Plasma processing with independent temperature control

Abstract

This disclosure provides a comprehensive system regarding the independent temperature control of an inductively coupled plasma source, a plasma processing apparatus, and plasma processing. In at least one embodiment, a method includes introducing a process gas into a gas injection channel and generating an inductively coupled plasma within the gas injection channel. The plasma includes at least one radical substance selected from oxygen, nitrogen, hydrogen, NH, and helium. The method includes transporting plasma from the plasma source to a process chamber coupled thereto by flowing the plasma through a separation grid between the plasma source and a substrate. The method includes processing the substrate. Processing the substrate includes contacting the plasma comprising the at least one radical substance with a first side of the substrate facing the separation grid, and heating the substrate using a plurality of lamps located on a second side of the substrate opposite the separation grid.

Description

[Technical Field]

[0001] The embodiments of this disclosure are systemic regarding inductively coupled plasma sources, plasma processing apparatuses and methods of using them, and independent temperature control for plasma processing. [Previous Technology]

[0002] Plasma processing is used in the semiconductor industry for the deposition, etching, resist removal, and related treatments of semiconductor substrates and other substrates. Plasma sources are typically used in plasma processing to generate high-density plasma and reactive materials for substrate treatment.

[0003] The formation of plasma breaks down molecules into free radicals (and / or generates ions), which can be used to perform substrate processing in a chamber. Typically, a gas mixture is fed into the plasma generation region (active region) of an inductively coupled plasma (ICP) source, and electrons accelerated in the high electric field region ionize and dissociate the mixture, thereby forming a new gas (plasma) with free radicals and ions.

[0004] Conventional ICP sources used for high plasma generation efficiency and wide operating range have relatively small active regions adjacent to the ICP coil. These active regions are designed to provide electron confinement in this region around the coil, and thus plasma formation is mainly confined in that region. However, when the plasma is directed to the substrate, some chemical reactions occur between the substances, thereby reducing the number of free radicals, but resulting in the formation of many new substances.

[0005] Therefore, there is a need for improved inductively coupled plasma sources and plasma processing devices, as well as their usage methods. In addition, there is a need for precise and independent temperature control for plasma processing. [Summary of the Invention]

[0006] The embodiments of this disclosure are systematically related to plasma processing methods.

[0007] In at least one embodiment, a plasma processing method includes introducing a process gas into a gas injection channel and generating an inductively coupled plasma within the gas injection channel. The plasma includes at least one free radical material selected from oxygen, nitrogen, hydrogen, NH, and helium. The method includes transporting plasma from a plasma source to a process chamber coupled thereto by flowing the plasma through a separation grid between the plasma source and a substrate. The method includes processing the substrate. Processing the substrate includes contacting a plasma comprising the at least one free radical material with a first side of the substrate facing the separation grid, and heating the substrate using a plurality of lamps located on a second side of the substrate opposite to the separation grid.

[0008] In another embodiment, a plasma processing method includes introducing a process gas into a gas injection channel defined between a gas injection insert and a sidewall of a plasma source, and generating plasma within the gas injection channel by means of an inductor coil positioned close to the sidewall and horizontally overlapping the gas injection channel. The plasma includes at least one of nitrogen or NH radicals. The method includes delivering plasma from the plasma source to a process chamber coupled thereto. The plasma flows through a separation grid disposed between the plasma source and a substrate to be processed. Processing the substrate within the process chamber includes contacting the plasma with a first side of the substrate facing the separation grid, and heating the substrate using a plurality of lamps located on a second side of the substrate opposite the separation grid.

[0009] In another embodiment, a plasma processing method includes introducing a process gas into a gas injection channel defined between a gas injection insert and a sidewall of a plasma source, and generating hydrogen plasma within the gas injection channel by means of an inductor coil positioned close to the sidewall and horizontally overlapping the gas injection channel. The hydrogen plasma includes hydrogen radicals. The method includes delivering the hydrogen plasma from the plasma source to a process chamber coupled to the plasma source. The hydrogen plasma flows through a separation grid disposed between the plasma source and a substrate to be processed. Processing the substrate within the process chamber includes contacting the hydrogen plasma, including hydrogen radicals, with a first side of the substrate facing the separation grid, and heating the substrate using a plurality of lamps located on a second side of the substrate opposite the separation grid.

Implementation Method

[0021] The embodiments of this disclosure pertain to a high-efficiency inductively coupled plasma source and plasma processing apparatus, and methods of using thereof. In addition to efficiently delivering high-density neutral plasma material (e.g., non-conventional material) to a substrate, the source and apparatus of this disclosure can provide improved plasma uniformity for substrate processing. Conventional assumptions hold that more efficient generation of material in the active region of the plasma source automatically results in a greater quantity of that material near the substrate; however, the inventors have noted that this is an unrealistic (or at least incomplete) assumption.

[0022] For illustrative and explanatory purposes, the forms of this disclosure are discussed with reference to a "substrate" or a semiconductor wafer. Using the disclosure provided herein, those skilled in the art will understand that the forms of this disclosure can be used in connection with any suitable semiconductor substrate or other suitable substrate. "Substrate support" refers to any structure that can be used to support a substrate.

[0023] Referring now to the figures, exemplary embodiments of the present disclosure will be described. Figure 1 depicts an exemplary plasma processing apparatus 100. The plasma processing apparatus 100 includes a processing chamber 110 and a plasma source 120 (e.g., a distal plasma source) coupled to the processing chamber 110. The processing chamber 110 includes a substrate support 112 for holding a substrate 114. In some embodiments, the substrate has a thickness of less than 1 mm. The substrate support 112 may be located near one or more heat sources (e.g., a plurality of lamps 176) that provide heat to the substrate during processing in the processing chamber 110. Heat may be provided using any suitable heat source (such as one or more lamps, such as one or more rapid heat treatment lamps) or via a heated base (e.g., a base having a resistive heating element embedded therein or coupled thereto). In operation, these heat sources enable independent temperature control of the substrate, as described in more detail below.

[0024] As shown in Figure 1, the processing chamber 110 includes a window 162 (such as a dome) and a plurality of lamps 176. The plurality of lamps 176 are disposed between the window 162 and the bottom wall of the chamber 110. The plurality of lamps 176 are positioned in an array. The plurality of lamps 176 may be arranged in a plurality of concentric rings surrounding the center of the processing chamber 110. The plurality of lamps 176 may include 100 or more lamps, such as 200 or more lamps, such as from 200 to 500 lamps, such as from 200 to 300 lamps, such as 240 lamps, such as from 300 to 400 lamps, such as from 400 to 500 lamps, such as 400 lamps. Each of the plurality of lamps 176 has a power ranging from 400 W to 1000 W, such as from 500 W to 800 W, such as from 500 W to 600 W, such as from 600 W to 700 W, such as from 645 W, such as from 700 W to 800 W. The distance from the plurality of lamps 176 to the substrate is about 50 mm or less, such as from about 5 mm to about 50 mm, such as from about 5 mm to about 20 mm, such as about 12.5 mm, such as from about 20 mm to about 50 mm, such as about 36.5 mm.

[0025] A controller (not shown) is coupled to chamber 110 and can be used to control the chamber process described herein, including controlling a plurality of lamps 176. A substrate support 112 is disposed between a separation grid 116 and a window 162. A plurality of sensors (not shown) may be positioned near one or more of the lamps 176 and / or the substrate support 112 to measure the temperature within chamber 110. The plurality of sensors may include one or more infrared pyrometers or miniature pyrometers. In some embodiments, the one or more pyrometers include two, three, or four pyrometers. In some embodiments, the pyrometers have a wavelength of 3.3 μm, although typically, commercially available pyrometers typically vary in wavelength from about 0.5 μm to about 14 μm. In some embodiments, the pyrometers are bottom pyrometers, meaning that the pyrometers are positioned below the substrate, such as near the plurality of lamps 176.

[0026] The substrate support 112 is coupled to the shaft 165. The shaft is connected to an actuator 178, which provides rotational movement of the shaft and the substrate support (about axis A). The actuator 178 may or may additionally provide height adjustment of the shaft 165 during processing.

[0027] The substrate support 112 includes a lifting pin hole 166 disposed therein. The lifting pin hole 166 is sized to receive a lifting pin 164 for lifting the substrate 114 from the substrate support 112 before or after the deposition process. When the substrate 114 descends from the processing position to the transfer position, the lifting pin 164 may rest on the lifting pin stop 168.

[0028] Plasma can be generated in plasma source 120 (e.g., in plasma generation region) by means of inductor coil 130, and the desired particles flow from plasma source 120 to surface of substrate 114 through holes 126 provided in separation grid 116, which separates plasma source 120 from processing chamber 110 (downstream region).

[0029] Plasma source 120 includes a dielectric sidewall 122. Plasma source 120 includes a top cover 124 (e.g., a top plate). The dielectric sidewall 122 and top cover 124, integrated with insert 140, define an internal volume 125 (e.g., a chamber internal volume) of the plasma source. The dielectric sidewall 122 may comprise any suitable dielectric material, such as quartz. Inductor coil 130 is positioned close to (e.g., adjacent to) the dielectric sidewall 122 surrounding plasma source 120. Inductor coil 130 is coupled to RF power generator 134 via any suitable matching network 132. Feed gas is introduced into the internal volume 125 of plasma source from gas supply 150. When inductor coil 130 is energized by RF power from RF power generator 134, plasma is generated in plasma source 120. In some embodiments, RF power is supplied to coil 130 at a rate of about 1 kW to about 15 kW (e.g., about 3 kW to about 10 kW). Inductor coil 130 can ignite and sustain plasma over a wide range of pressures and flow rates. In some embodiments, plasma handling apparatus 100 includes a grounded Faraday shield 128 to reduce capacitive coupling between inductor coil 130 and plasma.

[0030] To improve efficiency, the plasma processing apparatus 100 includes a gas injection insert 140 disposed within an internal volume 125 of the plasma source. A gas injection channel 151 supplies process gas to the internal volume 125 of the plasma source via an active region 172 (e.g., an active area), where thermionic electrons react with the feed gas due to enhanced electron confinement. The enhanced electron confinement region, or active region 172, is defined radially by the sidewalls of the gas injection insert and the vacuum tube, and vertically from the bottom by the edge of the bottom surface 180 of the insert. The active region 172 provides an electron confinement area within the internal volume 125 of the plasma source for efficient plasma generation and maintenance. The narrow gas injection channel 151 prevents plasma from spreading from the internal volume of the chamber into the gas channel 151. The diameter of the channel 151 may be about 1 mm or greater, such as about 10 mm or greater, such as about 1 mm to about 10 mm. The gas injection insert 140 forces the process gas through the active zone 172 in which plasma is formed.

[0031] As long as the wall system in direct contact with free radicals is made of a material with a low recombination rate of free radicals, the ability of the gas injection insert 140 to improve the efficiency of the plasma treatment apparatus 100 (e.g., a plasma reactor) is independent of the material of the gas injection insert 140. For example, in some embodiments, the gas injection insert 140 may be made of a metal (such as aluminum) having a coating configured to reduce surface recombination. Alternatively, the gas injection insert 140 may be a dielectric material (such as quartz) or an insulating material.

[0032] Coil 130 is aligned with the active region such that the top turn of the coil operates above the bottom surface 180 of the insert 140 and generally within the active region of its internal volume, while the bottom turn of the coil operates below the bottom surface 180 and generally outside the active region. The center of the coil is generally aligned with the bottom surface 180. Within these boundaries, the coil position can be adjusted to achieve the desired performance. The alignment of the coil with the bottom surface 180 (e.g., the surface edge) provides improved source efficiency, i.e., provides controlled generation of the required chemicals for plasma processes and delivers them to the wafer in a manner that reduces or eliminates losses. For example, plasma maintenance conditions (the balance between zone generation and ion loss) may not be optimal for generating materials for plasma processes. Regarding the delivery of materials to the substrate, efficiency may depend on the volume and wall remodeling of these specific materials. Therefore, controlling the alignment of the coil with the bottom surface 180 provides control over the source efficiency of the plasma process.

[0033] In some embodiments, the coil has a short transition region near the lead, and the remainder of the coil turns is parallel to the bottom surface 180°. In other embodiments, the coil is helical, but the top and bottom turns of the coil can always be defined. In some embodiments, the coil may have 2 to 5 turns.

[0034] In some embodiments, surface 180 is aligned with a portion of inductor coil 130 (e.g., coil loop 182) along axis 184 (e.g., aligned with a horizontal plane) using an appropriately sized insert 140 (and a top cover 124, which may be a pre-formed portion of insert 140) to form plasma source 120. Alternatively, surface 180 may be movable relative to plasma source 120 in a vertical direction V1 while the remaining portion of insert 140 remains stationary (e.g., fixed) as part of plasma source 120 to provide alignment of surface 180 with a portion of coil 130. For example, mechanism 170 may be coupled to any suitable portion of insert 140 to adjust the position of surface 180 such that a portion of insert 140 having a first length (L1) is adjusted to a second length (L2). Mechanism 170 may be any suitable mechanism, such as an actuator, e.g., a motor, electric motor, stepper motor, or pneumatic actuator. In some embodiments, the difference (Δ) between the lengths of L1 and L2 is about 0.1 cm to about 4 cm, such as about 1 cm to about 2 cm.

[0035] Alternatively, the insert 140 may be coupled to a mechanism (such as mechanism 170), and mechanism 170 is configured to allow the entire insert 140 to move vertically (e.g., in the vertical direction V1 relative to the plasma source 120) so that surface 180 is aligned with a portion of coil 130. Spacers (not shown) may be used to fill gaps between the insert 140 and another portion of the plasma source 120 (e.g., between the top cover 124 and the dielectric sidewall 122), gaps formed by the vertical movement of the insert. The spacers may be formed of, for example, a ceramic material (such as quartz).

[0036] Generally, positioning the center of coil 130 above surface 180 will increase the efficiency of ionization and dissociation, but will reduce the transport efficiency of these materials to the substrate, because many materials may recombine on the walls of narrow active regions. Positioning coil 130 below surface 180 can improve plasma transport efficiency, but may reduce plasma generation efficiency.

[0037] The separation grid 116 is configured to separate the processing chamber 110 region from plasma charged particles (ions or electrons) that recombine on the grid, allowing only neutral plasma material to pass through the grid into the processing chamber 110. The holes in the bottom portion of the separation grid 116 may have different patterns, for example, a uniform pattern 600 as shown in Figures 6a and 6b. In some embodiments, the separation grid 600 is formed of aluminum, anodized aluminum, quartz, aluminum nitride, aluminum oxide, tantalum, tantalum nitride, titanium, titanium nitride, or combinations thereof. For example, AlN can be beneficial for nitrogen radical flux, and conventional separation grids are more conducive to nitrogen radical recombination. Similarly, aluminum oxide can provide for oxygen or hydrogen radical flux, and conventional separation grids are more conducive to their recombination. In some embodiments, the separation grid 600 has a plurality of holes 602. As shown in Figure 6b, an aperture 602 is positioned to pass through a separation grid (e.g., the aperture 602 traverses the thickness of the separation grid). The aperture 602 may have an average diameter of about 4 mm to about 6 mm. In some embodiments, each of the plurality of apertures 602 has a diameter (D1) of about 4 mm to about 6 mm. In some embodiments, the separation grid 600 of Figures 6a and 6b has a thickness of about 5 mm to about 10 mm, which defines the aperture length (L1). The ratio of the grid thickness (length (L1)) to the average diameter of the plurality of apertures may be greater than about 1, such as about 1 to about 3.

[0038] The emission device 192 is coupled to the sidewall of the process chamber 110. In some embodiments, the emission device 192 may be coupled to the bottom wall of the process chamber 110 to provide orientation independence (e.g., if it is not a rotating base). If the lamp is rotating, the emission device 192 may be coupled to the sidewall because rotation reduces orientation dependence.

[0039] Various features of the ICP source and plasma processing apparatus will now be described with reference to Figures 2, 3, 4, and 5. Figures 2, 3, 4, and 5 are schematic diagrams of plasma processing apparatuses according to some embodiments of this disclosure. The plasma processing apparatuses of Figures 2, 3, 4, and 5 can be constructed in a similar manner to plasma processing apparatus 100 (Figure 1) and operate in the manner described above for processing apparatus 100. It will be understood that, in alternative exemplary embodiments, components of the plasma processing apparatuses of Figures 2, 3, 4, and 5 may also be incorporated into any other suitable plasma processing apparatus.

[0040] As shown in Figure 2, the plasma processing apparatus 200 includes a processing chamber 220 having a separation grid (not shown) disposed therein. The plasma processing apparatus 200 includes a plasma source 222 along a vertical direction V. A substrate can be positioned in the processing chamber directly below and at a certain distance from the grid, and neutral particles from the internal volume 230 of the plasma source can flow downward toward the substrate in the processing chamber 220 through the separation grid, and the neutral particles can contact the substrate to perform a process, such as a surface treatment process.

[0041] A plurality of inductor coils 250 are disposed at different positions along a vertical direction V on the plasma source 222, for example, such that the inductor coils (e.g., 252 and 254) are spaced apart from each other along the vertical direction V of the plasma source 222. For example, the inductor coils 250 may include a first inductor coil 252 and a second inductor coil 254. The first inductor coil 252 may be positioned at a first vertical position along a vertical surface of the dielectric sidewall 232. The second inductor coil 254 may be positioned at a second vertical position along a vertical surface of the dielectric sidewall 232. The first vertical position may differ from the second vertical position. For example, the first vertical position may be above the second vertical position. In some embodiments, as described above, a portion of the first inductor coil 252 may be substantially aligned with the surface 180 of the insert. The second inductor coil 254 is disposed at the bottom (e.g., lower) portion of the plasma source 200. The second inductor coil includes several magnetic field concentrators 280, thereby allowing the coil to be placed at the bottom of the plasma source, as shown in Figure 2. The use of magnetic field concentrators 280 improves plasma generation efficiency at the bottom of the source and significantly enhances radial control near the substrate (compared to the absence of magnetic field concentrators). In some embodiments, the inductor coil 254 is positioned at the bottom third height (e.g., bottom quarter height) of the plasma source 222.

[0042] Inductor coils 250 (252, 254) can be used to generate (or modify) inductive plasma within the internal volume 230 of the plasma source. For example, the plasma processing apparatus 200 may include a radio frequency power generator 262 (e.g., an RF generator and a matching network) coupled to coil 252. Inductor coil 254 is coupled to a second RF generator 264 (e.g., an RF generator and a matching network). The frequency and / or power of the RF energy applied to the first inductor coil 252 by the first RF generator 262 and to the second inductor coil 254 by the second RF generator 264 may be independent in order to better control the process parameters of the surface treatment process.

[0043] For example, the frequency and / or power of the RF energy applied by the second RF generator 264 may be less than the frequency and / or power of the RF energy applied by the first RF generator 262. The RF power generator 262 can be used to energize the inductor coil 252 to generate inductive plasma within the plasma source internal volume 230. Specifically, the RF power generator 262 can energize the inductor coil 252 by means of an alternating current (AC) of radio frequency (RF), such that the AC induces alternating magnetic and electric fields within the volume near the inductor coil 252, which heat electrons to generate inductive plasma. In some embodiments, RF power is provided to the coil 252 at about 1 kW to about 15 kW (e.g., about 3 kW to about 15 kW). The inductor coil 252 can ignite and sustain plasma over a wide range of pressures and flow rates.

[0044] The radio frequency power generator 264 can be used to energize the inductor coil 254 to generate and / or modify plasma within the plasma source internal volume 230. Specifically, the radio frequency power generator 264 can energize the inductor coil 254 by means of an alternating radio frequency (RF) current (AC) such that an inductive RF electric field within the volume adjacent to the inductor coil 254 accelerates electrons to generate plasma. In some embodiments, RF power is provided to the coil 254 at about 0.5 kW to about 6 kW (e.g., about 0.5 kW to about 3 kW). The inductor coil 254 can modify the plasma density in the plasma processing apparatus 200; for example, the inductor coil 254 can tune the radial profile of the plasma to facilitate additional plasma uniformity in movement toward the substrate in the chamber 220. Because coil 252 is farther from the substrate than coil 254 during use, the plasma and free radicals generated by coil 252 can create a dome-shaped profile near the substrate, and when the plasma approaches the substrate, coil 254 can flatten the dome-shaped plasma profile (or even raise the edges).

[0045] A dielectric sidewall 232 is positioned between the inductor coil 250 and the plasma source 222. The dielectric sidewall 232 has a generally cylindrical shape. A grounded Faraday shield 234 may be made of metal and / or positioned between the inductor coil 250 and the dielectric sidewall 232. The Faraday shield 234 has a cylindrical shape and is disposed around the dielectric sidewall 232. The grounded Faraday shield 234 extends the length of the plasma source 222. The dielectric sidewall 232 contains plasma within the plasma source internal volume 230 to allow RF fields from the inductor coil 250 to pass through to the plasma source internal volume 230, and the grounded Faraday shield 234 reduces the capacitive coupling between the coil 250 and the plasma within the plasma source internal volume 230. In some embodiments, the Faraday shield 234 may be a metal cylinder with slots perpendicular to the coil direction. The vertical slot is located in the coil region (e.g., adjacent to the coil), and at least one vertical end of the coil (above or below the coil) has a complete current path around the cylinder. The Faraday shield can have any suitable thickness, and / or the slot can have any suitable shape. Even when using a helical coil, the slot can be relatively narrow (e.g., from about 0.5 cm to about 2 cm) and generally vertical in the vicinity of the coil(s).

[0046] As described above, each inductor coil 250 is positioned at a different location on the plasma source 222 along the vertical direction V, adjacent to the vertical portion of the dielectric sidewall of the plasma source 222. In this way, each inductor coil 250 can be used to generate (or modify) plasma in the region adjacent to the coil along the vertical surface of the dielectric sidewall 232 of the plasma source 222.

[0047] In some embodiments, the plasma processing apparatus 200 includes one or more gas injection ports 270 arranged radially outward from the gas injection insert 240 of the plasma source 222. The side profiles of the gas injection ports 270 and the insert are designed to directly inject process gases into an active plasma generation region adjacent to the vertical surface of the dielectric sidewall 232 at the periphery of the plasma source internal volume 230. For example, there may be more than 20 (e.g., 70 to 200) vertical injection holes arranged through the insert 240. For example, a first inductor coil 252 may be used to generate plasma in region 272 near the vertical surface of the dielectric sidewall 232. A second inductor coil 254 may be used to generate or modify plasma present in region 275 near the vertical surface of the dielectric sidewall 232. In some embodiments, the gas injection insert 240 may further define an active region for generating plasma within the internal volume 230 of the plasma source, adjacent to the vertical surface of the dielectric sidewall 232. The top portion of the gas injection insert of this disclosure may have a diameter of about 10 cm to about 15 cm. The bottom portion of the gas injection insert of this disclosure may have a diameter of about 7 cm to about 10 cm.

[0048] The plasma processing apparatus 200 may have a bottom edge gas injection port 290 configured to introduce a gas, the same or different from the gas supplied to the plasma source internal volume 230 by the gas injection port 270, into the volume 210. The edge gas injection port 290 is coupled to the process chamber 220 and is the top plate of the process chamber 220. The edge gas injection port 290 includes a circular gas chamber 292 into which gas is introduced via an inlet 294. The gas flows from the gas chamber 292 into the volume 210 through one or more openings 296. The edge gas injection port 290 can provide fine tuning of the plasma chemistry near the substrate edge and / or improve plasma uniformity at the substrate. For example, the edge gas injection port 290 can provide modification of the flow rate (same gas) and / or modification of the chemical properties (chemical reaction between plasma radicals and fresh feed gas or different gases).

[0049] Compared to known plasma processing apparatuses, the plasma processing apparatus 200 has improved source tunability. For example, the inductor coil 250 can be positioned in two locations along the vertical surface of the dielectric sidewall 232, such that the top coil 252, closer to the active plasma generation region, functions to ignite and sustain the plasma within the plasma source internal volume 230, while the second coil 254, placed at the bottom of the source, allows for advantageous source tunability. The low positioning of the second coil is possible due to the use of the magnetic field concentrator 280, which provides coupling between the coil and the plasma rather than the surrounding metal (e.g., 290). In this way, the processing performed on the substrate by the plasma processing apparatus 200 can be more uniform.

[0050] Figure 3 is a schematic diagram of a plasma processing apparatus 300. The processing apparatus 300 includes a plasma source 322 and a processing chamber 220. The plasma source 322 includes an insert 302 having a peripheral gas injection port 270 and a central gas injection port 310. The central gas injection port 310 is formed by a top plate 318 and a bottom plate 340 forming a gas chamber 316. The bottom plate 340 has a plurality of holes (through holes) 312 such that the central gas injection port 310 / insert 302 has a plurality of holes (through holes) 312 for supplying process gas to a central process region 314. The dimensions of the central process region 314 are provided by a portion of the insert 302 (i.e., the central gas injection port 310 and the sidewall 320). The sidewall 320 has a cylindrical shape and is made of a dielectric material. For example, the sidewall 320 is formed of quartz or alumina. The peripheral process area 272 is sized by the dielectric sidewall 232 and the insert 302 (i.e., the gas injection port 270 and the sidewall 324). The sidewall 324 (generally speaking, and the insert 302) may have a cylindrical shape. The surface material of the sidewall 324 may be a dielectric material or a metal. For example, the sidewall 324 is formed of aluminum and may be covered with quartz or alumina, or have an exposed or anodized aluminum surface. Additionally, a first Faraday shield (not shown) may be disposed between the coil 252 and the dielectric sidewall 232. Similarly, a second Faraday shield (not shown) may be disposed between the coil 254 and the sidewall 320. In some embodiments, the sidewall 320 is quartz or ceramic and / or has a thickness of about 2.5 mm to about 5 mm.

[0051] The flow rate of the process gas supplied from the peripheral gas injection port 270 to the peripheral process region 272 via the conduit 326 may be greater than the flow rate of the process gas supplied from the central gas injection port 310 to the central process region 314. In some embodiments, the ratio of the flow rate of the process gas supplied from the peripheral gas injection port 270 to the flow rate of the process gas supplied from the central gas injection port 310 is about 2:1 to about 20:1, such as about 5:1 to about 10:1. Providing a higher flow rate to the peripheral process region 272 than to the central process region 314 provides improved center-edge uniformity of the plasma on the substrate surface of the substrate present in the processing chamber 220.

[0052] The processing apparatus 300 further includes a peripheral coil 252 and a central coil 254. The RF power provided by the peripheral coil 252 may be greater than the RF power provided by the central coil 254. In some embodiments, the ratio of the RF power provided by the peripheral coil 252 to the RF power provided by the central coil 254 is about 2:1 to about 20:1, such as about 3:1 to about 10:1, such as about 5:1. If the central coil is not energized, the secondary plasma source acts as an auxiliary gas injection, which reduces the flux of free radicals and ions / electrons generated by the main coil 252 toward the center of the substrate. Because the plasma density is typically higher at the center of the substrate during conventional plasma processes, providing a greater RF power to the peripheral inductor coil 254 than to the central inductor coil 252 promotes increased plasma density at several edge portions of the substrate, thereby improving plasma uniformity. The plasma separator 304 (cylindrical protrusion) between the central and edge regions improves the ability to independently control the center-edge plasma.

[0053] The peripheral coil 252 and the center coil 254 can be used to generate (or modify) inductive plasma within the internal volume 330 of the plasma source. For example, the plasma processing apparatus 300 may include a radio frequency power generator 262 (e.g., an RF generator and a matching network) coupled to the peripheral coil 252. The center coil 254 is coupled to a second RF generator 264 (e.g., an RF generator and a matching network). The frequency and / or power of the RF energy applied to the peripheral coil 252 by the first RF generator 262 and to the center coil 254 by the second RF generator 264 may be adjusted to be the same or different in order to control the process parameters of the substrate processing process.

[0054] For example, the frequency and / or power of the RF energy applied by the second RF generator 264 may be less than the frequency and / or power of the RF energy applied by the first RF generator 262. The RF power generator 262 may be used to energize the peripheral coil 252 to generate inductive plasma within the plasma source internal volume 330. Specifically, the RF power generator 262 may energize the peripheral coil 252 by means of an alternating current (AC) of radio frequency (RF) such that the AC induces an alternating magnetic field within the peripheral coil 252, which heats the gas to generate inductive plasma. In some embodiments, RF power is provided to the peripheral coil 252 at about 1 kW to about 15 kW (e.g., about 3 kW to about 10 kW).

[0055] The radio frequency power generator 264 can be used to energize the central coil 254 to generate and / or modify inductive plasma in the central region 314 of the plasma source 322. Specifically, the radio frequency power generator 264 can energize the central coil 254 by means of an alternating radio frequency (RF) current (AC) such that the AC induces an alternating magnetic field inside the inductive coil 254, which heats the gas to generate and / or modify inductive plasma. In some embodiments, RF power is provided to the central coil 254 at about 0.3 kW to about 3 kW (e.g., about 0.5 kW to about 2 kW). The central coil 254 can modify the plasma in the plasma processing apparatus 300; for example, the central coil 254 can tune the radial profile of the plasma to facilitate additional plasma uniformity in movement toward the substrate in the chamber 220.

[0056] In some embodiments, the plasma processing apparatus 300 includes a gas injection port 270 for injecting process gas around region 272 along the vertical surface of dielectric sidewall 232, thereby defining several active plasma generation regions adjacent to the vertical surface of dielectric sidewall 232. For example, a peripheral coil 252 can be used to generate plasma in region 272 near the vertical surface of dielectric sidewall 232. A central coil 254 can be used to generate and / or modify plasma present in a central region 314 near the vertical surface of sidewall 320. In some embodiments, the gas injection insert 302 can further define active regions for plasma generation within the internal volume of the plasma source adjacent to the vertical surfaces of dielectric sidewall 232 and sidewall 320.

[0057] In practice, the process plasma formed in region 314 can partially overlap with the process plasma formed in region 272. In summary, the peripheral and central process gas injection ports (270, 310) and inductors (252, 254) can provide improved plasma and process uniformity (center-to-edge plasma control) for plasma-processed substrates. To enhance center-to-edge process control, the insert 302 includes a separator 304. The separator 304 can be a uniform cylindrical separator coupled to (e.g., disposed along) an inert bottom surface 180.

[0058] Furthermore, in embodiments where the process gas supplied by the central gas injection port 310 differs from the process gas supplied by the peripheral gas injection port 270, new plasma chemistry properties can be obtained compared to conventional plasma processes using conventional plasma sources. For example, advantageous treatment of the substrate that cannot be obtained in conventional plasma processing can be provided. For example, if we mix the flow of free radicals and excited substances generated by plasma (e.g., some embodiments of region 272) with different plasma flows rich in different types of plasma substances (e.g., different free radicals), unique plasma mixtures can be generated. In addition, these unique plasma chemistry properties can be formed in embodiments where a portion of the surface 180 and the coil 252 are aligned (e.g., as described above).

[0059] Figure 4 is a schematic diagram of a plasma processing apparatus 400. The plasma processing apparatus 400 includes a plasma source 422. The plasma source 422 includes a gas injection insert 402, which can be integrated with a top cover, a peripheral gas injection port 270, and a central gas injection port 410. The central gas injection port 410 is disposed within the gas injection insert 402 to fluidly couple with a gas distribution chamber 416 of the gas injection insert 402. The gas distribution chamber 416 provides an increased diameter (compared to the diameter of the port 410) for the process gas to uniformly distribute the process gas before it enters the discharge area between the bottom of the insert 402 and the distribution platform 414. Once gas is supplied via the orifice 412, the platform 414 provides a second gas distribution chamber 418 (e.g., a region) and facilitates the outward flow of gas to the periphery of the plasma source 422 (e.g., to region 272). In some embodiments of this disclosure, no material is used to form the hole 412, and a larger gas chamber is formed. Platform 414 may be coupled to insert 402 via a plurality of bolts or screws (not shown). Platform 414 may be made of quartz or ceramic. Platform 414 may have any suitable design that allows for different materials. Compared to conventional plasma processing apparatuses, the outward / lateral flow of gas facilitated by platform 414 can influence the flow distribution of gas / plasma to the substrate during processing, thereby improving center-to-edge uniformity. Additionally, this outward flow of gas to the region adjacent to the plasma generation region (e.g., 272) of plasma source 400 provides benefits. Because a high plasma density can be generated in region 272 adjacent to the top portion of coil 130, the electric field does not penetrate far from the coil, and therefore the gas from the center injection 410-416-414 does not undergo significant ionization or dissociation, but the gas will chemically interact with the high density of free radicals and ions generated in the active region 272. Both free radicals and ions are chemically active and interact with the fresh feed gas from the central injection chambers 410-416-414. Compared to conventional plasma sources using plasma processing chambers, the new feed gas, free radicals, and ions can generate new plasma chemistry. For example, a unique plasma mixture can be generated by mixing a stream of plasma-generated free radicals and excited substances (e.g., in some embodiments of region 272) with a fresh gas flow that does not pass through the plasma generation region 272 with hot electrons (e.g., process gas supplied by injection port 410 and platform 414 / second gas distribution chamber 418). For example, we can mix the H+ and H- free radical streams obtained from the plasma from the H2 feed gas (e.g., gas supplied from the injection port 270) with the oxygen O2 stream (e.g., gas supplied from the injection port 410), where we can significantly increase the proportion of HO2, HO, H2O2 and other non-equilibrium molecules in the region adjacent to the active region 272 of the inductor coil 130.Additionally, these unique plasma chemistry properties can be formed in embodiments in which the edge of surface 180 is aligned with a portion of coil 130 (e.g., as described above).

[0060] In some embodiments, the ratio of the flow rate of the process gas supplied by the peripheral gas injection port 270 to the flow rate of the process gas supplied by the central gas injection port 410 is about 20:1 to about 1:20, such as about 10:1 to about 1:10, such as about 2:1 to about 1:2, such as about 1.2:1 to about 1:1.2, such as about 1:1. These flow rates can provide stoichiometry (e.g., substantially equal molar amounts) of different process gases to provide the required density of chemicals formed in the plasma in region 272.

[0061] Furthermore, the outward / lateral flow provided by the central gas injection port 410 and the platform 414 / second gas distribution chamber 418 can modify the flow pattern within the plasma source 400, thereby affecting the distribution of free radicals to the substrate. For example, in embodiments where the process gas provided by the central injection port 410 is substantially the same as the process gas provided by the peripheral injection port 270, more plasma flow toward the edge of the substrate is facilitated, thereby improving the center-edge plasma distribution (e.g., the uniformity of the plasma supplied to the substrate).

[0062] Furthermore, in embodiments where the process gas supplied by the central gas injection port 410 differs from that supplied by the peripheral gas injection port 270, new plasma chemistry properties can be obtained compared to conventional plasma processes using conventional plasma sources. For example, advantageous treatment of the substrate that cannot be obtained in conventional plasma processing can be provided. For example, a unique plasma mixture can be generated by mixing a stream of free radicals and excited substances generated by the plasma (e.g., in some embodiments of region 272) with a new gas flow that does not pass through a plasma region with hot electrons. For example, a stream of H+ and H- free radicals obtained from the plasma from the H2 feed gas can be mixed with an oxygen O2 stream, wherein a large number of different free radicals, such as HO2, H2O2 molecules, etc., can be generated in the region downstream of region 272 of the plasma processing apparatus 400. In addition, the formation of these unique plasma chemistry properties can be obtained in embodiments where a portion of the surface 180 and the coil 252 are aligned (e.g., as described above).

[0063] Figure 5 is a schematic diagram of a plasma processing apparatus 500. The processing apparatus 500 includes a plasma source 522 and a processing chamber 220. The plasma source 522 includes a gas injection insert 240, a peripheral gas injection port 270, a central gas injection port 510, and a top cover 124. The central gas injection port 510 may be positioned close to a wall 550 (e.g., adjacent to the wall 550). The central gas injection includes a port 510 having a generally cylindrical gas chamber / manifold, and a plurality of angled injection outlets 512 evenly distributed along the gas chamber. The gas injection insert 240 may also have a generally cylindrical shape. The central gas injection port 510 has angled outlets 512 to facilitate outward / lateral flow of process gases supplied by the central injection port 510 and the angled outlets 512. The angled outlet 512 may have an angle of about 0 degrees to about 90 degrees, such as about 30 degrees to about 60 degrees, such as about 45 degrees, relative to a vertical axis (such as vertical axis 186, which is parallel to the axial centerline of the processing device 500 and / or the axial centerline of the plasma source 522).

[0064] Compared to conventional plasma processing apparatuses, the outward / lateral flow of gas facilitated by the angled outlet 512 can influence the flow distribution of gas / plasma to the substrate during processing, thereby improving the uniformity from center to edge. Furthermore, because a high plasma density can be generated in the region adjacent to the coil 130 (and the electric field does not penetrate away from the coil), new plasma chemistry properties can be obtained compared to conventional plasma processes using plasma processing chambers. For example, if we mix the flow of free radicals and excited substances generated by plasma (e.g., in some embodiments of region 272) with a new gas flow that does not pass through the plasma region with hot electrons (e.g., process gas provided by the injection port 510 and the angled outlet 512), a unique plasma mixture can be generated. For example, we can mix the H+ and H- free radical streams obtained from the plasma from the H2 feed gas (e.g., gas supplied from injection port 270) with the oxygen O2 stream (e.g., gas supplied from injection port 510), where molecular free radicals such as HO2 and H2O2 can be generated in the process region 272 adjacent to the inductor coil 130. Additionally, the formation of these unique plasma chemistry properties can be achieved in embodiments utilizing the alignment of coil 130 with surface 180 (as described above).

[0065] In some embodiments, the ratio of the flow rate of the process gas supplied by the peripheral gas injection port 270 to the flow rate of the process gas supplied by the central gas injection port 510 is about 2:1 to about 1:2, such as about 1.2:1 to about 1:1.2, such as about 1:1. These flow rates can provide stoichiometry (e.g., substantially equal moles) of different process gases to provide the required density of chemicals formed in the plasma in region 272.

[0066] Furthermore, the outward / lateral flow provided by the central gas injection port 510 and the angled outlet 512 can modify the flow pattern within the plasma source 522, thereby affecting the distribution of free radicals to the substrate. For example, in embodiments where the process gas provided by the central injection port 510 is substantially the same as the process gas provided by the peripheral injection port 270, more plasma flow toward the edge of the substrate is facilitated, thereby improving the center-edge plasma distribution (e.g., the uniformity of the plasma supplied to the substrate).

[0067] Additionally, the gas injection insert 240 in Figure 5 has a fixed edge at the bottom surface 180, thereby defining the active region of the axis 184 of the marking inductor coil 130. The coil 130 is substantially aligned with the surface 180, such that the top turn of the coil is positioned above the axis 184 (surface 180), and the bottom turn is positioned below the edge. The position of the coil can be further adjusted within this range based on process results. The alignment of the coil's vertical center with the surface 180 provides improved source efficiency, i.e., controlled generation of the required chemicals for the plasma process and delivery to the wafer with minimal loss. For example, plasma maintenance conditions (the balance between zone generation and ion loss) may be unsuitable for generating materials for the plasma process. Regarding the delivery of materials to the substrate, efficiency may depend on the volume and wall remodeling of these specific materials. Therefore, controlling the alignment of the coil 130 with the surface 180 provides control over the source efficiency of the plasma process.

[0068] In some embodiments, the plasma source 120 is formed by utilizing an appropriately sized insert 240, with the bottom surface of the insert 240 aligned with the edge portion of the bottom surface 180 of the insert defining the active region of the coil (this alignment is shown as axis 184). Alternatively, a movable central portion of the insert 240, as shown in Figure 5, can be used to make the bottom surface of the insert 240 flexible, while the rest of the insert 240 is fixed as part of the plasma source 120. For example, a mechanism 170 can be electrically coupled to the central portion of the insert 240 to adjust the central portion such that the central portion of the insert 240 having a first position is adjusted to a second position. In some embodiments, the position difference (Δ) between the first position and the second position is from about 0.1 cm to about 10 cm, such as from about 1 cm to about 2 cm. The mechanism 170 can be any suitable mechanism, such as an actuator, for example, a motor, electric motor, stepper motor, or pneumatic actuator. The space between the central portion of the insert 240 and the top cover 124 is increased or decreased by the movement of the mechanism 170.

[0069] Generally, moving the central portion of the insert 240 downward along the vertical direction V will reduce the flow of active material toward the center of the substrate and thus reduce the ratio of the processing rate of the center to the edge, while moving the central portion upward will increase the ratio of the processing rate of the center to the edge.

[0070] Although the figures have been described independently, it should be understood that embodiments from one or more figures may be advantageously combined with embodiments from different figures. For example, the gas injection insert 140 of Figure 1 or the gas injection insert 240 of Figure 2 may be a configuration of the gas injection insert 302 of Figure 3, the gas injection insert 402 of Figure 4, or the gas injection insert 240 of Figure 5 and the central gas injection port 510. As another non-limiting example, as an embodiment having the plasma processing apparatus 300 of Figure 3, the plasma processing apparatus 400 of Figure 4, and the plasma processing apparatus 500 of Figure 5, the gas injection port 290 may be included.

[0071] Figure 7 shows an inductor 130 that can be used with a plasma source. The inductor 130 includes a plurality of coil loops, including coil loop 182. The inductor 130 includes three complete coils, but more or fewer coils are conceivable. For example, for an RF frequency of 13.56 MHz, the inductor may have 2 to 6 complete turns. Lower RF frequencies can be obtained using more turns.

[0072] Figure 8 is a flowchart of a method 800 for plasma processing a substrate using the plasma processing apparatus of this disclosure. Method 800 may include introducing a process gas into a plasma processing source (810). The process gas and its flow rate may be selected based on a specific substrate processing application. Generally, the process gas may include at least one of N2, NH3, O2, H2, or He, and the flow rate may be from about 100 sccm to about 3000 sccm. However, other process gases and other flow rates are contemplated. Method 800 further includes providing radio frequency power to generate inductive plasma within the plasma source (820). The radio frequency power may be controlled based on a specific substrate processing application. Generally, the radio frequency power may be from about 1 kW to about 10 kW; however, other power levels are also contemplated. From an internal region of the plasma source, neutral particles and / or free radicals of the inductive plasma flow through a separation grid to the substrate within the processing chamber. Although a separate grid is shown in Figure 1, method 800 can be performed without a separate grid.

[0073] Method 800 further includes processing a substrate (830) within a process chamber. The temperature and pressure of the process chamber can be controlled based on the specific substrate processing application. Typically, the temperature can be from about 200°C to about 1200°C, and the pressure can be from about 0.25 Torr to about 5 Torr. However, other temperatures and pressures are contemplated. The substrate in the process chamber can be exposed to neutral particles and / or free radicals generated in an inductive plasma passing through a separation grid. Specifically, the plasma (including the neutral particles and / or free radicals contained therein) contacts a first side of the substrate facing the plasma source. In some embodiments, a plurality of lamps arranged opposite the first side of the substrate are used to heat the substrate. For example, neutral particles and / or free radicals can be used as part of a surface treatment process for the substrate. Specifically, the gas flow rate and / or gas ratio can be selected such that the surface of the substrate is saturated with a supply of reactants of neutral particles and / or free radicals. The ability of the apparatus disclosed herein to provide surface saturation of reactive substances is attributed to the extremely high density of the source and the reduced distance between the plasma source and the substrate.

[0074] In plasma processing operations without surface saturation, the rate at which reactive material reaches the substrate surface determines the rate of reaction and / or coalescence of the reactive material. However, using the apparatus and / or method disclosed herein, the high material throughput leads to surface saturation of the reactive material, making diffusion of the reactive material the dominant factor. Since temperature determines the diffusion of the reactive material and drives the reaction, the reaction is temperature-dependent. Because thermal energy is inherently conformal and substantially homogeneous in three dimensions, the temperature-controlled method disclosed herein produces a more conformal surface treatment compared to plasma processing operations where the rate at which reactive material reaches the substrate is rate-determined.

[0075] Typically, depending on the specific substrate processing application, the processing time of operation 830 can be from about 10 seconds to about 10 minutes; however, other processing times are also expected. The numerous benefits of method 800 will be described in more detail below with respect to each exemplary substrate processing application. It will be understood that method 800 can be performed using any of the plasma processing apparatus of this disclosure.

[0076] Plasma can be generated by energizing one or more inductors near the plasma source with RF energy, thereby generating plasma using process gas introduced into the plasma source. For example, process gas can enter the plasma source from a gas source. RF energy from (a few) RF sources can be applied to (a few) coils to generate plasma in the plasma source.

[0077] Typically, method 800 can be used for a range of different substrate processing applications, including but not limited to nitrogen radical treatment (e.g., nitriding), oxygen radical treatment (e.g., oxidation), hydrogen radical treatment, helium radical treatment, and various pretreatments and posttreatments.

[0078] In some embodiments, the plasma processing apparatus of this disclosure can be used for silicon oxide (e.g., SiO2) nitriding according to method 800. In some instances, the substrate undergoing the nitriding process may include a silicon oxide layer having a thickness of about 10 angstroms to about 200 angstroms. During silicon oxide nitriding, at least one of diatomic nitrogen (N2), ammonia (NH3), or a mixture thereof is introduced to a plasma processing source to generate nitrogen and / or NH radicals. In embodiments using N2 source gas, the flow rate of N2 is about 100 sccm to about 500 sccm, such as about 300 sccm. In embodiments using a mixture of N2 and NH3 source gases, the ratio of N2 to NH3 is about 3:1 to about 1:3, such as about 3:1 to about 1:1, such as about 1:1, such as about 1:1 to about 1:3. In some embodiments that can be combined with other embodiments, the source gas is mixed with an inert gas (e.g., argon (Ar)).

[0079] During silicon nitriding, the process chamber may operate hot (e.g., greater than 250°C) or cold (e.g., 250°C or lower). In some embodiments that may be combined with other embodiments, the temperature in the process chamber is about 200°C or higher, such as about 200°C to about 1200°C, such as about 250°C to about 950°C, such as about 200°C to about 250°C, such as about 250°C, such as about 250°C or higher, such as about 500°C to about 1000°C, such as about 500°C to about 600°C, such as about 600°C to about 700°C, such as about 700°C to about 800°C, such as about 800°C to about 900°C, such as about 850°C, such as about 900°C to about 1000°C, such as about 950°C. The pressure in the process chamber is approximately 0.2 Torr to approximately 3 Torr, such as approximately 0.5 Torr to approximately 2 Torr, such as approximately 0.5 Torr, such as approximately 1 Torr, such as approximately 2 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW, such as approximately 1 kW to approximately 5 kW, such as approximately 2 kW, such as approximately 2 kW to approximately 8 kW, such as approximately 5 kW to approximately 10 kW, such as approximately 8 kW. The processing time is in the range of approximately 2 minutes to approximately 8 minutes, such as approximately 4 minutes to approximately 5 minutes, such as approximately 4 minutes, such as approximately 5 minutes.

[0080] Advantageously, compared to rapid thermal nitriding processes, silicon oxide nitriding performed using the plasma processing apparatus and method of this disclosure increases the nitrogen content in silicon oxide while maintaining a substantially similar level of nitrogen conformability. Furthermore, compared to ion-driven decoupled plasma nitriding processes, the silicon oxide nitriding process described herein also increases the nitrogen conformability in silicon oxide. Because nitrogen and / or NH radicals diffuse from the surface to the interface, the silicon oxide nitriding described herein creates peak nitrogen content at both the silicon-silicon oxide interface and the silicon oxide surface. Additionally, the silicon oxide nitriding described herein can increase conformability on gate all around (GAA) semiconductor structures.

[0081] In another example, the plasma processing apparatus of this disclosure can be used for silicon (Si) nitriding according to method 800. In some examples, the substrate undergoing the nitriding process may include a silicon layer, which can be treated with nitrogen free radicals to form a conformal layer of silicon nitride (e.g., SiN). In some embodiments of silicon nitriding, diatomic nitrogen (N2) is introduced into the plasma processing source to generate nitrogen free radicals. In embodiments using N2 source gas, the flow rate of N2 is from about 500 sccm to about 1500 sccm, such as about 1000 sccm. In some embodiments that can be combined with other embodiments, the source gas is mixed with an inert gas (e.g., Ar).

[0082] During silicon nitriding, the process chamber may operate hot (e.g., greater than 250°C) or cold (e.g., 250°C or lower). In some embodiments that may be combined with other embodiments, the temperature in the process chamber is about 200°C or higher, such as about 200°C to about 1200°C, such as about 250°C to about 950°C, such as about 200°C to about 250°C, such as about 250°C, such as about 250°C or higher, such as about 500°C to about 1000°C, such as about 500°C to about 600°C, such as about 550°C, such as about 600°C to about 700°C, such as about 700°C to about 800°C, such as about 800°C to about 900°C, such as about 900°C to about 1000°C, such as about 950°C. The pressure in the process chamber is approximately 0.2 Torr to approximately 3 Torr, such as approximately 0.3 Torr to approximately 2 Torr, such as approximately 0.3 Torr, such as approximately 2 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW, such as approximately 1 kW to approximately 5 kW, such as approximately 2 kW. The processing time is in the range of approximately 0.25 minutes to approximately 8 minutes, such as approximately 0.5 minutes to approximately 5 minutes, such as approximately 0.5 minutes, such as approximately 2 minutes, such as approximately 4 minutes, such as approximately 5 minutes.

[0083] Advantageously, silicon nitriding performed using the plasma processing apparatus and method of this disclosure can form a conformal layer of silicon nitride having a thickness of about 20 angstroms to about 60 angstroms. In one example, the silicon nitriding described herein enables the formation of a generally conformal nitrogen content, for example, a depth of 2.8 μm and an aspect ratio from 20:1 to 30:1, on the top and bottom sidewalls of polycrystalline silicon in an oxide / polycrystalline silicon (OPOP) stack.

[0084] In another example, the plasma processing apparatus of this disclosure can be used for tungsten (W) nitriding according to method 800. In some examples, the substrate undergoing the nitriding process includes a tungsten layer, which can be treated with nitrogen free radicals to form a conformal layer of tungsten nitride (e.g., WN). During tungsten nitriding, an N2 source gas is introduced into the plasma processing source to generate nitrogen free radicals. The N2 flow rate is from about 500 sccm to about 1500 sccm, such as about 1000 sccm. In some embodiments that can be combined with other embodiments, the source gas is mixed with an inert gas (e.g., Ar). Other nitrogen source gases are contemplated to be available.

[0085] During tungsten nitriding, the temperature in the process chamber is approximately 800°C or lower, such as approximately 700°C or lower, such as approximately 500°C to approximately 700°C, such as approximately 500°C to approximately 600°C, such as approximately 600°C to approximately 700°C, such as approximately 650°C. Using the apparatus and / or methods disclosed herein, temperature is negatively correlated with the nitrogen content of the treated film. For example, operating the process chamber at a temperature of approximately 850°C or higher results in a nitrogen content of only about 5% or less, while a temperature of approximately 780°C or lower increases the nitrogen content to approximately 25%, an increase of 5 times. Furthermore, operating the process chamber at a temperature of approximately 750°C results in a nitrogen content between approximately 25% and approximately 30%. Further reducing the temperature to approximately 650°C further increases the nitrogen content to between approximately 30% and approximately 35%, and further reducing the temperature to approximately 550°C can further increase the nitrogen content to between approximately 35% and approximately 40%. During tungsten nitriding, the pressure in the process chamber is from about 0.5 Torr to about 3 Torr, such as about 2 Torr. The radio frequency power is from about 1 kW to about 10 kW, such as from about 1 kW to about 5 kW, such as about 2 kW. The processing time is in the range of about 2 minutes to about 8 minutes, such as about 5 minutes. Advantageously, tungsten nitriding performed using the plasma processing apparatus and method of this disclosure results in a conformal layer of tungsten nitride with a thickness of about 25 angstroms to about 30 angstroms.

[0086] In another example, the plasma treatment apparatus of this disclosure can be used for hydrogen radical treatment of tungsten (W) according to method 800. In this example, the substrate undergoing the hydrogen radical treatment process includes a tungsten blanket layer deposited on a titanium nitride (e.g., TiN) layer. In this example, the tungsten layer can be formed, for example, by atomic layer deposition (ALD). The tungsten blanket layer has a thickness of about 600 angstroms to about 650 angstroms, however, other thicknesses are anticipated. Using the apparatus and / or method disclosed herein, hydrogen radical treatment of tungsten reduces the interfacial fluorine (F) content. For example, when the substrate includes tungsten deposited on a titanium nitride layer, hydrogen radical treatment reduces the interfacial fluorine content at the tungsten-titanium nitride interface. During the hydrogen radical treatment of tungsten, a diatomic hydrogen (H2) source gas is introduced into the plasma treatment source to generate hydrogen radicals. The flow rate of H2 is from about 100 sccm to about 1200 sccm, such as from about 200 sccm to about 1000 sccm, such as from about 100 sccm to about 500 sccm, such as from about 200 sccm, such as from about 500 sccm to about 1200 sccm, such as from about 1000 sccm. The source gas is expected to be mixable with an inert gas (e.g., Ar).

[0087] During the hydrogen radical treatment of tungsten, the temperature in the process chamber is approximately 500°C to approximately 1000°C, such as approximately 500°C to approximately 600°C, such as approximately 600°C to approximately 700°C, such as approximately 650°C, such as approximately 700°C to approximately 800°C, such as approximately 750°C, such as approximately 800°C to approximately 900°C, such as approximately 850°C, such as approximately 900°C to approximately 1000°C, such as approximately 950°C. During the treatment, increasing the temperature in the process chamber results in a significant reduction in the interfacial fluorine content; that is, temperature is positively correlated with the reduction in interfacial fluorine content, or in other words, temperature is negatively correlated with interfacial fluorine content. For example, operating the process chamber at approximately 950°C or higher results in a reduction of the interfacial fluorine content by up to 20 times, while temperatures of approximately 650°C or lower only reduce the interfacial fluorine content by about 1.4 times. A temperature of approximately 750°C reduces the interfacial fluorine content by about 2.1 times, and a temperature of approximately 850°C reduces the interfacial fluorine content by about 4.8 times.

[0088] During the hydrogen radical treatment of tungsten, the pressure in the process chamber is approximately 0.2 Torr to approximately 2 Torr, such as approximately 0.5 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW, such as approximately 5 kW to approximately 8 kW, such as approximately 5 kW, such as approximately 8 kW. The processing time is in the range of approximately 2 minutes to approximately 8 minutes, such as approximately 5 minutes.

[0089] Advantageously, the hydrogen radical treatment of tungsten performed using the plasma treatment apparatus and method disclosed herein reduces the interfacial fluorine content in tungsten by approximately 20 times or more. Increasing the hydrogen radical density (which is possible using the apparatus and method disclosed herein) leads to a greater reduction in the interfacial fluorine content. Furthermore, the effects of increasing temperature and increasing hydrogen radical density have an additional impact on the reduction of interfacial fluorine. In contrast to conventional methods (such as hot H2 annealing), conventional methods do not reduce the interfacial fluorine content. Using the samples described herein, compared to untreated films, the hydrogen radical treatment of tungsten results in a 10% reduction in the film resistivity (Rs) of the tungsten layer.

[0090] In another example, the plasma treatment apparatus of this disclosure can be used for hydrogen radical treatment of titanium nitride (e.g., TiN) according to method 800. Using the apparatus and / or method disclosed herein, by reducing impurities in the titanium nitride layer, hydrogen radical treatment of titanium nitride reduces the Rs of the titanium nitride layer by about 50% or more compared to an untreated film. During the hydrogen radical treatment of titanium nitride, an H2 source gas is introduced into the plasma treatment source to generate hydrogen radicals. The flow rate of H2 is about 200 sccm to about 1200 sccm, such as about 200 sccm to about 500 sccm, such as about 350 sccm, such as about 350 sccm to about 1000 sccm, such as about 500 sccm to about 1200 sccm, such as about 1000 sccm. In another example, the hydrogen radical treatment is a two-operation process, in which an H2 source gas is introduced in the first operation, followed by an N2 source gas after the first operation. It is anticipated that the source gas can be mixed with an inert gas (e.g., Ar). When the H2 source gas is mixed with Ar, the proportion of the H2 source gas is in the range of about 5% to about 90% by volume, such as about 50% by volume.

[0091] During the hydrogen radical treatment of titanium nitride, the temperature in the process chamber is approximately 500°C to approximately 1000°C, such as approximately 500°C to approximately 600°C, such as approximately 550°C, such as approximately 600°C to approximately 700°C, such as approximately 650°C, such as approximately 700°C to approximately 800°C, such as approximately 750°C, such as approximately 800°C to approximately 900°C, such as approximately 850°C, such as approximately 900°C to approximately 1000°C. During the treatment, increasing the temperature in the process chamber leads to a significant decrease in the Rs of the titanium nitride layer; that is, temperature is positively correlated with the decrease in the Rs of the titanium nitride layer, or in other words, temperature is negatively correlated with the Rs of the titanium nitride layer. For example, operating the process chamber at approximately 550°C results in a decrease in the Rs of the titanium nitride layer by approximately 30% to 40%, at approximately 650°C by approximately 40% to 50%, at approximately 750°C by approximately 50% to 60%, and at approximately 850°C by approximately 60% to 70%. During the hydrogen radical treatment of titanium nitride, the pressure in the process chamber is approximately 0.2 Torr to approximately 3 Torr, such as approximately 0.5 Torr to approximately 3 Torr, such as approximately 0.5 Torr, such as approximately 2 Torr. The radio frequency power is approximately 1 kW to approximately 5 kW, such as approximately 2 kW. The processing time is in the range of approximately 2 minutes to approximately 8 minutes, such as approximately 5 minutes.

[0092] Advantageously, hydrogen radical treatment of titanium nitride using the plasma treatment apparatus and method of this disclosure selectively reduces titanium-oxygen bonding, thereby reducing the oxygen content in the titanium nitride layer while maintaining the titanium-nitrogen bonding substantially constant. On the other hand, thermal treatment alone cannot reduce titanium-oxygen bonding. Using the state described herein, temperature is negatively correlated with oxygen content. Furthermore, similar to thermal treatment alone, hydrogen radical treatment reduces chlorine content. In addition, hydrogen radical treatment reduces carbon content, while thermal treatment alone cannot reduce carbon content. In summary, compared to thermal treatment alone, reducing the impurity content of at least one of chlorine, oxygen, or carbon via hydrogen radical treatment results in a decrease in the Rs of the titanium nitride layer. Using the state described herein, compared to thermal treatment alone, hydrogen radical treatment reduces the Rs of the titanium nitride layer by about 6% to about 11%. It is anticipated that hydrogen radical treatment can be performed with or without a grid (e.g., the separation grid 116 shown in Figure 1). It is noteworthy that the improvement attributed to hydrogen radical treatment is more pronounced without the use of a grid compared to heat treatment alone. Typically, applying higher temperatures in the process chamber increases the titanium nitride grain size, which reduces the Rs of the titanium nitride layer. In other words, temperature and grain size are each negatively correlated with the Rs of the titanium nitride layer.

[0093] In another example, the plasma processing apparatus of this disclosure can be used for hydrogen radical treatment of ruthenium (Ru) according to method 800. In some examples, the substrate undergoing the processing may include a ruthenium layer formed by chemical vapor deposition (CVD). Using the apparatus and / or method disclosed herein, compared with H2 annealing without hydrogen radicals, hydrogen radical treatment of ruthenium improves gap filling and reduces the Rs of the ruthenium layer. During the hydrogen radical treatment of ruthenium, an H2 source gas is introduced into the plasma processing source to generate hydrogen radicals. The flow rate of H2 is from about 100 sccm to about 2000 sccm. It is anticipated that the source gas may be mixed with an inert gas (e.g., Ar). When the H2 source gas is mixed with Ar, the proportion of the H2 source gas is in the range of from about 5 vol% to about 90 vol%, such as about 50%.

[0094] During the hydrogen radical treatment of ruthenium, the temperature in the process chamber is approximately 400°C to approximately 500°C, such as approximately 450°C. The pressure in the process chamber is approximately 0.2 Torr to approximately 3 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW. The treatment time is in the range of approximately 0.5 minutes to approximately 10 minutes, such as approximately 1 minute to approximately 5 minutes, such as approximately 1 minute, such as approximately 5 minutes. During the treatment, increasing the hydrogen radical density leads to a greater reduction in the Rs of the ruthenium layer. For example, compared to an untreated film, introducing 10% H2 source gas at 450°C for 1 minute reduces the Rs of the ruthenium layer by approximately 35% to approximately 40%. On the other hand, compared to an untreated film, introducing 50% H2 source gas at 450°C for 5 minutes (corresponding to a lower hydrogen radical density) only reduces the Rs of the ruthenium layer by approximately 30%.

[0095] Advantageously, compared to H2 annealing without hydrogen radicals, the hydrogen radical treatment of ruthenium performed using the plasma treatment apparatus and method of this disclosure improves the gap filling of the ruthenium layer. Furthermore, compared to H2 annealing, hydrogen radical treatment increases the grain size and reduces the seam size in the ruthenium layer. Using the apparatus and / or method disclosed herein, compared to H2 annealing without hydrogen radicals, the Rs of the ruthenium layer is reduced. Moreover, compared to H2 annealing without hydrogen radicals, hydrogen radical-assisted annealing improves reflow and reduces resistivity while lowering the thermal budget.

[0096] In another example, the plasma treatment apparatus of this disclosure can be used according to method 800 for hydrogen radical treatment and optional nitrogen radical treatment of tungsten carbonitride (e.g., WCN). Using the apparatus and / or method disclosed herein, compared with an untreated film, hydrogen radical treatment of tungsten carbonitride reduces the carbon content without increasing the nitrogen content in the tungsten carbonitride film. Using the sample described herein, compared with an untreated film, hydrogen radical and nitrogen radical treatment of tungsten carbonitride reduces the carbon content and increases the nitrogen content in the tungsten carbonitride film. During the hydrogen radical treatment of tungsten carbonitride, an H2 source gas is introduced into the plasma treatment source to generate hydrogen radicals. The flow rate of H2 is from about 100 sccm to about 2000 sccm. During the nitrogen radical treatment of tungsten carbonitride, an N2 source gas is introduced into the plasma treatment source to generate nitrogen radicals. The flow rate of N2 is from about 100 sccm to about 2000 sccm. The source gas is expected to be mixable with an inert gas (e.g., Ar).

[0097] During the hydrogen radical and / or nitrogen radical treatment of tungsten carbonitride, the temperature in the process chamber is approximately 500°C to approximately 1000°C, such as approximately 500°C to approximately 600°C, such as approximately 550°C, such as approximately 600°C to approximately 700°C, such as approximately 650°C, such as approximately 700°C to approximately 800°C, such as approximately 750°C, such as approximately 800°C to approximately 900°C, such as approximately 900°C to approximately 1000°C. The pressure in the process chamber is approximately 0.2 Torr to approximately 3 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW. During the hydrogen radical treatment, the treatment time is in the range of approximately 1 minute to approximately 10 minutes, such as approximately 1 minute to approximately 5 minutes, such as approximately 3 minutes. During the optional nitrogen radical treatment following the hydrogen radical treatment, the treatment time is in the range of approximately 10 seconds to approximately 2 minutes, such as approximately 30 seconds to approximately 1 minute, such as approximately 30 seconds, such as approximately 1 minute.

[0098] Advantageously, the hydrogen radical treatment of tungsten carbonitride thin films performed using the plasma treatment apparatus and method of this disclosure reduces the carbon content by about 3 to about 6 times, while the nitrogen content remains approximately the same compared to untreated films. Using the apparatus and / or method disclosed herein, further nitrogen radical treatment of tungsten carbonitride thin films increases the nitrogen content by about 2 to about 3 times compared to untreated films. Therefore, each step in the tungsten carbonitride treatment improves the film quality compared to untreated films.

[0099] In another example, the plasma treatment apparatus of this disclosure can be used for titanium nitride (e.g., TiN) seam removal according to method 800. In some instances, the substrate undergoing the treatment process may include a titanium nitride layer formed by ALD. The source gas anticipated for seam removal may include O2, H2, N2, or mixtures thereof. Introducing an O2 source gas improves seam removal compared to a single H2 or N2 source gas. Using the apparatus and / or method disclosed herein, a process with three operations (involving sequential treatment by oxygen radicals, followed by hydrogen radicals, followed by nitrogen radicals) and a separate oxygen radical treatment improves seam removal while also incorporating additional nitrogen to substantially restore the original stoichiometric ratio of titanium to nitrogen in the titanium nitride layer. Using the apparatus and / or method disclosed herein, the oxygen radical treatment oxidizes the titanium nitride layer, resulting in volume expansion and filling the gaps between features, thus removing the seam. Following oxygen radical treatment, hydrogen radical treatment reduces the oxygen content of the titanium nitride layer while preserving the titanium lattice structure. Following hydrogen radical treatment, nitrogen radical treatment replaces oxygen vacancies in the titanium lattice with nitrogen, thus restoring a seamless titanium nitride layer.

[0100] In another example, the plasma processing apparatus of this disclosure can be used for the selective oxidation of tungsten according to method 800. The selective oxidation of tungsten involves oxidizing a silicon layer without oxidizing adjacent tungsten layers. During the selective oxidation of tungsten, an O2 source gas is introduced into the plasma processing source to generate oxygen radicals. To minimize tungsten oxidation, excess H2 is added to the plasma to generate a large amount of hydrogen radicals. During the selective oxidation of tungsten, the concentration of H2 in the source gas is approximately 65% ​​to approximately 95% of the total flow volume of H2 and O2. The H2 to O2 ratio can be used to control selectivity. For example, keeping the H2 concentration below approximately 65% ​​limits the selectivity of the oxidation process. On the other hand, keeping the H2 concentration above approximately 95% reduces silicon oxidation. The apparatus and / or method disclosed herein, utilizing a top-down plasma source, provides a uniform concentration of hydrogen radicals from the center to the edge of the substrate. This improves the selective oxidation of tungsten compared to lateral injection plasma sources where the concentration of hydrogen radicals is depleted as the plasma moves toward the center of the substrate. The flow rate of H2 is approximately 400 sccm to 8000 sccm, and the flow rate of O2 is approximately 100 sccm to approximately 3000 sccm. It is anticipated that the source gas can be mixed with an inert gas (e.g., Ar).

[0101] During the selective oxidation of tungsten, the temperature in the process chamber is approximately 600°C to approximately 1000°C, such as approximately 700°C to approximately 900°C, such as approximately 800°C. The pressure in the process chamber is approximately 1 Torr to approximately 3 Torr. The radio frequency power is approximately 3 kW to approximately 5 kW, such as approximately 4 kW. The processing time for oxidation is in the range of approximately 1 minute to approximately 4 minutes.

[0102] Advantageously, selective oxidation of tungsten performed using the plasma treatment apparatus and method of this disclosure achieves a silicon oxide (e.g., SiO2) growth rate of about 3 angstroms / √(second) or greater, while reducing the oxygen content to about 40 atomic percent or less.

[0103] In another example, the plasma processing apparatus of this disclosure can be used for silicon oxidation according to method 800. In some examples, the substrate undergoing the oxidation process may include a silicon layer, which may be treated with oxygen free radicals to form a conformal layer of silicon oxide. In some examples, the substrate may have a 3D NAND structure including silicon nitride (e.g., SiN) vias deposited by ALD within a stack of alternating oxide / nitride layers, the vias having, for example, a depth of 8 μm, a critical dimension (CD) of 125 nm, and an aspect ratio of approximately 80:1. During the process, a mixture of O2 and H2 source gases is introduced into the plasma processing source to generate oxygen free radicals and hydrogen free radicals, respectively. The flow rate of O2 is from approximately 500 sccm to approximately 1000 sccm, such as approximately 750 sccm. The flow rate of H2 is from about 400 sccm to about 1000 sccm, such as from about 400 sccm to about 600 sccm, such as about 500 sccm, such as from about 600 sccm to about 900 sccm, such as about 750 sccm. The source gas is expected to be mixable with an inert gas (e.g., Ar). When the mixture of O2 and H2 source gases is mixed with Ar, the proportion of H2 relative to O2 is in the range of from about 5% by volume to about 50% by volume, such as from about 33% to about 50%.

[0104] During silicon oxidation, the temperature in the process chamber is approximately 600°C to approximately 1000°C, such as approximately 700°C to approximately 900°C, such as approximately 800°C. The pressure in the process chamber is approximately 1 Torr to approximately 3 Torr, such as approximately 2 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW. The processing time for oxidation is in the range of approximately 1 minute to approximately 10 minutes.

[0105] Advantageously, silicon oxidation performed using the plasma processing apparatus and method of this disclosure can achieve silicon oxide (e.g., SiO2) growth rates of about 5 Å / √(s), such as about 5 Å / √(s) to about 6 Å / √(s), and silicon oxide conformability of about 95% to about 100% (e.g., about 99%). Using the apparatus and / or method disclosed herein, the silicon oxide conformability is greater than that achieved using conventional remote plasma oxidation (RPO) processes. Using the methods described herein, the silicon oxide conformability depends on the concentration of the H2 source gas. Specifically, a higher proportion of H2 source gas is associated with greater silicon oxide conformability. In one example, introducing a source gas with 50% H2 results in approximately 98% silicon oxide conformability, while introducing a source gas with 33% H2 results in approximately 70% conformability, and introducing a source gas with 5% H2 results in approximately 61% conformability. Using the conditions described herein, at higher H2 concentrations in the source gas, silicon oxide conformability is independent of layer thickness. For example, for a source gas with approximately 5% H2, silicon oxide conformability depends on layer thickness, while at higher H2 proportions (e.g., approximately 50% H2), silicon oxide conformability is largely independent of layer thickness.

[0106] In another example, the plasma processing apparatus of this disclosure can be used for oxygen and hydrogen radical treatment of silicon oxide (e.g., SiOx) according to method 800. In some examples, the substrate undergoing the processing may include a silicon oxide layer formed by flowable CVD (FCVD). An O2 source gas, an H2 source gas, and a mixture thereof are introduced into the plasma processing source to generate oxygen radicals and / or hydrogen radicals, respectively. The flow rate of O2 is from about 500 sccm to about 3000 sccm. The flow rate of H2 is from about 25 sccm to about 200 sccm. It is anticipated that the source gas may be mixed with an inert gas (e.g., Ar).

[0107] During the silicon oxide oxygen radical and / or hydrogen radical treatment, the temperature in the process chamber is approximately 400°C to approximately 600°C, such as approximately 500°C. The pressure in the process chamber is approximately 0.5 Torr to approximately 3 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW. The processing time is in the range of approximately 1 minute to approximately 10 minutes, such as approximately 1 minute to approximately 5 minutes, such as approximately 1 minute, such as approximately 5 minutes.

[0108] Advantageously, compared to untreated films according to FTIR, oxygen and hydrogen radical treatment of silicon oxide performed using the plasma treatment apparatus and method of this disclosure reduces oxygen-hydrogen bonding, silicon-hydrogen bonding, and / or nitrogen-hydrogen bonding in the silicon oxide film. In one example, extending the oxygen and hydrogen radical treatment time to 5 minutes reduces the wet etch reaction rate (WERR) compared to the same treatment using a treatment time of 1 minute. Using the apparatus and / or method disclosed herein, the WERR of the silicon oxide film is lower than that of a silicon oxide film treated by an annealing process only.

[0109] In another example, the plasma processing apparatus of this disclosure can be used for helium radical treatment of silicon oxide (e.g., SiO2) according to method 800. In some examples, the substrate undergoing the processing may include a silicon oxide layer (e.g., a high-temperature oxide (HTO) layer) formed by ALD. It is contemplated that helium radical treatment can be used for all types of ALD thin films. During helium radical treatment, a helium (He) source gas is introduced into the plasma processing source to generate helium radicals. The flow rate of He is from about 100 sccm to about 2000 sccm. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar).

[0110] During the helium radical treatment of silicon oxide, the temperature in the process chamber is approximately 500°C to approximately 1000°C, such as approximately 700°C to approximately 800°C, such as approximately 700°C, such as approximately 800°C. The pressure in the process chamber is approximately 0.2 Torr to approximately 4 Torr, such as approximately 0.5 Torr to approximately 2 Torr, such as approximately 0.5 Torr, such as approximately 2 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW, such as approximately 5 kW to approximately 10 kW, such as approximately 8 kW. The processing time is in the range of approximately 0.25 minutes to approximately 5 minutes, such as approximately 0.5 minutes to approximately 3 minutes, such as approximately 0.5 minutes, such as approximately 3 minutes.

[0111] Advantageously, compared to untreated films, helium radical treatment of silicon oxide performed using the plasma treatment apparatus and method of this disclosure improves the film quality of the silicon oxide layer and reduces leakage of the silicon oxide layer. Using the apparatus and / or method disclosed herein, the film quality (represented by the reduction in WERR of the etched film portion and the treated film) is improved by approximately 50% to approximately 60% compared to untreated films. Furthermore, at lower pressures (i.e., at 0.5 Torr compared to 2 Torr), the conformability of the sidewalls of the silicon oxide layer after wet etching is further improved to a greater extent.

[0112] In another example, the plasma processing apparatus of this disclosure can be used for hydrogen radical treatment of a boron-rich amorphous carbon layer according to method 800. In some examples, the substrate undergoing the processing may include a boron-doped carbon-based hard masking layer. In one example, the boron-doped carbon-based hard masking layer is deposited by CVD, and hydrogen plasma treatment is performed after CVD. The hard masking layer may have a thickness of about 0.2 μm. During the hydrogen radical treatment, an H2 source gas is introduced into the plasma processing source to generate hydrogen radicals. The H2 flow rate is about 100 sccm to about 2000 sccm. It is anticipated that the source gas may be mixed with an inert gas (e.g., Ar).

[0113] During the hydrogen radical treatment, the temperature in the process chamber is approximately 400°C to approximately 1000°C, such as approximately 500°C to approximately 700°C, such as approximately 500°C, such as approximately 700°C. The pressure in the process chamber is approximately 0.5 Torr to approximately 3 Torr. The radio frequency power is approximately 1 kW to approximately 10 kW. The processing time is in the range of approximately 3 minutes to approximately 5 minutes, such as approximately 4 minutes.

[0114] Advantageously, compared to untreated films, hydrogen radical treatment of boron-rich amorphous carbon films performed using the plasma treatment apparatus and method of this disclosure reduces the hydrogen content of the film, thereby increasing the Young's modulus and density. Generally, compared to untreated films, hydrogen radical treatment produces denser films with lower total stress, which improves film stability.

[0115] In another example, the plasma treatment apparatus of this disclosure can be used according to method 800 for various ALD pretreatment and posttreatment using source gases (including at least one of H2, NH3, N2, O2 or Ar).

[0116] In one example, the plasma treatment apparatus of this disclosure can be used for the treatment of silicon nitride (e.g., SiN) thin films according to method 800. During hydrogen radical treatment, an H2 source gas is introduced into the plasma treatment source to generate hydrogen radicals. The flow rate of H2 is from about 500 sccm to about 1500 sccm, such as about 1000 sccm. The proportion of H2 in the source gas is about 50% by volume. During the combined treatment with hydrogen and nitrogen radicals, after the hydrogen radical treatment, N2 is added to the plasma treatment source as appropriate to generate nitrogen radicals. The flow rate of N2 is from about 200 sccm to about 400 sccm, such as about 300 sccm. The proportion of N2 in the source gas is about 10% by volume. Other nitrogen source gases are contemplated to be usable. For example, NH3 can be introduced into the plasma treatment source to generate NH radicals. The flow rate of NH3 is from about 200 sccm to about 400 sccm, such as about 300 sccm. The proportion of NH3 in the source gas is about 10% by volume. It is expected that the source gas can be mixed with an inert gas (e.g., Ar).

[0117] During the treatment of silicon nitride with hydrogen radicals, nitrogen radicals, and / or NH radicals, the temperature in the process chamber is approximately 800°C to approximately 1200°C, such as approximately 900°C to approximately 1000°C, such as approximately 950°C. The pressure in the process chamber is approximately 0.25 Torr to approximately 2 Torr, such as approximately 0.5 Torr to approximately 1 Torr, such as approximately 0.5 Torr, such as approximately 1 Torr. The radio frequency power is approximately 5 kW to approximately 10 kW, such as approximately 8 kW. The processing time is in the range of approximately 1 minute to approximately 10 minutes, such as approximately 1 minute to approximately 3 minutes, such as approximately 2.5 minutes, such as approximately 3 minutes to approximately 4 minutes, such as approximately 3.3 minutes, such as approximately 4 minutes to approximately 6 minutes, such as approximately 5 minutes.

[0118] Advantageously, compared to untreated films, silicon nitride film treatment performed using the plasma treatment apparatus and method of this disclosure reduces the impurity content of at least one of oxygen, hydrogen, or chlorine. Using the apparatus and / or method disclosed herein, compared to the WERR of silicon nitride films treated with rapid thermal processing (RTP) annealing, treatment with hydrogen radicals, nitrogen radicals, and / or NH radicals of silicon nitride films reduces WERR. Using the conditions described herein, the effect of silicon nitride treatment is most significant on the top surface of the film (e.g., within 20 angstroms of the surface). Notably, compared to treatment by using hydrogen or NH radicals generated separately from H2 or NH3 source gases, combined treatment using hydrogen and nitrogen radicals generated separately from H2 and N2 source gases improves hydrogen removal from silicon nitride films. Furthermore, compared with treatment using nitrogen or NH radicals generated by N2 or NH3 source gases alone, combined treatment using hydrogen and nitrogen radicals generated by H2 and N2 source gases respectively improved the removal of chlorine from silicon nitride films.

[0119] In another example, the plasma processing apparatus of this disclosure can be used for silicon nitride (e.g., SiN) seam removal according to method 800. In some examples, the substrate undergoing the processing may include a silicon nitride layer formed by ALD. The source gas is expected to include O2, H2, N2, or a mixture thereof. In one example, the processing includes only one operation involving the O2 source gas. In another example, the processing includes two operations involving the O2 source gas, followed by the H2 source gas. In yet another example, the processing includes three operations involving the O2 source gas, followed by the H2 source gas, followed by the N2 source gas. The O2 source gas is introduced into the plasma processing source to generate oxygen radicals. The flow rate of O2 is about 2500 sccm to about 3500 sccm, such as about 3000 sccm. After the oxygen radical treatment, the H2 source gas is introduced into the plasma processing source as appropriate to generate hydrogen radicals. The flow rate of H2 is from about 200 sccm to about 500 sccm, such as from about 300 sccm to about 350 sccm, such as about 300 sccm, such as about 350 sccm. After treatment with oxygen and hydrogen radicals, N2 source gas is added to the plasma treatment source as appropriate to generate nitrogen radicals. The flow rate of N2 is from about 200 sccm to about 400 sccm, such as about 300 sccm. It is anticipated that the source gas can be mixed with an inert gas (e.g., Ar).

[0120] During the treatment of silicon nitride with oxygen, hydrogen, and / or nitrogen radicals, the temperature in the process chamber is approximately 500°C to approximately 1000°C, such as approximately 600°C to approximately 700°C, such as approximately 650°C, such as approximately 700°C to approximately 800°C, such as approximately 750°C. The pressure in the process chamber is approximately 0.5 Torr to approximately 5 Torr, such as approximately 1 Torr to approximately 3 Torr, such as approximately 1 Torr, such as approximately 3 Torr. The radio frequency power is approximately 5 kW to approximately 10 kW, such as approximately 8 kW. The processing time is in the range of approximately 1 minute to approximately 10 minutes, such as approximately 1 minute to approximately 3 minutes, such as approximately 2.5 minutes, such as approximately 3 minutes to approximately 6 minutes, such as approximately 5 minutes.

[0121] Advantageously, the sequential treatment of oxygen radicals, followed by hydrogen radicals, followed by nitrogen radicals, and the separate oxygen radical treatment improves seam removal while also incorporating additional nitrogen to substantially restore the original stoichiometric ratio of silicon to nitrogen in the silicon nitride layer. Using the apparatus and / or methods disclosed herein, the oxygen radical treatment oxidizes the silicon nitride, resulting in volume expansion and filling the gaps between features, thus removing the seams. Following the oxygen radical treatment, the hydrogen radical treatment reduces the oxygen content of the silicon nitride layer while preserving the silicon lattice structure. Following the hydrogen radical treatment, the nitrogen radical treatment replaces the oxygen in the silicon lattice with nitrogen, thus restoring a seamless silicon nitride layer.

[0122] In another example, the plasma processing apparatus of this disclosure can be used according to method 800 for various gas phase doping processes using source gases (including at least one of PH3, BF3, AsH3 or Ga).

[0123] In another example, the plasma processing apparatus of this disclosure can be used for nitriding of high-dielectric-constant dielectric materials such as hafnium oxide (e.g., HfO2) according to method 800. In some examples, the substrate undergoing the processing includes a silicon substrate, an interface layer (e.g., including silicon oxide) on the silicon substrate, and a hafnium oxide layer on the interface layer. During high-dielectric-constant nitriding, a source gas comprising a mixture of N2 and NH3 is introduced into the plasma processing source to generate nitrogen and NH radicals. The flow rate of N2 is from about 30 sccm to about 180 sccm, such as from about 50 sccm to about 150 sccm, such as from about 50 sccm to about 100 sccm, such as from about 50 sccm, such as from about 100 sccm to about 150 sccm, such as from about 100 sccm, such as from about 120 sccm. The flow rate of NH3 is from about 10 sccm to about 50 sccm, such as from about 10 sccm to about 20 sccm, such as about 15 sccm. It is anticipated that the source gas can be mixed with an inert gas (e.g., Ar). The flow rate of Ar is from about 2500 sccm to about 3500 sccm, such as about 3000 sccm.

[0124] During hafnium oxide nitriding, the temperature in the process chamber is less than about 400°C, such as about 150°C to about 400°C, such as about 200°C to about 300°C, such as about 300°C to about 400°C, such as about 300°C, such as about 325°C. It is anticipated that the temperature can be gradually increased during hafnium oxide nitriding. For example, the temperature can gradually rise from less than about 200°C to greater than about 300°C. The gradual increase time can be from about 60 seconds to about 120 seconds, such as about 90 seconds. The pressure in the process chamber is about 0.5 Torr to about 2 Torr, such as about 0.75 Torr. The RF power is about 5 kW to about 10 kW, such as about 8 kW. The processing time is in the range of about 20 seconds to about 5 minutes, such as about 20 seconds to about 2 minutes, such as about 25 seconds, such as about 90 seconds, such as about 2 minutes to about 4 minutes, such as about 2.5 minutes, such as about 4 minutes. Compared to nitriding using a mixture of NH3 and Ar gases in a conventional ICP chamber, the reduced processing time associated with hafnium oxide nitriding using the apparatus and / or methods disclosed herein increases throughput.

[0125] Advantageously, compared to nitriding using a mixture of NH3 and Ar gases in a conventional ICP chamber, hafnium oxide nitriding using a mixture of N2 and NH3 largely prevents interfacial layer thinning. Adding N2 to the NH3 source gas reduces the concentration of hydrogen radicals by combining with them to form NH radicals. This reduction in hydrogen radicals decreases their attack on the interfacial layer, thereby preventing interfacial layer thinning. Furthermore, compared to N2 alone, using a mixture of N2 and NH3 largely prevents interfacial layer thickening. Compared to N2 and NH3 without Ar, adding Ar to the mixture of N2 and NH3 increases the nitriding rate.

[0126] Typically, using the apparatus and / or methods disclosed herein and a mixture of N2 and NH3, lowering the temperature further suppresses interfacial layer thinning. For example, temperatures below about 400°C suppress interfacial layer thinning compared to higher temperatures. Typically, using the apparatus and / or methods disclosed herein and a mixture of N2 and NH3, increasing the processing time increases the nitrogen content in the hafnium oxide layer. For example, a processing time in the range of about 2 minutes to about 3 minutes increases the nitrogen content from less than about 5% to as high as about 15% to about 20%, while maintaining the thickness of the interfacial layer approximately equal to its thickness before nitriding. However, processing times greater than about 4 minutes result in interfacial layer thickening compared to relatively short processing times. Therefore, it may be desirable to limit the processing time to less than about 4 minutes. Typically, using the apparatus and / or methods disclosed herein and a mixture of N2 and NH3, lowering the pressure increases the nitrogen content in the hafnium oxide layer and further suppresses interfacial layer thinning. For example, pressures below about 1 Torr increase the nitrogen content to greater than about 10% while maintaining the interfacial layer thickness approximately equal to that before nitriding. Using the apparatus and / or method disclosed herein, along with a mixture of N2 and NH3, increases hafnium-nitrogen bonding and substantially prevents the formation of nitrogen-oxygen metastable bonds. Compared to using a conventional ICP chamber, using the apparatus and / or method disclosed herein improves conformability and uniform pattern loading due to the increased concentration of NH radicals.

[0127] As used herein, the terms “internal” and “external”; “upper” and “lower”; “upper part” and “lower part”; “top” and “bottom”; “vertical” and “horizontal”; “upward” and “downward”; “above” and “below”; and other similar terms as used herein represent relative positions to each other and are not intended to indicate a particular orientation or spatial orientation of the entire source / device. As used herein, the terms “approximately” or “about” mean within at least ±5% of a reference value.

[0128] Although the foregoing describes an embodiment of this disclosure, other and additional embodiments of this disclosure may be designed without departing from the basic scope of this disclosure. [Simplified Explanation of the Diagram]

[0010] Therefore, the above-described features of this disclosure can be understood in detail by referring to the embodiments, which provide a more specific description of the disclosure briefly outlined above, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only exemplary embodiments and should not be construed as limiting the scope of this disclosure, and other equally effective embodiments are permissible.

[0011] Figure 1 is a schematic diagram of a plasma processing apparatus according to at least one embodiment.

[0012] Figure 2 is a schematic diagram of a plasma processing apparatus according to at least one embodiment.

[0013] Figure 3 is a schematic diagram of a plasma processing apparatus according to at least one embodiment.

[0014] Figure 4 is a schematic diagram of a plasma processing apparatus according to at least one embodiment.

[0015] Figure 5 is a schematic diagram of a plasma processing apparatus according to at least one embodiment.

[0016] Figure 6a is an isometric view of a separated grid according to at least one embodiment.

[0017] Figure 6b is a cross-sectional view (along line 6B) of the separated grid of Figure 6a according to at least one embodiment.

[0018] Figure 7 shows an inductor coil that can be used with a plasma source according to at least one embodiment.

[0019] Figure 8 is a flowchart of a process according to at least one embodiment.

[0020] For ease of understanding, the same element symbols have been used to denote common elements in the figures where possible. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. [Biomaterial Storage]

[0130] Domestic storage information (please note in order of storage institution, date, and number): None

[0131] Overseas Deposit Information (Please note in the order of deposit country, institution, date, and number) None

Claims

1. A plasma processing method, comprising the steps of: introducing a process gas into a processing region defined between a gas injection insert and a first sidewall of a plasma source, comprising the steps of: introducing a process gas into the processing region via a chamber of a central gas injection port and an outlet of a central gas injection port, the chamber of the central gas injection port being annularly arranged around a second sidewall of the gas injection insert, the outlet of the central gas injection port being at a first vertical position, wherein the central gas injection port is fluidly connected to an internal volume of a plasma source defined by the first sidewall and the gas injection insert; introducing the process gas into the processing region via an outlet of a peripheral gas injection port, the outlet of the peripheral gas injection port being radially arranged inside the first sidewall, radially arranged outside the central gas injection port, and fluidly connected to the internal volume of the plasma source, wherein the outlet is at a second vertical position different from the first vertical position; An inductively coupled plasma is generated in the processing area by an inductor coil radially disposed outside the first sidewall and surrounding the first sidewall. The inductively coupled plasma includes oxygen, nitrogen, hydrogen, NH, helium, or a combination of the foregoing substances. The plasma is transported from the plasma source to a process chamber coupled to the plasma source, comprising the following steps: flowing the plasma through a separation grid disposed between the plasma source and a substrate to be processed. The process chamber is used to process the substrate, including the following steps: bringing the plasma into contact with a first side of the substrate facing the separation grid; The substrate is heated using a plurality of lamps located on a second side of the substrate opposite to the separation grid.

2. The method as claimed in claim 1, wherein the substrate includes a tungsten carbonitride layer, wherein the process gas includes hydrogen, wherein the plasma includes hydrogen radicals, and wherein contacting the hydrogen radicals with the tungsten carbonitride layer during heating reduces the carbon content in the tungsten carbonitride layer by about 3 to about 6 times without reducing the nitrogen content in the tungsten carbonitride layer.

3. The method of claim 2, wherein after treating the substrate with the plasma, the method further comprises the steps of: introducing nitrogen gas into a gas injection channel of the peripheral gas injection port; generating a nitrogen plasma in the gas injection channel, wherein the nitrogen plasma includes nitrogen radicals; conveying the nitrogen plasma from the plasma source to the process chamber; and treating the substrate with the nitrogen plasma in the process chamber, wherein treating the substrate comprises the steps of: contacting the nitrogen plasma including the nitrogen radicals with a first side of the substrate facing the separation grid; and heating the substrate using the plurality of lamps located on a second side of the substrate opposite to the separation grid, wherein during heating, contacting the nitrogen radicals with the tungsten carbonitride layer increases the nitrogen content in the tungsten carbonitride layer by about 2 to about 3 times.

4. The method as claimed in claim 1, wherein the substrate includes a titanium nitride layer having a seam and an initial stoichiometric ratio of titanium to nitrogen, and wherein the method comprises three sequential operations, including the following steps: a first operation, wherein the process gas includes oxygen, wherein the plasma includes oxygen radicals, and wherein during heating, the oxygen radicals are contacted with the titanium nitride layer to oxidize the titanium nitride layer, thereby causing the volume of the titanium nitride layer to expand; A second operation, wherein the process gas includes hydrogen, the plasma includes hydrogen radicals, and wherein contacting the hydrogen radicals with the titanium nitride layer during heating reduces the oxygen content of the titanium nitride layer, thereby removing the seam and changing the stoichiometric ratio of titanium to nitrogen; and a third operation, wherein the process gas includes nitrogen, the plasma includes nitrogen radicals, and wherein contacting the nitrogen radicals with the titanium nitride layer during heating increases the nitrogen content of the titanium nitride layer, thereby substantially restoring the initial stoichiometric ratio of titanium to nitrogen of the titanium nitride layer without the seam.

5. The method as claimed in claim 1, wherein the substrate includes a tungsten layer, wherein the process gas includes oxygen, wherein the plasma includes oxygen radicals, and wherein contacting the oxygen radicals with the tungsten layer during heating increases the growth rate of silicon oxide to about 3 angstroms / √(second) or greater, and reduces the oxygen content to about 40 atomic percent or less.

6. The method of claim 1, wherein the substrate includes a silicon layer, wherein the process gas includes oxygen, wherein the plasma includes oxygen radicals, and wherein contacting the silicon layer with the oxygen radicals during heating increases the growth rate of silicon oxide to about 5 angstroms / √(second) or greater, wherein the conformability of silicon oxide is about 95% to about 100%.

7. The method of claim 1, wherein the substrate includes a silicon oxide layer, wherein the process gas includes a mixture of oxygen and hydrogen, wherein the plasma includes oxygen and hydrogen free radicals, and wherein, compared to the silicon oxide layer before processing, contacting the silicon oxide layer with the oxygen and hydrogen free radicals during heating reduces oxygen-hydrogen bonding, silicon-hydrogen bonding and nitrogen-hydrogen bonding in the silicon oxide layer.

8. The method of claim 1, wherein the substrate includes a silicon oxide layer, wherein the process gas includes helium, wherein the plasma includes helium radicals, and wherein contacting the silicon oxide layer with the helium radicals during heating improves the film quality of the silicon oxide layer compared to the silicon oxide layer before processing.

9. The method as described in claim 1, wherein the step of processing the substrate includes a chemical vapor deposition post-processing.

10. The method as described in claim 1, wherein the step of processing the substrate includes an atomic layer deposition pretreatment or posttreatment.

11. The method of claim 1, wherein the substrate includes a silicon nitride layer, wherein the process gas includes at least one of hydrogen, nitrogen or ammonia, wherein the plasma includes at least one of hydrogen, nitrogen or NH radicals, and wherein, similar to rapid thermal annealing, contacting the hydrogen, nitrogen or NH radicals with the silicon nitride layer during heating reduces the oxygen, hydrogen and chlorine impurity content in the silicon nitride layer.

12. The method of claim 1, wherein the substrate includes a silicon nitride layer having a seam and an initial stoichiometric ratio of silicon to nitrogen, and wherein the method comprises three sequential operations, including the following steps: a first operation, wherein the process gas includes oxygen, wherein the plasma includes oxygen radicals, and wherein during heating, the oxygen radicals are contacted with the silicon nitride layer to oxidize the silicon nitride layer, thereby causing the volume of the silicon nitride layer to expand, thereby removing the seam and changing the stoichiometric ratio of silicon to nitrogen; A second operation, wherein the process gas includes hydrogen, wherein the plasma includes hydrogen radicals, and wherein contacting the hydrogen radicals with the silicon nitride layer during heating reduces the oxygen content of the silicon nitride layer; and a third operation, wherein the process gas includes nitrogen, wherein the plasma includes nitrogen radicals, and wherein contacting the nitrogen radicals with the silicon nitride layer during heating increases the nitrogen content of the silicon nitride layer, thereby substantially restoring the initial silicon-to-nitrogen stoichiometry of the silicon nitride layer without the seam.

13. The method as claimed in claim 1, wherein the process gas includes at least one of PH3, BF3, AsH3 or Ga, and wherein processing the substrate includes gas phase doping.

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