has the formula B ｎ H （ｎ＋ｘ） wherein n is an integer from 1 to 10 and x is an even number.

12. The first reactant comprising boron and hydrogen has the formula B ｎ H （ｎ＋４） 12. The method of claim 11 , wherein the nido-borane is selected from the group consisting of:

13. The first reactant comprising boron and hydrogen has the formula B ｎ H （ｎ＋６） 12. The method of claim 11 , wherein the arachno-borane is selected from the group consisting of:

14. The first reactant comprising boron and hydrogen has the formula B ｎ H （ｎ＋８） 12. The method of claim 11 , wherein the hypo-borane is selected from the group consisting of:

15. The first reactant containing boron and hydrogen is diborane (B ２ H ６ 12. The method of claim 11 , wherein

16. The first reactant containing boron and hydrogen is conjuncto-borane B ｎ H ｍ wherein n is an integer from 1 to 10 and m is an integer from 1 to 10 different from n.

17. 10. The method of claim 1, wherein the first reactant comprising boron and hydrogen is provided to the reaction chamber to prepare a surface of the substrate before the precursor is provided to the reaction chamber.

18. 10. The method of claim 1 , wherein the substrate includes one or more gaps created during fabrication of features on the substrate, and the one or more gaps are at least partially filled by a method of depositing a molybdenum-containing layer on a substrate in a reaction chamber.

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