Method for removing molybdenum oxide from substrate

Abstract

A method for cleaning oxide from a surface of a substrate is performed without affecting a low-k dielectric material or a carbon material on the substrate. In some embodiments, the method may include performing a pre-cleaning process in a back-of-line (BEOL) process using chlorine-based soak to remove oxides from a surface of a substrate, and treating the surface of the substrate with hydrogen and at least one inert gas using a remote plasma to remove residual chlorine residues from the surface of the substrate, and the low-k dielectric material or the carbon material on the substrate is not damaged.

Description

Technical Field

[0001] Embodiments of the present principles generally relate to semiconductor chambers used in semiconductor processing. Background Art

[0002] When exposed to oxygen, the molybdenum (Mo) surface forms molybdenum oxide (MoO x ) layer. The inventors have observed that removing the MoO x This requires stringent processes that are incompatible with the back-end-of-the-line (BEOL) packaging process. x Can be formed in areas of low-k dielectric material that are susceptible to damage caused by traditional pre-clean processes.

[0003] Therefore, the inventors provide improved methods to remove molybdenum oxide from low-k dielectric materials in BEOL packaging processes without damaging the low-k dielectric materials. Summary of the invention

[0004] A method for chlorine-based immersion and dilute plasma pre-cleaning of molybdenum oxide is provided herein.

[0005] In some embodiments, a method for cleaning a surface of a substrate may include: performing a chlorine-based soak process in a back-end of line (BEOL) process to remove molybdenum oxide from a surface of a substrate, wherein the substrate at least partially contains a low-k dielectric material; and performing a plasma treatment on the surface of the substrate using a remote plasma to remove residual chlorine residues from the surface of the substrate, the remote plasma containing hydrogen diluted with at least one inert gas.

[0006] In some embodiments, the method may further include: wherein the chlorine-based soaking process uses molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5); performing the chlorine-based soaking process at a temperature of about 350 degrees Celsius to about 460 degrees Celsius; performing the chlorine-based soaking process at a pressure of about 2 Torr to about 20 Torr; performing the chlorine-based soaking process using a chlorine-based gas flowing at a rate of about 10 sccm to about 1000 sccm; performing the chlorine-based soaking process for a time of about 5 seconds to about 60 seconds; wherein at least one inert gas is argon or helium; performing the chlorine-based soaking process at a pressure of about 250 degrees Celsius to about 460 degrees Celsius performing plasma treatment at a temperature of about 100 mTorr to about 200 mTorr; performing plasma treatment using a plasma source power of about 400 watts to about 900 watts; performing plasma treatment using a bias power of zero watts to about 300 watts; performing plasma treatment using hydrogen gas diluted by about 1% to about 99% by volume with at least one inert gas; and / or performing plasma treatment using hydrogen gas flowing at a rate of about 1 sccm to about 100 sccm and at least one inert gas flowing at a rate of about 5 sccm to about 200 sccm.

[0007] In some embodiments, a method for cleaning a surface of a substrate may include: performing a chlorine-based soak process using molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5) at a temperature of about 350 degrees Celsius to about 460 degrees Celsius for a time of about 5 seconds to about 60 seconds in a back-end of line (BEOL) process to remove molybdenum oxide from the surface of the substrate, wherein the substrate at least partially contains a low-k dielectric material; and performing a plasma treatment on the surface of the substrate using a remote plasma at a temperature of about 250 degrees Celsius to about 460 degrees Celsius to remove residual chlorine residue from the surface of the substrate, wherein the remote plasma contains hydrogen diluted with argon and helium, wherein the hydrogen is diluted by about 3% to about 10% by volume with the argon and helium.

[0008] In some embodiments, a non-transitory computer readable medium (non-transitory, computer readable medium) has instructions stored thereon that, when executed, result in a method for cleaning a surface of a substrate, the method may include: performing a chlorine-based soak process using molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5) at a temperature of about 350 degrees Celsius to about 460 degrees Celsius for a time of about 5 seconds to about 60 seconds in a back-end of line (BEOL) process to remove molybdenum oxide from a surface of a substrate, wherein the substrate at least partially contains a low-k dielectric material; and performing a plasma treatment on the surface of the substrate using a remote plasma at a temperature of about 250 degrees Celsius to about 460 degrees Celsius to remove residual chlorine residue from the surface of the substrate, the remote plasma containing hydrogen diluted with argon and helium, wherein the hydrogen is diluted by about 3% to about 10% by volume with the argon and helium.

[0009] Other and further embodiments are disclosed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments of the present principles briefly summarized above and discussed in more detail below can be understood by reference to the illustrative embodiments of the principles depicted in the accompanying drawings. However, the drawings illustrate only typical embodiments of the principles and are therefore not to be considered limiting in scope, as the principles may admit to other equally effective embodiments.

[0011] Figure 1 Methods for reducing molybdenum oxide from low-k dielectric materials according to some embodiments of the present principles are described.

[0012] Figure 2 Depicted is a cross-sectional view of a substrate subjected to a chlorine-based soak according to some embodiments.

[0013] Figure 3 Graph depicting the effect of chlorine based soaking on molybdenum oxide and molybdenum according to some embodiments of the present principles.

[0014] Figure 4 Depicted is a cross-sectional view of a substrate having chlorine residue after exposure to a chlorine-based soak according to some embodiments.

[0015] Figure 5 Depicted is a cross-sectional view of a substrate undergoing remote plasma processing using diluted hydrogen gas according to some embodiments.

[0016] Figure 6 Depicted is a cross-sectional view of a chlorine-based soaking chamber, according to some embodiments of the present principles.

[0017] Figure 7Depicted is a cross-sectional view of a remote plasma chamber according to some embodiments of the present principles.

[0018] Figure 8 An integrated tool according to some embodiments of the present principles is described.

[0019] To facilitate understanding, the same reference numerals are used where possible to refer to the same elements common to the drawings. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further description. DETAILED DESCRIPTION

[0020] Methods are provided for removing molybdenum oxide (MoO) in back-end-of-line (BEOL) processes x ) is an improved process. Current BEOL pre-cleaning processes face the challenge of reducing or removing molybdenum oxide without damaging low-k materials. The advantage of the method over conventional BEOL pre-cleaning processes is that the method can achieve MoO x The method is also compatible with current BEOL hydrogen (H2) pre-cleaning methods and integration flows.

[0021] Although Mo materials / doping have been used in front-end-of-the-line (FEOL) structure manufacturing processes, the inability to remove MoO in areas containing low-k materials is x , Molybdenum materials / doping are not used in BEOL processes. Molybdenum materials / doping would allow for the formation of enhanced performance contacts formed during middle-of-the-line (MOL) processes (e.g., in logic applications). Such MOL contacts would be possible if the oxide formed on the exposed Molybdenum materials could be removed during the BEOL packaging process. Current processes lack any feasible way to reduce or remove MoO for the BEOL. x The high-intensity plasma treatment can completely reduce the MoO x , but it will inevitably lead to unacceptable damage to low-k dielectric materials, so this approach cannot be used in BEOL applications. x In some embodiments, a chlorine-based soak pre-cleaning process (e.g., a molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5) soaking process, etc.) is used to remove MoO at a process temperature of about 400 degrees Celsius. xA plasma based treatment of hydrogen (H2) diluted with an inert gas (such as but not limited to argon and / or helium, etc.) may then be used to remove possible surface chlorine residues and / or dry etch residues, etc. without damaging the low-k material.

[0022] Figure 1 1 is a method 100 for reducing molybdenum oxide from a low-k dielectric material according to some embodiments. As used herein, "low-k" refers to a material having a smaller dielectric constant or "k" relative to silicon dioxide (i.e., a low-k dielectric material has a "k" value less than 3.9). The method 100 is fully compatible with BEOL processes and can also be used in other processes. In block 102, as Figure 2 As shown in FIG. 200 , a chlorine-based soak 210 is used to clean a MoO-containing substrate on a molybdenum material 206 in a BEOL process. x The surface 204 of the substrate 202 is provided with a layer 208 to reduce / remove MoO x Layer 208. In some embodiments, the molybdenum material 206 may be a molybdenum-doped material. In some embodiments, the chlorine-based soak 210 may be a MoCl5 or WCl5-based soak. In some embodiments, the chlorine-based soak 210 may be performed at a temperature of about 350 degrees Celsius to about 450 degrees Celsius. In some embodiments, the chlorine-based soak 210 may be performed at a temperature of about 400 degrees Celsius. In some embodiments, the chlorine-based soak 210 may be performed at a pressure of about 2 Torr to about 20 Torr. In some embodiments, the chlorine-based soak 210 may be performed at a chlorine-based gas flow rate of about 10 sccm to about 1000 sccm. In some embodiments, the chlorine-based soak 210 may have a duration of about 5 seconds to about 60 seconds.

[0023] In some embodiments, as depicted in graph 300, for example, the process temperature may be about 425 degrees Celsius, the MoCl5 gas flow rate may be about 700 sccm, the pressure may be about 10 Torr, and the duration may be about 5 seconds to about 30 seconds. x The etch rate 302 is approximately 4 angstroms / second, while the molybdenum etch rate 304 is negligible (e.g., less than 0.01 angstroms / second, etc.). The chlorine-based soak 210 effectively reduces and / or removes MoO x layer 208. The duration of the chlorine-based soak 210 may be based on the MoO x The thickness of the stack and / or on which MoO is found x The soak time can be adjusted based on the type of structure (e.g., high aspect ratio structures may require longer soaking times, etc.). Figure 4 As depicted in View 400, although MoO xThe layer 208 has been reduced / removed, but the chlorine-based soak 210 has resulted in a chlorine residue 402 being formed on the surface 204 of the substrate 202 .

[0024] exist Figure 1 In block 104 of method 100, Figure 5 As depicted in FIG. 500 , the surface 204 of the substrate in the BEOL process is exposed to a plasma treatment 506 using a remote plasma 502 formed by a diluted hydrogen gas 504. The plasma treatment 506 serves to remove any residual chlorine and / or dry etch residue from the surface 204 of the substrate 112 after the chlorine-based soak 210. In some embodiments, the diluted hydrogen gas 504 is diluted with an inert gas, such as, but not limited to, argon and / or helium. Since the substrate 202 may contain low-k materials, using undiluted hydrogen gas with the plasma generates a strong plasma that causes hydrogen to recombine not only with chlorine atoms but also with carbon atoms in the low-k material, thereby damaging the low-k material via carbon loss. The inventors have discovered that by diluting the hydrogen gas by about 1% to about 99% by volume using argon and / or helium, carbon loss from the low-k material of the substrate 202 is minimized while effectively reducing and / or removing chlorine residues 402 on the surface 204 of the substrate 202. In some embodiments, the hydrogen is diluted by about 3% to about 10% by volume using argon and / or helium, etc., to optimize chlorine removal while minimizing low-k damage. After further testing, the inventors found that chlorine diffusion and carbon consumption were at noise levels on both virgin and ashes low-k materials (less than 1% below chlorine detection levels, less than 1% carbon loss in low-k materials). The inventors also found that time-dependent dielectric breakdown (TDDB) after performing method 100 produced similar results (e.g., greater than 10 years) to other BEOL clean processes (carbon loss in low-k materials was negligible and did not negatively impact TDDB).

[0025] In some embodiments, the plasma treatment 506 is performed on the substrate 202 at a temperature of about 250 degrees Celsius to about 460 degrees Celsius. In some embodiments, the plasma treatment 506 is performed on the substrate 202 at a temperature of about 350 degrees Celsius. The inventors have found that lower pressures during the plasma treatment 506 produce better results (chlorine removal and minimized damage to low-k materials, etc.). In some embodiments, the plasma treatment 506 is performed at a pressure of about 10 mTorr to about 200 mTorr. In some embodiments, the plasma treatment 506 is performed at a pressure of about 10 mTorr to about 50 mTorr. In some embodiments, the plasma treatment 506 is performed at a plasma power level of about 400 watts to about 900 watts. In some embodiments, no bias power is applied to the substrate 202 during the plasma treatment 506. In some embodiments, a bias power of greater than 0 watts to about 300 watts is used during the plasma treatment 506. In some embodiments, a bias power of greater than 0 watts to about 100 watts is used during the plasma treatment 506. In some embodiments, H2 gas flows at a rate of about 1 sccm to about 200 sccm during the plasma treatment 506. In some embodiments, H2 gas flows at a rate of about 3 sccm to about 10 sccm during the plasma treatment 506. In some embodiments, argon gas flows at a rate of about 5 sccm to about 200 sccm during the plasma treatment 506. In some embodiments, argon gas flows at a rate of about 5 sccm to about 200 sccm during the plasma treatment 506. In some embodiments, helium gas flows at a rate of about 5 sccm to about 200 sccm during the plasma treatment 506. In some embodiments, helium gas flows at a rate of about 50 sccm to about 200 sccm during the plasma treatment 506. In some embodiments, the duration of the plasma treatment 506 may be from about 10 seconds to about 60 seconds.

[0026] The chlorine-based soaking process disclosed herein can be used in any chamber that provides a chlorine-based gas for soaking along with temperature and pressure control. Figure 6600 depicts an example soak chamber for performing a chlorine-based soak 210. The soak chamber 602 includes a substrate support 622 that supports a substrate holder 610 and a shield 614 that surrounds a processing volume 618. A showerhead 604 provides one or more process gases (e.g., chlorine-based gases, such as but not limited to WCl5, MoCl5, etc.) from a gas supply source 608 through a gas supply conduit 606 into the processing volume 618. The process gas flow rate is controlled by a gas flow valve 644. In some embodiments, the process gas can be supplied at a flow rate of about 10 sccm to about 1000 sccm. Contaminants or unwanted gases are removed from the soak chamber 602 by a pump 620. The pump 620 can also be used to maintain a process pressure within the soak chamber 602. In some embodiments, the process pressure can be from about 2 Torr to about 20 Torr. The soak chamber 602 can also have a thermal control element or channel 642 that allows temperature control of the substrate 612 by a temperature controller 640 during processing. In some embodiments, the process temperature may be about 350 degrees Celsius to about 460 degrees Celsius.

[0027] The controller 630 controls the operation of the infusion chamber 602 using direct control of the infusion chamber 602 or alternatively by controlling a computer (or controller) associated with the infusion chamber 602. In operation, the controller 630 implements data collection and feedback from individual systems to optimize the performance of the infusion chamber 602. The controller 630 typically includes a central processing unit (CPU) 632, a memory 634, and a support circuit 636. The CPU 632 can be any form of general-purpose computer processor that can be used in industrial stereotypes. The support circuit 636 is conventionally coupled to the CPU 632 and may include a cache, a frequency circuit, an input / output subsystem, a power supply, etc. Software routines (such as the methods described herein) can be stored in the memory 634 and, when executed by the CPU 632, convert the CPU 632 into a special-purpose computer (controller 630). The software routines can also be stored and / or executed by a second controller (not shown) located remote from the infusion chamber 602. In some embodiments, the use of a plasma may be included to facilitate exposure of the substrate to an oxygen-rich environment during an optional oxygen-based treatment. The optional oxygen-based treatment may also assist in higher rates of gap fill and provide another knob for tuning feature-to-feature gap fill height variation with temperature, pressure, flow rate, and gas combinations.

[0028] The memory 634 is in the form of a computer-readable storage medium containing instructions that, when executed by the CPU 632, facilitate the operation of the semiconductor process and the device. The instructions in the memory 634 are in the form of a program product, such as a program that implements the method of the present principles. The program code may conform to any of a number of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. One or more programs of the program product define the functions of multiple aspects (including the methods described herein). Illustrative computer-readable storage media include, but are not limited to: non-writable storage media on which information is permanently stored (e.g., a read-only memory device within a computer, such as a CD-ROM disk that can be read by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory); and writable storage media on which information that can be modified is stored (e.g., a floppy disk within a disk drive or hard drive or any type of solid-state random access semiconductor memory). Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are aspects of the present principles.

[0029] As an example chamber for performing the plasma process 506, Figure 7 A processing chamber 700 with a remote plasma source 764 is depicted according to some embodiments. The processing chamber 700 is a vacuum chamber adapted to maintain a sub-atmospheric pressure within an interior space 702 during substrate processing. In some embodiments, the processing chamber 700 can maintain a pressure of about 10 mTorr to about 200 mTorr. The processing chamber 700 includes a chamber body 706 that surrounds a processing space 708 located in an upper portion of the interior space 702. The chamber body 704 can be made of a metal, such as aluminum, etc. The chamber body 704 can be grounded via a coupling to a ground 710.

[0030] The substrate support 712 is disposed within the interior space 702 to support and hold a substrate 714, such as, for example, a semiconductor wafer, or other such substrate. The substrate support 712 may generally include a pedestal 716 and a hollow support shaft 718 for supporting the pedestal 716. The pedestal 716 may be composed of an aluminum-based material or a ceramic-based material, among others. A pedestal formed of a ceramic-based material may be used for high temperature processes. The hollow support shaft 718 provides a conduit to provide, for example, backside gas, process gas, fluid, coolant, power, etc. to the pedestal 716. In some embodiments, the substrate support 712 includes a focus ring 720 disposed around the pedestal 716 to enhance process uniformity at the edge of the substrate 714. In some embodiments, the focus ring 720 is made of a quartz-based material. In some embodiments, the focus ring 720 is made of a ceramic-based material. Ceramic-based materials facilitate high pressure process capabilities. A slit valve 722 may be coupled to the chamber body 704 to facilitate transferring the substrate 714 into and out of the interior space 702.

[0031] In some embodiments, the hollow support shaft 718 is coupled to a lift actuator 724, such as a motor, which provides vertical movement of the pedestal 716 between an upper processing position and a lower transfer position. The substrate elevator 726 can include lift pins 728 mounted on a platform 730 connected to a shaft 732, which is coupled to a second lift actuator 734 for raising and lowering the substrate elevator 726 so that the substrate 714 can be placed on or removed from the pedestal 716. The pedestal 716 can include through holes to receive the lift pins 728. The hollow support shaft 718 provides a path for a gas conduit 794 for coupling a backside gas supply 736 and / or an RF power supply 738 to the pedestal 716. In some embodiments, the RF power supply 738 provides bias power to the pedestal 716 via a matching network 740 to a power conduit 742. In some embodiments, the RF energy supplied by the RF power supply 738 can have a frequency of about 2 MHz or greater. In some embodiments, the RF power source 738 can have a frequency of approximately 13.56 MHz.

[0032] In some embodiments, a backside gas supply 736 is disposed outside the chamber body 704 and supplies gas to the susceptor 716. In some embodiments, the susceptor 716 includes a gas channel 744 to allow gas to interact with the back side of the substrate 714 to maintain a given temperature. The gas channel 744 is configured to provide a backside gas, such as nitrogen (N2), argon (Ar), or helium (He), to an upper surface 746 of the susceptor 716 to act as a heat transfer medium. The gas channel 744 is in fluid communication with the backside gas supply 736 via a gas conduit 794 to control the temperature and / or temperature distribution of the substrate 714 during use. For example, the backside gas supply 736 can supply gas to cool and / or heat the substrate 714 during use. In some embodiments, the substrate 714 can be heated from about 275 degrees Celsius to about 420 degrees Celsius.

[0033] The processing chamber 700 includes a process kit surrounding various chamber components to prevent undesirable reactions between these components and contaminants. The processing kit includes an upper shield 748. In some embodiments, the upper shield 748 may be made of metal, such as aluminum. In some embodiments, the processing kit may be composed of quartz. In some embodiments, a mixing reservoir 756 is coupled to the processing space 708 and is in fluid communication with the processing space 708. The mixing reservoir 756 is also fluidly connected to the RPS 764. The mixing reservoir 756 allows the plasma gas to mix with other gases provided by the gas delivery system 750. The gas delivery system 750 may include an ampoule for supplying gas (e.g., chlorine-based gas, etc.) to the processing space 708. The flow rate of other gases from the gas delivery system 750 may be controlled by a first flow valve 788.

[0034] The showerhead 758 is located above the processing volume 708 and below the ceiling 762 of the chamber body 704. The showerhead 758 includes a through hole 760 to allow gas to flow from the mixing reservoir 756 into the processing volume 708. The RPS 764 is fluidly connected to the mixing reservoir 756 to allow ionized gas to flow from the RPS 764 into the mixing reservoir 756, through the showerhead 758, and into the processing volume 708. Plasma is generated in the RPS 764 by a plasma RF power source 766 that provides RF energy to the RPS 764. The process gas used to form the plasma is supplied by the process gas source 770 and controlled by the second flow valve 786. The plasma gas supplied by the process gas source 770 may include, but is not limited to, hydrogen, helium, and / or argon, etc. The second flow valve 786 may contain one or more flow valves to control the amount and flow rate of the gas entering the RPS 764. The controller 778 can be used to achieve the desired flow rate of the individual gases and the desired hydrogen dilution as described in the method 100 above. The RPS 764 generates ions and radicals of the process gas to facilitate processing the substrate 714. In some embodiments, a plasma is generated directly within the processing volume 708 and used with, for example, diluted hydrogen using one or more inert gases to facilitate removal of any chlorine and / or etch-based residues after soaking the substrate surface in accordance with methods of the present principles.

[0035] The pump port 772 is configured to facilitate the removal of particles and gases from the interior space 702. The processing chamber 700 is coupled to and in fluid communication with a vacuum system 774, which includes a throttle valve (not shown) and a pump (not shown) for exhausting the processing chamber 700. In some embodiments, the vacuum system 774 is coupled to the pump port 772 disposed on a bottom surface 776 of the chamber body 704. The pressure inside the processing chamber 700 can be adjusted by adjusting the throttle valve and / or the vacuum pump. In some embodiments, the pump has a flow rate of about 1900 liters per second to about 3000 liters per second. In some embodiments, the vacuum system 774 can be used to facilitate regulating the substrate temperature.

[0036] In some embodiments, a controller 778 is used for the operation of the process chamber 700. The controller 778 may use direct control of the process chamber 700, or alternatively use indirect control of the process chamber 700 by controlling a computer (or controller) associated with the process chamber 700. In operation, the controller 778 enables data collection and feedback from the process chamber 700 to optimize the performance of the process chamber 700. The controller 778 typically includes a central processing unit (CPU) 780, a memory 782, and support circuits 784. The CPU 780 may be any form of general-purpose computer processor that can be used in industrial stereotypes. The support circuits 784 are conventionally coupled to the CPU 780 and may include caches, clock circuits, input / output subsystems, power supplies, etc. Software routines (such as the methods described below herein) may be stored in the memory 782 and, when executed by the CPU 780, convert the CPU 780 into a special-purpose computer (controller 778). The software routines may also be stored and / or executed by a second controller (not shown) located remotely from the processing chamber 700 .

[0037] The memory 782 is in the form of a computer-readable storage medium containing instructions that, when executed by the CPU 780, facilitate the operation of the semiconductor process and the device. The instructions in the memory 782 are in the form of a program product, such as a program that implements the method of the present principles. The program code may conform to any of a variety of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. One or more programs of the program product define the functions of multiple aspects (including the methods described herein). Illustrative computer-readable storage media include, but are not limited to: non-writable storage media on which information is permanently stored (e.g., a read-only memory device within a computer, such as a CD-ROM disk that can be read by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory); and writable storage media on which information that can be modified is stored (e.g., a floppy disk within a disk drive or hard drive or any type of solid-state random access semiconductor memory). Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are aspects of the present principles.

[0038] The methods described herein may be performed in a separate process chamber, which may be configured independently or provided as part of a cluster tool, for example, as described below with reference to Figure 8The integrated tool 800 (i.e., cluster tool) is described. An advantage of using the integrated tool 800 is that there is no vacuum break between chambers, and therefore there is no need to degas and pre-clean the substrate prior to processing in the chamber. For example, in some embodiments, the inventive method discussed above can be advantageously performed in an integrated tool so that there is limited or no vacuum break between processes, thereby limiting or preventing contamination of the substrate, such as oxidation, etc. The integrated tool 800 includes a vacuum sealed processing platform 801, a factory interface 804, and a system controller 802. The processing platform 801 includes a plurality of processing chambers, such as processing chambers 814A, 814B, 814C, 814D, 814E, and 814F that are operably coupled to a vacuum substrate transfer chamber (transfer chambers 803A, 803B). The factory interface 804 consists of one or more load lock chambers (two load lock chambers, such as Figure 8 806A and 806B) shown in FIG. 806A are operably coupled to the transfer chamber 803A.

[0039] In some embodiments, the factory interface 804 includes at least one docking station 807 and at least one factory interface robot 838 to facilitate the transfer of semiconductor substrates. The docking station 807 is configured to receive one or more front opening unified pods (FOUPs). Figure 8 In the embodiment of FIG. 8 , four FOUPs are shown, such as 805A, 805B, 805C, and 805D. A factory interface robot 838 is configured to transfer substrates from the factory interface 804 to the processing platform 801 via load lock chambers (e.g., 806A and 806B). Each of the load lock chambers 806A and 806B has a first port coupled to the factory interface 804 and a second port coupled to the transfer chamber 803A. The load lock chambers 806A and 806B are coupled to a pressure control system (not shown) that pumps and exhausts the load lock chambers 806A and 806B to facilitate transferring substrates between the vacuum environment of the transfer chamber 803A and the substantially atmospheric (e.g., atmospheric pressure) environment of the factory interface 804. The transfer chambers 803A, 803B have vacuum robots 842A, 842B disposed in the respective transfer chambers 803A, 803B. The vacuum robot 842A can transfer the substrate 821 between the load lock chambers 806A, 806B, the processing chambers 814A and 814F, and the cooling station 840 or the pre-cleaning station 842. The vacuum robot 842B can transfer the substrate 821 between the cooling station 840 or the pre-cleaning station 842 and the processing chambers 814B, 814C, 814D, and 814E.

[0040] In some embodiments, processing chambers 814A, 814B, 814C, 814D, 814E, and 814F are coupled to transfer chambers 803A, 803B. Processing chambers 814A, 814B, 814C, 814D, 814E, and 814F may include, for example, substrate immersion chambers, atomic layer deposition (ALD) processing chambers, physical vapor deposition (PVD) processing chambers, remote plasma chambers, chemical vapor deposition (CVD) chambers, annealing chambers, and the like. The chambers may include any chamber suitable for performing all or part of the methods described herein, as discussed above, such as chlorine-based immersion chambers, remote plasma processing chambers, and the like. In some embodiments, one or more optional service chambers (shown as 816A and 816B) may be coupled to transfer chamber 803A. The service chambers 816A and 816B may be configured to perform other substrate processes such as degassing, orientation, substrate metrology, cooling, and the like.

[0041] The system controller 802 controls the operation of the tool 800 using direct control of the processing chambers 814A, 814B, 814C, 814D, 814E, and 814F, or alternatively by controlling a computer (or controller) associated with the processing chambers 814A, 814B, 814C, 814D, 814E, and 814F and the tool 800. In operation, the system controller 802 enables data collection and feedback from the individual chambers and systems to optimize the performance of the tool 800. The system controller 802 typically includes a central processing unit (CPU) 830, a memory 834, and support circuits 832. The CPU 830 can be any form of general purpose computer processor that can be used in an industrial environment. The support circuits 832 are conventionally coupled to the CPU 830 and can include caches, clock circuits, input / output subsystems, power supplies, etc. Software routines (such as the methods described above) may be stored in memory 834 and, when executed by CPU 830, convert CPU 830 into a special purpose computer (system controller 802). Software routines may also be stored and / or executed by a second controller (not shown) located remotely from tool 800.

[0042] Embodiments according to the present principles may be implemented in hardware, firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored using one or more computer-readable media, which may be read and executed by one or more processors. Computer-readable media may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing platform or a "virtual machine" running on one or more computing platforms). For example, a computer-readable medium may include any suitable form of volatile or non-volatile memory. In some embodiments, a computer-readable medium may include a non-transitory computer-readable medium.

[0043] While the foregoing is directed to embodiments of the present principles, other and further embodiments of the principles may be devised without departing from the basic scope thereof.

Claims

1. A method for cleaning the surface of a substrate, comprising the steps of: performing a chlorine-based soak process to remove molybdenum oxide from the surface of the substrate in a back-end of line (BEOL) process, wherein the substrate at least partially contains a low-k dielectric material; and Plasma treatment is performed on the surface of the substrate using a remote plasma containing hydrogen gas diluted with at least one inert gas to remove residual chlorine residues from the surface of the substrate.

2. The method of claim 1, wherein the chlorine-based soaking process uses molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5).

3. The method of claim 1, further comprising the steps of: The chlorine-based soaking process is performed at a temperature of about 350 degrees Celsius to about 460 degrees Celsius.

4. The method of claim 1, further comprising the steps of: The chlorine-based soaking process is performed at a pressure of about 2 Torr to about 20 Torr.

5. The method of claim 1, further comprising the steps of: The chlorine-based soak process is performed using a chlorine-based gas flowing at a rate of about 10 sccm to about 1000 sccm.

6. The method of claim 1, further comprising the steps of: The chlorine-based soaking process is performed for a period of time ranging from about 5 seconds to about 60 seconds.

7. The method of claim 1, wherein the at least one inert gas is argon or helium.

8. The method of claim 1, further comprising the steps of: The plasma treatment is performed at a temperature of about 250 degrees Celsius to about 460 degrees Celsius.

9. The method of claim 1, further comprising the steps of: The plasma treatment is performed at a pressure of about 10 mTorr to about 200 mTorr.

10. The method of claim 1, further comprising the steps of: The plasma treatment is performed using a plasma source power of about 400 watts to about 900 watts.

11. The method of claim 1, further comprising the steps of: The plasma processing is performed using a bias power ranging from zero watts to about 300 watts.

12. The method of claim 1, further comprising the steps of: The plasma treatment is performed using the hydrogen gas diluted by about 1% to about 99% by volume with the at least one inert gas.

13. The method of claim 1, further comprising the steps of: The plasma treatment is performed using the hydrogen gas flowing at a rate of about 1 sccm to about 100 sccm and the at least one inert gas flowing at a rate of about 5 sccm to about 200 sccm.

14. A method for cleaning the surface of a substrate, comprising the steps of: performing a chlorine-based soak process using molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5) at a temperature of about 350 degrees Celsius to about 460 degrees Celsius for a time of about 5 seconds to about 60 seconds in a back-end of line (BEOL) process to remove molybdenum oxide from the surface of the substrate, wherein the substrate at least partially contains a low-k dielectric material; and Plasma treatment is performed on the surface of the substrate at a temperature of about 250 degrees Celsius to about 460 degrees Celsius using a remote plasma to remove residual chlorine residue from the surface of the substrate, the remote plasma containing hydrogen gas diluted with argon gas and helium gas, wherein the hydrogen gas is diluted with argon gas and helium gas by about 3% to about 10% by volume.

15. The method of claim 14, further comprising the steps of: performing the chlorine-based soaking process at a pressure of about 2 Torr to about 20 Torr; or The chlorine-based soak process is performed using a chlorine-based gas flowing at a rate of about 10 sccm to about 1000 sccm.

16. The method of claim 14, further comprising the steps of: The plasma treatment is performed at a pressure of about 10 mTorr to about 200 mTorr.

17. The method of claim 14, further comprising the steps of: The plasma treatment is performed using the hydrogen gas flowing at a first rate of about 3 sccm to about 10 sccm, the argon gas flowing at a second rate of about 50 sccm to about 200 sccm, and the helium gas flowing at a third rate of about 50 sccm to about 200 sccm.

18. The method of claim 14, further comprising the steps of: performing the plasma treatment using a plasma source power of about 400 watts to about 900 watts; or The plasma processing is performed using a bias power ranging from zero watts to about 300 watts.

19. A non-transitory computer readable medium having stored thereon instructions which, when executed, result in a method for cleaning a surface of a substrate, the method comprising the steps of: performing a chlorine-based soak process using molybdenum pentachloride (MoCl5) or tungsten pentachloride (WCl5) at a temperature of about 350 degrees Celsius to about 460 degrees Celsius for a time of about 5 seconds to about 60 seconds in a back-end of line (BEOL) process to remove molybdenum oxide from the surface of the substrate, wherein the substrate at least partially contains a low-k dielectric material; and Plasma treatment is performed on the surface of the substrate at a temperature of about 250 degrees Celsius to about 460 degrees Celsius using a remote plasma to remove residual chlorine residue from the surface of the substrate, the remote plasma containing hydrogen gas diluted with argon gas and helium gas, wherein the hydrogen gas is diluted with argon gas and helium gas by about 3% to about 10% by volume.

20. The non-transitory computer readable medium of claim 19, further comprising: performing the chlorine-based soaking process at a pressure of about 2 Torr to about 20 Torr; performing the chlorine-based soak process using a chlorine-based gas flowing at a rate of about 10 sccm to about 1000 sccm; performing the plasma treatment at a pressure of about 10 mTorr to about 200 mTorr; or The plasma treatment is performed using the hydrogen gas flowing at a first rate of about 3 sccm to about 10 sccm, the argon gas flowing at a second rate of about 50 sccm to about 200 sccm, and the helium gas flowing at a third rate of about 50 sccm to about 200 sccm.

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