High ion bombardment driven advanced patterning carbon film

Abstract

Embodiments of the present invention generally relate to process systems, chambers, and methods for depositing or otherwise fabricating carbon films, such as hardmask layers with improved properties including density. In some embodiments, a plasma processing chamber contains a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor, an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber, one or more RF current tuners, a showerhead, and a vacuum system including a pump and a gate valve. In some examples, a method of forming a carbon-containing layer includes introducing precursor gas and inert gas into the plasma processing chamber, the precursor gas is a hydrocarbon-containing gas mixture; generating an RF plasma and depositing a carbon-containing layer on the substrate.

Description

44025340W001HIGH ION BOMBARDMENT DRIVEN ADVANCED PATTERNING CARBON FILMBACKGROUNDField

[0001] Embodiments of the present invention generally relate to the fabrication of integrated circuits. More particularly, the implementations described herein provide systems, chambers, and methods for depositing or otherwise fabricating carbon films on a substrate.Description of the Related Art

[0002] Integrated circuits have evolved into complex devices that can include millions of transistors, capacitors and resistors on a single chip. The evolution of chip designs continually involves faster circuitry and greater circuit density. The demands for faster circuits with greater circuit densities impose corresponding demands on the materials used to fabricate such integrated circuits. In particular, as the dimensions of integrated circuit components are reduced to the sub-micron scale, low resistivity conductive materials as well as low dielectric constant insulating materials are used to obtain suitable electrical performance from such components.

[0003] The demands for greater integrated circuit densities also impose demands on the process sequences used in the manufacture of integrated circuit components. For example, in process sequences that use conventional photolithographic techniques, a layer of energy sensitive resist is formed over a stack of material layers deposited on a substrate. The energy sensitive resist layer is exposed to an image of a pattern to form a photoresist mask. Thereafter, the mask pattern is transferred to one or more of the material layers of the stack using an etch process. The chemical etchant used in the etch process is selected to have a greater etch selectivity for the material layers of the stack than for the mask of energy sensitive resist. That is, the chemical etchant etches the one or more layers of the material stack at a rate much faster than the energy sensitive resist. The etch selectivity to the one or more material44025340W001 layers of the stack over the resist prevents the energy sensitive resist from being consumed prior to completion of the pattern transfer.

[0004] As the pattern dimensions are reduced, the thickness of the energy sensitive resist is correspondingly reduced in order to control pattern resolution. Such thin resist layers can be insufficient to mask underlying material layers during the pattern transfer process due to attack by the chemical etchant. An intermediate layer (e.g., silicon oxynitride, silicon carbine, or carbon film), called a hardmask, is often used between the energy sensitive resist layer and the underlying material layers to facilitate pattern transfer because of greater resistance to the chemical etchant. Maintaining good critical dimensions (CD) of both isolated and dense features of the integrated circuit components requires hardmask materials having high density and low stress.

[0005] Therefore, there is a need for improved process systems, chambers, and methods for depositing or otherwise fabricating carbon films, such as hardmask layers.SUMMARY

[0006] Embodiments of the present invention generally relate to process systems, chambers, and methods for depositing or otherwise fabricating carbon films, such as hardmask layers with improved properties including density. In one or more embodiments, a plasma processing chamber contains a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor at least one frequency, an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber, a first RF current tuner that electrically couples an electrically conductive element to ground via a first conductive path, and a second RF current tuner that electrically couples an electrode to ground via a second conductive path, where the second conductive path is configured to have a lower impedance than the first conductive path. The plasma processing chamber also contains a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower44025340W001 surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber; and a vacuum system including a pump and a gate valve.

[0007] In some embodiments, a plasma processing chamber comprising a sensor array configured to measure RF current that is transmitted via a conductor at least one frequency; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber, each gas passage of the array of gas passages comprises a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening, a width of the third opening is less than a width of the first opening and less than a width of the second opening; a plurality of gas passages disposed along at least one wall of the plasma processing chamber; and a vacuum system including a pump, a gate valve, and a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber.

[0008] In some embodiments, a method of forming a carbon-containing layer includes positioning a substrate in a plasma processing chamber; introducing at least one precursor gas and at least one inert gas into the plasma processing chamber, the precursor gas is a hydrocarbon-containing gas mixture; generating an RF plasma with the at least one precursor gas and inert gas; depositing a carbon-containing layer on the substrate with the RF plasma;44025340W001 introducing at least one purge gas into the plasma processing chamber; and purge the plasma processing chamber with at least one purging gas, the plasma processing chamber is purged via a side vacuum pump disposed on a sidewall of the plasma processing chamber.

[0009] In one example, a method of forming a carbon-containing layer comprising positioning a substrate in a plasma processing chamber; introducing at least one precursor gas, at least one purging gas, and at least one inert gas into the plasma processing chamber, the precursor gas is comprising a hydrocarbon-containing gas mixture; generating an RF plasma with the at least one precursor gas, the last least one purging gas, and the at least one inert gas; depositing a carbon-containing layer on the substrate with the RF plasma; introducing at least one purge gas into the plasma processing chamber; and bottom purging, via a side vacuum pump disposed on a sidewall of the plasma processing chamber, the plasma processing chamber with the at least one purging gas.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

[0011] Figure 1 depicts a schematic illustration of a plasma processing chamber, according to one or more embodiments of the disclosure.

[0012] Figure 2 depicts a schematic illustration of a plasma processing chamber with a showerhead and side vacuum pump, according to one or more embodiments of the disclosure.44025340W001

[0013] Figure 3A depicts a schematic illustration of a plasma processing chamber with a bottom tuner, according to one or more embodiments of the disclosure.

[0014] Figure 3B depicts a block diagram of a bottom tuner, according to one or more embodiments of the disclosure.

[0015] Figure 4 depicts a schematic illustration of a current tuner, according to one or more embodiments of the disclosure.

[0016] Figure 5 depicts a flow diagram of a method for forming a carbon hardmask layer on a film stack disposed on a substrate, according to one or more embodiments of the disclosure.

[0017] Figure 6A depicts a plot showing the relationship between sp3 carbon content in-film and ion energy of plasma, according to one or more embodiments of the disclosure.

[0018] Figure 6B depicts a plot showing the relationship between stress and film density, according to one or more embodiments of the disclosure.

[0019] Figure 7A illustrates a cross-sectional view of a gas distribution showerhead of a plasma processing chamber, according to one or more embodiments of the disclosure.

[0020] Figure 7B illustrates a cross-sectional view of a gas passage of a gas distribution showerhead, according to one or more embodiments of the disclosure.

[0021] 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

[0022] Embodiments of the present invention generally relate to process systems, chambers, and methods for depositing or otherwise fabricating carbon44025340W001 films, such as hardmask layers with improved properties including density. Certain details are set forth in the following description and in Figures 1 -7B to provide a thorough understanding of various implementations of the disclosure. Other details describing well-known structures and systems often associated with plasma-processing and ion implantation are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various implementations.

[0023] Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular implementations. Accordingly, other implementations can have other details, components, dimensions, angles and features without departing from the spirit or scope of the present disclosure. In addition, further implementations of the disclosure can be practiced without several of the details described below.

[0024] Implementations herein will be described below in reference to a plasma-enhanced chemical vapor deposition (PE-CVD) process and an ion implantation process that can be carried out using any suitable thin film deposition and implant systems. Other tools capable of performing PE-CVD and / or ion implantation processes may also be adapted to benefit from the implementations described herein. In addition, any system enabling the PE- CVD and / or ion implant processes described herein can be used to advantage. The apparatus description described herein is illustrative and should not be construed or interpreted as limiting the scope of the implementations described herein.

[0025] Disclosed herein are techniques for depositing a carbon hardmask layer with improved density and apparatus for the same. In some embodiments, a method of forming a carbon-containing layer includes positioning a substrate in a processing chamber; introducing at least one precursor gas and at least one inert gas into the processing chamber, the precursor gas is a hydrocarbon- containing gas mixture; generating a radio frequency (RF) plasma with the at least one precursor gas and inert gas; depositing a carbon-containing layer on the substrate with the RF plasma; introducing at least one purge gas into the processing chamber; and purge the processing chamber with at least one44025340W001 purging gas, the processing chamber is purged via a side vacuum pump disposed on a sidewall of the processing chamber.

[0026] Figure 1 is a schematic cross sectional view of a plasma processing chamber 100, according to one or more embodiments, which may be combined with other embodiments, of the disclosure. By way of example, the implementation of the plasma processing chamber 100 in Figure 1 is described in terms of a PE-CVD system, but any other plasma processing chamber may fall within the scope of the implementations, including other plasma deposition chambers or plasma etch chambers. The plasma processing chamber 100 includes walls 102, a bottom 104, and a chamber lid 124 that together enclose a susceptor 105 and a processing region 146. The plasma processing chamber 100 further includes a vacuum pump 114, a first RF generator 151 , a second RF generator 152, an RF match 153, a gas source 154, a top RF current tuner 155, a bottom RF current tuner 157, and a system controller 158, each coupled externally to the plasma processing chamber 100 as shown.

[0027] The walls 102 and the bottom 104 may comprise an electrically conductive material, such as aluminum or stainless steel. Through one or more of the walls 102, a slit valve opening may be present that is configured to facilitate insertion of a substrate 110 into and removal of the substrate 110 from the plasma processing chamber 100. A slit valve configured to seal slit valve opening may be disposed either inside or outside of the plasma processing chamber 100. For clarity, no slit valve or slit valve opening is shown in Figure 1.

[0028] The vacuum pump 114 is coupled to the plasma processing chamber 100 and is configured to adjust the vacuum level therein. As shown, a valve 116 may be coupled between the plasma processing chamber 100 and the vacuum pump 114. The vacuum pump 114 evacuates the plasma processing chamber 100 prior to substrate processing and removes process gas therefrom during processing through the valve 116. The valve 116 may be adjustable to facilitate regulation of the evacuation rate of the plasma processing chamber 100. The evacuation rate through the valve 116 and the incoming gas flow rate44025340W001 from the gas source 154 determine chamber pressure and process gas residency time in the plasma processing chamber 100.

[0029] The gas source 154 is coupled to the plasma processing chamber 100 via a tube 123 that passes through the chamber lid 124. The tube 123 is fluidly coupled to a plenum 148 between a backing plate 106 and a gas distribution showerhead 128 included in the chamber lid 124. During operation, process gas introduced into the plasma processing chamber 100 from the gas source 154 fills the plenum 148 and then passes through the gas passages 129 formed in the gas distribution showerhead 128 to uniformly enter the processing region 146. In alternative implementations, process gas may be introduced into the processing region 146 via inlets and / or nozzles (not shown) that are attached to the walls 102 in addition to or in lieu of the gas distribution showerhead 128.

[0030] The susceptor 105 may include any technically feasible apparatus for supporting a substrate during processing by the plasma processing chamber 100, such as the substrate 110 in Figure 1. In some implementations, the susceptor 105 is disposed on a shaft 112 that is configured to raise and lower the susceptor 105. In some implementations, the shaft 112 and the susceptor 105 may be formed at least in part from or contain an electrically conductive material, such as tungsten, copper, molybdenum, aluminum, or stainless steel. Alternatively or additionally, the susceptor 105 may be formed at least in part from or contain a ceramic material, such as aluminum oxide (AI2O3), aluminum nitride (AIN), silicon dioxide (SiC>2), and the like. In implementations in which the plasma processing chamber 100 is a capacitively coupled plasma chamber, the susceptor 105 may be configured to contain an electrode 113. In such implementations, a metal rod 115 or other conductor is electrically coupled to electrode 113 and is configured to provide a portion of a ground path for RF power delivered to the plasma processing chamber 100. That is, the metal rod 115 enables RF power delivered to the plasma processing chamber 100 to pass through the electrode 113 and out of the plasma processing chamber 100 to ground.44025340W001

[0031] In some implementations, electrode 113 is also configured to provide an electrical bias from a DC power source (not shown) to enable electrostatic clamping of the substrate 110 onto the susceptor 105 during plasma processing. In such implementations, the susceptor 105 generally includes a body including one or more ceramic materials, such as the above-described ceramic materials, or any other ceramic material suitable for use in an electrostatic chuck. In such implementations, the electrode 113 may be a mesh, such as an RF mesh, or a perforated sheet of material made of molybdenum (Mo), tungsten (W), or other material with a coefficient of thermal expansion that is substantially similar to that of the ceramic material or materials included in the body of the susceptor 105. Together, electrode 113 and the gas distribution showerhead 128 define the boundaries of the processing region 146 in which plasma is formed. For example, during processing, the susceptor 105 and the substrate 110 may be raised and positioned near the lower surface of the gas distribution showerhead 128 (e.g., within 10-30 mm) to form the at least partially enclosed the processing region 146.

[0032] The first RF generator 151 is an RF power source configured to provide high-frequency power at a first RF frequency to discharge electrode 126 via the RF match 153. Similarly, the second RF generator 152 is an RF power source configured to provide high-frequency power at a second RF frequency to the discharge electrode 126 via RF match 153. In some implementations, first RF generator 151 includes an RF power supply capable of generating RF currents at a high frequency (HF), for example, about 13.56 MHz. Alternatively, or additionally, the first RF generator 151 includes a VHF generator capable of generating VHF power, such as VHF power at frequencies between about 20 MHz to 200 MHz or more. By contrast, the second RF generator 152 includes an RF power supply capable of generating RF currents at so-called low frequency (LF) RF, for example, about 350 kHz. Alternatively, or additionally, the second RF generator 152 includes an RF generator capable of generating RF power at frequencies between about 1 kHz to about 1 MHz. The first RF generator 151 and the second RF generator 152 are configured to facilitate generation of plasma between the discharge electrode 126 and the susceptor 105.44025340W001

[0033] The discharge electrode 126 may include a process gas distribution element, such as the gas distribution showerhead 128 (as shown in Figure 1 ), and / or an array of gas injection nozzles, through which process gases are introduced into the processing region 146. The discharge electrode 126, e.g., the gas distribution showerhead 128, may be oriented substantially parallel to the surface of the substrate 110, and capacitively couples plasma source power into the processing region 146, which is disposed between the substrate 110 and the gas distribution showerhead 128.

[0034] The RF match 153 may be any technically feasible impedance matching apparatus that is coupled between the first RF generator 151 and the powered electrode of the plasma processing chamber 100, e.g., the gas distribution showerhead 128. RF match 153 is also coupled between the second RF generator 152 and the powered electrode of the plasma processing chamber 100. The RF match 153 is configured to match a load impedance (the plasma processing chamber 100) to the source or internal impedance of a driving source (the first RF generator 151 , the second RF generator 152) to enable the maximum transfer of RF power from the first RF generator 151 and the second RF generator 152 to the plasma processing chamber 100.

[0035] In one or more embodiments, an upper isolator 107, a tuning ring 108, and a lower isolator 109 may together form a portion of the walls 102. In some embodiments, not shown in the Figures, the tuning ring 108 may be omitted and the upper isolator 107 and the lower isolator 109 may be extended to meet each other and together form a portion of the walls 102. In other embodiments, not shown in the Figures, the tuning ring 108 may be omitted and a single isolator 107 or 109 may be extended from the backing plate 106 and form a portion of the walls 102.

[0036] In one or more embodiments, the upper isolator 107 is configured to electrically isolate the tuning ring 108, which is formed from an electrically conductive material, from the backing plate 106, which in some implementations is energized with RF power during operation. Thus, upper isolator 107 is positioned between the backing plate 106 and the tuning ring 108 and prevents the tuning ring 108 from being energized with RF power via44025340W001 the backing plate 106. In some implementations, the upper isolator 107 is configured as a ceramic ring or annulus that is positioned concentrically about the processing region 146. Similarly, the lower isolator 109 is configured to electrically isolate the tuning ring 108 from the walls 102. The walls 102 are typically formed from an electrically conductive material and can therefore act as a ground path for a portion of RF power delivered to the plasma processing chamber 100 during processing. Thus, the lower isolator 109 enables the tuning ring 108 to be part of a different ground path for RF power delivered to the plasma processing chamber 100 than that of the walls 102. In some implementations, the upper isolator 107 is configured as a ceramic ring, or is configured to include a ceramic ring that is positioned concentrically about the processing region 146.

[0037] The tuning ring 108 is disposed between the upper isolator 107 and the lower isolator 109, is formed from an electrically conductive material, and is disposed adjacent the processing region 146. For example, in some implementations, the tuning ring 108 is formed from a suitable metal, such as aluminum, copper, titanium, or stainless steel. In some implementations, the tuning ring 108 is a metallic ring or annulus that is positioned concentrically about the susceptor 105 and the substrate 110 during processing of the substrate 110. In addition, the tuning ring 108 is electrically coupled to ground via the top RF current tuner 155 via a conductor 156, as shown. Thus, the tuning ring 108 is not a powered electrode, and is generally disposed outside of and around the processing region 146. In some examples, the tuning ring 108 is positioned in a plane substantially parallel with the substrate 110, and is part of a ground path for the RF energy used to form plasma in the processing region 146. As a result, an additional RF ground path 141 is established between the gas distribution showerhead 128 and ground, via the top RF current tuner 155. Thus, by changing the impedance of the top RF current tuner 155 at a particular frequency, the impedance for the RF ground path 141 at that particular frequency changes, causing a change in the RF field that is coupled to the tuning ring 108 at that frequency. Therefore, the shape of plasma in the processing region 146 may be independently modulated along the + / - X- and Y-directions for the RF frequency associated with either the first RF generator44025340W001151 or the second RF generator 152. That is, the shape, volume or uniformity of the plasma formed in the processing region 146 may be independently modulated for multiple RF frequencies across the surface of the substrate 110 by use, for example, of the tuning ring 108 or vertically between the substrate 110 and the gas distribution showerhead 128 using the electrode 113.

[0038] The system controller 158 is configured to control the components and functions of the plasma processing chamber 100, such as the vacuum pump 114, the first RF generator 151 , the second RF generator 152, the RF match 153, the gas source 154, the top RF current tuner 155, and the bottom RF current tuner 157. As such, the system controller 158 receives sensor inputs, e.g., voltage-current inputs from the top RF current tuner 155 and the bottom RF current tuner 157 and transmits control outputs for operation of the plasma processing chamber 100. The functionality of the system controller 158 may include any technically feasible implementation, including via software, hardware, and / or firmware, and may be divided between multiple separate controllers associated with the plasma processing chamber 100.

[0039] Not to be bound by theory, but it is believed that by delivering different frequencies of RF power to a processing region of a plasma processing chamber during a plasma enhanced deposition process, the properties of a deposited film can be adjusted. For example, adjusting the low-frequency RF plasma power and / or frequency delivered to the processing region 146, e.g., forming an RF plasma in the 1 kHz to 1 MHz regime, can be beneficial to adjust some deposited film properties, such as film stress, while adjusting the high- frequency RF plasma power and / or frequency delivered to the processing region 146, e.g., forming an RF plasma in the 1 MHz to 200 MHz regime, can be beneficial to adjust other deposited film properties, such as thickness uniformity. According to various implementations of the disclosure, a tuning apparatus enables independent control of the flow of RF current in the plasma processing chamber 100 at multiple RF frequencies. In some implementations, such a tuning apparatus is employed at multiple locations in the plasma processing chamber 100, e.g., the top RF current tuner 155 and the bottom RF current tuner 157.44025340W001

[0040] The top RF current tuner 155, as noted above, is electrically coupled to the tuning ring 108 and is terminated to ground, thus providing a controllable RF ground path 141 for the plasma processing chamber 100. Similarly, the bottom RF current tuner 157 is electrically coupled to the metal rod 115 and is terminated to ground, thus providing a different controllable RF ground path 142 for the plasma processing chamber 100. As described herein, the top RF current tuner 155 and the bottom RF current tuner 157 are each configured to control the flow of RF current to ground at multiple RF frequencies. Thus, the distribution of RF current at a first RF frequency between the tuning ring 108 and the metal rod 115 can be controlled independently from the distribution of RF current at a second RF frequency between the tuning ring 108 and the metal rod 115.

[0041] A plasma 180 is formed in processing region 146 in between the electrode 113 and the discharge electrode 126. A distance or “spacing” between the bottom surface of the electrode 113 and a top surface of the susceptor 105 is represented by “x”.

[0042] Other deposition chambers may also benefit from the present disclosure and the parameters listed above may vary according to the particular deposition chamber used to form the carbon layer. For example, other deposition chambers may have a larger or smaller volume, requiring gas flow rates that are larger or smaller than those recited for deposition chambers available from Applied Materials, Inc.

[0043] The atomic percentage (at%) of dopant or inert species incorporation in the carbon film is calculated as follows: (dopant concentration in cm-3divided by the number of carbon atoms per cm-3expected for a carbon film of a particular density. The carbon film may contain at least 0.1 , 1 , or 10 atomic percentage of dopant or inert species. The carbon film may contain up to 1 , 10, or 30 atomic percentage of dopant or inert species. The carbon film may contain from about 1 to about 30 atomic percentage of dopant or inert species. Carbon films may contain from about 10 to about 30 atomic percentage of dopant or inert species. The carbon film may contain at least 3, 5, or 10 atomic percentage of hydrogen. The carbon film may contain up to 5, 10, or 15 atomic percentage44025340W001 of hydrogen. The carbon film may contain from about 3 to about 15 atomic percentage of hydrogen.

[0044] In some implementations where the dopant is carbon, the atomic percentage of carbon incorporation in the carbon film is calculated as follows: ((C / (H+C)) %). The carbon film may contain at least 70, 75, 85, 90, or 95 atomic percentage of carbon. The carbon film may contain up to 90, 95, or 97 atomic percentage of carbon. The carbon film may contain from about 60 to about 97 atomic percentage of carbon. The carbon film may contain from about 70 to about 97 atomic percentage of carbon. The carbon film may contain at least 3, 5, 10, 15, 20, 24, or 30 atomic percentage of hydrogen. The carbon film may contain up to 5, 10, 15, 20, 24, or 30 atomic percentage of hydrogen. The carbon film may contain from about 3 to about 30 atomic percentage of hydrogen. The carbon film may contain from about 20 to about 30 atomic percentage of hydrogen. The carbon film may contain from about 24 to about 30 atomic percentage of hydrogen.

[0045] In general, the following exemplary deposition process parameters may be used to for the PE-CVD portion of the carbon film deposition process described herein. The process parameters may range from a wafer temperature of about 100 degrees Celsius to about 700 degrees Celsius (e.g., between about 300 degrees Celsius to about 700 degrees Celsius). The chamber pressure may range from about 0.1 Torr to about 20 Torr, between about 0.1 Torr to about 5 Torr, between about 0.1 Torr to about 2 Torr, such as 1 Torr. The flow rate of the hydrocarbon-containing gas may be from about 100 standard cubic centimeters per minute (seem) to about 5,000 seem (e.g., between about 100 seem and about 2,000 seem; or between about 160 seem and about 500 seem). The flow rate of a dilution gas may individually range from about 0 seem to about 5,000 seem (e.g., from about 2,000 seem to about 4,080 seem). The flow rate of an inert gas may individually range from about 0 seem to about 10,000 seem (e.g., from about 0 seem to about 2,000 seem; from about 200 seem to about 2,000 seem). The RF power may be between 1 ,000 Watts and 3,000 Watts. The plate spacing between the top surface of the substrate 110 and the gas distribution showerhead 128 may be set to between44025340W001 about 200 mils to about 1 ,000 mils (e.g., between about 200 mils and about 600 mils; between about 300 mils to about 1 ,000 mils; or between about 400 mils and about 600 mils). The carbon film may be deposited to have a thickness between about 10 A and about 50,000 A (e.g., between about 300 A and about 3,000 A; or between about 500 A to about 1 ,000 A). The above process parameters provide a typical deposition rate for the carbon film in the range of about 100 A / minute to about 5,000 A / minute (e.g., from about 1 ,400 A / minute to about 3,200 A / minute) and can be implemented on a 300 mm substrate in a deposition chamber available from Applied Materials, Inc. of Santa Clara, CA.

[0046] Current approaches to achieving high density films include using an inductively coupled plasma (ICP) reactor at low pressures or using a bottom feed RF generator with a high pump capacity for driving high ion bombardment. However, maintaining good critical dimensions (CD) of both isolated and dense features of the integrated circuit components requires a carbon hardmask with high density for patterning fidelity and low stress to prevent bending of features and managing wafer bow requirements. It is equally important to minimize the generation of parasitic plasma during these processes, high amounts of parasitic plasma during processing results in non-uniform ities and defects in the features and decreases the RF coupling to the electrode (e.g., electrode 113). As a result, the reduction of RF coupling to the electrode negatively impacts film density and stress.

[0047] High ion energy driven high-density carbon films may be achieved in a capacitively coupled plasma (CCP) reactor by pushing the density-stress limit. The density-stress limit may be pushed by stabilizing low-pressure plasma processes and implementing in a CCP reactor improved chamber lid stacks and pumping channels, precursor modifications, or a combination thereof. More specifically, by using a top fed RF architecture along with a bottom tuner, stable plasma at low pressure is achieved. Stable plasma at low pressure is further improved by implementing a chamber lid stack with a showerhead design to accommodate low flow conductance, and a pumping liner design with O2 bottom gas for flow optimization and plasma densification. Due to the abovestated implementations, CCP reactors having conventional architecture may44025340W001 still achieve superior plasma-power coupling and plasma confinement. The resulting high-density carbon films have high sp3carbon content (e.g., for improved mechanical properties) and low hydrogen content (e.g., for selectivity benefit) and can be used across different nodes at temperatures amendable to Back End of Line (BEOL) or Front End of Line (FEOL) stack integrations.

[0048] Figure 2 depicts a schematic illustration of a plasma processing chamber 200, according to one or more embodiments, which may be combined with other embodiments, of the disclosure. By way of example, the implementation of the plasma processing chamber 200 is described in terms of a PE-CVD system, but any other plasma processing chamber may fall within the scope of the implementations, including other plasma deposition chambers or plasma etch chambers. The configuration of chamber 200 is similar to the configuration of chamber 100 of Figure 1 , but instead comprises vacuum pump 214, chamber lid 224, side pumping liner 210, inlets / nozzles 206, and bottom RF current tuner 257.

[0049] Vacuum pump 214 may be an implementation of vacuum pump 114 of Figure 1. The vacuum pump 214 is coupled to the plasma processing chamber 200 and is configured to adjust the vacuum level therein. As shown, a valve 216 may be coupled between the plasma processing chamber 200 and the vacuum pump 214 via a channel 240. In some embodiments, a ceramic containing material is disposed on a surface of channel 240. The vacuum pump 214 evacuates the plasma processing chamber 200 via side pumping evacuation prior to substrate processing and removes process gas therefrom during processing through the valve 216.

[0050] The valve 216 may be adjustable to facilitate regulation of the evacuation rate of the plasma processing chamber 200. The evacuation rate through the valve 216 and the incoming gas flow rate from the gas source 154 determine chamber pressure and process gas residency time in the plasma processing chamber 200.

[0051] The gas source 154 is coupled to the plasma processing chamber 200 via a tube 123 that passes through the chamber lid 224. The tube 123 is44025340W001 fluidly coupled to a plenum 148 between a backing plate 106 and a gas distribution showerhead 228 included in the chamber lid 224. Though not shown in Figure 2, gas source 154 is also fluidly coupled to a side pumping liner 210 by any suitable means. The side pumping liner 210 comprises a plurality of inlets / nozzles 206 disposed along the side pumping liner 210. During operation, the process gas introduced into the plasma processing chamber 200 from the gas source 154 fills the plenum 148 and then passes through the gas passages 229 formed in the gas distribution showerhead 228 to uniformly enter the processing region 146. In addition to or in lieu of the gas distribution showerhead 228, during operation the process gas may also be introduced into the plasma processing chamber 200 via the side pumping liner 210, which is fluidly coupled to the gas source 154, by passing the process gas through the inlets / nozzles 206. One example of the inlets and / or nozzles 206 includes a ceramic liner for arching stability and plasma densification.

[0052] Previously, down pumping metal-grounded parts in the pumping path provided less isolation to chamber body walls, which reduces the margin for LPAPF regime. By configuring chamber 200 with a vacuum pump 214 and a side pumping liner 210, including inlets / nozzles 206, to implement sidepumping evacuation, the increased isolation provides improved shielding from the chamber body for better coupling, stability in the LPAPF regime. Thus, implementing side pumping evacuation in the plasma processing chamber 200 promotes the streamlining of gas flow of gases therein (e.g., process gas or purge gas). Put differently, in low-pressure operations, plasma (e.g., plasma 180) may spill over the heater (e.g., heater plate 242) because the ion path is large. However, by using side pumping evacuation, plasma is better contained in the processing region 146 and does not fall beneath the heater, thereby improving plasma density in the processing region 146 and, in turn, plasma power coupling. As an additional benefit, during purging operations (e.g., bottom purge operations), the flow path of the chamber gases acts as a plasma curtain, narrowing the plasma 180. As a result, the plasma density and the number of ion flux for a film increases. An example flow path during the side pumping evacuation of the process gas is shown via the arrows 236 of Figure 2. For example, gas from below the heater plate 242 and gas from the process44025340W001 region 146 may flow through an opening 218 and a channel 212 before being pumped from plasma processing chamber 200 via the vacuum pump 214.

[0053] As explained in more detail below, flow conductance of the gas distribution showerhead 228 may also be reduced by adjusting the number and shape of gas passages 229, which in turn reduces parasitic plasma. Since parasitic plasma decreases RF coupling to the heater, which in turn negatively affects film density, there is a need to decrease or eliminate the presence of parasitic plasma in the plasma processing chamber 200 during film processing.

[0054] The discharge electrode 226 may be an implementation of discharge electrode 126 of Figure 1 . Discharge electrode 226 may include a process gas distribution element, such as the gas distribution showerhead 228, and / or an array of gas injection inlets / nozzles 206, through which process gases are introduced into the processing region 146. The discharge electrode 226, e.g., the gas distribution showerhead 228, may be oriented substantially parallel to the surface of the substrate 110, and capacitively couples plasma source power into the processing region 146, which is disposed between substrate 110 and the gas distribution showerhead 228.

[0055] In some embodiments, shaft 112 may be coupled to a heater plate 242 configured to support a substrate during semiconductor processing. The heater plate 242 may be made from a metal, such as aluminum, or a ceramic or other material, and may be treated or coated with other materials that provide improved corrosion resistance, improved contact with the substrate, or reduced erosion from plasma effluents, for example. Shaft 112 may include one or more internal channels configured to deliver and receive temperature controlled fluids, pressurized fluids, gases, as well as providing a conduit for components including thermocouples, rods (e.g., metal rod 115), and other connective items. The heater plate 242 may include an embedded electrode 244, which may receive a current for temperature control of the heater plate 242. Additionally, the heater plate 242 may include a ground plate (not shown) on which the heater plate 242 may be positioned. The ground plate may be coupled with the shaft 112 and may be electrically isolated from the electrode embedded within the heater plate. For example, because current may be44025340W001 delivered to the electrode, heater plate 242, which may be ceramic as noted previously, may operate as an insulator to limit shorting from the electrode. Bottom RF current tuner 257 may be an implementation of bottom RF current tuner 157 of Figure 1 and is further discussed below in Figures 3 and 4. In some embodiments, bottom RF current tuner 257 is capacitive coupled to the heater plate 242.

[0056] Figure 3A depicts a schematic illustration of a plasma processing chamber 300, according to one or more embodiments, which may be combined with other embodiments, of the disclosure. By way of example, the implementation of the plasma processing chamber 300 is described in terms of a PE-CVD system, but any other plasma processing chamber may fall within the scope of the implementations, including other plasma deposition chambers or plasma etch chambers. The configuration of chamber 300 is similar to the configuration of chamber 100 of Figure 1 but without top RF tuner 151 , and chamber 200 of Figure 2.

[0057] The RF generator 302 of chamber 300 may be an implementation of RF generators 152 of Figure 1 . The RF match 353 of chamber 300 may be an implementation of the RF match 153 of Figure 1. RF generator 302 is a RF power source configured to provide high-frequency power at a RF frequency to the faceplate / electrode 332 (e.g., faceplate 232) via the RF match 353. That is, the faceplate / electrode 332 of chamber 300 is coupled to the RF generator 302 by the RF match 353. The RF generator 302 is electrically coupled to the tuning ring 108 and is terminated to ground, thus providing a controllable RF ground path 141 for the chamber 300.

[0058] Bottom RF current tuner 257 (also shown in Figure 2) comprises a voltage-current sensor 310 and one or more variable capacitors 312. Voltagecurrent sensor 310 measures the RF current as it travels along RF ground path 142. Variable capacitor 312 is configured to control the flow of the RF current to the ground, such as at 13.56 MHz. The bottom RF current tuner 257 is electrically coupled to the metal rod 115 and is terminated to the ground, thus providing a different controllable RF ground path 142 for the plasma processing chamber 300. The RF generator 302 and the bottom RF current tuner 257 are44025340W001 each configured to control the flow of RF current to ground at multiple RF frequencies. Thus, the distribution of RF current at a first RF frequency between the tuning ring 108 and the metal rod 115 can be controlled independently from the distribution of RF current at a second RF frequency between the tuning ring 108 and the metal rod 115. Because of the two ground paths 141 , 142, RF current can travel through the metal rod 115 or the tuning ring 108. As a result, the reduced impedance to the metal rod 115 results in a higher current towards the bottom tuner, resulting in less parasitic plasma being generated.

[0059] Figure 3B is a block diagram illustrating bottom RF current tuner 257, according to various embodiments, which may be combined with other embodiments, of the disclosure. Bottom RF current tuner 257 includes a voltage-current sensor 310 electrically coupled to an HF leg 320 and a LF leg 330 of a current control circuit at node 315. HF leg 320 and LF leg 330 are each a conductive path to ground for RF energy delivered to processing region 146. It is noted that HF leg 320 and LF leg 330 are each included as parallel portions of RF ground path 142 illustrated in Figure 1. In embodiments in which susceptor 105 in Figure 1 includes an electrostatic chucking capability, bottom RF current tuner 257 may be electrically coupled to a DC power supply 301 for delivering a DC voltage to the electrode 113, as shown in Figure 1 , for providing chucking voltage.

[0060] HF leg 320 is configured to provide a variable termination for high- frequency RF current to ground, for example, for the frequency of RF power delivered to processing region 146 by first RF generator 151. Similarly, LF leg 330 is configured to provide a variable termination for low-frequency RF current to ground, for example, for the frequency of RF power delivered to processing region 146 by second RF generator 152. Therefore, by adjusting variable capacitor 321 , the magnitude of high-frequency RF current that passes through bottom current tuner 157 is changed, and by adjusting variable capacitor 331 , the magnitude of low-frequency RF current that passes through bottom current tuner 157 is changed.

[0061] Figure 4 depicts a schematic illustration of a RF current tuner 400, according to one or more embodiments, which may be combined with other44025340W001 embodiments, of the disclosure. By way of example, the implementation of the RF current tuner 400 is described in terms of a PE-CVD system, but any other plasma processing chamber may fall within the scope of the implementations, including other plasma deposition chambers or plasma etch chambers. The configuration of RF current tuner 400 is similar to the configuration of bottom RF current tuner 157 of Figure 1 and bottom RF current tuner 257 of Figure 2 and 3. RF current tuner 400 comprises electrodes 402, a nut 406, and a leadscrew 404, coupled via a coupling 408 to a motor 410.

[0062] Figure 5 depicts a flow diagram of a method 500 for forming a carbon hardmask layer on a film stack disposed on a substrate, according to one or more embodiments, which may be combined with other embodiments, of the disclosure. The method 500 may be used to deposit a carbon film / hardmask. The method 500 begins at operation 510 by providing a substrate in a processing region of a processing chamber. The processing chamber may be the plasma processing chamber 100 depicted in Figure 1 , the plasma processing chamber 200 depicted in Figure 2, or the plasma processing chamber 300 depicted in Figure 3. The substrate may be substrate 110, also depicted in Figures 1 and 2.

[0063] At operation 520, a hydrocarbon-containing gas mixture flows into a processing region (e.g., processing region 146). The hydrocarbon-containing gas mixture may be flowed from the gas source (e.g., gas source 154) into the processing region through a gas distribution showerhead (e.g., showerhead 128, 228). The gas mixture may include at least one hydrocarbon source and / or carbon-containing source. The gas mixture may further include an inert gas, a dilution gas, a nitrogen-containing gas, or combinations thereof. The hydrocarbon and / or carbon-containing source can be any liquid or gas. In some examples, the precursor is vapor at room temperature, which simplifies the hardware for material metering, control, and delivery to the chamber.

[0064] In some embodiments, a purging gas may be co-flowed with the hydrocarbon-containing gas mixture during operation 520 into the processing region. In some embodiments, the purging gas is O2. In some embodiments, the O2 purging gas is co-flowed into the processing region at a flow rate44025340W001 between about 500 seem to about 2000 seem, such as between about 700 seem to about 1800 seem, such as between about 900 seem to about 1600 seem, such as between about 900 seem to about 1400 seem, such as between about 900 seem to about 1200 seem, such as about 1000 seem. Co-flowing the purging gas during operation 520 creates a plasma curtain via the side pump evacuation, which increases the plasma density in processing region 146. In addition, utilizing ( as the purge gas increases the sheath potential above the wafer, which excites the ions. As a result, flux increases, thus there is an increase in high power coupling on the wafer plane with purge gas in a side pump configuration.

[0065] In some implementations, the hydrocarbon source is a gaseous hydrocarbon, such as a linear hydrocarbon. In some implementations, the hydrocarbon compound has a general formula CxHy, where x has a range of between 1 and 20 and y has a range of between 1 and 20. In some implementations, the hydrocarbon compound is an alkane. Suitable hydrocarbon compounds include, for example, methane (CH4), acetylene (C2H2) (also known as ethyne), ethylene (C2H4), ethane (C2H6), propylene (CsHe), and butylenes (C4H8), cyclobutane (C4H8), and methylcyclopropane (C4H8). Suitable butylenes include 1 -butene, 2-butene, and isobutylene. Other suitable carbon-containing gases include carbon dioxide (CO2) and carbon tetrafluoride (CF4). In some examples, C2H2 is preferable due to a reduced atomic percentage of H in the carbon film, which results in a higher deposition rate, density, refractive index (n), and extinction coefficient (k). Although density increases, pressure decreases, which leads to increased ion energy. As a result, the pattern fidelity of the resulting carbon film has a smooth, amorphous film microstructure. Accordingly, intermediate sp2low pressure processes give the benefit of high ion energy at reduced stress.

[0066] Suitable dilution gases such as helium (He), argon (Ar), hydrogen (H2), nitrogen (N2), ammonia (NH3), or combinations thereof, among others, may be added to the gas mixture. Ar, He, and [Sh are used to control the density and deposition rate of the carbon layer. In some cases, the addition of N2 and / or44025340W001NHscan be used to control the hydrogen ratio of the carbon layer, as discussed below. Alternatively, dilution gases may not be used during the deposition.

[0067] A nitrogen-containing gas may be supplied with the hydrocarbon- containing gas mixture into plasma processing chambers 100, 200, 300. Suitable nitrogen-containing compounds include, for example, pyridine, aliphatic amine, amines, nitriles, ammonia and similar compounds.

[0068] An inert gas, such as argon (Ar) and / or helium (He) may be supplied with the hydrocarbon-containing gas mixture into plasma processing chambers 100, 200, 300. Other gases, such as nitrogen (N2) and nitric oxide (NO), may also be used to control the density and deposition rate of the carbon layer. Additionally, a variety of other processing gases may be added to the gas mixture to modify properties of the carbon material. In some implementations, the processing gases may be reactive gases, such as hydrogen (H2), ammonia (NH3), a mixture of hydrogen (H2) and nitrogen (N2), or combinations thereof. The addition of H2 and / or NHs may be used to control the hydrogen ratio (e.g., carbon to hydrogen ratio) of the deposited carbon layer. The hydrogen ratio present in the carbon film provides control over layer properties, such as reflectivity.

[0069] At operation 530, RF plasma is generated in the processing region to deposit a carbon film, such as the carbon hardmask. The plasma may be formed by capacitive or inductive means and may be energized by coupling RF power into the precursor gas mixture. RF power may be a dual-frequency RF power that has a high frequency component and a low frequency component. The RF power is typically applied at a power level between about 50 W and about 2,500 W (e.g., between about 2,000 W and about 2,500 W), which may be all high-frequency RF power, for example, at a frequency of about 13.56 MHz, or may be a mixture of high-frequency power and low frequency power, for example, at a frequency of about 300 kHz. For most applications, plasma is maintained for a time period to deposit a carbon layer having a thickness between about 100 A and about 5,000 A. The flow of hydrocarbon-containing gas mixture may be stopped when a targeted thickness of the carbon film is44025340W001 reached. The process of operation 530 may be performed simultaneously, sequentially or may partially overlap with the processes of operation 520.

[0070] In any of the PE-CVD implementations described herein, during deposition of the carbon film, the chamber, the wafer, or both may be maintained at a temperature between about 200 degrees Celsius to about 700 degrees Celsius (e.g., between about 400 degrees Celsius to about 700 degrees Celsius; or between about 500 degrees Celsius to about 700 degrees Celsius). The chamber pressure may range from about 0.1 Torr to about 5 Torr, such as between about 0.1 Torr to about 2 Torr, such as between about 0.1 Torr to about 1 Torr, such as less than or equal to 1 Torr, such as 1 Torr. The distance between the susceptor and gas distribution showerhead (e.g., “spacing”) may be set to between about 200 mils to about 1 ,000 mils (e.g., between about 200 mils and about 600 mils; between about 300 mils to about 1 ,000 mils; or between about 400 mils and about 600 mils).

[0071] The carbon film may be deposited to have a thickness between about 10 A and about 50,000 A (e.g., between about 300 A and about 30,000 A; between about 500 A to about 1 ,000 A). The deposited carbon film may have a density (g / cc) between about 1.900 g / cc and about 2.000 g / cc, such as between about 1 .900 g / cc and about 1 .940 g / cc. The deposited carbon film may have a Young's modulus (GPa) of from about 100 GPa to about 200 GPa, such as from about 120 GPa to about 180 GPa, such as from about 130 GPa to about 170 GPa, such as from about 139 GPa to about 150 GPa, such as from about 139 GPa to about 148 GPa. The deposited carbon film may have a stress (MPa) of from about -1300 MPa to about -800 MPa, such as from about -1250 MPa to about -900 MPa, such as from about -1202 MPa to about -955 MPa.

[0072] At optional operation 540, any excess process gases and byproducts from the deposition of the season layer may then be removed from the processing region by performing an optional purge / evacuation process. During the optional chamber purge / evacuation process, a purge gas (e.g., an inert gas such as argon, nitrogen, or oxygen) may be delivered via top flow into the processing chamber from a gas source (e.g., gas source 154) through discharge electrode (e.g., discharge electrode 126, 226). In some44025340W001 embodiments, the purge gas, either in addition to top flow or alone, may be delivered via bottom flow into the processing chamber. In some embodiments, the purge gas may be delivered via bottom flow by inlets / nozzles (e.g., inlets / nozzles 206) disposed along a side pumping liner of the processing chamber. Pressure within the chamber may be controlled using a valve system, which controls the rate at which the purge gases are drawn from the chamber. In some implementations, the purge gas is O2. In some embodiments, the O2 purging gas is flowed into the processing region at a flow rate between about 500 seem to about 2000 seem, such as between about 700 seem to about 1800 seem, such as between about 900 seem to about 1600 seem, such as between about 900 seem to about 1400 seem, such as between about 900 seem to about 1200 seem, such as about 1000 seem.

[0073] In some embodiments, during optional operation 540, another purge gas is co-flowed into the processing chamber with purge gas O2. In some embodiments, the second purge gas is Argon. In some embodiments, purge gas O2 is bottom flowed into the processing chamber, and Ar is top flowed into the processing chamber at a flow rate between about 3000 seem and about 5000 seem, such as about 4000 seem.

[0074] Figure 6A depicts a plot showing the relationship between sp3 carbon content in-film and ion energy of plasma, according to one or more embodiments of the disclosure. By increasing ion energy and lowering surface diffusion, carbon film density is increased. This can be achieved by implementing a low-pressure plasma process that is stabilized with a C2H2 precursor gas and a top fed RF generator that provides for superior carbon films with high density, high modulus, low hydrogen content, and good uniformity. There are additional benefits of lowering the cost and thermal budget, and improving the arcing margin, power coupling, and productivity of the process.

[0075] Figure 6B depicts a plot showing the relationship between stress and film density, according to one or more embodiments of the disclosure. The solid line depicts the density-stress curve for conventional ICP reactors at lower pressure or using a bottom feed RF generator with high pump capacity for driving high ion bombardment. The dotted line depicts the density-stress curve44025340W001 pushed by the present disclosure, which uses a low-pressure plasma process stabilized with C2H2 precursor and top feed RF generator.

[0076] Figure 7A illustrates a cross-sectional view of a gas distribution showerhead 700 of a plasma processing chamber, according to one or more embodiments of the disclosure. Gas distribution showerhead 700A may be an implementation of gas distribution showerhead 128 of Figure 1 and gas distribution showerhead 228 of Figure 2.

[0077] Gas distribution showerhead 700 comprises gas passages 729 formed through the gas distribution showerhead 700 and backing plate 730. During processing, backside carbon may form on backing plate 730 (e.g., a backside of the showerhead 700 facing the plenum) of showerhead 700. This indicates parasitic plasma on those areas.

[0078] By limiting the number of gas passages 729 formed in the gas distribution showerhead 700 and backing plate 730, flow conductance is reduced (e.g. from 5x to 1x), which in turn reduces parasitic plasma. As a result, plasma stability is improved as well as coupling over the wafer. That is, a decrease in showerhead conductance means that more gas is staying in the processing region, which in turn means higher pressures and breakdown voltage shift, and thus, a reduction in parasitic plasma. Accordingly, ion energy at the wafer surface and density of the film (e.g., carbon hardmask) is increased. In some embodiments, the number of gas passages 729 formed in the gas distribution showerhead 700 and backing plate 730 is between about 500 passages to about 4000 passages, such as between about 500 passages to about 3500 passages, such as between about 500 passages to about 3000 passages, such as between about 500 passages to about 2500 passages, such as between about 500 passages to about 2000 passages, such as between about 500 passages to about 1500 passages, such as between about 500 passages to 1000 passages, such as about 721 passages.

[0079] Figure 7B illustrates a cross-sectional view of a gas passage 729 of showerhead 700, according one or more embodiments of the disclosure. A plurality of gas passages 729 are formed through showerhead 700 of Figure44025340W0017A. Each gas passage 729 comprises a top opening 702, neck portion 704, and bottom opening 706. Gas passage 729 has an hourglass figure. That is, a width (D3) of the neck portion 704 is less than a width (D1 ) of the top opening 702 and a width (D2) of the bottom opening 706.

[0080] Electron diffusion sustains plasma at the backing plate 730 of showerhead 700, thus increasing recombination by reducing edge plasma, or increasing the neck portion 704 of the gas passages 729 reduces carbon deposition on the backside of the showerhead. In some embodiments, a width (D1 ) of the top opening 702 is between about 0.010 inches (in) to about 0.200 in, such as between about 0.010 in to about 0.100 in, such as between about 0.050 in to about 0.100 in, such as between about 0.060 in to about 0.100 in, such as between about 0.070 in to about 0.100 in, such as about 0.080 in. In some embodiments, a width (D2) of the bottom opening 706 is between about 0.10 in to about 0.30 in, such as between about 0.10 in to about 0.20 in, such as between about 0.12 in to about 0.18 in, such as between about 0.14 in to about 0.16 in, such as about 0.15 in. In some embodiments, a width (D3) of the neck portion 704 is between about 0.001 in to about 0.100 inches, such as between about 0.005 in to about 0.080 in, such as between about 0.010 in to about 0.060 in, such as between about 0.010 in to about 0.040 in, such as between about 0.010 in to about 0.020 in, such as about 0.016 in.

[0081] Reducing flow conductance of showerhead 700 increases pressure build up in the plenum above the showerhead (e.g., backing plate 730) which prevents plasma from occurring in the plenum (e.g., plenum 148). However, this cannot prevent deposition in between faceplate and backing plate 730. The energetic electrons in the plasma can trickle up the faceplate and interact with incoming gas flow and cause pockets of carbon deposition. To prevent this issue, the neck region of the faceplate is sufficiently wide enough to promote electron recombination on the channel hole wall.

[0082] In one example, a method of forming a carbon-containing layer comprising positioning a substrate in a processing chamber; introducing at least one precursor gas, at least one purging gas, and at least one inert gas into the processing chamber, the precursor gas is comprising a hydrocarbon-containing44025340W001 gas mixture; generating an RF plasma with the at least one precursor gas, the last least one purging gas, and the at least one inert gas; depositing a carbon- containing layer on the substrate with the RF plasma; introducing at least one purge gas into the processing chamber; and bottom purging, via a side vacuum pump disposed on a sidewall of the processing chamber, the processing chamber with the at least one purging gas.

[0083] The hydrocarbon-containing gas mixture may be or contain acetylene (C2H2). The hydrocarbon-containing gas mixture has a flow rate between 160 standard cubic centimeters per minute (seem) to 500 seem. The at least one inert gas comprises argon or helium. The at least one purge gas comprises an oxygen-containing gas. The oxygen-containing gas comprises O2, and the introducing co-flows O2 at flow rate between 900 standard cubic centimeters per minute (seem) to 1400 seem. The oxygen-containing gas comprises O2, and the introducing co-flows O2 at flow rate of 1000 seem. The carbon-containing layer comprises between about 20% to about 30% H by atomic percentage. The carbon-containing layer has a Young's modulus of about 100 GPa to about 150 GPa. The carbon-containing layer has a Young's modulus of about 139 GPa to about 148 GPa. The carbon-containing layer has a stress of about -1250 MPa to about -900 MPa. The carbon-containing layer has a density of about 1.900 g / cc to about 1.940 g / cc. A pressure of the processing chamber during the generation of the RF plasma is less than or equal to 1 Torr.

[0084] In another example, a plasma processing chamber includes a sensor array configured to measure RF current that is transmitted via a conductor at least one frequency; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples an electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and44025340W001 an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber; and a vacuum system including a pump and a gate valve.

[0085] The vacuum system further comprises a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber. A ceramic containing material is disposed on a surface of a channel of the pump. Each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening, wherein a width of the third opening is less than a width of the first opening and less than a width of the second opening. The width of the first opening is less than the width of the second opening. The width of the third opening is between 0.010 inches (in) to 0.040 in.

[0086] In yet another example, a plasma processing chamber comprising a sensor array configured to measure RF current that is transmitted via a conductor at least one frequency; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber, each gas passage of the array of gas passages comprises a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed44025340W001 along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening, a width of the third opening is less than a width of the first opening and less than a width of the second opening; a plurality of gas passages disposed along at least one wall of the plasma processing chamber; and a vacuum system including a pump, a gate valve, and a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber.

[0087] The present disclosure provides, among others, the following embodiments, each of which may be considered as optionally including any alternate embodiments per one or more of the following Clauses 1 -21 :

[0088] Clause 1. A plasma processing chamber is provided and contains a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber; and a vacuum system including a pump and a gate valve.

[0089] Clause 2. A plasma processing chamber is provided and contains a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current44025340W001 tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber, each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening, a width of the third opening is less than a width of the first opening and less than a width of the second opening; and a vacuum system comprising a pump, a gate valve, and a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber.

[0090] Clause 3. A plasma processing chamber is provided and contains a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; and a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber, each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening.44025340W001

[0091] Clause 4. The plasma processing chamber according to any one of Clauses 1 -3, wherein the vacuum system further comprises a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber.

[0092] Clause 5. The plasma processing chamber according to any one of Clauses 1-4, wherein a ceramic containing material is disposed on a surface of a channel of the pump.

[0093] Clause 6. The plasma processing chamber according to any one of Clauses 1 -5, wherein each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening, wherein a width of the third opening is less than a width of the first opening and less than a width of the second opening.

[0094] Clause 7. The plasma processing chamber according to any one of Clauses 1 -6, wherein the width of the first opening is less than the width of the second opening.

[0095] Clause 8. The plasma processing chamber according to any one of Clauses 1 -7, wherein the width of the third opening of about 0.010 inches (in) to about 0.040 in.

[0096] Clause 9. A method of forming a carbon-containing layer is provided and includes positioning the substrate in the substrate processing region of the plasma processing chamber according to any one of Clauses 1 -8; introducing at least one precursor gas, at least one purging gas, and at least one inert gas into the substrate processing region, the precursor gas comprising a hydrocarbon-containing gas mixture; generating a radio frequency (RF) plasma with the at least one precursor gas, the least one purging gas, and the at least one inert gas; depositing a carbon-containing layer on the substrate with the44025340W001RF plasma; and bottom purging, via the vacuum system, the plasma processing chamber with the at least one purging gas.

[0097] Clause 10. The plasma processing chamber and / or the method according to any one of Clauses 1 -9, wherein the hydrocarbon-containing gas mixture comprises acetylene (C2H2).

[0098] Clause 11. The plasma processing chamber and / or the method according to any one of Clauses 1 -10, wherein the hydrocarbon-containing gas mixture has a flow rate between about 160 standard cubic centimeters per minute (seem) and about 500 seem.

[0099] Clause 12. The plasma processing chamber and / or the method according to any one of Clauses 1-11 , wherein the at least one inert gas comprises argon or helium.

[0100] Clause 13. The plasma processing chamber and / or the method according to any one of Clauses 1 -12, wherein the at least one purging gas comprises an oxygen-containing gas.

[0101] Clause 14. The plasma processing chamber and / or the method according to any one of Clauses 1 -13, wherein the oxygen-containing gas comprises oxygen (O2), and the introducing comprises co-flowing O2 at flow rate between about 900 standard cubic centimeters per minute (seem) to about 1400 seem.

[0102] Clause 15. The plasma processing chamber and / or the method according to any one of Clauses 1 -14, wherein the oxygen-containing gas comprises O2, and the introducing comprises co-flowing O2 at flow rate of about 1000 seem.

[0103] Clause 16. The plasma processing chamber and / or the method according to any one of Clauses 1-15, wherein the carbon-containing layer comprises between about 20% to about 30% H by atomic percentage.44025340W001

[0104] Clause 17. The plasma processing chamber and / or the method according to any one of Clauses 1 -16, wherein the carbon-containing layer has a Young's modulus of about 100 GPa to about 150 GPa.

[0105] Clause 18. The plasma processing chamber and / or the method according to any one of Clauses 1 -17, wherein the carbon-containing layer has a Young's modulus of about 139 GPa to about 148 GPa.

[0106] Clause 19. The plasma processing chamber and / or the method according to any one of Clauses 1 -18, wherein the carbon-containing layer has a stress of about -1250 MPa to about -900 MPa.

[0107] Clause 20. The plasma processing chamber and / or the method according to any one of Clauses 1 -19, wherein the carbon-containing layer has a density of about 1 .900 g / cc to about 1 .940 g / cc.

[0108] Clause 21. The plasma processing chamber and / or the method according to any one of Clauses 1-20, wherein a pressure of the plasma processing chamber during the generation of the RF plasma is less than or equal to 1 Torr.

[0109] While the foregoing is directed to embodiments of the disclosure, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. All documents described herein are incorporated by reference herein, including any priority documents and / or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term "comprising" is considered synonymous with the term "including" for purposes of United States law. Likewise, whenever a composition, an element, or a group of elements is preceded with the transitional phrase "comprising", it is understood that the same composition or group of elements with transitional44025340W001 phrases "consisting essentially of", "consisting of", "selected from the group of consisting of", or "is" preceding the recitation of the composition, element, or elements and vice versa, are contemplated. As used herein, the term "about" refers to a + / -10% variation from the nominal value. It is to be understood that such a variation can be included in any value provided herein.

[0110] Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any lower value with any upper value, the combination of any two lower values, and / or the combination of any two upper values are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below.

Claims

44025340W001WHAT IS CLAIMED IS:1 . A plasma processing chamber, comprising: a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber; and a vacuum system including a pump and a gate valve.

2. The plasma processing chamber of claim 1 , wherein the vacuum system further comprises a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber.

3. The plasma processing chamber of claim 1 , wherein a ceramic containing material is disposed on a surface of a channel of the pump.

4. The plasma processing chamber of claim 1 , wherein each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and44025340W001 a third opening disposed between the first opening and the second opening, wherein a width of the third opening is less than a width of the first opening and less than a width of the second opening.

5. The plasma processing chamber of claim 4, wherein the width of the first opening is less than the width of the second opening.

6. The plasma processing chamber of claim 4, wherein the width of the third opening of about 0.010 inches (in) to about 0.040 in.

7. A method of forming a carbon-containing layer, comprising: positioning the substrate in the substrate processing region of the plasma processing chamber of claim 1 ; introducing at least one precursor gas, at least one purging gas, and at least one inert gas into the substrate processing region, the precursor gas comprising a hydrocarbon-containing gas mixture; generating a radio frequency (RF) plasma with the at least one precursor gas, the least one purging gas, and the at least one inert gas; depositing a carbon-containing layer on the substrate with the RF plasma; and bottom purging, via the vacuum system, the plasma processing chamber with the at least one purging gas.

8. The method of claim 7, wherein the hydrocarbon-containing gas mixture comprises acetylene (C2H2).

9. The method of claim 8, wherein the hydrocarbon-containing gas mixture has a flow rate between about 160 standard cubic centimeters per minute (seem) and about 500 seem.

10. The method of claim 7, wherein the at least one inert gas comprises argon or helium.44025340W00111 . The method of claim 7, wherein the at least one purging gas comprises an oxygen-containing gas.

12. The method of claim 11 , wherein the oxygen-containing gas comprises oxygen (O2), and the introducing comprises co-flowing O2 at flow rate between about 900 standard cubic centimeters per minute (seem) to about 1400 seem.

13. The method of claim 11 , wherein the oxygen-containing gas comprises O2, and the introducing comprises co-flowing O2 at flow rate of about 1000 seem.

14. The method of claim 7, wherein the carbon-containing layer comprises between about 20% to about 30% H by atomic percentage.

15. The method of claim 7, wherein the carbon-containing layer has a Young's modulus of about 100 GPa to about 150 GPa.

16. The method of claim 7, wherein the carbon-containing layer has a stress of about -1250 MPa to about -900 MPa.

17. The method of claim 7, wherein the carbon-containing layer has a density of about 1 .900 g / cc to about 1 .940 g / cc.

18. The method of claim 7, wherein a pressure of the plasma processing chamber during the generation of the RF plasma is less than or equal to 1 Torr.

19. A plasma processing chamber, comprising: a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber;44025340W001 a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber, each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening, a width of the third opening is less than a width of the first opening and less than a width of the second opening; and a vacuum system comprising a pump, a gate valve, and a side pumping liner disposed along at least one wall of a processing chamber, the side pumping liner comprising a plurality of inlets, the inlets configured to introduce at least one gas into the processing chamber.

20. A plasma processing chamber, comprising: a sensor array configured to measure radio frequency (RF) current that is transmitted via a conductor; an electrically conductive element disposed around a substrate processing region of the plasma processing chamber and electrically isolated from a substrate support of the plasma processing chamber; a first RF current tuner that electrically couples the electrically conductive element to ground via a first conductive path; a second RF current tuner that electrically couples an electrode to ground via a second conductive path, wherein the second conductive path is configured to have a lower impedance than the first conductive path; and44025340W001 a showerhead having an upper surface, a lower surface, and an array of gas passages that extend from the upper surface to the lower surface, the showerhead disposed adjacent to the substrate processing region of the plasma processing chamber, each gas passage of the array of gas passages comprises: a first opening disposed along a plane of the upper surface of the showerhead; a second opening disposed along a plane of the lower surface of the showerhead; and a third opening disposed between the first opening and the second opening.

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