Method and apparatus for processing a substrate

Abstract

The present disclosure provides methods and apparatuses for processing substrates. For example, a method for processing a substrate may include: selectively etching an exposed first material layer from a substrate disposed in a PVD chamber using both process gas ions and metal ions formed from a target in the PVD chamber, the exposed first material layer covering a underlying second material layer and adjacent to an exposed third material layer, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer onto the third material layer; and subsequently depositing metal from the target onto the second material layer.

Description

[0001] Field

[0002] Embodiments of the present disclosure generally relate to methods and apparatuses for processing substrates, and more particularly to methods and apparatuses using a physical vapor deposition (PVD) chamber configured to perform PVD and pre-cleaning processes on a substrate. Background Art

[0003] It is known to configure a process chamber to perform a pre-cleaning process. For example, in under bump metallization (UBM), such a chamber is configured to remove native oxides and other materials on metal contact pads of a substrate prior to PVD for depositing one or more barrier layers (e.g., titanium (Ti), copper (Cu), tungsten (W), etc.) on the substrate. A pre-cleaning chamber typically uses ion bombardment (initiated by an RF plasma) to remove native oxides on metal contact pads. For example, the pre-cleaning process can etch away native oxides from metal contact pads. The pre-cleaning process is configured to reduce the contact resistance between metal contacts on the substrate to improve the performance and power consumption of an integrated circuit (IC) on the substrate.

[0004] After pre-cleaning the substrate, the substrate is moved from the pre-cleaning chamber to one or more other process chambers for further processing. For example, as described above, the substrate can be moved from the pre-cleaning chamber to a PVD chamber such that one or more additional barrier layers can be formed on the substrate. However, unfortunately, when the substrate is moved from the pre-cleaning chamber to the PVD chamber, exposure of the substrate to the atmosphere can cause additional native oxides to form on the metal contacts, which can in turn have a negative impact on the performance and power consumption of the integrated circuit (IC) on the substrate.

[0005] Accordingly, the inventors have provided methods and apparatuses using a PVD chamber configured to perform both PVD and pre-cleaning processes on a substrate. Summary of the Invention

[0006] Methods and apparatuses for processing substrates are provided herein. In some embodiments, for example, a method for processing a substrate in a physical vapor deposition (PVD) chamber can include: selectively etching an exposed first material layer covering a underlying second material layer and adjacent to an exposed third material layer from the substrate disposed in the PVD chamber using both process gas ions and metal ions formed from a target of the PVD chamber, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer onto the third material layer; and subsequently depositing a metal from the target onto the second material layer.

[0007] According to at least some embodiments, a physical vapor deposition (PVD) chamber for processing a substrate includes: a DC power source and an RF power source; a target configured to form metal ions that are sputtered onto a surface of a substrate disposed within a processing volume of the PVD chamber; a gas source configured to provide at least one process gas into the processing volume of the PVD chamber; and a controller coupled to the DC power source and the RF power source and configured to: selectively etch an exposed first material layer from the substrate using both process gas ions and metal ions, the exposed first material layer covering a underlying second material layer and adjacent to an exposed third material layer, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer onto the third material layer; and subsequently deposit metal from the target onto the second material layer.

[0008] According to at least some embodiments, a non-transitory computer-readable storage medium having instructions stored thereon that, when executed by a processor, perform a method for processing a substrate in a physical vapor deposition (PVD) chamber. The method includes: selectively etching an exposed first material layer from a substrate disposed in a PVD chamber using both process gas ions and metal ions formed from a target of the PVD chamber, the exposed first material layer covering a underlying second material layer and adjacent to an exposed third material layer, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer onto the third material layer; and subsequently depositing metal from the target onto the second material layer.

[0009] Other and further embodiments of the present disclosure are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the present disclosure, briefly summarized above and discussed in more detail below, may be understood by reference to the illustrative embodiments of the present disclosure depicted in the drawings. However, the drawings merely illustrate typical embodiments of the present disclosure and should not be considered limiting of the scope as the present disclosure may admit to other equivalent embodiments.

[0011] Figure 1 FIG. is a schematic cross-sectional view of a process chamber according to at least some embodiments of the present disclosure.

[0012] Figure 2 FIG. is a flow chart of a method for processing a substrate according to at least some embodiments of the present disclosure.

[0013] Figures 3A to 3C FIG. is a schematic illustration showing multiple stages of a substrate processed using the method of Figure 2 according to at least some embodiments of the present disclosure.

[0014] For ease of understanding, the same reference numerals are used throughout the figures to designate like elements where possible. The figures 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 recitation. DETAILED DESCRIPTION

[0015] Embodiments of methods and apparatuses using a PVD chamber configured to perform PVD and pre-clean (or etch) processes on a substrate are described herein. The PVD chambers described herein overcome disadvantages associated with conventional methods and apparatuses used to perform PVD and pre-clean processes. For example, since both the PVD and pre-clean processes are performed in the same chamber, there is no queue time (e.g., the substrate is exposed to the atmosphere) between the pre-clean process and the PVD process, thus eliminating the possibility of re-oxidation of the metal pads of the substrate. In addition, since both the PVD and pre-clean processes are performed in the same chamber, the throughput of the substrate will be increased. Also, polymers that may sometimes be present on the substrate (e.g., prior to performing the pre-clean process on the substrate) will not be inadvertently removed (polymer decomposition) due to the outgassing process typically performed on the substrate prior to removing the substrate from the pre-clean chamber. More specifically, according to the present disclosure, since a combination of metal ions and gas ions is used in the pre-clean process, any polymers that may be present on the substrate are passivated (e.g., covered) by the metal ions during the pre-clean process. Thus, the polymers are protected from polymer decomposition during the outgassing process in which the gas ions are removed from the PVD chamber.

[0016] Figure 1 FIG. is a schematic cross-sectional view of a system for processing a substrate 104 (or wafer) according to at least some embodiments of the present disclosure. The system includes apparatuses that may be implemented in a process chamber 100. In at least some embodiments, for example, a PVD process chamber that may be configured for use with the system may be a Plus and SIP PVD series, both of which are commercially available from Applied Materials, Inc., Santa Clara, Calif. The process chamber 100 may be incorporated on a cluster tool (e.g., )). For example, the cluster tool may be configured to perform ALD, CVD, epitaxy, etching, photomask fabrication, PVD, plasma doping, plasma nitridation, and RTP, as well as integrated multi-step processes such as high-k transistor gate stack fabrication.

[0017] The process chamber 100 is configured to perform PVD of materials on a substrate 104 disposed within the process chamber 100. Additionally, as described above, the process chamber 100 is configured to perform one or more additional processes. For example, as will be described in more detail below, the process chamber 100 may be configured to perform a pre-clean process to remove (e.g., etch) one or more materials from the substrate 104.

[0018] Continuing to refer to Figure 1 , the process chamber 100 includes a substrate support base 102 and a sputtering source, the substrate support base 102 being for receiving the substrate 104 thereon, and the sputtering source such as a target 106 (target 106) of source material. The substrate support base 102 may be located within a grounded enclosure wall 108, and the grounded enclosure wall 108 may be a chamber wall (as shown) or a ground shield. In Figure 1 , a ground shield 140 is shown covering at least some portions of the process chamber 100 above the target 106. In some embodiments, the ground shield 140 may extend beneath the target to also surround the base 102.

[0019] The process chamber includes a feed structure 110 for coupling RF and DC energy to the target 106. For example, as described below, the feed structure is a device for coupling RF energy and DC energy to the target 106 or to a component containing the target. In some embodiments, the feed structure 110 may be tubular. The feed structure 110 includes a body 112 having a first end 114 and a second end 116 opposite the first end 114. In some embodiments, the body 112 further includes a central opening 115 disposed to pass through the body 112 from the first end 114 to the second end 116.

[0020] The first end 114 of the feed structure 110 may be coupled to an RF power source 118 and a DC power source 120, which may be used to supply RF and DC energy to the target 106, respectively. For example, as will be described in more detail below, in a first processing state, both the RF power source 118 and the DC power source 120 may be used to perform a pre-cleaning process on the substrate 104, and in a second processing state, the DC power source 120 may be used to perform a PVD process on the substrate 104. In some embodiments, the DC power source 120 may be used to apply a negative voltage or bias to the target 106. In some embodiments, the RF energy supplied by the RF power source 118 may be in a frequency range from about 2 MHz to about 60 MHz, or, for example, non-limiting frequencies such as 2 MHz, 13.56 MHz, 27.12 MHz, or 60 MHz may be used. In some embodiments, multiple RF power sources (i.e., two or more RF power sources) may be provided to supply RF energy at multiple of the above frequencies. The feed structure 110 may be made of a suitable conductive material to conduct RF and DC energy from the RF power source 118 and the DC power source 120. The DC power source 120 may alternatively be coupled to the target 106 without passing through the feed structure 110.

[0021] The DC power source 120 and the RF power source 118 may be used synchronously to create a first processing state (e.g., for etching the substrate 104) within the processing volume 148 of the process chamber 100. For example, the first processing state may include a plasma 119 that includes both gas ions and metal ions and may be used to pre-clean the substrate 104 to remove one or more materials (e.g., native oxide) from the substrate 104. The DC power source may be used to create a second processing state (e.g., for performing PVD on the substrate 104). For example, as will be described in more detail below, the second processing state may include only metal atoms and / or ions and may be used to perform PVD on the substrate 104 to deposit one or more metals on the substrate 104.

[0022] In addition, an RF bias power source 162 may be coupled to the substrate support base 102 to induce a negative DC bias on the substrate 104. Further, in some embodiments, a negative DC self-bias may be formed on the substrate 104 during processing. For example, the RF power supplied by the RF bias power source 162 may be in a frequency range from about 2 MHz to about 60 MHz, and, for example, non-limiting frequencies such as 2 MHz, 13.56 MHz, or 60 MHz may be used. In other applications, the substrate support base 102 may be grounded or maintained electrically floating. For example, a capacitance tuner 164 may be coupled to the substrate support base to adjust the voltage on the substrate 104 in applications where RF bias power may not be desired.

[0023] The feed structure 110 may have a suitable length that promotes substantially uniform distribution of the respective RF and DC energy around the periphery of the feed structure 110. For example, in some embodiments, the feed structure 110 may have a length of from about 0.75 inches to about 12 inches, or about 3.26 inches.

[0024] In some embodiments, the body 112 may have a length-to-inner diameter ratio of at least about 1:1. In some embodiments, the body may have a length-to-outer diameter ratio of at least about 0.5:1 (e.g., about 0.6:1).

[0025] The inner diameter of the feed structure 110 (i.e., the diameter of the central opening 115) can be made as small as possible while still allowing the magnetron axis to extend therethrough, e.g., from about 1 inch to about 11 inches, or about 3.9 inches. In some embodiments, in the absence of the magnetron axis (e.g., when not using a magnetron, or where the magnetron is not controlled via an axis centered above the back side of the target), the inner diameter of the feed structure 110 can be as small as zero inches (e.g., a body 112 can be provided without a central opening 115). In such embodiments, the inner diameter of the feed structure 110 (if any) can be, for example, from about 0 inches to about 11 inches.

[0026] The outer diameter of the feed structure 110 can be made as small as possible while maintaining a sufficient wall thickness of the feed structure 110 for mechanical integrity, e.g., from about 1.5 inches to about 12 inches, or about 5.8 inches. In some embodiments, in the absence of the magnetron axis, the outer diameter 250 of the feed structure 110 can be as small as about 0.5 inches. In such embodiments, the outer diameter of the feed structure 110 can be, for example, from about 0.5 inches to about 12 inches.

[0027] Providing a smaller inner diameter (and a smaller outer diameter) helps to increase the length-to-ID ratio (and length-to-OD ratio) without increasing the length of the feed structure 110. Although described above as being used to couple both RF and DC energy to the target 106, the feed structure 110 can also be used to couple only RF energy to the target, where DC energy is coupled to the target from a different location. In such embodiments, for example, when performing an etching process to remove material from the substrate 104, although the DC energy may not be as uniform as that provided via the feed structure 110, the RF energy is still provided more uniformly to the target to facilitate more uniform plasma processing.

[0028] The second end 116 of the body 112 is coupled to a source distribution plate 122. The source distribution plate includes a hole 124 that is configured to pass through the source distribution plate 122 and align with the central opening 115 of the body 112. The source distribution plate 122 can be made of a suitable conductive material to conduct RF and DC energy from the feed structure 110.

[0029] The source distribution plate 122 can be coupled to the target 106 via a conductive member 125. The conductive member 125 can be a tubular member having a first end 126 that is coupled to the target-facing surface 128 of the source distribution plate 122 adjacent to the circumferential edge of the source distribution plate 122. The conductive member 125 further includes a second end 130 that is coupled to the target-facing surface 132 of the target 106 (or coupled to the backing plate 146 of the target 106) adjacent to the circumferential edge of the target 106.

[0030] A cavity 134 can be defined by the inward-facing wall of the conductive member 125, the target-facing surface 128 of the source distribution plate 122, and the target-facing surface 132 of the target 106. The cavity 134 is fluidly coupled to the central opening 115 of the body 112 via the hole 124 of the source distribution plate 122. As Figure 1 shown and further described below, the cavity 134 and the central opening 115 of the body 112 can be utilized to at least partially accommodate one or more portions of the rotatable magnetron assembly 136. In some embodiments, the cavity can be at least partially filled with a cooling fluid (such as water (H2O), etc.).

[0031] A ground shield 140 can be provided to cover the outer surface of the lid of the process chamber 100. The ground shield 140 can be coupled to ground, for example, via a ground connection of the chamber body. The ground shield 140 has a central opening to allow the feed structure 110 to pass through the ground shield 140 and be coupled to the source distribution plate 122. The ground shield 140 can comprise any suitable conductive material, such as aluminum, copper, etc. An insulating gap 139 is provided between the ground shield 140 and the outer surfaces of the source distribution plate 122, the conductive member 125, and the target 106 (and / or the backing plate 146) to prevent RF and DC energy from being directly guided to ground. The insulating gap can be filled with air or some other suitable dielectric material (such as ceramic, plastic, etc.).

[0032] In some embodiments, a ground collar 141 may be disposed around the lower portion of the body 112 and the feed structure 110. The ground collar 141 is coupled to the ground shield 140 and may be an integral part of the ground shield 140 or may be a separate component coupled to the ground shield to provide grounding for the feed structure 110. The ground collar 141 may be made of a suitable conductive material such as aluminum or copper. In some embodiments, the gap between the inner diameter of the ground collar 141 and the outer diameter of the body 112 of the feed structure 110 may be kept to a minimum and just sufficient to provide electrical isolation. The gap may be filled with an insulating material such as plastic or ceramic or may be an air gap. The ground collar 141 prevents crosstalk between the RF feed and the body 112, thereby improving plasma and process uniformity.

[0033] An isolator plate 138 may be disposed between the power distribution plate 122 and the ground shield 140 to prevent RF and DC energy from being directly routed to ground. The isolator plate 138 has a central opening to allow the feed structure 110 to be coupled to the power distribution plate 122 through the isolator plate 138. The isolator plate 138 may comprise a suitable dielectric material such as ceramic, plastic, etc. Alternatively, an air gap may be provided in place of the isolator plate 138. In embodiments where an air gap is provided in place of the isolator plate, the ground shield 140 is structurally reliable enough to support any components placed on the ground shield 140.

[0034] Return Figure 1 , the target 106 may be supported on a grounded conductive aluminum adapter 142 by a dielectric insulator 144. Generally, the target 106 may be any material commonly used in thin film fabrication via PVD, such as metals or metal oxides. For example, in some embodiments, the target 106 may be a metal such as titanium (Ti) suitable for depositing Ti or titanium nitride (TiN), tungsten (W), copper (Cu), etc. on the substrate 104. Other materials may also be suitably used in accordance with the teachings provided herein.

[0035] The target 106 is generally elongated and may be, for example, cylindrical or rectangular. The dimensions of the target 106 may vary depending on the dimensions of the substrate 104 and / or the configuration of the process chamber 100. For example, for processing a 300 mm diameter semiconductor wafer, the width or diameter of the target 106 may be between about 100 mm and about 200 mm and may have a length of about 400 mm to about 600 mm. The target 106 may be stationary or movable, including rotatable along the longitudinal axis of the target 106.

[0036] In some embodiments, the backplate 146 may be coupled to the surface 132 of the target 106 that faces the power distribution plate. The backplate 146 may comprise a conductive material, such as copper - zinc, copper - chromium, or the same material as the target, such that RF and DC power may be coupled to the target 106 via the backplate 146. Alternatively, the backplate 146 may be non - conductive and may include conductive members (not shown), such as electrical feed - throughs, for coupling the surface 132 of the target 106 that faces the power distribution plate to the second end 130 of the conductive member 125. The backplate 146 may be included, for example, to improve the structural stability of the target 106.

[0037] The substrate support base 102 has a material receiving surface facing the main surface of the target 106 and supports the substrate 104 to be sputter - coated in a planar position opposite the main surface of the target 106. The substrate support base 102 may support the substrate 104 within the processing volume 148 of the process chamber 100. The processing volume 148 is defined as the region above the substrate support base 102 during processing (e.g., between the target 106 and the substrate support base 102 in the processing position).

[0038] In some embodiments, the substrate support base 102 may be vertically moved by a bellows 150 connected to the bottom chamber wall 152 to allow the substrate 104 to be transferred onto the substrate support base 102 via a load - lock valve (not shown) in the lower part of the process chamber 100 and then raised to a deposition or processing position, such as a pre - cleaning processing position.

[0039] One or more process gases may be supplied to the lower part of the process chamber 100 from a gas source 154 through a mass flow controller 156. The process gas may be any suitable process gas, such as an inert gas (e.g., argon) or nitrogen (N2), for forming a plasma within the processing volume 148 when sputtering the material 107 from the target 106. As will be described in more detail below, the process gas may also be used to perform a pre - cleaning process on the substrate 104. An exhaust port 158 may be provided and coupled via a valve 160 to a pump (not shown) for exhausting or degassing the used process gas from the interior of the process chamber 100 and / or for helping to maintain a desired pressure within the process chamber 100.

[0040] The rotatable magnetron assembly 136 can be positioned adjacent to the rear surface of the target 106 (e.g., the surface 132 facing the power distribution board). The rotatable magnetron assembly 136 includes a plurality of magnets 166 supported by a base plate 168. The base plate 168 is connected to a rotating shaft 170 that coincides with the central axis of the process chamber 100 and the substrate 104. A motor 172 can be coupled to the upper end of the rotating shaft 170 to drive the rotation of the rotatable magnetron assembly 136. The magnets 166 generate a magnetic field within the process chamber 100 that is generally parallel to and close to the surface of the target 106 to trap electrons and increase the local plasma density, which in turn (e.g., during PVD) increases the sputtering rate. The magnets 166 generate an electromagnetic field around the top of the process chamber 100 and rotate the magnets 166 to rotate the electromagnetic field, which affects the plasma density of the process to sputter the target 106 more uniformly. For example, the rotating shaft 170 can rotate at about 0 to about 150 revolutions per minute.

[0041] In some embodiments, the process chamber 100 can further include a grounded bottom shield 174 that is connected to a protrusion 176 of the adapter 142. A dark space shield 178 can be supported on the bottom shield 174 and fastened to the bottom shield 174 by screws or other suitable means. The metal threaded connection between the bottom shield 174 and the dark space shield 178 allows the bottom shield 174 and the dark space shield 178 to be grounded to the adapter 142. The adapter 142 is in turn sealed and grounded to the chamber wall 108. Both the bottom shield 174 and the dark space shield 178 are typically made of hard non-magnetic stainless steel.

[0042] The bottom shield 174 extends downward and can include a generally tubular portion 180 having a generally constant diameter. The bottom shield 174 extends downward along the wall of the adapter 142 and the chamber wall 108 below the top surface of the substrate support base 302 and then returns upward until it reaches the top surface of the substrate support base 102 (e.g., thus forming a U-shaped portion 184 at the bottom). When the substrate support base 102 is in the lower loading position, the cover ring 186 is placed on the top end of the upwardly extending inner portion 188 of the bottom shield 174, but when the substrate support base 102 is in the higher deposition position, the cover ring 186 is placed on the outer periphery of the substrate support base 102 to protect the substrate support base 102 from sputter deposition. An additional deposition ring (not shown) can be used to shield the periphery of the substrate 104 from deposition.

[0043] In some embodiments, magnets 190 can be disposed around the process chamber 100 for selectively providing a magnetic field between the substrate support base 102 and the target 106. For example, asFigure 1 As shown, when in the processing position, the magnet 190 can be disposed around the outside of the chamber wall 108 in the region directly above the substrate support base 102. In some embodiments, the magnet 190 can be additionally or alternatively disposed at other locations, such as adjacent to the adapter 142. The magnet 190 can be an electromagnet and can be coupled to a power source (not shown) to control the magnetic field strength generated by the electromagnet.

[0044] The controller 121 including the processor 123 is configured (or programmed) to control the overall operation of the process chamber 100. For example, under the control of the processor 123, the controller 121 can receive a recipe input into the memory 127 of the processor 123. For example, the memory 127 can be a non-transitory computer-readable storage medium having instructions that, when executed by the processor 123 (or the controller 121), perform the methods described herein. The recipe can include information related to one or more parameters associated with one or more of the foregoing components for processing the substrate 104. For example, the controller 121 can use the information in the recipe to control the RF power source 118 and the DC power source 120 to control the amount of power used during operation; to adjust the RF power source 118 and the DC power source 120, for example, to select one or both of the RF power source 118 and the DC power source 120 to generate inert gas ions, metal ions, and / or a combination of gas ions and metal ions; to control the height of the substrate support base 102 (such as when the substrate 104 is loaded into the process chamber 100 or being processed); to control the gas source 154 to control the amount of process gas to be supplied to the process chamber 100; to control the plurality of magnets 166 to control the position of the magnets or the speed at which the plurality of magnets 166 rotate, etc.

[0045] Figure 2 is a flow chart of a method 200 for processing a substrate, and Figures 3A to 3C is a schematic diagram showing multiple stages of a substrate processed using the method 200 according to at least some embodiments of the present disclosure Figure 2 thereof.

[0046] Initially, a substrate (e.g., substrate 104) can be formed using one or more process chambers (e.g., CVD chamber, ALD chamber, etc.) and can be made of any suitable material for forming the substrates described herein, including but not limited to silicon or germanium. For example, in at least some embodiments, the substrate can be a substrate 300 having a base layer 302 made of silicon ( Figure 3A)。One or more additional material layers may be deposited on top of the base layer 302, including but not limited to, oxides (such as thermal oxides), one or more types of metals, one or more types of polymers, and the like. For example, in at least some embodiments, the base layer 302 may have a thermal oxide layer 304 deposited thereon; a conductive layer, such as a metal layer, at least partially covering the thermal oxide layer 304, for example, an aluminum layer 306 (e.g., the second material layer); and a polymer layer 308 (e.g., the third material layer) at least partially covering the thermal oxide layer 304 and the aluminum layer 306, thereby forming a trench (or via) 310 that exposes at least a portion of the aluminum layer 306 (e.g., see Figure 3A )。In at least some embodiments, the thermal oxide may be silicon dioxide (SiO2) (or other suitable thermal oxide), and the polymer may include but not be limited to, polyimide (PI), polybenzoxazole (PBO), and the like. Additionally, the thermal oxide layer 304 may have a thickness of about to about .

[0047] After forming the Figure 3A substrate 300, it may be necessary to perform one or more additional processes on the substrate 300. For illustrative purposes, assume that the additional process is PVD for depositing one or more additional metal layers on the substrate 300. However, as described above, when transferring the substrate from one process chamber to another, a native oxide (e.g., a first material layer, such as a metal oxide layer) may sometimes form on the metal contact pads (e.g., the aluminum layer 306) on the substrate. Thus, for illustrative purposes, an aluminum oxide layer 312 is shown on top of the aluminum layer 306 ( Figure 3A ).

[0048] The substrate 300 may be loaded into the process chamber (e.g., by load lock, slit valve, etc.) in the appropriate manner described above. Once loaded, in at least some embodiments, the controller (e.g., controller 121) may select one or both of the DC power source 120 and the RF power source 118 to generate one or more process states to perform one or more corresponding processes (at 202). For example, at 202, the controller may generate a first process state that may be used to perform a pre-cleaning process (e.g., selectively etch) on the substrate.

[0049] For example, the inventors have found that a first process state can be generated by selecting both the DC power source 120 and the RF power source 118, and a plasma (e.g., plasma 119) can be generated in the process chamber according to the target material and process gas provided within the internal volume of the process chamber. The plasma includes one or more target ions (e.g., target 106 ions) and gas ions. The plasma including one or more target ions and gas ions can be used to perform a pre-cleaning process to remove (e.g., selectively etch) native oxides (e.g., remove metal oxides such as alumina layer 312 from substrate 300), and / or deposit a thin film layer of the target material on top of one or more layers (e.g., polymer layer 308) on the substrate.

[0050] Thus, in at least some embodiments, the target material can include metals (e.g., titanium, tungsten, copper, etc.) and the process gas can include inert gases (e.g., argon, nitrogen, or other inert gases, such as one or more inert gases). Thus, when the controller selects both the DC power source 120 and the RF power source 118, a first processing state is generated that includes a plasma (depicted by the arrow 314 in Figure 3B ), the plasma including both metal ions and inert gas ions, to perform a pre-cleaning process to remove (e.g., selectively etch) native oxides and / or deposit a metal thin film layer.

[0051] For example, during the etching of substrate 300, at 202, the metal ions and inert gas ions bombard substrate 300 to remove a first material layer (e.g., native oxide) from a second material layer (e.g., aluminum layer 306). Additionally, during the etching of substrate 300 at 202 (or at 204 after etching), a metal thin film layer 316 is also deposited on top of a third material layer (e.g., polymer layer 308). The metal thin film layer 316 on top of the polymer layer 308 can protect the polymer layer 308 during a degassing or outgassing procedure used to remove the spent process gas from the internal volume of the process chamber. The controller can also be configured to adjust one or more parameters (e.g., the amount of power supplied from the RF power source 118 and the DC power source 120, pressure, temperature, magnet rotation, gas flow, bias, etc.) to control the thickness of the metal thin layer 316 deposited on top of the polymer layer 308, and / or the amount of metal ions and / or inert gas ions generated within the internal volume of the process chamber.

[0052] Additionally, at 204 (e.g., after completion of the etching process), the controller can deposit one or more materials on the substrate. For example, the controller can select only the DC power source 120 to generate a second processing state that includes only metal ions (depicted by the Figure 3Cas depicted by arrow 318 in FIG. to perform PVD to deposit metal layer 320 on top of the etched aluminum layer 306, and / or deposit additional metal layers on top of the polymer layer 308. In at least some embodiments, the metal used to perform the etching process may be the same as or different from the metal used to perform PVD. In some embodiments, one or more process gases may also be used during PVD of the substrate. Again, the controller may also be configured to adjust one or more parameters (e.g., the amount of power supplied from RF power source 118 and DC power source 120, pressure, temperature, magnet rotation, gas flow, bias, etc.) to control the thickness of the thin metal layer 320 deposited on top of the aluminum layer 306 (and / or deposited on top of the polymer layer 308), and / or the amount of metal ions generated within the interior volume of the process chamber.

[0053] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. A method for processing a substrate in a physical vapor deposition (PVD) chamber, comprising the steps of: selectively etching an exposed first material layer from a substrate disposed in the PVD chamber using both process gas ions and metal ions formed from a target in the PVD chamber, the exposed first material layer covering a underlying second material layer and adjacent to a third material layer, the third material layer having a top surface exposed over the entire first material layer, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer to passivate the third material layer, thereby protecting the third material layer from decomposition during a degassing process; and subsequently depositing metal from the target onto the second material layer.

2. The method of claim 1, wherein the step of subsequently depositing metal from the target onto the second material layer comprises: depositing metal from the target onto a material layer deposited on the third material layer.

3. The method of claim 1, wherein the step of selectively etching the first material layer comprises: using both a DC power source and an RF power source.

4. The method of claim 1, wherein the step of depositing metal comprises: using only a DC power source.

5. The method of claim 1, wherein the first material layer is a metal oxide layer, the second material layer is a metal, and the third material layer is a polymer layer.

6. The method of any one of claims 1 to 5, wherein the metal oxide layer is alumina, the metal layer is aluminum, and the polymer layer is one of polyimide (PI) or polybenzoxazole (PBO).

7. The method of claim 1, wherein the target is made of at least one of: titanium, tungsten, or copper.

8. The method of claim 1, further comprising the step of: performing a degassing procedure after selectively etching the substrate to remove used process gas from the PVD chamber.

9. The method of any one of claims 1 to 5, 7, or 8, wherein the process gas ions are at least one of: argon or nitrogen.

10. A physical vapor deposition (PVD) chamber for processing a substrate, the PVD chamber comprising: a DC power source and an RF power source; a gas source for providing at least one process gas into a processing volume of the PVD chamber; and a controller coupled to the DC power source and the RF power source and configured to: Form metal ions to be sputtered onto the surface of a substrate disposed within the processing volume of the PVD chamber, using both process gas ions and metal ions to selectively etch an exposed first material layer from the substrate, the exposed first material layer covering a underlying second material layer and adjacent to a third material layer, the third material layer having a top surface exposed over the entire first material layer, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer to passivate the third material layer, thereby protecting the third material layer from decomposition during a degassing process; and subsequently deposit metal onto the second material layer.

11. The PVD chamber of claim 10, wherein the step of subsequently depositing metal onto the second material layer comprises: depositing metal onto a material layer deposited on the third material layer.

12. The PVD chamber of claim 10, wherein the controller is further configured to: selectively etch the first material layer using both the DC power source and the RF power source.

13. The PVD chamber of claim 10, wherein the controller is further configured to: deposit the metal using only the DC power source.

14. The PVD chamber of claim 10, wherein the first material layer is a metal oxide layer, the second material layer is a metal, and the third material layer is a polymer layer.

15. The PVD chamber of any one of claims 10 to 14, wherein the metal oxide layer is alumina, the metal layer is aluminum, and the polymer layer is one of polyimide (PI) or polybenzoxazole (PBO).

16. The PVD chamber of claim 10, wherein the target for forming the metal ions is made of at least one of: titanium, tungsten, or copper.

17. The PVD chamber of any one of claims 10 to 14 or 16, wherein the process gas ions are at least one of: argon or nitrogen.

18. A non-transitory computer-readable storage medium having instructions stored thereon that, when executed by a processor, perform a method for processing a substrate in a physical vapor deposition (PVD) chamber, the method comprising the steps of: using both process gas ions and metal ions formed from a target of the PVD chamber to selectively etch an exposed first material layer from a substrate disposed within the PVD chamber, the exposed first material layer covering a underlying second material layer and adjacent to a third material layer, the third material layer having a top surface exposed over the entire first material layer, the amounts of the process gas ions and the metal ions being sufficient to expose the second material layer while depositing a metal layer to passivate the third material layer, thereby protecting the third material layer from decomposition during a degassing process; and subsequently deposit metal from the target onto the second material layer.

19. The non-transitory computer-readable storage medium according to claim 18, wherein the step of subsequently depositing the metal from the target onto the second material layer comprises: depositing the metal from the target onto a material layer deposited on the third material layer.

20. The non-transitory computer-readable storage medium according to any one of claims 18 or 19, wherein selectively etching the first material layer comprises: using both a DC power source and an RF power source.

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