Gas delivery for tungsten-containing layers

Abstract

A method of forming a tungsten-containing layer over a substrate includes a) positioning the substrate on a substrate support in a processing volume of a processing chamber; b) providing a precursor gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber by opening a pulse valve on the tungsten-containing gas delivery line for a second duration to form a tungsten-containing layer over the substrate, the second duration occurring after the first duration. The tungsten-containing gas delivery line includes a first section connected to the inlet of the pulse valve, the first section connecting the inlet of the pulse valve to the reservoir of tungsten-containing gas, and a second section connected to the outlet of the pulse valve, the second section connecting the outlet of the pulse valve to the inlet of the process chamber.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to forming tungsten-containing layers. More specifically, embodiments described herein relate to gas delivery systems and methods for forming tungsten-containing layers. Background Art

[0002] Metal-containing layers, such as tungsten-containing layers, are used in a variety of structures in devices, such as semiconductor devices. One type of structure that is often formed on a substrate is a high aspect ratio structure. As the aspect ratio of the structure increases, it may be challenging to adequately fill the high aspect ratio structure with a given material, such as a metal-containing layer (e.g., a tungsten-containing layer).

[0003] To assist in filling high aspect ratio structures with tungsten, a tungsten containing gas (e.g., tungsten hexafluoride) may be pulsed into the processing chamber along with a gas (e.g., diborane) to react with the tungsten containing gas. The pulses may assist in getting the tungsten from the tungsten containing gas to reach deeper portions of the high aspect ratio structures.

[0004] Although pulses can assist in getting tungsten to deeper parts of high aspect ratio structures, problems still exist. For example, tungsten layers formed by these pulse processes often have a certain haze and / or may not be formed to a target level of purity or composition ratio. In one such example, a tungsten layer formed by a pulse process may include too high a percentage of boron.

[0005] Therefore, what is needed is a system and associated process for forming a tungsten layer without the problems mentioned above. Summary of the invention

[0006] In one embodiment, a method of forming a tungsten-containing layer on a substrate is provided. The method includes: a) positioning a substrate on a substrate support in a processing volume of a processing chamber; b) providing a precursor gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber for a second duration by opening a pulse valve on a tungsten-containing gas delivery line to form a tungsten-containing layer on the substrate, the second duration occurring after the first duration, wherein the tungsten-containing gas delivery line includes a first section connected to an inlet of the pulse valve and a second section connected to an outlet of the pulse valve, the first section connecting the inlet of the pulse valve to a reservoir of the tungsten-containing gas, the second section connecting the outlet of the pulse valve to an inlet leading to the processing chamber, and the internal cross-sectional area of ​​the first section of the tungsten-containing gas delivery line is at least 10% greater than the internal cross-sectional area of ​​the second section of the tungsten-containing gas delivery line.

[0007] In another embodiment, a method of forming a tungsten-containing layer is provided. The method includes: a) positioning a substrate on a substrate support in a processing volume of a processing chamber; b) providing a precursor gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber for a second duration to form a tungsten-containing layer above the substrate by opening a pulse valve on a tungsten-containing gas delivery line for a second duration, the second duration occurring after the first duration, wherein the tungsten-containing gas delivery line includes a first section connected to an inlet of the pulse valve and a second section connected to an outlet of the pulse valve, the first section connecting the inlet of the pulse valve to a reservoir of the tungsten-containing gas, and the second section connecting the outlet of the pulse valve to an inlet leading to the processing chamber; and providing a carrier gas to the second section of the tungsten-containing gas delivery line.

[0008] In another embodiment, a method of forming a tungsten-containing layer is provided. The method includes: a) positioning a substrate on a substrate support in a processing volume of a processing chamber; b) providing a boron-containing gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber for a second duration by opening a pulse valve on a tungsten-containing gas delivery line to form a tungsten-containing layer above the substrate, the second duration occurring after the first duration, the tungsten-containing layer filling a plurality of high aspect ratio structures disposed on the substrate, wherein the tungsten-containing gas delivery line includes a first section connected to an inlet of the pulse valve and a second section connected to an outlet of the pulse valve, the first section connecting the inlet of the pulse valve to a reservoir of the tungsten-containing gas, the second section connecting the outlet of the pulse valve to an inlet leading to the processing chamber, and the internal cross-sectional area of ​​the first section of the tungsten-containing gas delivery line is at least 10% greater than the internal cross-sectional area of ​​the second section of the tungsten-containing gas delivery line. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to understand the features of the present disclosure set forth above in detail, a more specific description of the present disclosure briefly outlined above may be made with reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the drawings only show exemplary embodiments and are therefore not to be considered as limiting the scope thereof, and other equally effective embodiments may be admitted.

[0010] Figure 1 is a schematic diagram of a processing system according to one embodiment.

[0011] Figure 2 According to one embodiment, Figure 1 0014] A process flow chart of a method for forming a tungsten-containing layer is shown in FIG.

[0012] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0013] Embodiments of the present disclosure generally relate to forming tungsten-containing layers. More specifically, embodiments described herein relate to gas delivery systems and methods for forming tungsten-containing layers.

[0014] Figure 1 1 is a schematic diagram of a processing system 100 according to one embodiment. The processing system 100 can be used to deposit a metal-containing layer, such as a tungsten-containing layer, on a substrate. Although the following disclosure primarily describes the use of a pulsed chemical vapor deposition (CVD) process to form a nucleation layer of a tungsten-containing material on a high aspect ratio structure formed on a substrate, the benefits of the present disclosure are generally applicable to any process (e.g., atomic layer deposition, bulk CVD, plasma enhanced CVD, etc.) that supplies a tungsten-containing gas (e.g., tungsten hexafluoride WF6) to a processing chamber.

[0015] The processing system 100 includes a processing chamber 101, a first gas delivery line 120 (also referred to as a tungsten-containing gas delivery line), a second gas delivery line 160, and a carrier gas delivery line 140. The gas delivery lines 120, 140, 160 may provide gas to the interior of the processing chamber 101 so that a deposition process on a substrate positioned inside the processing chamber 101 may be performed. The processing system 100 further includes an exhaust line 130 connected to an exhaust inlet 131 of the processing chamber 101. The exhaust line 130 may be used to exhaust gas from the processing volume 104. The exhaust line 130 may be connected to a vacuum pump (not shown).

[0016] The processing chamber 101 includes a chamber body 107 that encloses a processing volume 104. The chamber body 107 includes a top 106, a bottom 103, and one or more sidewalls 102 that connect the top 106 to the bottom 103. For ease of illustration, simplified versions of the top 106 and the bottom 103 are shown, and each simplified version can include additional equipment (not shown). For example, the top 106 can include additional equipment, such as a showerhead or other equipment for evenly distributing gas to the processing volume 104.

[0017] The processing chamber 101 further includes a substrate support 105 positioned in the processing volume 104. The substrate 50 can be positioned on the substrate support 105 in the processing volume 104 so that a tungsten-containing layer 51 can be formed (e.g., deposited) on the substrate 50. Examples of tungsten-containing layers that can be formed using the processes described herein include tungsten doped with boron, for example, where the boron has a concentration of from about 1% to about 20% (such as about 10%) of the tungsten-containing layer. Although not shown, the substrate 50 may include a plurality of high aspect ratio structures formed on the substrate before performing the deposition. In a non-limiting example, these high aspect ratio structures can be formed of titanium nitride. The deposition process described below can be used to form a tungsten-containing layer to fill these high aspect ratio structures (such as filling trenches having an aspect ratio of 10:1, 20:1, or a higher aspect ratio).

[0018] During deposition of the tungsten containing layer 51, the first gas delivery line 120 may be used to provide a tungsten containing gas such as tungsten hexafluoride (WF6) to the processing volume 104 of the processing chamber 101. In some embodiments, other tungsten containing gases may be used instead of tungsten hexafluoride to form the tungsten containing layer 51.

[0019] The second gas delivery line 160 can be used to provide a precursor gas, such as a boron-containing gas, such as diborane (B2H6), to the processing volume 104 of the processing chamber 101. In some embodiments, other boron-containing gases such as borane (BH3) can be used instead of diborane. In addition, in some embodiments, precursors including elements other than boron can also be used. For example, in some embodiments, monosilane (SiH4) or disilane (Si2H6) can be used as precursors to react with a tungsten-containing gas instead of a boron-containing gas (such as diborane).

[0020] The carrier gas delivery line 140 can be used to provide a carrier gas such as argon to the first gas delivery line 120 and to the second gas delivery line 160 to assist in delivering the tungsten-containing gas and the precursor gas to the processing volume 104 of the processing chamber 101 through the delivery lines 120, 160. In some embodiments, other carrier gases such as hydrogen, helium, or nitrogen can also be used as an alternative to or in addition to argon. For example, in one embodiment, hydrogen is used as a carrier gas for B2H6, and argon is used as a carrier gas for WF6. The carrier gas provided by the carrier gas delivery line 140 can also be used to purge equipment upstream of the processing volume, for example, if the tungsten-containing gas and the precursor gas each enter the process through any shared equipment (such as a showerhead used by both the tungsten-containing gas and the precursor gas). Even if no equipment is shared, a carrier gas can be used between pulses of the precursor gas and the tungsten-containing gas to increase the proportion of the reaction between the precursor gas and the tungsten-containing gas that occurs near the substrate 50 compared to the reaction between the precursor gas and the tungsten-containing gas that occurs in a portion of the processing volume 104, such as near the top 106 of the processing chamber 101.

[0021] The first gas delivery line 120 may include a tungsten-containing gas source 125 (e.g., a pressurized tank of WF6), a tungsten-containing gas reservoir 126, a pulse valve 127, and sections of fluid conduits described below (e.g., sections of pipelines, pipes, fittings, etc. that can be used to transport fluids (such as gases or liquids). These sections of the fluid conduits are described with respect to the pulse valve 127.

[0022] The first gas delivery line 120 may include an inlet section 121 that connects a tungsten-containing gas source 125 to a pulse valve 127. The inlet section 121 includes a reservoir supply section 121A and a reservoir exhaust section 121B (also referred to as a first section). The reservoir supply section 121A connects a tungsten-containing gas reservoir 126 to the tungsten-containing gas source 125. The reservoir exhaust section 121B connects the tungsten-containing gas reservoir 126 to the inlet side of the pulse valve 127. The tungsten-containing gas reservoir 126 may store a certain volume of tungsten-containing gas near the pulse valve 127, so that when the pulse valve 127 is opened, a sufficient volume and pressure of tungsten-containing gas is provided through the pulse valve 127.

[0023] The first gas delivery line 120 may further include an outlet section 122 (also referred to as a second section) connecting the outlet side of the pulse valve 127 with the processing volume 104 of the processing chamber 101 .

[0024] The pulse valve 127 can be configured to open for a specified pulse duration to deliver a predetermined amount of tungsten-containing gas from the inlet section 121 to the outlet section 122 and the processing volume 104 of the processing chamber 101. In some embodiments, the pulse valve 127 is configured to open for a pulse duration from about 0.1 seconds to about 10.0 seconds, such as from about 1.0 seconds to about 3.0 seconds, such as about 2.0 seconds.

[0025] The first gas delivery line 120 may further include a diverter section 123, which may be used to provide a tungsten-containing gas stream to an exhaust line 130 (also referred to as a foreline). The diverter section 123 may include a diverter valve 124 to control the tungsten-containing gas stream to the exhaust line 130. The diverter section 123 is connected to a reservoir supply section 121A upstream of a tungsten-containing gas reservoir 126. In some other embodiments, the diverter section 123 is connected to a reservoir discharge section 121B between the tungsten-containing gas reservoir 126 and a pulse valve 127. Providing a tungsten-containing gas stream to the exhaust line 130 can help reduce the concentration of other gases that accumulate between production runs within the first gas delivery line 120 and the processing volume 104. The diverter valve 124 is typically opened at the start of the process to assist in removing these other gases, and once the tungsten-containing gas reservoir 126 is filled to a sufficient pressure, the diverter valve 124 is typically closed. Although not shown, the first gas delivery line 120 and the other gas delivery lines 140 , 160 may include a number of other sensors, valves, and flow controllers (eg, mass flow controllers), not shown, to assist in delivering gas from the respective gas sources 125 , 145 , 165 .

[0026] The second gas delivery line 160 may include a precursor gas source 165 such as a boron-containing gas source (e.g., a pressurized tank of B2H6), a precursor gas reservoir 166, a pulse valve 167, and sections of fluid conduits described below (e.g., sections of lines, tubing, fittings, etc. that can be used to transport fluids). These sections are described with respect to the pulse valve 167.

[0027] The second gas delivery line 160 may include an inlet section 161 that connects a precursor gas source 165 to a pulse valve 167. The inlet section 161 includes a reservoir supply section 161A and a reservoir exhaust section 161B. The reservoir supply section 161A connects a precursor gas reservoir 166 to the precursor gas source 165. The reservoir exhaust section 161B connects the precursor gas reservoir 166 to the inlet side of the pulse valve 167. The precursor gas reservoir 166 may store a certain volume of precursor gas near the pulse valve 167 so that when the pulse valve 167 is opened, a sufficient volume and pressure of precursor gas is provided through the pulse valve 167.

[0028] The second gas delivery line 160 may further include an outlet section 162 connecting the outlet side of the pulse valve 167 with the processing volume 104 of the processing chamber 101 .

[0029] The pulse valve 167 can be configured to open for a specified pulse duration to deliver a predetermined amount of tungsten-containing gas from the inlet section 161 to the outlet section 162 and the processing volume 104 of the processing chamber 101. In some embodiments, the pulse valve 167 is configured to open for a pulse duration from about 0.1 seconds to about 10.0 seconds (such as from about 1.0 seconds to about 3.0 seconds, such as about 2.0 seconds). Although not shown, the second gas delivery line 160 can also include a diverter section with a diverter valve similar to the diverter section 123 described above to reduce the concentration of gases other than the precursor gas. This diverter section can be used at the beginning of the process to assist in removing other gases that accumulate between production runs.

[0030] The carrier gas delivery line 140 may include a carrier gas source 145 (e.g., a pressurized tank of argon), a first valve 147, a second valve 148, and sections of fluid conduits described below (e.g., sections of pipelines, tubing, fittings, etc. that may be used to transport fluids). These sections are described with respect to valves 147, 148.

[0031] The carrier gas delivery line 140 can include an inlet section 141 that connects a carrier gas source 145 with valves 147, 148. The carrier gas delivery line 140 can further include a first outlet section 142 that connects an outlet side of a first valve 147 with the outlet section 122 of the first gas delivery line 120 at a location 128 on the outlet section 122. The location 128 can be relatively close to the pulse valve 127, as described in more detail below. The first outlet section 142 is configured to provide a carrier gas to the outlet section 122 so that the carrier gas can assist in providing a tungsten-containing gas to the processing volume 104 of the processing chamber 101.

[0032] The carrier gas delivery line 140 may further include a second outlet section 143 connecting the outlet side of the second valve 148 with the outlet section 162 of the second gas delivery line 160. The second outlet section 143 is configured to provide a carrier gas to the outlet section 162 so that the carrier gas can assist in providing the precursor gas to the processing volume 104 of the processing chamber 101.

[0033] Although a single carrier gas source 145 is shown, in some embodiments, separate carrier gas sources are used so that the carrier gas lines are completely independent. Having separate carrier gas sources and lines can allow different carrier gases (e.g., hydrogen and argon) to be used for the precursor gas and the tungsten-containing gas and can also help prevent any mixing of the precursor gas and the tungsten-containing gas outside of the processing volume 104 of the processing chamber 101.

[0034] Processing system 100 includes features that improve deposition of tungsten-containing layer 51 compared to conventional processing systems. For example, processing system 100 can be used to deposit a tungsten-containing layer having a target ratio of materials (eg, 90% tungsten and 10% boron) more consistently than conventional processing systems.

[0035] The first feature that provides improvement is that the inner diameter (or cross-sectional area) of the reservoir discharge section 121B is at least 10% larger than the inner diameter (or cross-sectional area) of the outlet section 122. In some embodiments, the inner diameter (or cross-sectional area) of the reservoir discharge section 121B is at least 30%, at least 50%, or at least 100% larger than the inner diameter (or cross-sectional area) of the outlet section 122. In a specific embodiment, the inner diameter of the reservoir discharge section 121B is 3 / 8 inch, while the inner diameter of the outlet section 122 is 1 / 4 inch.

[0036] During processing, the portion of outlet section 122 downstream of location 128 includes both the flow of tungsten-containing gas from reservoir discharge section 121B and the flow of carrier gas from carrier gas delivery line 140, while reservoir discharge section 121B includes only the flow of tungsten-containing gas flowing through reservoir discharge section 121B. Thus, outlet section 122 includes the sum of the flow rate of gas from reservoir discharge section 121B plus the flow rate of gas from carrier gas delivery line 140. Thus, the total flow rate of outlet section 122 is significantly higher than the total flow rate of gas in reservoir discharge section 121B.

[0037] In general, the inner diameter of a fluid conduit is designed to increase or at least remain unchanged when the flow rate of the fluid through the conduit increases. Therefore, it is counterintuitive to design a fluid conduit with a lower flow rate (i.e., the reservoir discharge section 121B) to have a larger inner diameter than a fluid conduit with a higher flow rate (i.e., the outlet section 122). Without being bound by any theory, it is believed that a larger diameter in the reservoir discharge section 121B when compared to the outlet section 122 may result in a less sudden pressure change in the reservoir outlet section 121B than when the reservoir discharge section 121B is designed to have the same or smaller inner diameter relative to the inner diameter of the outlet section 122. Sudden pressure changes may result in possible condensation of tungsten-containing gas and non-uniform gas flow rates. Because the pressure change in the reservoir exhaust section 12 IB is less abrupt, a more consistent flow rate of tungsten-containing gas may be provided to the outlet section 122 and ultimately to the processing volume 104 of the processing chamber 101 , which improves the consistency of the deposition being performed.

[0038] A second feature that provides an improvement over conventional processing systems for the treatment system 100 is that a carrier gas is provided to the first gas delivery line 120 downstream of a pulse valve 127 of the first gas delivery line 120. In some embodiments, the carrier gas is provided to the first gas delivery line 120 at a location 128 on the outlet section 122 that is downstream of and relatively close to the pulse valve 127. For example, the location 128 may be about 0.5 inches to about 6.0 inches downstream of the pulse valve 127, such as about 1.0 inches to about 3.0 inches downstream of the pulse valve 127, such as about 2.0 inches. Providing the carrier gas downstream of the pulse valve 127 may also reduce sudden pressure changes in the reservoir discharge section 121B compared to when the carrier gas is provided upstream of the pulse valve 127. Other features that may also reduce these pressure changes may include not placing diverter valves along the flow paths used during production and selecting the type of pulse valve being used. For example, a vacuum coupled radiation (VCR) valve may cause less abrupt pressure changes than a standard surface mount valve.

[0039] The processing system 100 may further include a device connected to Figure 1 1. The controller 190 of the device shown in FIG. 1 may be any type of controller used in an industrial environment, such as a programmable logic controller (PLC). The controller 190 includes a processor 192, a memory 194, and an input / output (I / O) circuit 196. The controller 190 may further include one or more of the following components (not shown), such as one or more power supplies, clocks, communication components (e.g., a network interface card), and a user interface that are typically present in a controller of a semiconductor device.

[0040] The memory 194 may include non-volatile memory. The non-volatile memory may be used to store programs and settings described below. The memory 194 may include one or more readily available types of memory, such as read-only memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM), flash memory, a floppy disk, a hard disk, or a random access memory (RAM) (e.g., non-volatile random access memory (NVRAM)).

[0041] The processor 192 is configured to execute various programs stored in the memory 194, such as being configured to execute the following reference Figure 2 The memory 194 may further include various operating settings for controlling the processing system 100. For example, the settings may include settings for controlling: (1) the following settings: (a) the following settings: (b) the following settings: (c) the following settings: (d) the following settings: (i) the following settings: (i) the following settings: (i) the following settings: (i) the following settings: (i) the following settings: (ii) the following settings: (iii) the following settings: (iv) the following settings: (v) the following settings: (v) the following settings: (vi) the following settings: (vi) the following settings: (vi) the following settings: (vi) the following settings: (vi) the following settings: (i) the following settings: (i) the following settings: Figure 2 The durations of boxes 1004, 1006, 1008, 1010 and 1014 in the method 1000, (2) the temperature and pressure inside the processing chamber 101 during the deposition of the tungsten-containing layer 51 as described herein, and (3) the flow rate of gas provided to the processing volume 104 during different portions of the method 1000 described below with reference to Table 2, as well as various other settings.

[0042] Figure 2 According to one embodiment, Figure 1 1. A process flow diagram of a method 1000 for forming a tungsten-containing layer 51 is shown in FIG. The method 1000 begins at block 1002.

[0043] At block 1002, the substrate 50 is positioned on the substrate support 105 in the processing volume 104 of the processing chamber 101. The split process for the first gas delivery line 120 described above may also begin at this time. It is assumed that the split process described above is completed before proceeding to block 1004.

[0044] At block 1004, valves 147, 148 are opened and a carrier gas (e.g., argon) is provided to the processing volume 104 through sections 122, 162. During block 1004, the carrier gas may be provided at a flow rate from about 1 liter / minute to about 10 liters / minute, such as from about 2 liters / minute to about 5 liters / minute. In some embodiments, the flow rate of the carrier gas may remain relatively constant throughout the method 1000.

[0045] At block 1006, a pulse of a precursor gas, such as a boron-containing gas (e.g., diborane), may be provided to the processing volume 104 of the processing chamber 101 by opening the pulse valve 167 for a specified pulse duration (also referred to as a first duration). In some embodiments, the pulse valve 167 is configured to be opened for a pulse duration from about 0.1 seconds to about 10.0 seconds (such as from about 1.0 seconds to about 3.0 seconds, such as about 2.0 seconds). After the specified pulse duration, the pulse valve 167 is closed. During block 1006, the precursor gas may be provided at a flow rate from about 100 sccm to about 1000 sccm, such as from about 200 sccm to about 600 sccm (e.g., 350 sccm). Starting with a pulse of the precursor gas may help to help the nucleation process begin to form a tungsten-containing layer on top of another layer on the substrate (e.g., on top of a plurality of high aspect ratio structures formed of titanium nitride).

[0046] At block 1008, the carrier gas continues to be provided to the processing volume 104. Block 1008 may continue for a predetermined duration, such as from about 0.1 seconds to about 10.0 seconds, such as from about 1.0 seconds to about 3.0 seconds, such as about 2.0 seconds. The duration of block 1008 may be adjusted to increase the proportion of the reaction between the tungsten-containing gas (provided at block 1010) and the precursor gas (provided at block 1006) occurring near the substrate 50 as compared to other locations in the processing volume 104, such as locations in the processing volume 104 near the top 106 of the processing chamber 101.

[0047] At block 1010, a pulse of a tungsten-containing gas (e.g., WF6) can be provided to the processing volume 104 of the processing chamber 101 by opening the pulse valve 127 for a specified pulse duration (also referred to as a second duration). In some embodiments, the pulse valve 167 is configured to be opened for a pulse duration from about 0.1 seconds to about 10.0 seconds (such as from about 1.0 seconds to about 3.0 seconds, such as about 2.0 seconds). After the specified pulse duration, the pulse valve 167 is closed. During block 1010, the tungsten-containing gas can be provided at a flow rate from about 20 sccm to about 400 sccm (such as from about 50 sccm to about 150 sccm).

[0048] Providing a tungsten-containing gas at box 1010 enables a reaction between a precursor gas (e.g., B2H6) and a tungsten-containing gas (e.g., WF6) to occur, so that a tungsten-containing layer 51 can be deposited on the substrate 50, for example, deposited on a high aspect ratio structure (e.g., a trench) formed on the substrate 50.

[0049] At box 1010, a tungsten-containing gas is provided through a reservoir discharge section 121B having an internal cross-sectional area that is at least 10% greater (such as at least 30%, at least 50%, or at least 100%) than the internal cross-sectional area of ​​the outlet section 122. As described above, this increased cross-sectional area of ​​the reservoir discharge section 121B can reduce sudden pressure changes of the tungsten-containing gas, which can cause non-uniform flow rates and possible condensation of the tungsten-containing gas. In addition, in some embodiments, a carrier gas is provided to the first gas delivery line 120 at a position 128 on the outlet section 122, which is downstream of and relatively close to the pulse valve 127. Providing a carrier gas downstream of the pulse valve 127 can also reduce sudden pressure changes in the reservoir discharge section 121B compared to when the carrier gas is provided upstream of the pulse valve 127. Reducing these sudden pressure changes can result in a more uniform and consistent deposition of the tungsten-containing layer 51.

[0050] At block 1012, a determination may be made as to whether a target thickness of the tungsten-containing layer 51 being deposited has been reached. In some embodiments, the target thickness may be from about 25 angstroms to about 200 angstroms, such as about 100 angstroms. In one embodiment, this thickness determination may be made based on the total number of times blocks 1004 to 1010 have been performed. In general, blocks 1004 to 1012 may be repeated five or more times, such as about ten to twenty times.

[0051] At block 1012, if the target thickness has not been reached, blocks 1004 through 1010 are repeated. When the blocks are repeated, the repeated blocks 1004 may have a duration similar to the duration of block 1008 described above to increase the percentage of reactions occurring near the substrate 50 as compared to other locations in the processing volume 104. At block 1012, if the target thickness has been reached, the method 1000 proceeds to block 1014.

[0052] At block 1014, an additional pulse of precursor gas is provided to the processing volume 104. Such additional pulses of precursor gas may assist, for example, when using a bulk CVD process to form a thicker tungsten-containing layer over the tungsten-containing layer 51 formed using the method 1000 described herein.

[0053] While the foregoing is directed to examples of the present disclosure, other and further examples of the disclosure may be devised without departing from the basic scope of the disclosure, and the scope of the disclosure is determined by the claims that follow.

Claims

1. A method for forming a tungsten-containing layer on a substrate, the method comprising: a) positioning a substrate on a substrate support in a processing volume of a processing chamber; b) providing a precursor gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber for a second duration by opening a pulse valve on a tungsten-containing gas delivery line to form a tungsten-containing layer over the substrate, the second duration occurring after the first duration, wherein The tungsten-containing gas delivery line includes a first section connected to an inlet of the pulse valve and a second section connected to an outlet of the pulse valve, The first section connects the inlet of the pulse valve to a reservoir of tungsten-containing gas, the second section connects the outlet of the pulse valve to an inlet of the processing volume of the processing chamber, and The first section of the tungsten-containing gas delivery line has an interior cross-sectional area that is at least 10% greater than an interior cross-sectional area of ​​the second section of the tungsten-containing gas delivery line.

2. The method of claim 1, further comprising providing a carrier gas to the second section of the tungsten-containing gas delivery line when the tungsten-containing gas is provided to the processing volume of the processing chamber. 3 . The method of claim 2 , wherein operations b) and c) are repeated five or more times to increase the thickness of the tungsten-containing layer formed over the substrate.

4. The method of claim 2, wherein the interior cross-sectional area of ​​the first section of the tungsten-containing gas delivery line is at least 30% greater than the interior cross-sectional area of ​​the second section of the tungsten-containing gas delivery line.

5. The method of claim 2, wherein the interior cross-sectional area of ​​the first section of the tungsten-containing gas delivery line is at least 50% greater than the interior cross-sectional area of ​​the second section of the tungsten-containing gas delivery line.

6. The method of claim 2, wherein the first section has an inner diameter of 3 / 8 inch and the second section has an inner diameter of 1 / 4 inch.

7. The method of claim 4, wherein the carrier gas is argon.

8. The method of claim 1, wherein the tungsten-containing gas is tungsten hexafluoride.

9. The method of claim 1, wherein the tungsten-containing gas is provided to the processing volume of the processing chamber by opening the pulse valve for a duration of from about 0.5 seconds to about 10.0 seconds.

10. A method of forming a tungsten-containing layer, the method comprising: a) positioning a substrate on a substrate support in a processing volume of a processing chamber; b) providing a precursor gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber for a second duration by opening a pulse valve on a tungsten-containing gas delivery line to form a tungsten-containing layer over the substrate, the second duration occurring after the first duration, wherein The tungsten-containing gas delivery line includes a first section connected to an inlet of the pulse valve and a second section connected to an outlet of the pulse valve, The first section connects the inlet of the pulse valve to a reservoir of tungsten-containing gas, and the second section connects the outlet of the pulse valve to an inlet of the processing volume of the processing chamber; and A carrier gas is provided to the second section of the tungsten-containing gas delivery line.

11. The method of claim 10, wherein the carrier gas is provided on the second section of the tungsten-containing gas delivery line at a location between about 0.5 inches and about 6.0 inches downstream of the outlet of the pulse valve.

12. The method of claim 10, wherein the carrier gas is provided on the second section of the tungsten-containing gas delivery line at a location between about 1.0 inches and about 3.0 inches downstream of the outlet of the pulse valve.

13. The method of claim 10, wherein the tungsten-containing gas is tungsten hexafluoride.

14. The method of claim 13, wherein the tungsten-containing gas is provided to the processing volume of the processing chamber by opening the pulse valve for a duration of from about 0.5 seconds to about 10.0 seconds.

15. A method of forming a tungsten-containing layer on a substrate, the method comprising: a) positioning a substrate on a substrate support in a processing volume of a processing chamber; b) providing a boron-containing gas to the processing volume of the processing chamber for a first duration; and c) providing a tungsten-containing gas to the processing volume of the processing chamber for a second duration by opening a pulse valve on a tungsten-containing gas delivery line to form a tungsten-containing layer over the substrate, the second duration occurring after the first duration, the tungsten-containing layer filling a plurality of high aspect ratio structures disposed over the substrate, wherein The tungsten-containing gas delivery line includes a first section connected to an inlet of the pulse valve and a second section connected to an outlet of the pulse valve, The first section connects the inlet of the pulse valve to a reservoir of tungsten-containing gas, the second section connects the outlet of the pulse valve to an inlet of the processing volume of the processing chamber, and The first section of the tungsten-containing gas delivery line has an interior cross-sectional area that is at least 10% greater than an interior cross-sectional area of ​​the second section of the tungsten-containing gas delivery line.

16. The method of claim 15, further comprising providing a carrier gas to the second section of the tungsten-containing gas delivery line when the tungsten-containing gas is provided to the processing volume of the processing chamber. 17 . The method of claim 16 , wherein operations b) and c) are repeated five or more times to increase the thickness of the tungsten-containing layer formed over the substrate.

18. The method of claim 16, wherein the carrier gas is provided on the second section of the tungsten-containing gas delivery line at a location between about 1.0 inches and about 3.0 inches downstream of the outlet of the pulse valve.

19. The method of claim 15, wherein the tungsten-containing gas is tungsten hexafluoride.

20. The method of claim 18, wherein the boron-containing gas is diborane.

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