Plasma processing with independent temperature control

Abstract

The embodiments of the present disclosure generally relate to an inductively coupled plasma source, a plasma processing apparatus, and independent temperature control of 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 in the gas injection channel. The plasma includes at least one radical species selected from oxygen, nitrogen, hydrogen, NH, and helium. The method includes delivering plasma from a plasma source to a process chamber coupled to the plasma source by flowing the plasma through a separation grid between the plasma source and the substrate. The method includes processing the substrate. Processing the substrate includes contacting a plasma including at least one radical species with a first side of the substrate facing the separation grid and heating the substrate using a plurality of lamps positioned on a second side of the substrate opposite the separation grid.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure generally relate to inductively coupled plasma sources, plasma processing apparatus, and methods for using the same, as well as independent temperature control of plasma processing. [Background technology]

[0002]

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

[0003]

[0003] The generation of plasma breaks down molecules into radicals (and / or creates ions), which can be used to achieve substrate processing within a chamber. Typically, a mixture of gases is fed into the plasma-generating region (active zone) of an inductively coupled plasma (ICP) source, and electrons accelerated in a high electric field region ionize and dissociate the mixture, creating a new gas (plasma) with radicals and ions.

[0004]

[0004] Conventional ICP sources for high plasma generation efficiency and wide operating range have a relatively small active zone adjacent to the ICP coil. Such an active zone is designed to confine electrons to this zone around the coil, so that plasma generation is primarily confined within this zone. However, as the plasma is directed toward the substrate, some chemical reactions occur between the nuclear species, reducing the number of radicals but resulting in the generation of some new nuclear species.

[0005]

[0005] Therefore, there is a need for improved inductively coupled plasma sources and plasma processing apparatus and methods for using them. Additionally, there is a need for accurate and independent temperature control of plasma processing. Summary of the Invention

[0006]

[0006] Embodiments of the present disclosure generally relate 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 in the gas injection channel. The plasma includes at least one radical species selected from oxygen, nitrogen, hydrogen, NH, and helium. The method includes delivering the plasma from a plasma source to a process chamber coupled to the plasma source by flowing the plasma through a separation grid between the plasma source and the substrate. The method includes processing the substrate. Processing the substrate includes contacting the plasma including the at least one radical species with a first side of the substrate facing the separation grid and heating the substrate using a plurality of lamps positioned on a second side of the substrate opposite 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 a plasma in the gas injection channel using an inductive coil positioned proximate the sidewall and horizontally overlapping the gas injection channel. The plasma includes at least one of nitrogen radicals or NH radicals. The method includes supplying the plasma from a plasma source to a process chamber coupled to the plasma source. The plasma flows through a separation grid positioned between the plasma source and a substrate to be processed. Processing the substrate in 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 positioned on a second side of the substrate opposite the separation grid.

[0009] In yet 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 a hydrogen plasma in the gas injection channel using an inductive coil positioned proximate the sidewall and horizontally overlapping the gas injection channel. The hydrogen plasma includes hydrogen radicals. The method includes supplying the hydrogen plasma from a plasma source to a process chamber coupled to the plasma source. The hydrogen plasma flows through a separation grid positioned between the plasma source and a substrate to be processed. Processing the substrate in 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 positioned on a second side of the substrate opposite the separation grid.

[0010]

[0010] So that the features of the present disclosure described above may be understood in detail, a more particular description of the present disclosure briefly summarized above may be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the attached drawings illustrate only exemplary embodiments and therefore should not be considered to limit the scope of the present disclosure, as other equally effective embodiments may also be permissible. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a plasma processing apparatus according to at least one embodiment. [Figure 2]

[0012] 1 is a schematic diagram of a plasma processing apparatus according to at least one embodiment. [Figure 3]

[0013] 1 is a schematic diagram of a plasma processing apparatus according to at least one embodiment. [Figure 4]

[0014] 1 is a schematic diagram of a plasma processing apparatus according to at least one embodiment. [Figure 5]

[0015] 1 is a schematic diagram of a plasma processing apparatus according to at least one embodiment. [Figure 6a]

[0016] FIG. 1 illustrates an isometric view of a separation grid according to at least one embodiment. [Figure 6b]

[0017] 6B is a cross-sectional view (along line 6B) of the separation grid of FIG. 6a according to at least one embodiment. [Figure 7]

[0018] 1 is an induction coil that may be used with a plasma source, according to at least one embodiment. [Figure 8]

[0019] FIG. 1 is a flow diagram of a process according to at least one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0020] For ease of understanding, wherever possible, like reference numerals have been used to designate like elements common to the figures. It is believed that elements and features of one embodiment may be beneficially incorporated in multiple other embodiments without further recitation.

[0013]

[0021] Embodiments of the present disclosure generally relate to high-efficiency inductively coupled plasma sources and plasma processing apparatus, and methods of using the same. The disclosed sources and apparatus can provide improved plasma uniformity for processing substrates, as well as efficient delivery of high-density neutral plasma species (e.g., unconventional species) to a substrate. While it has traditionally been assumed that more efficient generation of species within the active zone of a plasma source would automatically result in an increase of those species near the substrate, the inventors have realized that this is an untrue (or at least incomplete) assumption.

[0014]

[0022] Aspects of the present disclosure are described with reference to a "substrate" or semiconductor wafer for purposes of illustration and explanation. Those skilled in the art will understand, using the disclosure provided herein, that exemplary aspects of the present disclosure can be used in connection with any suitable semiconductor or other suitable substrate. "Substrate support" refers to any structure that can be used to support a substrate.

[0015]

[0023] Referring now to the drawings, exemplary embodiments of the present disclosure will now be described. FIG. 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 remote plasma source) coupled to the processing chamber 110. The processing chamber 110 includes a substrate support 112 operable to hold a substrate 114. In some embodiments, the substrate has a thickness of less than 1 mm. The substrate support 112 may be proximate one or more heat sources (e.g., a plurality of lamps 176), which provide heat to the substrate during processing of the substrate in the process chamber 110. Heat may be provided using any suitable heat source, such as one or more lamps, such as one or more rapid thermal processing lamps, or via a heated pedestal (e.g., a pedestal having a resistive heating element embedded within or coupled to the pedestal). In operation, the heat sources enable independent temperature control of the substrate, as described in more detail below.

[0016]

[0024] 1, the processing chamber 110 includes a window 162, such as a dome, and a plurality of lamps 176. The plurality of lamps 176 is disposed between the window 162 and a bottom wall of the chamber 110. The plurality of lamps 176 is arranged in an array. The plurality of lamps 176 may be arranged in multiple 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 200 to 500 lamps, such as 200 to 300 lamps, such as 240 lamps, such as 300 to 400 lamps, such as 400 to 500 lamps, 400 lamps, etc. The power of each of the plurality of lamps 176 may be between 400 W and 1000 W, such as between 500 W and 800 W, such as between 500 W and 600 W, such as between 600 W and 700 W, such as between 645 W, such as between 700 W and 800 W. The distance from the plurality of lamps 176 to the substrate may be less than or equal to about 50 mm, such as between about 5 mm and about 50 mm, such as between about 5 mm and about 20 mm, such as about 12.5 mm, such as between about 20 mm and about 50 mm, such as about 36.5 mm.

[0017]

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

[0018]

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

[0019]

[0027] The substrate support 112 includes lift pin holes 166 disposed therein. The lift pin holes 166 are sized to accommodate lift pins 164 for lifting the substrate 114 from the substrate support 112 either before or after a deposition process is performed. The lift pins 164 may rest on lift pin stops 168 when the substrate 114 is lowered from the processing position to the transfer position.

[0020]

[0028] A plasma can be generated in the plasma source 120 (e.g., in a plasma generating region) by an inductive coil 130. Desired particles flow from the plasma source 120 through holes 126 in a separation grid 116 to the surface of the substrate 114. The separation grid 116 separates the plasma source 120 from the processing chamber 110 (downstream region).

[0021]

[0029] The plasma source 120 includes a dielectric sidewall 122. The plasma source 120 includes a top cover 124 (e.g., a top plate). The dielectric sidewall 122 and the top cover 124, which are integrated into an insert 140, define a plasma source interior 125 (e.g., a chamber interior). The dielectric sidewall 122 may include any suitable dielectric material, such as quartz. An inductive coil 130 is disposed proximate (e.g., adjacent) to the dielectric sidewall 122 around the plasma source 120. The inductive coil 130 is coupled to an RF power generator 134 via any suitable matching network 132. A feed gas is introduced into the plasma source interior 125 from a gas source 150. A plasma is generated in the plasma source 120 when the inductive coil 130 is energized with RF power from the RF power generator 134. In some embodiments, RF power is provided to the coil 130 at about 1 kW to about 15 kW, about 3 kW to about 10 kW, etc. The inductive coil 130 may ignite and sustain a plasma over a wide range of pressures and flow rates. In some embodiments, the plasma processing apparatus 100 includes a grounded Faraday shield 128 to reduce capacitive coupling of the inductive coil 130 to the plasma.

[0022]

[0030] To enhance efficiency, the plasma processing apparatus 100 includes a gas injection insert 140 disposed within the plasma source interior 125. A gas injection channel 151 provides process gas to the plasma source interior 125 through an active zone 172 (e.g., active region). The active zone 172 enhances confinement of hot electrons, allowing for reaction between the hot electrons and the feed gas. The enhanced electron confinement region, or active zone 172, is defined radially by the sidewalls and vacuum tube of the gas injection insert and vertically from below by the edge of the insert's lower surface 180. The active zone 172 provides an electron confinement region within the plasma source interior 125 for efficient plasma generation and maintenance. The narrow gas injection channel 151 prevents the plasma from spreading from the chamber interior into the gas channel 151. The channel 151 can have a diameter of about 1 mm to about 10 mm, such as about 1 mm or more, about 10 mm or more, or the like. The gas injection insert 140 forces the process gas through the active zone 172, where the plasma is generated.

[0023]

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

[0024]

[0032] The coil 130 is aligned with the active area in such a way that the upper turns of the coil are above the lower surface 180 of the insert 140 and operate substantially within the active area of ​​the inner space, while the lower turns of the coil are below the lower surface 180 and operate substantially outside the active area. The center of the coil is substantially aligned with the lower surface 180. Within these boundaries, the position of the coil can be adjusted for desired performance. Aligning the coil with the lower surface 180 (e.g., the surface edge) results in improved source efficiency, i.e., controlled generation of desired chemical species for the plasma process and their delivery to the wafer with reduced or eliminated losses. For example, plasma sustaining conditions (balance between local generation and loss of ions) may not be optimal for generating species for the plasma process. With regard to delivery of species to the substrate, efficiency may depend on the amount of these specific species and wall recombination. Thus, controlling the alignment of the coil with the lower surface 180 provides control of source efficiency for the plasma process.

[0025]

[0033] In some embodiments, the coil has a short transition region near the lead, with the remaining turns of the coil parallel to the lower surface 180, while in other embodiments the coil is helical, but always defines an upper turn and a lower turn of the coil. In some embodiments, the coil may have 2 to 5 turns.

[0026]

[0034] In some embodiments, by utilizing an appropriately sized insert 140 (and top cover 124, which may be a pre-formed portion of the insert 140) to form the plasma source 120, the surface 180 is aligned with a portion of the inductive coil 130 (e.g., the coil loop 182) along an axis 184 (e.g., an alignment level). Alternatively, to provide alignment of the surface 180 with the portion of the coil 130, the surface 180 may be movable along a vertical direction V1 relative to the plasma source 120, while the remainder of the insert 140 is static (e.g., fixed) as part of the plasma source 120. For example, a mechanism 170 may be coupled to any appropriate portion of the insert 140 to adjust the position of the surface 180. Thereby, a portion of the insert 140 having a first length (L1) is adjusted to a second length (L2). The mechanism 170 may be any appropriate mechanism, such as an actuator (e.g., a motor, an electric motor, a stepping motor, or a gas pressure actuator). In some embodiments, the difference in length (Δ) from L1 to L2 is from about 0.1 cm to about 4 cm, such as from about 1 cm to about 2 cm.

[0027]

[0035] Additionally or alternatively, the insert 140 may be coupled to a mechanism (such as mechanism 170) to align the surface 180 with a portion of the coil 130. The mechanism 170 is configured to move the entire insert 140 vertically (e.g., along a vertical direction V1 relative to the plasma source 120). A spacer (not shown) may be used to fill gap(s) between the insert 140 and another portion of the plasma source 120 (e.g., between the top cover 124 and the dielectric sidewall 122) formed by moving the insert vertically. The spacer may be formed from a ceramic material such as quartz, for example.

[0028]

[0036] Generally, locating the center of coil 130 above surface 180 improves the efficiency of ionization and dissociation, but reduces the efficiency of transport of these species to the substrate, because many of the species may recombine at the walls of the narrow active region. Locating coil 130 below surface 180 may improve the efficiency of plasma delivery, but may reduce the efficiency of plasma generation.

[0029]

[0037] The separation grid 116 is configured to separate areas of the processing chamber 110 from plasma charged particles (ions and electrons). The plasma charged particles recombine on the grid, allowing only neutral plasma species to pass through the grid and enter the processing chamber 110. The holes in the lower section of the separation grid 116 may have different patterns, such as the uniformity 600 shown in FIGS. 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 a combination(s) thereof. For example, AlN may be useful for the flux of nitrogen radicals, while conventional separation grids are prone to recombination of nitride radicals. Similarly, aluminum oxide may provide a flux of oxygen radicals or hydrogen radicals, while conventional separation grids are prone to their recombination. In some embodiments, the separation grid 600 has a plurality of holes 602. As shown in FIG. 6b, holes 602 are disposed through the separation grid (e.g., holes 602 traverse the thickness of the separation grid). Holes 602 may have an average diameter of about 4 mm to about 6 mm. In some embodiments, each hole of the plurality of holes 602 has a diameter (D1) of about 4 mm to about 6 mm. In some embodiments, separation grid 600 of FIGS. 6a and 6b has a thickness of about 5 mm to about 10 mm, which defines the length (L1) of the hole. The ratio of the grid thickness (length (L1)) to the average diameter of the plurality of holes may be greater than about 1, such as from about 1 to about 3.

[0030]

[0038] An exhaust port 192 is coupled to the sidewall of the process chamber 110. In some embodiments (e.g., when the pedestal is not rotating), the exhaust port 192 may be coupled to the bottom wall of the process chamber 110 to provide azimuthal independence. If the lamp is rotating, the exhaust port 192 may be coupled to the sidewall, since rotation reduces azimuthal dependency.

[0031]

[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 the present disclosure. The plasma processing apparatuses of Figures 2, 3, 4, and 5 may be constructed in a manner similar to plasma processing apparatus 100 (Figure 1) and may operate in the manner described above for processing apparatus 100. It will be understood that the components of the plasma processing apparatuses of Figures 2, 3, 4, and 5 may also be incorporated into any other suitable plasma processing apparatus in alternative exemplary embodiments.

[0032]

[0040] As shown in FIG. 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 may be positioned in the processing chamber directly below the grid at some distance from the grid. Neutral particles from the plasma source interior 230 may flow downward through the separating grid toward the substrate in the processing chamber 220. The neutral particles may contact the substrate, for example, to perform a process (e.g., a substrate treatment process).

[0033]

[0041] The multiple induction coils 250 are disposed at different positions along the vertical direction V of the plasma source 222. For example, the induction coils (e.g., 252 and 254) are spaced apart from one another along the vertical direction V along the plasma source 222. For example, the induction coils 250 may include a first induction coil 252 and a second induction coil 254. The first induction coil 252 may be disposed at a first vertical position along the vertical surface of the dielectric sidewall 232. The second induction coil 254 may be disposed at a second vertical position along the vertical surface of the dielectric sidewall 232. The first vertical position may be different 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 induction coil 252 is substantially aligned with the surface 180 of the insert. The second induction coil 254 is disposed in a lower (e.g., lower) portion of the plasma source 200. The second induction coil includes one or more magnetic field concentrators 280, as shown in Figure 2, allowing the coil to be positioned below the plasma source. The use of magnetic field concentrators 280 improves the efficiency of plasma generation at the bottom of the source and significantly increases radial control near the substrate (compared to without the magnetic field concentrator). In some embodiments, the induction coil 254 is positioned at the bottom third, bottom quarter, etc. of the plasma source 222.

[0034]

[0042] The induction coil 250 (252, 254) may be operable to generate (or modify) an inductive plasma within the plasma source interior 230. 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 the coil 252. The induction 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 induction coil 252 by the first RF generator 262 and the frequency and / or power of the RF energy applied to the second induction coil 254 by the second RF generator 264 may be independent to better control process parameters of the surface treatment process.

[0035]

[0043] For example, the frequency and / or power of the RF energy applied by the second RF generator 264 can be less than the frequency and / or power of the RF energy applied by the first RF generator 262. The RF power generator 262 is operable to energize the induction coil 252 to generate an inductive plasma in the plasma source interior 230. In particular, the RF power generator 262 may energize the induction coil 252 with radio frequency (RF) alternating current (AC). The AC thereby induces alternating magnetic and electric fields inside a space near the induction coil 252 that heats electrons to generate the inductive plasma. In some embodiments, RF power is provided to the coil 252 at about 1 kW to about 15 kW, about 3 kW to about 15 kW, etc. The induction coil 252 may ignite and sustain plasma over a wide range of pressures and flow rates.

[0036]

[0044] The radio frequency power generator 264 is operable to energize the induction coil 254 to generate and / or modify a plasma in the plasma source interior 230. In particular, the radio frequency power generator 264 may energize the induction coil 254 with radio frequency (RF) alternating current (AC). An inductive RF field inside the space adjacent to the induction coil 254 thereby accelerates electrons to generate the plasma. In some embodiments, RF power is provided to the coil 254 at about 0.5 kW to about 6 kW, about 0.5 kW to about 3 kW, etc. The induction coil 254 may modify the plasma density in the plasma processing apparatus 200. For example, the induction coil 254 may adjust the radial profile of the plasma to promote more uniformity in the plasma moving toward the substrate within the chamber 220. Because the coil 252 is further from the substrate than the coil 254 during use, the plasma and radicals generated by the coil 252 may promote a dome-shaped profile near the substrate. The coil 254 can flatten (or even raise the edges of) the dome-shaped plasma profile as the plasma approaches the substrate.

[0037]

[0045] A dielectric sidewall 232 is disposed between the inductive coil 250 and the plasma source 222. The dielectric sidewall 232 has a generally cylindrical shape. An electrically grounded Faraday shield 234 may be made of metal and / or is disposed between the inductive 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 the plasma within the plasma source interior 230 and allows the RF field from the inductive coil 250 to pass through to the plasma source interior 230. The grounded Faraday shield 234 reduces capacitive coupling of the coil 250 to the plasma within the plasma source interior 230. In some embodiments, the Faraday shield 234 can be a metal cylinder with a slot perpendicular to the direction of the coil. The perpendicular slot is in the area of ​​the coil (e.g., adjacent to the coil). Meanwhile, at least one upper or lower end of the coil (above or below the coil) has a complete current path around the cylinder. The Faraday shield may have any suitable thickness and / or the slot may have any suitable shape. Even when utilizing a helical coil, the slot near the coil(s) may be relatively narrow (e.g., about 0.5 cm to about 2 cm) and substantially vertical.

[0038]

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

[0039]

[0047] In some embodiments, the plasma processing apparatus 200 includes one or more gas injection ports 270 disposed radially outward of and through the injection insert 240 of the plasma source 222. The gas injection ports 270 and the side profile of the insert are operable to inject process gas directly into the active plasma generation region adjacent the vertical surface of the dielectric sidewall 232 at the periphery of the plasma source interior 230. For example, there may be more than 20 (e.g., 70-200) vertical injection holes disposed through the insert 240. For example, the first induction coil 252 may be operable to generate a plasma in a region 272 adjacent to the vertical surface of the dielectric sidewall 232. The second induction coil 254 may be operable to generate or modify a plasma existing in a region 275 adjacent to the vertical surface of the dielectric sidewall 232. Gas inject insert 240, in some embodiments, can further define an active area for generating plasma in plasma source interior 230 adjacent the vertical surface of dielectric sidewall 232. The upper portion of a gas inject insert of the present disclosure can have a diameter of about 10 cm to about 15 cm. The lower portion of a gas inject insert of the present disclosure can have a diameter of about 7 cm to 10 cm.

[0040]

[0048] The plasma processing apparatus 200 may have a lower edge-gas injection port 290 configured to introduce the same or different gas into the volume 210 as the gas injection port 270 provides to the plasma source interior 230. 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 plenum 292 into which gas is introduced through an inlet 294. The gas flows from the plenum 292 through one or more openings 296 into the volume 210. The edge-gas injection port 290 may provide fine tuning of the plasma chemistry near the edge of the substrate and / or improve plasma uniformity at the substrate. For example, the edge-gas injection port 290 may provide modification of the flow (of the same gas) and / or modification of the chemistry (chemical reaction between plasma radicals and a new feed gas or a different gas).

[0041]

[0049] The plasma processing apparatus 200 has improved source tunability relative to known plasma processing apparatuses. For example, the induction coil 250 can be positioned at two locations along the vertical surface of the dielectric sidewall 232. The function of the upper coil 252, located near the active plasma generation region, is to ignite and maintain the plasma in the plasma source interior 230, while the function of the second coil 254, located below the source, allows for advantageous source tunability. The lower placement of the second coil is made possible by the use of a magnetic field concentrator 280, which results in coupling of the coil to the plasma rather than to the surrounding metal (e.g., 290). In this manner, processing processes performed on substrates using the plasma processing apparatus 200 may be more uniform.

[0042]

[0050] FIG. 3 is a schematic diagram of a plasma processing apparatus 300. The processing apparatus 300 includes a plasma source 322 and a processing channel 220. The plasma source 322 includes an insert 302 having peripheral gas injection ports 270 and a central gas injection port 310. The central gas injection port 310 is formed by an upper plate 318 and a lower plate 340 that form a plenum 316. The lower plate 340 has a plurality of holes (through-holes) 312, allowing the central gas injection port 310 / insert 302 to have a plurality of holes (through-holes) 312 for providing process gas into a central processing region 314. The dimensions of the central processing region 314 are provided by portions of the insert 302, namely, the central gas injection port 310 and a sidewall 320. The sidewall 320 has a cylindrical shape and is a dielectric material. For example, the sidewall 320 is formed from quartz or alumina. The dimensions of the peripheral process region 272 are provided by the dielectric sidewall 232 and the insert 302 (i.e., the gas injection port 270 and the sidewall 324). The sidewall 324 (and the insert 302 generally) 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 may be formed of aluminum and covered with quartz or alumina, or may have bare aluminum or anodized aluminum. In addition, 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.

[0043]

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

[0044]

[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 can 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. When the central coil is not energized, the secondary plasma source acts as a supplemental gas injection that reduces the flux of radicals and ions / electrons generated by the primary coil 252 toward the center of the substrate. Because plasma density is typically higher at the center of the substrate during conventional plasma processes, providing greater RF power to the peripheral induction coil 254 than to the central induction coil 252 promotes increased plasma density at the edge(s) of the substrate, improving plasma uniformity. The plasma separator 304 (cylindrical protrusion) between the central and edge areas improves the ability of independent central and edge plasma control.

[0045]

[0053] The peripheral coil 252 and the central coil 254 may be operable to generate (or modify) an inductive plasma within the plasma source interior 330. 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 central 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 the frequency and / or power of the RF energy applied to the central coil 254 by the second RF generator 264 may be adjusted to be the same or different to control process parameters of the substrate processing process.

[0046]

[0054] For example, the frequency and / or power of the RF energy applied by the second RF generator 264 can be less than the frequency and / or power of the RF energy applied by the first RF generator 262. The radio frequency power generator 262 is operable to energize the peripheral coil 252 to generate an inductive plasma in the plasma source interior 330. In particular, the radio frequency power generator 262 may energize the peripheral coil 252 with radio frequency (RF) alternating current (AC). The AC thereby induces an AC magnetic field inside the peripheral coil 252 that heats the gas to generate the inductive plasma. In some embodiments, RF power is provided to the peripheral coil 252 at about 1 kW to about 15 kW, about 3 kW to about 10 kW, etc.

[0047]

[0055] The radio frequency power generator 264 is operable to energize the central coil 254 to generate and / or modify an inductive plasma in the central region 314 of the plasma source 322. In particular, the radio frequency power generator 264 may energize the peripheral coil 254 with radio frequency (RF) alternating current (AC). The AC thereby induces an AC magnetic field inside the peripheral coil 254 that heats the gas to generate and / or modify the inductive plasma. In some embodiments, RF power is provided to the central coil 254 at about 0.3 kW to about 3 kW, about 0.5 kW to about 2 kW, etc. The central coil 254 may modify the plasma in the plasma processing apparatus 300; for example, the central coil 254 may adjust the radial profile of the plasma to promote more uniformity in the plasma moving toward the substrate in the chamber 220.

[0048]

[0056] In some embodiments, the plasma processing apparatus 300 includes gas injection ports 270 operable to inject process gas at the periphery of a region 272 along the vertical surface of the dielectric sidewall 232, defining one or more active plasma generation regions adjacent the vertical surface of the dielectric sidewall 232. For example, the peripheral coil 252 may be operable to generate a plasma in the region 272 adjacent the vertical surface of the dielectric sidewall 232. The central coil 254 may be operable to generate and / or modify a plasma existing in the central region 314 adjacent the vertical surface of the sidewall 320. The gas injection insert 302, in some embodiments, may further define an active region for generation of plasma within the plasma source adjacent the vertical surface of the dielectric sidewall 232 and the vertical surface of the sidewall 320.

[0049]

[0057] In practice, the substrate may be provided with some overlap of the process plasma generated in region 314 with the process plasma generated in region 272. Collectively, the peripheral and central process gas injection ports (270, 310) and induction coils (252, 254) may provide improved plasma and process uniformity (center-to-edge plasma control) for treating the substrate with the plasma. To enhance center-to-edge process control, insert 302 includes separator 304. Separator 304 may be a uniform, cylindrically shaped separator coupled to (e.g., disposed along) inert lower surface 180.

[0050]

[0058] Additionally, in embodiments in which the process gas provided by central gas injection port 310 is different from the process gas provided by peripheral gas injection ports 270, new plasma chemistries may be obtained compared to conventional plasma processes using conventional plasma sources. For example, advantageous substrate processing may be provided that is not obtainable with conventional plasma processing. For example, when mixing a plasma-generated flow of radicals and excited species (e.g., in some embodiments of region 272) with a different plasma flow enriched in a different type of plasma species (e.g., different radicals), unique mixtures of plasmas may be generated. Additionally, the generation of these unique plasma chemistries may be obtained, for example, in embodiments utilizing alignment of surface 180 with a portion of coil 252, as described above.

[0051]

[0059] FIG. 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 inject insert 402, which may be integrated with a top cover, peripheral gas inject ports 270, and a central gas inject port 410. The central gas inject port 410 is disposed within the gas inject insert 402 to fluidly couple the central gas inject port 410 to a gas supply plenum 416 of the gas inject insert 402. The gas supply plenum 416 provides an increased diameter (compared to the diameter of the port 410) to ensure that process gas is uniformly distributed before entering the exhaust region between the bottom of the insert 402 and a feed platform 414. As gas is provided through the holes 412, the platform 414 provides a second gas supply plenum 418 (e.g., region) to facilitate an outward flow of gas toward the periphery of the plasma source 422 (e.g., into region 272). In some embodiments of the present disclosure, no material is present to form the holes 412, creating a larger plenum. The platform 414 may be coupled to the insert 402 via multiple screws or bolts (not shown). The platform 414 may be made of quartz or ceramic. The platform 414 may have any suitable design, allowing for different materials. The outward / lateral flow of gas promoted by the platform 414 may affect the gas / plasma flow profile to the substrate being processed, improving center-to-edge uniformity compared to conventional plasma processing apparatus. Additionally, this outward flow of gas to the region adjacent to the plasma generation region (e.g., 272) of the plasma source 400 provides an advantage. High plasma density may be generated in the region 272 adjacent to the top of the coil 130, so the electric field does not penetrate far from the coil. Therefore, gas from the central injections 410-416-414 does not experience much ionization or dissociation, but the gas chemically interacts with the high density of radicals and ions generated in the active region 272. Both radicals and ions become chemically activated and interact with the fresh feed gas from the central injection 410-416-414.The new feed gases, radicals, and ions may create new plasma chemistries compared to conventional plasma sources using plasma processing chambers. For example, when the plasma-generating flow of radicals and excited species (e.g., some embodiments of region 272) is mixed with a new flow of gas that did not pass through plasma generating region 272 with hot electrons (e.g., process gas provided by injection port 410 and platform 414 / second gas supply plenum 418), a unique mixture of plasmas can be created. For example, H obtained in the plasma from the H2 feed gas (e.g., from gas provided by injection port 270). + and H - The flow of radicals can be mixed with a flow of oxygen O (e.g., from gas supplied by injection port 410), which can significantly increase the fraction of HO, HO, HO, and other non-equilibrium molecules in the region adjacent to active region 272 associated with inductive coil 130. Additionally, the generation of these unique plasma chemistries can be achieved in several embodiments utilizing, for example, alignment of the edge of surface 180 with a portion of coil 130, as described above.

[0052]

[0060] In some embodiments, the ratio of the flow rate of the process gas provided by the peripheral gas injection ports 270 to the flow rate of the process gas provided by the central gas injection port 410 is from about 20:1 to about 1:20, such as from about 10:1 to about 1:10, such as from about 2:1 to about 1:2, such as from about 1.2:1 to about 1:1.2, such as about 1.1. Such flow rates may provide stoichiometries (e.g., substantially equimolar amounts) of the different process gases to provide desired densities of chemical species in the plasma generated in region 272.

[0053]

[0061] Additionally, the outward / lateral flow provided by the central gas injection port 410 and the platform 414 / second gas supply plenum 418 can modify the flow pattern within the plasma source 400 and affect the delivery profile of radicals to the substrate. For example, in embodiments where the process gas provided by the central gas injection port 410 is substantially the same as the process gas provided by the peripheral gas injection ports 270, more plasma flow is promoted toward the edge of the substrate, improving the center-to-edge plasma profile (e.g., uniformity of the plasma delivered to the substrate).

[0054]

[0062] Additionally, in embodiments where the process gas provided by the central gas injection port 410 is different from the process gas provided by the peripheral gas injection ports 270, new plasma chemistries may be obtained compared to conventional plasma processes using conventional plasma sources. For example, advantageous substrate processing may be provided that is not obtainable with conventional plasma processing. For example, when mixing the plasma-generated flow of radicals and excited species (e.g., in some embodiments of region 272) with a new flow of gas that has not passed through the plasma region with hot electrons, a unique mixture of plasmas may be created. For example, the H obtained in the plasma from the H feed gas may be mixed with the H + and H - The flow of oxygen (O) can be mixed with a flow of oxygen (O), which can then generate a number of different radicals, such as HO, H2O2 molecules, etc., in a region of the plasma processing device 400 downstream of region 272. Additionally, the generation of these unique plasma chemistries can be achieved in several embodiments utilizing, for example, alignment of surface 180 with a portion of coil 252, as described above.

[0055]

[0063] FIG. 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, peripheral gas injection ports 270, a central gas injection port 510, and a top cover 124. The central gas injection port 510 may be located proximate (e.g., adjacent) to a wall 550. The central gas injection includes a port 510 having a generally cylindrical plenum / manifold and a plurality of angled injection outlets 512 uniformly spread along the plenum. The gas injection insert 240 may also have a generally cylindrical shape. The central gas injection port 510 has angled outlets 512 to promote outward / lateral flow of process gas provided by the central gas injection port 510 and the angled outlets 512. The angled outlet 512 may have an angle of about 0 degrees to about 90 degrees, about 30 degrees to about 60 degrees, about 45 degrees, etc., relative to a vertical axis (such as the vertical axis 186 parallel to the axial centerline of the processing device 500 and / or the axial centerline of the plasma source 522).

[0056]

[0064] The outward / lateral flow of gas facilitated by angled outlet 512 can affect the gas / plasma flow profile to the substrate during processing, improving center-to-edge uniformity compared to conventional plasma processing apparatus. Additionally, because high plasma density can be generated in the region adjacent to coil 130 (and the electric field does not penetrate far from the coil), new plasma chemistries can be achieved compared to conventional plasma processes using plasma processing chambers. For example, when the plasma-generated flow of radicals and excited species (e.g., some embodiments of region 272) is mixed with a new flow of gas (e.g., process gas provided by injection port 510 and angled outlet 512) that did not pass through the plasma region with hot electrons, a unique mixture of plasmas can be created. For example, the H2 obtained in the plasma from the H2 feed gas (e.g., from the gas provided by injection port 270) can be mixed with the H2 generated in the plasma. + and H -The radical flow can be mixed with a flow of oxygen O (e.g., from gas supplied by injection port 510), in which case molecular radicals such as HO, HO can be generated in the process region 272 adjacent to the induction coil 130. Additionally, the generation of these unique plasma chemistries can be obtained in several embodiments utilizing the alignment of the coil 130 with the surface 180, as described above.

[0057]

[0065] In some embodiments, the ratio of the flow rate of the process gas provided by the peripheral gas injection ports 270 to the flow rate of the process gas provided by the central gas injection port 510 is from about 2:1 to about 1:2, such as from about 1.2:1 to about 1:1.2, such as about 1:1. Such flow rates may provide stoichiometries (e.g., substantially equimolar amounts) of the different process gases to provide desired densities of chemical species in the plasma generated in region 272.

[0058]

[0066] Additionally, the outward / sideward flow provided by the central gas injection port 510 and angled outlet 512 can modify the flow pattern within the plasma source 522, affecting the delivery profile of radicals to the substrate. For example, in embodiments where the process gas provided by the central gas injection port 510 is substantially the same as the process gas provided by the peripheral gas injection ports 270, more plasma flow is promoted toward the edge of the substrate, improving the center-to-edge plasma profile (e.g., uniformity of the plasma delivered to the substrate).

[0059]

[0067] Furthermore, the gas injection insert 240 of FIG. 5 has a fixed edge at the lower surface 180, defining an active area that points to the axis 184 of the induction coil 130. The coil 130 is substantially aligned with the surface 180 such that the upper turns of the coil are positioned above the axis 184 (surface 180) and the lower turns are positioned below the edge. The coil position may be further adjusted within this range based on process results. Aligning the coil's vertical center with the lower surface 180 results in improved source efficiency, i.e., controlled generation of desired chemical species for the plasma process and their delivery to the wafer with minimal loss. For example, plasma sustaining conditions (balance between local generation and loss of ions) may not be favorable for generating species for the plasma process. With regard to delivery of species to the substrate, efficiency may depend on the amount and wall recombination of these specific species. Therefore, controlling the alignment of the coil 130 with the lower surface 180 provides control of source efficiency for the plasma process.

[0060]

[0068] In some embodiments, by utilizing an appropriately sized insert 240 to form the plasma source 120, the lower surface of the insert 240 is aligned with the edge portion of the insert's lower surface 180 that defines the active area for the coil (the level of this alignment is illustrated as axis 184). Alternatively, the lower surface of the insert 240 can be made flexible using a movable central portion of the insert 240, as shown in FIG. 5, while the remainder of the insert 240 is fixed as part of the plasma source 120. For example, a mechanism 170 can be coupled to the central portion of the insert 240 to adjust the central portion. This adjusts the central portion of the insert 240 from a first position to a second position. In some embodiments, the difference in position (Δ) from the first position to the second position is about 0.1 cm to about 10 cm, about 1 cm to about 2 cm, etc. The mechanism 170 can be any suitable mechanism, such as an actuator (e.g., a motor, an electric motor, a stepper motor, or a gas pressure actuator). Movement of the central portion of the insert 240 by the mechanism 170 increases or decreases the space between the central portion and the top cover 124 .

[0061]

[0069] Generally, moving the central portion of the insert 240 downward along the vertical direction V will reduce the flow of activated species toward the center of the substrate, thus decreasing the process rate at the center relative to the edge, while moving the central portion upward will increase the process rate at the center relative to the edge.

[0062]

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

[0063]

[0071] 7 is an inductive coil 130 that can be used with the plasma source. The inductive coil 130 includes multiple coil loops, including coil loop 182. The inductive coil 130 includes three complete turns, although more or fewer turns are contemplated. For example, the inductive coil may have two to six complete turns for an RF frequency of 13.56 MHz. For lower RF frequencies, more turns may be utilized.

[0064]

[0072] FIG. 8 is a flow diagram of a method 800 for plasma processing a substrate using a plasma processing apparatus of the present disclosure. Method 800 may include introducing 810 a plasma gas into the plasma processing source. The process gas and its flow rate may be selected based on the particular substrate processing application. Typically, 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 also contemplated. Method 800 further includes providing 820 radio frequency power to generate an inductive plasma within the plasma source. The radio frequency power may be controlled based on the particular substrate processing application. Typically, the radio frequency power may be from about 1 kW to about 10 kW, although other power levels are also contemplated. From the interior region of the plasma source, neutral particles and / or radicals of the inductive plasma flow through a separation grid to the substrate in the processing chamber. Although a separation grid is shown in FIG. 1, method 800 may be performed without a separation grid.

[0065]

[0073] The method 800 further includes processing 830 the substrate in the process chamber. The temperature and pressure of the processing chamber can be controlled based on the specific substrate processing application. Generally, 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 processing chamber can be exposed to neutrals and / or radicals generated in an inductive plasma passing through a separating grid. In particular, the plasma containing the neutrals and / or radicals contacts a first side of the substrate facing the plasma source. In some embodiments, the substrate is heated using multiple lamps positioned opposite the first side of the substrate. The neutrals and / or radicals can be used, for example, as part of a surface treatment process for the substrate. In practice, gas flow rates and / or gas ratios can be selected such that the surface of the substrate is saturated with a reactant supply of neutrals and / or radicals. The ability of the apparatus disclosed herein to provide surface saturation of reactive species is due to the very high density of the source and the short distance between the plasma source and the substrate.

[0066]

[0074] In plasma processing operations without surface saturation, the arrival rate of reactive species at the substrate surface determines the reaction and / or incorporation rate of the reactive species. However, using the apparatus and / or method disclosed herein, reactive species are saturated on the surface with a high flux of reactive species, thereby causing diffusion of the reactive species to become the dominant factor. Because temperature determines the diffusion of reactive species and drives the reaction, the reaction is temperature dependent. Because thermal energy is inherently conformal and substantially uniform in three dimensions, the temperature-based controlled method disclosed herein results in a more conformal surface treatment compared to plasma processing operations where the arrival rate of reactive species determines the rate.

[0067]

[0075] Generally, the processing time for operation 830 may be from about 10 seconds to about 10 minutes, depending on the particular substrate processing application, although other processing times are contemplated. Numerous advantages of method 800 will be described in more detail below with respect to each exemplary substrate processing application. Method 800 may be performed using any of the plasma processing apparatuses of the present disclosure.

[0068]

[0076] The plasma can be generated by energizing one or more inductive coils proximate to the plasma source with RF energy to generate a plasma using a process gas introduced into the plasma source. For example, the process gas can be introduced into the plasma source from a gas source. RF energy from one or more RF sources can be applied to the inductive coil(s) to generate a plasma in the plasma source.

[0069]

[0077] In general, method 800 can be used for many different substrate processing applications, including, but not limited to, nitrogen radical processing (e.g., nitridation), oxygen radical processing (e.g., oxidation), hydrogen radical processing, helium radical processing, and various pre-processing and post-processing.

[0070]

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

[0071]

[0079] During the nitridation of the silicon oxide, the process chamber can be operated at either a high temperature (e.g., above 250°C) or a low temperature (e.g., below 250°C). In certain embodiments that may be combined with other embodiments, the temperature in the process chamber is about 200°C or higher, such as from about 200°C to about 1200°C, such as from about 250°C to about 950°C, such as from about 200°C to about 250°C, such as from about 250°C, such as from about 250°C or higher, such as from about 500°C to about 1000°C, such as from about 500°C to about 600°C, such as from about 600°C to about 700°C, such as from about 700°C to about 800°C, such as from about 800°C to about 900°C, such as from about 850°C, such as from about 900°C to about 1000°C, or such as about 950°C. The pressure in the process chamber is about 0.2 Torr to about 3 Torr, such as about 0.5 Torr to about 2 Torr, such as about 0.5 Torr, such as about 1 Torr, such as about 2 Torr. The radio frequency power is about 1 kW to about 10 kW, such as about 1 kW to about 5 kW, such as about 2 kW, such as about 2 kW to about 8 kW, such as about 5 kW to about 10 kW, such as about 8 kW. The processing time is in the range of about 2 minutes to about 8 minutes, such as about 4 minutes to about 5 minutes, such as about 4 minutes, such as about 5 minutes.

[0072]

[0080] Beneficially, silicon oxide nitridation performed using the disclosed plasma processing apparatus and method increases the nitrogen content in the silicon oxide compared to rapid thermal nitridation processes at approximately the same level of nitrogen conformality. Furthermore, the silicon oxide nitridation process described herein also increases the nitrogen conformality in the silicon oxide compared to ion-driven uncoupled plasma nitridation processes. The silicon oxide nitridation described herein generates peaks in nitrogen content at both the silicon-silicon oxide interface and the silicon oxide surface due to the diffusion of nitrogen and / or NH radicals from the surface to the interface. Furthermore, the silicon oxide nitridation described herein can increase the conformality of gate-all-around (GAA) semiconductor structures.

[0073]

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

[0074]

[0082] During silicon nitridation, the process chamber can be operated at either a high temperature (e.g., above 250° C.) or a low temperature (e.g., below 250° C.). In certain embodiments that may be combined with other embodiments, the temperature in the process chamber is about 200° C. or higher, such as from about 200° C. to about 1200° C., such as from about 250° C. to about 950° C., such as from about 200° C. to about 250° C., such as from about 250° C., above about 250° C., such as from about 500° C. to about 1000° C., such as from about 500° C. to about 600° C., such as about 550° C., such as from about 600° C. to about 700° C., such as from about 700° C. to about 800° C., such as from about 800° C. to about 900° C., such as from about 900° C. to about 1000° C., or about 950° C. The pressure in the process chamber is about 0.2 Torr to about 3 Torr, such as about 0.3 Torr to about 2 Torr, such as about 0.3 Torr, such as about 2 Torr. The radio frequency power is about 1 kW to about 10 kW, such as about 1 kW to about 5 kW, such as about 2 kW. The processing time is in the range of about 0.25 minutes to about 8 minutes, such as about 0.5 minutes to about 5 minutes, such as about 0.5 minutes, such as about 2 minutes, such as about 4 minutes, such as about 5 minutes.

[0075]

[0083] Advantageously, silicon nitridation performed using the disclosed plasma processing apparatus and methods can form a conformal layer of silicon nitride having a thickness of about 20 angstroms to about 60 angstroms. In one example, the silicon nitride described herein enables the formation of substantially conformal nitrogen inclusions on the top and bottom sidewalls of polysilicon in an oxide / polysilicon (OPOP) stack, e.g., having a depth of 2.8 μm and an aspect ratio of 20:1 to 30:1.

[0076]

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

[0077]

[0085] During tungsten nitridation, the temperature in the process chamber may be about 800°C or less, such as about 700°C or less, such as about 500°C to about 700°C, such as about 500°C to about 600°C, such as about 600°C to about 700°C, or about 650°C. Using the apparatus and / or methods disclosed herein, the temperature and nitrogen content of the processed film are inversely related. For example, operating the process chamber at a temperature of about 850°C or greater results in a nitrogen content of only about 5% or less. Meanwhile, a temperature of about 780°C or less increases the nitrogen content five-fold to about 25%. Furthermore, operating the process chamber at a temperature of about 750°C results in a nitrogen content between about 25% and about 30%. Further reducing the temperature to about 650°C further increases the nitrogen content to between about 30% and about 35%. Reducing the temperature even further to about 550°C may further increase the nitrogen content to between about 35% and about 40%. During tungsten nitridation, the pressure in the process chamber is about 0.5 Torr to about 3 Torr, such as about 2 Torr. The radio frequency power is about 1 kW to about 10 kW, such as about 1 kW to about 5 kW, such as about 2 kW. The processing time is within a range from about 2 minutes to about 8 minutes, such as about 5 minutes. Advantageously, tungsten nitridation performed using the disclosed plasma processing apparatus and method results in a conformal layer of tungsten nitride having a thickness of about 25 Angstroms to about 30 Angstroms.

[0078]

[0086] In another example, a plasma processing apparatus disclosed herein may be used for hydrogen radical treatment of tungsten (W) according to method 800. In one such example, a substrate undergoing the hydrogen radical treatment process includes a blanket layer of tungsten disposed on a layer of titanium nitride (e.g., TiN). In one such example, the tungsten layer may be formed, for example, by atomic layer deposition (ALD). The blanket layer of tungsten has a thickness of about 600 angstroms to about 650 angstroms, although other thicknesses are contemplated. Using the apparatus and / or method disclosed herein, treatment of tungsten with hydrogen radicals reduces the interfacial fluorine (F) content. For example, when a substrate includes tungsten disposed on a layer of titanium nitride, the hydrogen radical treatment reduces the interfacial fluorine (F) content at the interface between the tungsten and the titanium nitride. During hydrogen radical treatment of tungsten, a diatomic hydrogen (H) 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 1200 sccm, such as from about 200 sccm to about 1000 sccm, such as from about 100 sccm to about 500 sccm, such as about 200 sccm, such as from about 500 sccm to about 1200 sccm, such as about 1000 sccm. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar).

[0079]

[0087] During hydrogen radical treatment of tungsten, the temperature in the process chamber may be 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 650°C, such as about 700°C to about 800°C, such as about 750°C, such as about 800°C to about 900°C, such as about 850°C, such as about 900°C to about 1000°C, or about 950°C. Increasing the temperature in the process chamber during treatment increases the reduction in interfacial fluorine content. That is, there is a direct correlation between temperature and the reduction in interfacial fluorine content, or, in other words, there is an inverse correlation between temperature and interfacial fluorine content. For example, operating the process chamber at temperatures above about 950°C reduces the interfacial fluorine content by as much as 20 times. On the other hand, temperatures below about 650°C reduce the interfacial fluorine content by only about 1.4 times. A temperature of about 750° C. reduces the interfacial fluorine content by a factor of about 2.1. A temperature of about 850° C. reduces the interfacial fluorine content by a factor of about 4.8.

[0080]

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

[0081]

[0089] Advantageously, hydrogen radical treatment of tungsten performed using the disclosed plasma processing apparatus and methods reduces the interfacial fluorine content by a factor of about 20 or more. The increased hydrogen radical density possible using the apparatus and methods disclosed herein leads to further reduction in interfacial fluorine content. Furthermore, the effect of increasing the temperature and increasing the density of hydrogen radicals further impacts the reduction of interfacial fluorine. This is in contrast to conventional approaches, such as thermal H annealing, which do not reduce the interfacial fluorine content. Using the embodiments described herein, hydrogen radical treatment of tungsten reduces the sheet resistance (R s ) leading to a 10% reduction.

[0082]

[0090] In another example, the plasma processing apparatus of the present disclosure may be used for hydrogen radical treatment of titanium nitride (e.g., TiN) according to method 800. Using the apparatus and / or method disclosed herein, treatment of titanium nitride with hydrogen radicals may improve the R of the titanium nitride layer compared to an untreated film by reducing impurities in the titanium nitride layer. s The hydrogen radical treatment of titanium nitride reduces the H2 concentration by about 50% or more. During the hydrogen radical treatment, 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, or about 1000 sccm. In another embodiment, the hydrogen radical treatment is a two-step process, introducing an H2 source gas in a first step and then introducing an N2 source gas after the first step. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar). When the H2 source gas is mixed with Ar, the fraction of the H2 source gas is in a range of about 5% to about 90% by volume, such as about 50% by volume.

[0083]

[0091] During the hydrogen radical treatment of the titanium nitride, the temperature in the process chamber may be from about 500° C. to about 1000° C., such as from about 500° C. to about 600° C., such as from about 550° C., such as from about 600° C. to about 700° C., such as from about 650° C., such as from about 700° C. to about 800° C., such as from about 750° C., such as from about 800° C. to about 900° C., such as from about 850° C., or from about 900° C. to about 1000° C. Increasing the temperature in the process chamber during treatment increases the R of the titanium nitride layer. s The decrease in R of the titanium nitride layer increases with temperature. s The decrease in R of the titanium nitride layer is positively correlated with the temperature. s For example, operation of the process chamber at a temperature of about 550°C increases the R s decreases by between about 30% and 40%, and at a temperature of about 650°C, the R sdecreases by between about 40% and 50%, and at a temperature of about 750°C, the R s decreases by between about 50% and 60%, and at a temperature of about 850°C, the R s is reduced by between about 60% and 70%. During the hydrogen radical treatment of titanium nitride, the pressure in the process gas is about 0.2 Torr to about 3 Torr, such as about 0.5 Torr to about 3 Torr, such as about 0.5 Torr, such as about 2 Torr. The radio frequency power is about 1 kW to about 5 kW, such as about 2 kW. The treatment time is in the range of about 2 minutes to about 8 minutes, such as about 5 minutes.

[0084]

[0092] Advantageously, hydrogen radical treatment of titanium nitride performed using the plasma processing apparatus and method of the present disclosure selectively reduces titanium-oxygen bonding, thereby reducing the oxygen content in the titanium nitride layer while maintaining titanium-nitrogen bonding substantially constant. In contrast, thermal-only treatments are unable to reduce titanium-oxygen bonding. Using the embodiments described herein, there is an inverse correlation between temperature and oxygen content. Furthermore, hydrogen radical treatment reduces chlorine content similarly to thermal-only treatments. Furthermore, hydrogen radical treatment reduces carbon content, whereas thermal-only treatments are unable to reduce carbon content. Overall, reducing the impurity content of at least one of chlorine, oxygen, or carbon via hydrogen radical treatment improves the R of the titanium nitride layer compared to thermal-only treatments. s Using embodiments described herein, hydrogen radical treatment leads to a reduction in R of the titanium nitride layer compared to thermal-only treatment. s by about 6% to about 11%. It is contemplated that the hydrogen radical treatment may be performed with or without the use of a grid (e.g., the separating grid 116 shown in FIG. 1). Notably, the improvement from the hydrogen radical treatment is more pronounced without the use of a grid compared to the thermal-only treatment. In general, the application of higher temperatures in the process chamber reduces the R of the titanium nitride layer. s In other words, the temperature and grain size each affect the R of the titanium nitride layer.s is inversely correlated with

[0085]

[0093] In another example, the plasma processing apparatus of the present disclosure may be used for hydrogen radical treatment of ruthenium (Ru) according to method 800. In particular examples, the substrate undergoing the treatment process may include ruthenium formed by chemical vapor deposition (CVD). Using the apparatus and / or method disclosed herein, treatment of ruthenium with hydrogen radicals may improve gap filling and reduce R annealing of the ruthenium layer compared to H annealing without hydrogen radicals. s During hydrogen radical treatment of ruthenium, an H2 source gas is introduced into the plasma treatment source to generate hydrogen radicals. The flow rate of H2 is about 100 sccm to about 2000 sccm. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar). When the H2 source gas is mixed with Ar, the fraction of the H2 source gas is in the range of about 5% to about 90% by volume, such as about 50% by volume.

[0086]

[0094] During the hydrogen radical treatment of ruthenium, the temperature in the process chamber is about 400°C to about 500°C, such as about 450°C. The pressure in the process chamber is about 0.2 Torr to about 3 Torr. The RF power is about 1 kW to about 10 kW. The treatment time is in the range of about 0.5 minutes to about 10 minutes, such as about 1 minute to about 5 minutes, such as about 1 minute, such as about 5 minutes. As the hydrogen radical density increases during treatment, the R of the ruthenium layer is reduced. s For example, when 10% H2 source gas is introduced at 450 °C for 1 minute, the R s is reduced by about 35% to about 40% compared to the untreated film. On the other hand, when 50% H source gas is introduced at 450° C. for 5 minutes, this corresponds to a lower hydrogen radical density, and the R s is reduced by only about 30% compared to the untreated membrane.

[0087]

[0095] Advantageously, the treatment of ruthenium with hydrogen radicals carried out using the plasma processing apparatus and method of the present disclosure is similar to that of H 2 The hydrogen radical treatment improves gap filling of the ruthenium layer compared to an H anneal. Additionally, the hydrogen radical treatment increases the ruthenium grain size and reduces seam size in the ruthenium layer compared to an H anneal. Using the apparatus and / or method disclosed herein, the R annealing of the ruthenium layer is improved compared to an H anneal without hydrogen radicals. s Furthermore, hydrogen radical assisted annealing improves reflow and reduces resistance while reducing the thermal budget compared to H2 annealing without hydrogen radicals.

[0088]

[0096] In another example, a plasma processing apparatus of the present disclosure may be used for hydrogen radical treatment and optional nitrogen radical treatment of tungsten carbonitride (e.g., WCN) according to method 800. Using the apparatus and / or method disclosed herein, treating tungsten carbonitride with hydrogen radicals reduces the carbon content without increasing the nitrogen content in the tungsten carbonitride film compared to an untreated film. Using aspects described herein, treating tungsten carbonitride with hydrogen radicals and nitrogen radicals reduces the carbon content and increases the nitrogen content in the tungsten carbonitride film compared to an untreated film. During the hydrogen radical treatment of tungsten carbonitride, a H source gas is introduced into the plasma processing source to generate hydrogen radicals. The H flow rate is about 100 sccm to about 2000 sccm. During the nitrogen radical treatment of tungsten carbonitride, a N source gas is introduced into the plasma processing source to generate nitrogen radicals. The N flow rate is about 100 sccm to about 2000 sccm. It is contemplated that the source gas may be mixed with an inert gas (eg, Ar).

[0089]

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

[0090]

[0098] Beneficially, treatment of tungsten carbonitride with hydrogen radicals performed using the plasma processing apparatus and methods disclosed herein reduces the carbon content in the tungsten carbonitride film by about one-third to one-sixth of that of the untreated film, while maintaining approximately the same nitrogen content. Further treatment of the tungsten carbonitride with nitrogen radicals, using the apparatus and / or methods disclosed herein, increases the nitrogen content in the tungsten carbonitride film by about two to three times as much as the untreated film. Thus, each treatment of the tungsten carbonitride improves the film's quality compared to the untreated film.

[0091]

[0099] In another example, the plasma processing apparatus of the present disclosure may be used for seam removal of titanium nitride (e.g., TiN) according to method 800. In specific examples, the substrate undergoing the processing process may include a titanium nitride layer formed by ALD. It is contemplated that the source gas for seam removal may include O, H, N, or a mixture thereof. Introducing an O source gas improves seam removal rates compared to either H or N source gas alone. Using the apparatus and / or method disclosed herein, a three-operation process including sequential treatment with oxygen radicals followed by hydrogen radicals followed by nitrogen radicals improves seam removal rates similar to oxygen radical treatment alone, 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 gap filling between features, which removes the seam. After the oxygen radical treatment, the hydrogen radical treatment reduces the oxygen content of the titanium nitride layer while maintaining the structure of the titanium lattice. After the hydrogen radical treatment, the nitrogen radical treatment replaces the oxygen vacancies in the titanium lattice with nitrogen. This restores the titanium nitride layer without seams.

[0092]

[0100] In another embodiment, the plasma processing apparatus of the present disclosure may be used for selective oxidation of tungsten according to method 800. The selective oxidation of tungsten includes oxidizing a layer of silicon without oxidizing an adjacent layer of tungsten. During the selective oxidation of tungsten, an O source gas is introduced into the plasma processing source to generate oxygen radicals. To minimize tungsten oxidation, excess H is added to the plasma to generate a large amount of hydrogen radicals. During the selective oxidation of tungsten, the concentration of H in the source gas is about 65% to about 95% of the total flow rate of H and O. The ratio of H to O can be operable to control selectivity. For example, a concentration of H less than about 65% limits the selectivity of the oxidation process. On the other hand, a concentration of H greater than about 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 a side-inject plasma source, in which the concentration of hydrogen radicals decreases toward the center of the substrate. The flow rate of H2 is about 400 scmm to about 8000 scmm, and the flow rate of O2 is about 100 scmm to about 3000 scmm. It is contemplated that the source gases may be mixed with an inert gas (e.g., Ar).

[0093]

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

[0094]

[0102] Advantageously, selective oxidation of tungsten using the plasma processing apparatus and methods of the present disclosure achieves silicon oxide (e.g., SiO) growth rates of about 3 Å / √(sec) or greater while reducing the oxygen content to about 40 atomic % or less.

[0095]

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

[0096]

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

[0097]

[0105] Advantageously, silicon oxidation performed using the plasma processing apparatus and method of the present disclosure can achieve silicon oxide (e.g., SiO) growth rates of about 5 Å / √(sec) or greater, such as about 5 Å / √(sec) to about 6 Å / √(sec), with silicon oxide conformality of about 95% to about 100%, such as about 99%. Using the apparatus and / or method disclosed herein, the silicon oxide conformality is greater than that achieved using conventional remote plasma oxidation (RPO) processes. Using several embodiments described herein, the silicon oxide conformality depends on the concentration of the H source gas. In particular, the greater the fraction of H source gas, the greater the silicon oxide conformality. In one example, introducing a source gas having 50% H resulted in a silicon oxide conformality of about 98%, while introducing a source gas having 33% H resulted in a silicon oxide conformality of about 70%, and introducing a source gas having 5% H resulted in a silicon oxide conformality of only about 61%. Using embodiments described herein, silicon oxide conformality is independent of layer thickness at higher concentrations of H in the source gas. For example, with a source gas having about 5% H, silicon oxide conformality is dependent on layer thickness, while at higher H fractions, such as about 50% H, silicon oxide conformality is substantially independent of layer thickness.

[0098]

[0106] In another embodiment, the plasma processing apparatus of the present disclosure can be used to deposit silicon oxide (e.g., SiO x ) may be used for oxygen radical treatment and optional hydrogen radical treatment. In certain embodiments, the substrate undergoing the treatment process may include a silicon oxide layer formed by flowable CVD (FCVD). To generate oxygen radicals and / or hydrogen radicals, respectively, an O2 source gas, an H2 source gas, or a mixture thereof is introduced into the plasma treatment source. The flow rate of O2 is about 500 sccm to about 3000 sccm. The flow rate of H2 is about 25 sccm to about 200 sccm. It is contemplated that the source gases may be mixed with an inert gas (e.g., Ar).

[0099]

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

[0100]

[0108] Beneficially, oxygen radical and hydrogen radical treatment of silicon oxide films performed using the plasma processing apparatus and methods disclosed herein reduces oxygen-hydrogen bonding, silicon-hydrogen bonding, and / or nitrogen-hydrogen bonding, as measured by FTIR, compared to untreated films. In one example, extending the treatment time of oxygen radical and hydrogen radical treatment to 5 minutes can reduce the wet etch reaction rate (WERR) compared to a treatment time of 1 minute. Using the apparatus and / or methods disclosed herein, the WERR of silicon oxide films is lower than silicon oxide films treated with an anneal-only process.

[0101]

[0109] In another example, the plasma processing apparatus of the present disclosure may be used for helium radical treatment of silicon oxide (e.g., SiO) according to method 800. In specific examples, the substrate undergoing the treatment process may include a silicon oxide layer (e.g., a high-temperature oxide (HTO) layer) formed by ALD. It is contemplated that the helium radical treatment may be used for all types of ALD films. During the 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 about 100 sccm to about 2000 sccm. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar).

[0102]

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

[0103]

[0111] Beneficially, helium radical treatment of silicon oxide layers using the disclosed plasma processing apparatus and method improves the film quality and reduces leakage of the silicon oxide layer compared to untreated films. Using the apparatus and / or method disclosed herein, film quality is improved by about 50% to about 60% compared to untreated films. Film quality refers to the portion of the film that is etched, resulting in a reduction in the WERR of the treated film. Furthermore, sidewall conformality after wet etching of the silicon oxide layer is improved to a greater extent at lower pressures (i.e., at 0.5 Torr compared to 2 Torr).

[0104]

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

[0105]

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

[0106]

[0114] Advantageously, hydrogen radical treatment of boron-rich amorphous carbon films performed using the plasma processing apparatus and methods of the present disclosure reduces the hydrogen content of the films, thereby increasing their Young's modulus and density compared to untreated films. Generally, hydrogen radical treatment results in films with lower overall stress and higher density, which improves film stability compared to untreated films.

[0107]

[0115] In another embodiment, the plasma processing apparatus of the present disclosure may be used for various ALD pre- and post-treatments using a source gas including at least one of H, NH, N, O, or Ar according to method 800.

[0108]

[0116] In one embodiment, the plasma processing apparatus of the present disclosure may be used to process silicon nitride (e.g., SiN) films according to method 800. During hydrogen radical processing, an H source gas is introduced into the plasma processing source to generate hydrogen radicals. The flow rate of H is about 500 sccm to about 1500 sccm, such as about 1000 sccm. The fraction of H in the source gas is about 50% by volume. During combined hydrogen and nitrogen radical processing, N is optionally added to the plasma processing source to generate nitrogen radicals after processing with hydrogen radicals. The flow rate of N is about 200 sccm to about 400 sccm, such as about 300 sccm. The fraction of H in the source gas is about 10% by volume. It is contemplated that other nitrogen source gases may be utilized. For example, NH may be introduced into the plasma processing source to generate NH radicals. The flow rate of NH3 is about 200 sccm to about 400 sccm, about 300 sccm, etc. The fraction of NH3 in the source gas is about 10% by volume. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar).

[0109]

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

[0110]

[0118] Beneficially, treatment of silicon nitride films performed using the disclosed plasma processing apparatus and method reduces the impurity content of at least one of oxygen, hydrogen, or chlorine compared to untreated films. Using the apparatus and / or method disclosed herein, hydrogen radical treatment, nitrogen radical treatment, and / or NH radical treatment of silicon nitride films reduces WERR compared to WERR of silicon nitride films treated using rapid thermal processing (RTP) annealing. Using the embodiments described herein, the effects of silicon nitride treatment are most pronounced on the top surface of the film (e.g., within 20 angstroms of the surface). Notably, combined treatment with hydrogen radicals and nitrogen radicals generated using H and N source gases, respectively, improves hydrogen removal from silicon nitride films compared to single treatments using either hydrogen radicals or NH radicals generated using H or NH source gases, respectively. Furthermore, a combined treatment with hydrogen radicals and nitrogen radicals generated using H2 and N2 source gases, respectively, improves the removal of chlorine from silicon nitride films compared to a single treatment with either nitrogen radicals or NH radicals generated using N2 or NH3 source gases, respectively.

[0111]

[0119] In another example, the plasma processing apparatus of the present disclosure may be used for silicon nitride (e.g., SiN) seam removal according to method 800. In specific examples, the substrate undergoing the processing process may include a silicon nitride layer formed by ALD. It is contemplated that the source gas may include O, H, N, or a mixture thereof. In one example, the processing includes only one operation including an O source gas. In another example, the processing includes two operations including an O source gas before an H source gas. In yet another example, the processing includes three operations including an O source gas before an H source gas before an N source gas. An O source gas is introduced into the plasma processing source to generate oxygen radicals. The O flow rate is about 2500 sccm to about 3500 sccm, such as about 3000 sccm. After processing with oxygen radicals, an H source gas is optionally introduced into the plasma processing source to generate hydrogen radicals. The flow rate of H2 is about 200 sccm to about 500 sccm, such as about 300 sccm to about 350 sccm, such as about 300 sccm, such as about 350 sccm. After processing with oxygen radicals and hydrogen radicals, an N2 source gas is optionally added to the plasma processing source to generate nitrogen radicals. The flow rate of N2 is about 200 sccm to about 400 sccm, such as about 300 sccm. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar).

[0112]

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

[0113]

[0121] Beneficially, a sequential process using oxygen radicals followed by hydrogen radicals followed by nitrogen radicals improves seam removal rates similar to oxygen radical treatment alone, 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 method disclosed herein, the oxygen radical treatment oxidizes the silicon nitride, resulting in volume expansion and gap filling between features. This removes seams. After the oxygen radical treatment, a hydrogen radical treatment reduces the oxygen content of the silicon nitride layer while maintaining the structure of the silicon lattice. After the hydrogen radical treatment, a nitrogen radical treatment replaces oxygen in the silicon lattice with nitrogen. This restores the silicon nitride layer without seams.

[0114]

[0122] In another embodiment, the plasma processing apparatus of the present disclosure may be used for various gas-phase doping processes using a source gas including at least one of PH, BF, AsH, or Ga according to method 800.

[0115]

[0123] In another example, the plasma processing apparatus of the present disclosure may be used to nitridize a high-k dielectric material, such as hafnium oxide (e.g., HfO), according to method 800. In specific examples, the substrate undergoing the processing process includes a silicon substrate, an interfacial layer (e.g., comprising silicon oxide) on the silicon substrate, and a layer of hafnium oxide on the interfacial layer. During the high-k nitridation, a mixture of N and NH is introduced into the plasma processing source to generate nitrogen and NH radicals. The flow rate of N is about 30 sccm to about 180 sccm, such as about 50 sccm to about 150 sccm, such as about 50 sccm to about 100 sccm, such as about 50 sccm, about 100 sccm to about 150 sccm, such as about 100 sccm, or about 120 sccm. The flow rate of NH is about 10 sccm to about 50 sccm, such as about 10 sccm to about 20 sccm, such as about 15 sccm. It is contemplated that the source gas may be mixed with an inert gas (e.g., Ar), with the flow rate of Ar being from about 2500 sccm to about 3500 sccm, such as about 3000 sccm.

[0116]

[0124] During the nitridation of hafnium oxide, the temperature in the process chamber may be less than about 400°C, such as from about 150°C to about 400°C, such as from about 200°C to about 300°C, such as from about 300°C to about 400°C, such as about 300°C, or about 325°C. The temperature may be increased during the nitridation of hafnium oxide. For example, the temperature may be increased from less than about 200°C to above about 300°C. The increase time may be from about 60 seconds to about 120 seconds, such as about 90 seconds. The pressure in the process chamber may be from about 0.5 Torr to about 2 Torr, such as about 0.75 Torr. The radio frequency power may be from about 5 kW to about 10 kW, such as about 8 kW. The processing time may be in the range of about 20 seconds to about 5 minutes, such as from 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, or about 4 minutes. The reduced processing time associated with nitriding hafnium oxide using the apparatus and / or methods disclosed herein improves throughput compared to nitriding using a mixture of NH3 and Ar gas in a conventional ICP chamber.

[0117]

[0125] Beneficially, nitriding hafnium oxide using a mixture of N2 and NH3 gases substantially prevents thinning of the interfacial layer compared to nitriding using a mixture of NH3 and Ar gases in a conventional ICP chamber. The addition of N2 source gas to the NH3 source gas reduces the concentration of hydrogen radicals by combining with them to produce NH radicals. This reduction in hydrogen radicals reduces their attack on the interfacial layer, thereby preventing thinning of the interfacial layer. Furthermore, using a mixture of N2 and NH3 substantially prevents thinning of the interfacial layer compared to N2 alone. The addition of Ar to the N2 and NH3 mixture increases the nitriding rate compared to N2 and NH3 without the addition of Ar.

[0118]

[0126] Generally, when using the apparatus and / or method disclosed herein with a mixture of N2 and NH3, reducing the temperature further inhibits thinning of the interfacial layer. For example, temperatures below about 400°C inhibit thinning of the interfacial layer compared to higher temperatures. Generally, when using the apparatus and / or method disclosed herein with a mixture of N2 and NH3, increasing the treatment time increases the nitrogen content in the hafnium oxide layer. For example, a treatment time in the range of about 2 to about 3 minutes increases the nitrogen content from less than about 5% to about 15 to about 20%, maintaining the interfacial layer thickness approximately equal to the pre-nitridation thickness. However, treatment times above about 4 minutes lead to thickening of the interfacial layer compared to relatively shorter treatment times. Therefore, it may be desirable to limit the treatment time to less than about 4 minutes. Generally, when using the apparatus and / or method disclosed herein with a mixture of N2 and NH3, reducing the pressure increases the nitrogen content in the hafnium oxide layer and further inhibits thinning of the interfacial layer. For example, a pressure of less than about 1 Torr increases the nitrogen content above about 10% while maintaining the interfacial layer thickness approximately equal to the pre-nitridation thickness. Generally, using the apparatus and / or methods disclosed herein with a mixture of N2 and NH3 increases hafnium-nitrogen bonding and substantially prevents the formation of nitrogen-oxygen metastable bonds. Using the apparatus and / or methods disclosed herein improves conformality and uniform pattern loading due to the increased concentration of NH radicals compared to using conventional ICP chambers.

[0119]

[0127] As used herein, terms such as "inside" and "outside," "up" and "down," "upper" and "lower," "top" and "bottom," "vertical" and "horizontal," "upward" and "downward," "above" and "below," and other similar terms refer to positions relative to one another and are not intended to indicate a particular direction or spatial orientation of the overall source / device. As used herein, the term "approximately" or "about" refers to being within at least ±5% of a reference value.

[0120]

[0128] While the forgoing is directed to several embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.

Claims

1. a first sidewall forming a cylinder; a gas injection insert disposed within the cylinder and positioned at an upper end of the first sidewall, the gas injection insert having a second sidewall having a cylindrical shape, the gas injection insert and the first sidewall defining a plasma source interior volume, the gas injection insert comprising: a peripheral gas injection port coupled to the first sidewall, the peripheral gas injection port being disposed radially outward of the central gas injection port and the second sidewall and radially inward of the first sidewall, the peripheral gas injection port fluidly communicating with the plasma source interior volume and having an outlet positioned at a first vertical position; a gas injection insert disposed about the second sidewall, the gas injection insert including a central gas injection port having an outlet positioned at a second vertical position different from the first vertical position, the central gas injection port in fluid communication with the plasma source interior; and the central gas injection port having an angled gas outlet at an angle of about 0 degrees to about 60 degrees relative to a central axis of the central gas injection port.

2. The plasma source of claim 1 , wherein the peripheral gas injection ports are adjacent to and arranged around the central gas injection port.

3. The plasma source of claim 1 , wherein the central gas injection port has a cylindrical shape.

4. 10. The plasma source of claim 1, wherein the vertical center of the induction coil is substantially aligned along a plane of a lower surface of the central gas injection port within about 1 cm to about 2 cm of the vertical center.

5. an induction coil disposed adjacent to and around the sidewall; and The plasma source of claim 1 further comprising a radio frequency power generator coupled to the induction coil.

6. a first sidewall and a gas injection insert defining a plasma source interior volume, the gas injection insert including a peripheral gas injection port; a central gas injection port and a second sidewall, the central gas injection port being proximate to and disposed about the second sidewall; an induction coil disposed proximate to the first sidewall and disposed about the first sidewall; and a radio frequency power generator coupled to the induction coil; a plasma source, wherein the induction coil is aligned with the plane of the lower surface of the gas injection insert such that an upper portion of the induction coil is above the lower surface and a lower portion of the induction coil is below the lower surface, and wherein the central gas injection port has an angled gas outlet at an angle of about 0 degrees to about 60 degrees relative to a central axis of the central gas injection port.

7. the plasma source further comprises a separate induction coil; The plasma source of claim 6 , wherein the induction coil is disposed around the first sidewall, the further induction coil, and the second sidewall.

8. The plasma source of claim 7 further comprising a separator coupled to a surface of the gas injection insert.

9. A plasma processing method, comprising: introducing a first process gas into a region of the plasma source through outlets of one or more peripheral channels fluidly connected to one or more peripheral gas injection ports of the plasma source, and introducing a second process gas into the region through a central channel fluidly connected to a central gas injection port of the plasma source, the central channel being fluidly isolated from the peripheral channels upstream of the region, the central channel being disposed within a gas injection insert and fluidly coupled to a first gas supply plenum, the first gas supply plenum being fluidly coupled to a second gas supply plenum between a lower edge of the gas injection insert and a feed platform, the feed platform being configured to direct gas horizontally, the second gas supply plenum being vertically offset from the outlets of the one or more peripheral channels, the plasma source including a dielectric sidewall surrounding the gas injection insert and the region, the plasma source being surrounded by an inductive coil; generating an inductively coupled plasma in the region using the inductive coil positioned proximate a sidewall of the dielectric and horizontally overlapping the region, the plasma comprising at least one radical species selected from oxygen, nitrogen, hydrogen, NH, and helium; supplying the plasma from the plasma source to a process chamber coupled to the plasma source, the plasma flowing through a separation grid positioned between the plasma source and a substrate to be processed; processing the substrate in the process chamber, wherein processing the substrate comprises: contacting the plasma containing the at least one radical species with a first side of the substrate facing the separation grid; and heating the substrate using a plurality of lamps positioned on a second side of the substrate opposite the separation grid, wherein the central gas injection port has an angled gas outlet at an angle of about 0 degrees to about 60 degrees relative to a central axis of the central gas injection port.

10. 10. The method of claim 9, wherein the substrate comprises a layer of tungsten carbonitride, the process gas comprises hydrogen gas, the plasma comprises hydrogen radicals, and wherein contacting the hydrogen radicals with the layer of tungsten carbonitride during heating reduces the carbon content in the layer of tungsten carbonitride by about three to about six times without reducing the nitrogen content in the layer of tungsten carbonitride.

11. After treating the substrate with the plasma, the method comprises: introducing nitrogen gas into the region of the plasma source through the one or more peripheral gas injection ports and the central gas injection port; generating a nitrogen plasma in the region, the nitrogen plasma including nitrogen radicals; providing the nitrogen plasma from the plasma source to the process chamber; and further comprising treating the substrate with the nitrogen plasma in the process chamber, wherein treating the substrate comprises: contacting the nitrogen plasma containing the nitrogen radicals with the first side of the substrate facing the separation grid; and 11. The method of claim 10, comprising heating the substrate using the plurality of lamps positioned on the second side of the substrate opposite the separation grid, wherein contacting the nitrogen radicals with the tungsten carbonitride layer during heating increases the nitrogen content in the tungsten carbonitride layer by about two to about three times.

12. The substrate includes a seam and a layer of titanium nitride having a starting stoichiometric ratio of titanium to nitrogen, and the method includes a series of three operations, the operations being: a first operation, wherein the process gas comprises oxygen gas, the plasma comprises oxygen radicals, and contacting the oxygen radicals with the titanium nitride layer during heating oxidizes the titanium nitride layer and causes a volume expansion of the titanium nitride layer; a second operation, wherein the process gas comprises hydrogen gas and the plasma comprises 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 eliminating the seam and changing the stoichiometric ratio of titanium to nitrogen; and 10. The method of claim 9, further comprising a third operation in which the process gas comprises nitrogen gas, the plasma comprises nitrogen radicals, and contacting the nitrogen radicals with the titanium nitride layer during heating increases the nitrogen content of the titanium nitride layer, thereby substantially restoring the starting stoichiometric ratio of titanium to nitrogen in the titanium nitride layer without the seam.

13. 10. The method of claim 9, wherein the substrate comprises a layer of silicon oxide, the process gas comprises a mixture of oxygen gas and hydrogen gas, the plasma comprises oxygen radicals and hydrogen radicals, and wherein contacting the oxygen radicals and the hydrogen radicals with the silicon oxide layer during heating reduces oxygen-hydrogen bonds, silicon-hydrogen bonds, and nitrogen-hydrogen bonds in the silicon oxide layer compared to the silicon oxide layer before treatment.

14. 10. The method of claim 9, wherein the substrate comprises a layer of silicon oxide, the process gas comprises helium gas, the plasma comprises helium radicals, and wherein contacting the helium radicals with the silicon oxide layer during heating improves film quality of the silicon oxide layer compared to the silicon oxide layer before treatment.

15. The method of claim 9 , wherein treating the substrate comprises a post-chemical vapor deposition treatment.

16. The method of claim 9 , wherein treating the substrate comprises atomic layer deposition pre- or post-treatment.

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