Remote plasma source and plasma processing chamber equipped therewith

Abstract

A method and apparatus for a use-point type remote plasma source are provided. In an embodiment, the remote plasma apparatus comprises an enclosure surrounding a cavity, a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The first and second portions of the enclosure overlap by an amount of overlap. Each of the first and second conductors is discontinuous in the circumferential direction. The remote plasma apparatus comprises a dielectric layer disposed between the first and second conductors and separating them, a gas inlet for introducing gas into the cavity, and a gas outlet located at the bottom of the enclosure for releasing gas from the cavity.

Description

Field

[0001] Embodiments of the present disclosure generally relate to substrate processing, and more particularly to plasma processing of substrates. Background

[0002] Plasma-assisted processing is often used in substrate processing (e.g., deposition, etching, or processing of a material layer on a substrate). In addition to plasma processing, radical etching and other radical processes generated from a remote plasma device are also used in substrate processing. Accordingly, the inventor provides an improved remote plasma source for substrate processing. This remote plasma source can be suitably used in conjunction with a chamber configured for plasma processing. Summary

[0003] A method and apparatus for a use-point type remote plasma source are provided. In an embodiment, the remote plasma device includes an enclosure surrounding a cavity, a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The first portion of the enclosure and the second portion of the enclosure overlap by an overlapping amount, and each of the first conductor and the second conductor is circumferentially discontinuous. The remote plasma device includes a dielectric layer disposed between and separating the first conductor and the second conductor, a gas inlet for introducing gas into the cavity, and a gas outlet disposed at the bottom of the enclosure for exhausting gas from the cavity.

[0004] In some embodiments, the remote plasma apparatus comprises an enclosure having an upper end, one or more side walls forming a cavity inside, and an opening lower end that can engage with a processing chamber, the enclosure having an enclosure circumference and enclosure height, a first conductor disposed on a first portion of the enclosure and in contact with the outer surfaces of one or more side walls, a dielectric layer comprising sheets of dielectric material disposed on the outer surfaces of the first conductor and one or more side walls, and a second conductor disposed on a second portion of the enclosure and in contact with the outer surface of the dielectric layer, comprising a metal sheet. Each of the first and second conductors independently has a conductor length of about 99% or less of the enclosure circumference and a conductor height of about 50% or more of the enclosure height. The first and second portions of the enclosure are different and overlap by an amount. The first conductor, the second conductor and the dielectric layer are sized to resonate at RF (radio frequency) frequencies in the range of about 400 kHz to 10,000 GHz and are arranged around the enclosure. The gas inlet comprises a first set of inlet conduits sized and positioned to direct the gas flow into the cavity, and a second set of inlet gas conduits sized and positioned to direct the gas flow around the cavity to a processing chamber where a remote plasma device is installed. The gas outlet is located at the bottom of the enclosure and is configured to allow the gas to flow out of the cavity. The gas outlet includes a gas distribution plate with multiple holes arranged through it.

[0005] In some embodiments, the plasma processing chamber comprises a chamber surrounding a processing volume, a substrate support configured to support a substrate within the processing volume during use, a first RF source configured to supply RF energy at a predetermined frequency, and a remote plasma device coupled to the chamber and the first RF source. The remote plasma device may comprise an enclosure surrounding a cavity, a first gas inlet configured to allow gas to flow into the cavity, a gas outlet located at the bottom of the enclosure and configured to allow gas to flow out of the cavity into the processing volume, a first conductor surrounding a first portion of the enclosure, a dielectric layer disposed on the first conductor, and a second conductor surrounding a second portion of the enclosure. The first and second portions of the enclosure overlap by an amount. The first conductor, the dielectric layer, and the second conductor, when placed within the enclosure, at least partially form a capacitor that resonates near a frequency suitable for creating an electromagnetic field within the enclosure that is suitable for forming radicals from the gas.

[0006] Other and further embodiments of this disclosure are described below. [Brief explanation of the drawing]

[0007] The embodiments of this disclosure, briefly outlined above and described in more detail below, can be understood by referring to the exemplary embodiments of this disclosure shown in the accompanying drawings. However, the accompanying drawings only show typical embodiments of this disclosure and therefore do not limit the scope of this disclosure. This disclosure may also encompass other equally effective embodiments. [Figure 1A] This is a side cross-sectional view of a remote plasma apparatus according to embodiments disclosed herein. [Figure 1B] A schematic cross-sectional top view of a remote plasma apparatus according to embodiments disclosed herein is shown. [Figure 1C] A cross-sectional view of a gas distribution plate according to an embodiment disclosed herein is shown. [Figure 1D] A cross-sectional view of a gas distribution plate according to an embodiment disclosed herein is shown. [Figure 1E] A schematic side view of a remote plasma apparatus having a helical first conductor according to an embodiment disclosed herein is shown. [Figure 2A] This is a perspective view of an enclosure for a remote plasma device according to embodiments disclosed herein. [Figure 2B] An embodiment disclosed herein shows a first conductor as a flat sheet. [Figure 2C] Figure 2B shows the first conductor, which is formed in the shape of a "C", according to an embodiment disclosed herein. [Figure 2D] An embodiment disclosed herein shows a first conductor as a flat sheet having a nonlinear edge. [Figure 3A] This document shows an exploded view of a remote plasma device according to embodiments disclosed herein. [Figure 3B] A schematic diagram of a conductor combined with a capacitor according to an embodiment disclosed herein is shown. [Figure 4] This is a block diagram showing a processing chamber according to an embodiment disclosed herein. [Figure 5] This is a block diagram showing a remote plasma apparatus having various gas inlets in a cavity according to embodiments disclosed herein. [Figure 6A] ~ [Figure 6B] This shows a side cross-sectional view of a remote plasma apparatus according to an embodiment disclosed herein. [Figure 7] This is a block diagram showing a processing chamber equipped with multiple remote plasma devices according to embodiments disclosed herein. [Figure 8] This is a flowchart illustrating a method for generating plasma according to embodiments disclosed herein.

[0008] For ease of understanding, the same reference numerals have been used for identical elements common to the drawings whenever possible. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment can be usefully incorporated into other embodiments without further explanation. Detailed description

[0009] In this specification, the terms “above,” “above,” “above,” “below,” and “between” mean the relative position of one component (e.g., a layer) to another component. Therefore, when a component is positioned above, above, above, or below another component, that component may be in direct contact with the other component or may have one or more intervening components. Furthermore, when a component is positioned between two other components, that component may be in direct contact with these components or may have one or more intervening components. On the other hand, when a component is in contact with another component, that means the two components are in direct contact with each other.

[0010] In this embodiment, the remote plasma apparatus comprises an enclosure surrounding a cavity, a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The area of ​​the first portion and the area of ​​each of the second portions are smaller than the total area of ​​the enclosure. The second conductor is separated from the first conductor by a dielectric layer. The first and second portions of the enclosure overlap by a certain amount. The remote plasma apparatus comprises a gas inlet for introducing gas into the cavity and a gas outlet for releasing gas from the cavity. In this embodiment, the first and second portions are different.

[0011] In this embodiment, the remote plasma device comprises an enclosure surrounding a cavity, a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The first and second portions of the enclosure overlap by a certain amount. The first and second conductors are discontinuous in the circumferential direction. The remote plasma device comprises a dielectric layer positioned between the first and second conductors to separate them, a gas inlet for introducing gas into the cavity, and a gas outlet positioned at the bottom of the enclosure for releasing gas from the cavity. In this embodiment, the first and second portions are different.

[0012] In this embodiment, the enclosure comprises a hollow cylinder with one end closed opposite the gas outlet, having an enclosure circumference and a cylindrical height, with a cavity formed within the hollow cylinder. Each of the first and second conductors is a C-shaped metal plate, with each conductor length being approximately 99% or less of the enclosure circumference and a height being approximately 50% or more of the cylindrical height. In this embodiment, the dielectric is a cylindrical sheet of dielectric material, with a dielectric height equal to or greater than the conductor height of the first conductor.

[0013] In the embodiment, the first conductor includes a metal sheet disposed on the outer surface of the enclosure. The dielectric layer includes a dielectric sheet disposed on the outer surface of the first conductor and the outer surface of the enclosure. The second conductor is a metal sheet disposed on the outer surface of the dielectric layer. In the embodiment, the dielectric layer includes a dielectric cylinder disposed on the outer surface of the first conductor and the outer surface of the enclosure.

[0014] In the embodiment, at least one of the first or second conductor is helical, comprising a plurality of windings arranged around a corresponding portion of the enclosure. In the embodiment, the first conductor is helical, comprising a plurality of windings arranged around a first portion of the enclosure.

[0015] In the embodiment, at least one of the first and second conductors is provided with at least one through-hole and / or nonlinear edge, which is sized and arranged to reduce or eliminate eddy currents induced in the remote plasma device by an external RF source.

[0016] In an embodiment, the first conductor, the second conductor, and the dielectric layer are dimensioned to resonate at an RF frequency in the range of about 400 kHz to 10,000 GHz and are disposed around the enclosure. Further, in an alternative embodiment, the remote plasma device includes one or more capacitors that are electrically communicative between the first conductor and the second conductor, whereby the remote plasma device resonates at an RF frequency in the range of about 400 kHz to 10,000 GHz. In an embodiment, the second conductor is movable relative to the first conductor to vary the amount of overlap, and resonance can be variably controlled. In an embodiment in which the remote plasma device is used connected to another RF plasma source for forming and / or supplying plasma to the processing space of a processing chamber to which the remote plasma device is coupled, the remote plasma device can be advantageously configured to resonate at a frequency different from that of the other RF plasma source to prevent interference between the two RF systems.

[0017] In an embodiment, the gas inlet includes a plurality of inlet ducts. The inlet ducts are dimensioned and arranged to direct a gas flow into the cavity. The direction of its inflow is diametrically opposite to the direction of the gas flow flowing out of the cavity through the gas outlet. In an embodiment, the gas inlet includes a plurality of first inlet ducts dimensioned and arranged to direct a gas flow into the cavity and a plurality of second inlet gas ducts dimensioned and arranged to direct a gas flow around the cavity and into the processing chamber to which the remote plasma device is attached.

[0018] Further, in an embodiment, the remote plasma device includes a gas distribution plate that covers the gas outlet. The plate is provided with a plurality of through holes. Further, in an embodiment, the remote plasma device is disposed within or in the vicinity of the gas outlet and includes a grounding element configured to limit or prevent ions from flowing out of the cavity.

[0019] In an embodiment, the remote plasma device includes an enclosure having an upper end, a plurality of sidewalls that form a cavity therein, and an opening lower end that can engage with a processing chamber. The enclosure has an enclosure circumference and an enclosure height. A first conductor including a metal sheet is disposed on a first portion of the enclosure so as to contact the outer surface of the sidewall. A dielectric layer including a dielectric sheet is disposed on the outer surface of the first conductor and the outer surfaces of the plurality of sidewalls. A second conductor including a metal sheet is disposed on a second portion of the enclosure so as to contact the outer surface of the dielectric layer. Each of the first conductor and the second conductor independently has a conductor length of about 99% or less of the enclosure circumference and a conductor height of about 50% or more of the enclosure height. The first portion and the second portion of the enclosure are different and overlap by an overlap amount. A gas inlet including a first plurality of inlet conduits is sized and arranged to guide a gas flow into the cavity. A second plurality of inlet gas conduits can be sized and arranged to bypass the cavity and guide a gas flow to a processing chamber to which the remote plasma device is attached. A gas outlet is configured to allow gas to flow out of the cavity. The gas outlet can include a gas distribution plate having a plurality of through holes. The first conductor, the second conductor, and the dielectric layer are sized to resonate at an RF frequency in the range of about 400 kHz to 10,000 GHz (e.g., a frequency provided by an RF source coupled to the remote plasma device) and are disposed around the enclosure. Further, in some such embodiments, the remote plasma device includes one or more capacitors that are electrically communicative between the first conductor and the second conductor to provide a desired resonance at an RF frequency in the range of about 400 kHz to 10,000 GHz. [[ID=…]] [[ID=…]]

[0020] {[[ID=…]] In some embodiments, the processing chamber comprises a conductive body and a dielectric lid defining the processing volume. Furthermore, the processing chamber may include an RF source, which includes an RF feeding structure for coupling the RF source to one or more inductive coils coaxially arranged near the processing chamber, and is configured to inductively couple RF energy to the processing volume. Alternatively, the RF source may be capacitively coupled to the processing chamber via electrodes located, for example, on the lid, showerhead, substrate support, or other components of the processing chamber. Furthermore, the processing chamber comprises at least one remote plasma device comprising an enclosure surrounding the cavity, a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The second conductor is separated from the first conductor by a dielectric layer. Parts of each conductor overlap by an amount of overlap. A first gas inlet is provided for introducing gas into the cavity. In some embodiments, a second gas inlet is provided independently of the first gas inlet for introducing gas into the processing volume.

[0021] In the embodiment, the gas outlet of the remote plasma device is directly attached to the outer surface of the processing chamber (e.g., the lid, side, or bottom of the processing chamber), and the gas outlet is essentially located at the entrance of the processing chamber. In the embodiment, the remote plasma device is mounted close to the processing chamber such that the gas outlet is located within approximately 30.5 cm of the processing chamber. By positioning the gas outlet of the remote plasma device close to the processing volume of the processing chamber, radical recombination that may occur due to increased transit time and travel distance when the remote plasma device is positioned far from the processing volume can be advantageously suppressed.

[0022] Furthermore, in the embodiment, the remote plasma device includes a grounding element near the gas outlet to adequately prevent at least some ions from flowing out of the gas outlet. In the embodiment, the gas flow flowing out of the gas outlet contains radicals generated in the cavity. In the embodiment, the first and second conductors are sized and positioned to prevent parasitic loads on the RF source. In the embodiment, at least one of the first and second conductors has at least one through-hole and / or nonlinear edge, which is sized and positioned to reduce or eliminate eddy currents induced in the remote plasma device by the RF source. In the embodiment, the first conductor, the second conductor and the dielectric layer are sized and positioned around the enclosure and / or one or more capacitors are placed electrically in communication between the first and second conductors. This causes the remote plasma device to resonate at RF frequencies in the range of approximately 400 kHz to 10,000 GHz.

[0023] In embodiments, a plasma generation method is provided, comprising the step of flowing gas through a gas inlet of a remote plasma device, according to one or more embodiments disclosed herein. Furthermore, the plasma generation method may include the step of positioning the remote plasma device in close proximity to an RF source. In embodiments of the plasma generation method, the first conductor, the second conductor, and the dielectric layer are sized to resonate at an RF frequency sufficient to generate plasma in the cavity and are arranged around the enclosure.

[0024] Figure 1A is a side cross-sectional view of a remote plasma apparatus 100 according to an embodiment disclosed herein. An enclosure 102 surrounds a cavity 104 formed within one or more side walls 106 of the enclosure 102. The enclosure 102 is generally suitable for operation at vacuum pressures such as pressures in the range of 0.1 mTorr to 100 Torr, or other pressures as needed. In the embodiment, a first conductor 108 surrounds a first portion of the enclosure, and a second conductor 114 surrounds a second portion of the enclosure. In the embodiment, each of the first conductor 108 and the second conductor 114 is discontinuous in the circumferential direction to avoid the formation of eddy currents, for example, during use. The second conductor 114 is separated from the first conductor 108 by a dielectric layer 116. For example, the first conductor 108 can be placed around the outer surface 132 of the enclosure 102, the first conductor 108 can be surrounded by a dielectric layer 116 (for example, a tubular dielectric sleeve), and the second conductor 114 can be placed around the dielectric layer 116.

[0025] Furthermore, the remote plasma apparatus 100 includes one or more first gas inlets 130, each containing one or more inlet conduits 134 having dimensions, arrangement, or other configurations that allow gas to flow into the cavity 104 via a terminal gas inlet 135, and a gas outlet 120 configured to allow gas to flow out of the cavity 104. A gas line 145 can be connected to one or more first gas inlets 130 to supply gas to the cavity 104.

[0026] The enclosure 102 (or cup 101) and dielectric layer 116 can be formed from ceramic (e.g., alumina), quartz, etc. The first conductor 108 and the second conductor 114 can be formed from suitable conductive materials such as copper, aluminum, etc.

[0027] For example, in some embodiments, the enclosure 102 is formed by a cup 101 surrounding a cavity 104, with a flange 103 provided around the open end of the cup 101. The cup 101 can be mounted on a base 113. The base 113 may include projections or recesses for receiving the flange 103. To facilitate sealing between the cup 101 and the base 113, grooves for receiving a gasket (e.g., an O-ring) can be formed in at least one of the base 113 or the flange 103. The first conductor 108, the dielectric layer 116, and the second conductor 114 can be arranged around the side wall (e.g., side wall 106) of the cup 101.

[0028] An RF source 152 is coupled to the remote plasma device 100. The RF source 152 can be capacitively or inductively coupled to the remote plasma device 100. For example, an RF signal from the RF source 152 can be coupled to either a first conductor 108 or a second conductor 114 via a conductor, with the other providing an RF feedback path to ground. Alternatively, conductors can be arranged in a loop around the remote plasma device 100 in close proximity to the first conductor 108 and the second conductor 114, thereby inductively coupling the RF energy flowing through the conductors to the remote plasma device 100. The first conductor 108 and the second conductor 114 are configured to resonate at or near the frequency of the RF source 152.

[0029] In some embodiments, one or more inlet conduits 134 of the first gas inlet 130 have dimensions, arrangement, or other configurations that allow gas to flow into the cavity. In some embodiments, one or more inlet conduits 134 allow gas to flow into the cavity in an inlet direction 136 that is linearly opposite to the outflow direction 138 of the gas flow that flows out of the cavity through the gas outlet. In the illustrated example, the first gas inlet 130 is located at the lower end 112 of the enclosure 102. However, the first gas inlet 130 can also be located on the side wall or upper end 110 of the enclosure 102, either alternatively or in combination (see, for example, Figure 5 below).

[0030] In some embodiments, the remote plasma apparatus 100 includes one or more baffles positioned within the cavity 104 of the enclosure 102, which can extend the gas residence time in the plasma volume and enhance radical generation. For example, as shown in Figure 6A, the remote plasma apparatus 100 includes a baffle 602 positioned within the cavity 104. The baffle 602 can be formed as a tube having an open end adjacent to the gas outlet 120 (and gas distribution plate 126) and a closed end on the opposite side positioned near the top of the enclosure 102. In the embodiment shown in Figure 6A, the baffle 602 can be sized to form a larger plasma volume 604 enclosed by the baffle 602 and a smaller gap 606 that is large enough to prevent plasma formation within the gap 606, based on processing conditions (e.g., pressure, RF frequency, applied RF power, etc.). The closed end of the tube includes one or more through holes 608. As indicated by the arrows in Figure 6A, the gas supplied through the gas inlet 135 flows along the gap 606 outside the baffle 602, reaches the top of the cavity 104, passes through one or more through-holes 608, and flows into the plasma volume 604. In the plasma volume 604, the plasma can decompose the gas to form radicals. The gas then passes through the gas outlet 120 (e.g., the gas distribution plate 126) and flows into the processing volume 146 of the processing chamber to which the remote plasma device 100 is installed.

[0031] In some embodiments, as shown in Figure 6B, the remote plasma apparatus 100 includes a baffle 602 located within a cavity 104. The baffle 602 can be formed as a tube having an open end adjacent to the gas outlet 120 (and gas distribution plate 126) and an opposite closed end located near the top of the enclosure 102. In the embodiment shown in Figure 6B, the baffle 602 can be sized to form an inner plasma volume 604 enclosed by the baffle 602 and an outer plasma volume 607 located between the baffle 602 and the inner sidewall of the enclosure 102. Plasma can be formed in both the inner plasma volume 604 and the outer plasma volume 607. In embodiments, the plasma in the outer plasma volume 607 may be a stronger plasma (e.g., a primary plasma or dominant plasma), and the plasma formed in the inner plasma volume 604 may be a weaker plasma. The baffle 602 has a plurality of through holes 608 formed near the closed end of the tube. For example, through-holes can be formed near the end of the baffle 602 opposite to the open end (e.g., along the side wall of the baffle 602). Alternatively or in combination, through-holes 608 can be formed at the closed end of the tube. As indicated by the arrows in Figure 6A, the gas supplied from the gas inlet 135 flows outside the baffle 602 along the outer plasma space 607, where the plasma can dissociate the gas to form radicals. It then reaches the top of the cavity 104 and then enters the inner plasma space 604 through a number of through-holes 608, where the plasma can further dissociate the gas to form radicals. The gas then passes through the gas outlet 120 (e.g., the gas distribution plate 126) and flows into the processing space 146 of the processing chamber to which the remote plasma device 100 is mounted.

[0032] As shown in Figure 1A, in this embodiment, the remote plasma apparatus 100 may further include a clamp feature 154 which may include an upper clamp element 156 and a lower clamp element 158. The clamp feature 154 may also include one or more mounting holes 160 which may include screw members or other types of fasteners 161 for securing the remote plasma apparatus 100 to the wall or lid 162 of the processing chamber. As shown in Figure 1A, the clamp feature 154 may engage with the wall or lid 162 of the processing chamber via a corresponding channel 164 having an engaging surface 166 that engages with the lower clamp element 158.

[0033] As shown in Figure 1A, in an embodiment, the remote plasma apparatus 100 may further include one or more sealing gaskets located within the enclosure 102. For example, one or more sealing gaskets 170 (e.g., O-rings) may be provided between the lower end 112 of the enclosure 102 and the nozzle 172. Alternatively or in combination, one or more sealing gaskets 168 (e.g., O-rings) may be provided between the lower end 112 of the enclosure 102 and a corresponding chamber component such as the chamber wall or lid 162 of the processing chamber in which the remote plasma apparatus 100 is installed. As shown in Figure 1A, in an embodiment, the gas outlet 120 of the remote plasma apparatus 100 may be coupled to a nozzle 172 located adjacent to the gas outlet 120. The nozzle includes a central opening fluidly coupled to the cavity 104, facilitating the flow of gas from the cavity 104 in the outflow direction 138 into the processing volume 146 of the processing chamber in which the remote plasma apparatus 100 is installed.

[0034] As shown in Figure 1A, in some embodiments, the remote plasma apparatus 100 may further include an insulating ring 174 positioned between the upper clamping element 156 and the lower ends of the first conductor 108 and the second conductor 114. In some embodiments, the insulating ring 174 includes notches or recesses along its upper surface, thereby facilitating the positioning and alignment of one or more of the first conductor 108, the dielectric layer 116, or the second conductor 114. In some embodiments, a shield can be provided that substantially covers the conductive components of the remote plasma apparatus 100. For example, as shown in Figure 1A, a shield wall 190 can be provided that surrounds or substantially surrounds the second conductor 114. The shield wall 190 may have, for example, an opening 192 for observing glow discharges during use of the remote plasma apparatus 100. In some embodiments, a cap 194 can be placed on top of the shield wall 190. The cap 194 can be fixed to the shield wall 190 by any suitable method, such as bolting. In some embodiments, a notch or recess is provided on the bottom surface of the cap 194, thereby facilitating the positioning and alignment of one or more of the first conductor 108, dielectric layer 116, second conductor 114, or shield wall 190.

[0035] Figure 1B shows a schematic cross-sectional top view of the remote plasma device 100. As shown in Figure 1B, in the embodiment, the first portion 122 of the outer surface 132 of the enclosure 102 is surrounded by the first conductor 108. Also, as shown in Figure 1B, in the embodiment, the second portion 124 of the outer surface 132 of the enclosure 102 is surrounded by the second conductor 114. Also, as shown in Figure 1B, in the embodiment, the first portion 122 and the second portion 124 of the outer surface 132 of the enclosure 102 overlap each other by an overlap of 118. Also, as shown in Figure 1B, in the embodiment, the second conductor 114 is movable relative to the first conductor (for example, by rotation indicated by the dotted arrow 148) to change the amount of overlap.

[0036] Furthermore, in the embodiment, the remote plasma apparatus 100 includes a gas distribution plate 126 that covers the gas outlet 120 or is arranged in series with the gas outlet 120. The gas distribution plate 126 is provided with a plurality of holes 128 through it to facilitate the passage and distribution of gas flowing from the cavity 104 to the processing volume 146. The gas distribution plate can advantageously limit the number of ions flowing out of the cavity 104 of the remote plasma apparatus 100. For example, it is preferable that the gas distribution plate 126 is sized and positioned to reduce or prevent ions flowing out of the gas outlet. This ensures that the gas flow flowing out of the gas outlet contains a higher proportion of radicals generated in the cavity.

[0037] As shown in Figure 1A, in this embodiment, the gas distribution plate 126 can be arranged with multiple holes 128 passing through two or more plates. The holes 128 are not aligned, and there are no visible paths through the gas distribution plate 126. Similarly, as shown in Figure 1C, in this embodiment, the gas distribution plate 126 can be arranged with multiple holes 128 passing through two or more plates (for example, an upper plate 176 and a lower plate 178). The holes 128 are not aligned, and there are no visible paths through the gas distribution plate 126. Such configurations have the advantage of making the flow paths more complex, which allows for a further limitation of the number of ions discharged from the cavity 104 of the remote plasma device 100.

[0038] As shown in Figure 1D, in the embodiment, the gas distribution plate 126 is formed from two or more segments and has a plurality of through-holes 128. As shown in Figure 1D, the gas distribution plate 126 is formed from a first grounding segment 180 and a second grounding segment 182 that form a pair of D-shaped (or semicircular) structures. In the embodiment, the first grounding segment 180 and / or the second grounding segment 182 may be electrically floating or grounded. The embodiment shown in Figure 1C may be conductive and electrically floating or grounded.

[0039] Alternatively, as shown in Figures 6A and 6B, in some embodiments, the gas distribution plate 126 may comprise a single plate through which multiple holes 128 pass. In some embodiments, the gas distribution plate 126 may be formed of a dielectric material. In some embodiments, the gas distribution plate 126 (whether a single plate or two or more plates) may be formed of a conductive material and may be electrically grounded or floating to control the amount of ions discharged from the cavity 104.

[0040] In this embodiment, the first conductor surrounding the first portion of the enclosure has a helical shape with multiple windings arranged around the first portion of the enclosure. As shown in Figure 1E, in this embodiment, the first conductor is a helical first conductor 108', which is helically oriented, arranged radially around the center of the enclosure 102, and positioned around the outer surface 132 of the enclosure 102. The dielectric layer 116 is formed in a cylindrical shape and is positioned on the outer surface 109 of the helical first conductor 108'. The second conductor 114 has a substantially C-shape as described above and is positioned on the outer surface 111 of the dielectric layer 116.

[0041] In the embodiment, the helical first conductor 108' is formed from a flat plate having a width 117 of the conductors forming the helical first conductor 108'. The helical windings are oriented with a spacing 115 between the helices, thereby positioning the first conductor in a first portion of the enclosure. The area of ​​the first portion covered by the helical first conductor 108' can be varied by the width of the conductor, the spacing between the windings of the conductor, and the length and / or number of turns of the conductor around the enclosure. In the embodiment, the helical first conductor 108' and the second conductor 114 are sized and positioned to produce resonance at a desired frequency. In the embodiment, the helical first conductor 108' may be directly electrically connected to the second conductor 114 at one position, or, in some embodiments, may be directly electrically connected at multiple positions, for example, as shown by conductor 121 coupling the upper end of the helical first conductor 108' to a point along the top of the second conductor 114.

[0042] Figure 2A shows an enclosure 102 having an upper end 110 located opposite the lower end 112, side walls 106, an enclosure circumference 200, and an enclosure height 202, where the cavity 104 is formed within the multiple side walls 106 and between the upper end 110 and the lower end 112 (see Figure 1A).

[0043] Figure 2B shows a flat metal plate having a conductor length 204 of approximately 99%, 90%, or 80% of the enclosure circumference 200, and a conductor height 206 of approximately 50%, 60%, 70%, or substantially equal to the enclosure height 202. As shown in Figure 2C, the flat metal plate of the first conductor 108 is formed into a C-shaped metal plate 208 that is sized and positioned to fit the outer surface 132 of the enclosure 102. By forming the flat metal plate into a C-shaped structure, the conductor length 204 of the metal plate is oriented around or along the enclosure circumference 200.

[0044] The second conductor 114 can be formed in a similar manner, but is sized and positioned to fit the outer surface of the dielectric layer 116 (see Figure 3A, 302) placed between the first conductor 108 and the second conductor 114. In the embodiment, the dimensions of the first conductor 108 and the second conductor 114 (e.g., conductor length 204, conductor height 206, surface area, thickness, etc.) are substantially identical. In the embodiment, the first conductor 108 and the second conductor 114 have at least one different dimension.

[0045] The first conductor 108 and the second conductor 114 can be formed from any suitable conductive material. Suitable examples include copper, aluminum, iron alloys, etc. In embodiments, the first conductor 108 and the second conductor 114 are formed from the same material. In embodiments, the first conductor 108 and the second conductor 114 are formed from different materials.

[0046] As shown in Figure 2D, in the embodiment, at least one of the first conductor 108 and the second conductor 114 is sized and positioned to reduce or eliminate eddy currents induced in the remote plasma device by an external RF source, with at least one through-hole 210 and / or nonlinear edge or side surface 212.

[0047] As shown in Figure 3A, the first conductor 108 is placed on the outer surface 132 of the enclosure 102. The dielectric layer 116 may consist of a sheet of dielectric material (similar in shape to the first conductor shown in Figure 2B), or it may consist of a single continuous layer (for example, one formed in a cylindrical shape). The dielectric layer 116 is placed on the outer surface 300 of the first conductor 108 and the outer surface 132 of the enclosure, and the second conductor 114 is placed on the outer surface 302 of the dielectric layer 116.

[0048] In one embodiment, the dielectric layer 116 can be formed from an air gap. In another embodiment, the dielectric layer 116 comprises a dielectric material. Suitable dielectric materials include ceramics (e.g., alumina), quartz, and the like.

[0049] In this embodiment, the thickness of the dielectric layer 116 is approximately 0.1 mm or more, approximately 0.5 mm or more, approximately 1 mm or more, approximately 3 mm or more, approximately 10 mm or less, approximately 8 mm or less, approximately 7 mm or less, and approximately 5 mm or less.

[0050] In this embodiment, the first conductor 108, the second conductor 114, and the dielectric layer 116 are sized to resonate at RF frequencies in the range of approximately 400 kHz to approximately 10,000 GHz and are arranged around the enclosure 102. In this embodiment, this range may be approximately 1 MHz or more, approximately 3 MHz or more, approximately 10 MHz or more, approximately 5,000 GHz or less, approximately 1,000 GHz or less, approximately 5 GHz or less, and approximately 200 MHz or less.

[0051] As schematically shown in Figure 3B, in the embodiment, a portion of the first conductor 108 is directly electrically connected 305 to the second conductor 114 by a conductor coupled to each of the first conductor 108 and the second conductor 114. Alternatively or in combination, the remote plasma device 100 may include one or more capacitors 304 electrically communicating between the first conductor 108 and the second conductor 114, these capacitors connected in series and / or parallel, so that the remote plasma device 100 resonates at an RF frequency in the range of approximately 400 kHz to 10,000 GHz (e.g., at an RF frequency provided by an RF source 152).

[0052] Figure 4 shows a schematic side view of a substrate processing chamber 400 equipped with a remote plasma apparatus 100 suitable for the present invention. The processing chamber 400 can be used alone or as a processing module of an integrated semiconductor substrate processing system (e.g., a cluster tool). Examples of suitable processing chambers that can be advantageously modified according to embodiments of this disclosure include plasma processing chambers (e.g., capacitively coupled or inductively coupled plasma processing chambers). Exemplary plasma processing chambers include etching reactors, CVD reactors, substrate plasma processing reactors, etc. Although the remote plasma apparatus taught herein is described as being used in a plasma processing chamber with a separate plasma source, it can also be used in processing chambers that do not have additional plasma capabilities.

[0053] Generally, the processing chamber 400 comprises a chamber body 402 and a lid 406, which together define a processing volume 404. A substrate support 428 is placed within the processing volume. The processing chamber 400 may optionally include an inductive plasma source or a capacitive plasma source. In the embodiment shown in Figure 4, an inductive plasma source is provided, which includes one or more electrodes (e.g., conductive coils 416) located near the lid 406. In such an embodiment, the lid 406 is dielectric and the chamber body is conductive. One or more conductive coils 416 may be located above the dielectric lid 406 and configured to inductively couple RF energy to the processing volume 404.

[0054] In the embodiment shown in Figure 4A, the inductive plasma source includes an RF feeding structure for coupling an RF source 410 (e.g., a second RF source) to one or more conduction coils 416 (e.g., a first conduction coil 418 and a second conduction coil 420). The one or more conduction coils are coaxially positioned near the processing chamber 400 (e.g., on the dielectric cover 406 of the processing chamber 400) and are configured to inductively couple RF energy into the processing volume 404 and to form or control plasma from a processing gas supplied into the processing volume 404 via a gas source 422 coupled to a gas inlet. As shown in Figure 1A, the gas inlet may be at least one of the first gas inlet 130 and the second gas inlet 140 (see Figure 1A) of the remote plasma device 100. Alternatively or in combination, the gas source 422 can be coupled to other locations within the processing space 404. The gas outlet 120 of the remote plasma device 100 can function as a showerhead or nozzle 408 (for example, nozzle 172 shown in Figure 1A), or it can be directly connected to the showerhead or nozzle 408.

[0055] The RF source 410 is coupled to the RF power supply structure via a matching network 412. A power distributor 414 may be provided to adjust the RF power supplied to the first conduction coil 418 and the second conduction coil 420, respectively. The power distributor 414 may be coupled between the matching network 412 and the RF power supply structure, or it may be part of the matching network 412. The RF source 410 can generate sufficient power at an adjustable frequency within the range of approximately 400 kHz to approximately 10,000 GHz, or approximately 400 kHz to approximately 13.56 MHz. Other frequencies and power levels may also be provided depending on the specific application.

[0056] The remote plasma device (e.g., remote plasma device 100) is coupled to the chamber body 402 or the lid 406. The gas outlet of the remote plasma device can be directly attached to the outer surface of the processing chamber, e.g., the lid 406, the side or bottom of the chamber body 402, and the gas outlet is substantially located at the inlet of the processing volume 404. For example, the remote plasma device is mounted to the processing chamber such that the gas outlet is located within approximately 30.5 cm of the processing chamber. The remote plasma device is coupled to the RF source 424 in any of the above-described manner. The remote plasma device resonates at a frequency close to the frequency of the RF source 424. In an embodiment, the RF source 424 has a different frequency from the RF source 410, advantageously limiting the parasitic load from the remote plasma device 100 to the RF source 410. In an embodiment, the RF frequency of the RF source 424 is higher than the RF frequency of the RF source 410. In an embodiment, the RF frequency of the RF source 424 is lower than the RF frequency of the RF source 410.

[0057] Figure 5 is a block diagram of the remote plasma apparatus 100, showing various positions and orientations of one or more first gas inlets 130a, 130b, and 130c. Each of the first gas inlets 130a, 130b, and 130c may contain a corresponding number of inlet conduits (see Figure 1A). Each of the first gas inlets 130a, 130b, and 130c generates corresponding inflow directions 136a, 136b, and 136c with respect to the outflow direction 138 through the gas outlet 120.

[0058] In the embodiment, in addition to one or more first gas inlets 130 that guide the gas flow into the cavity 104, the remote plasma apparatus 100 may include one or more second gas inlets 140. The second gas inlets 140 include one or more second gas inlet gas conduits 142 that are sized and positioned to bypass the cavity 104 and guide the flow of gas 144 to the processing volume 146 via one or more corresponding second gas outlets 150. The gas line 147 can be coupled to one or more second gas inlets 140 and supply gas to the processing volume 146. For example, as shown in Figure 1A, one or more second gas inlet gas conduits 142 can be positioned at the lower end 112 of the enclosure 102 and guide gas from the cavity 104 toward the nozzle 172. The nozzle 172 may include one or more second gas outlets 150 that are positioned through the nozzle 172, for example, close to the central opening of the nozzle. In embodiments where multiple second gas outlets 150 are provided, the multiple second gas outlets 150 can be arranged symmetrically around the central axis of the central opening of the nozzle 172.

[0059] Figure 7 shows a portion of the processing chamber 700 and indicates a location where the remote plasma device 100 can be mounted. As shown in Figure 7, the remote plasma device 100 can be directly mounted on the surface of the processing chamber 700. As shown in Figure 7, in the embodiment, the processing chamber 700 comprises one or more remote plasma devices 100. These remote plasma devices 100 can be located on the lid or top of the processing chamber, on the side of the processing chamber, or on the bottom of the processing chamber. In the embodiment, multiple remote plasma devices 100 can be arranged symmetrically or asymmetrically around one or more outer surfaces of the processing chamber. In the embodiment, each remote plasma device 100 can be independently powered by an RF source 712. Optionally, additional plasma sources such as conductive coils 418, 420 coupled to the RF source 710 can be provided. In the embodiment, the remote plasma device 100 can be used as a use-point plasma source and / or use-point radical source for substrate processing. Accordingly, in this embodiment, the gas outlet 120 of the remote plasma device 100 can be connected to the processing chamber 700 via the conduit 714, and the gas outlet can be positioned approximately 30.5 cm or less, approximately 20 cm or less, approximately 10 cm or less, or approximately 5 cm or less from the processing chamber.

[0060] In the embodiment, the processing chamber comprises a first RF source coupled to a remote plasma source. Optionally, a second RF source can be coupled to one or more electrodes located near the chamber and configured to form plasma within the processing volume independently of the first RF source. In the embodiment, the second RF source is inductively coupled to one or more conductive coils located at the top of the processing chamber. In the embodiment, the first RF source is directly or inductively coupled to the remote plasma device. In the embodiment, the first RF source is coupled to the remote plasma device via one or more capacitors located between the first RF source and the remote plasma device. In the embodiment, one of the conductors of the remote plasma device is grounded via the capacitor. The second RF source has a different RF frequency from the first RF source. In the embodiment, the RF frequency of the second RF source is higher than that of the first RF source. In the embodiment, the RF frequency of the second RF source is lower than that of the first RF source.

[0061] Figure 8 is a flowchart showing a plasma generation method according to embodiments disclosed herein. For the purposes of this specification, the method or process of Figure 8, one or more process blocks, can be executed by one or more substrate processing systems. The substrate processing systems are controllable by a controller, which may include a memory or computer-readable medium storing one or more process blocks of process 800. When executed by the controller, one or more substrate processing systems are controlled to execute one or more blocks of process 800 as described herein. For example, one or more process blocks of Figure 8 can be executed by a remote plasma apparatus 100 according to an example of this disclosure.

[0062] As shown in Figure 8, process 800 includes introducing gas through a gas inlet into a remote plasma apparatus comprising an enclosure surrounding a cavity, a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The second conductor is separated from the first conductor by a dielectric layer, and the first and second portions of the enclosure overlap by an amount (block 802).

[0063] For example, the remote plasma apparatus 100 can flow a gas containing one or more radical-forming compounds (e.g., processing gas). The radical-forming compounds form radicals in the cavity and then flow into the processing chamber from the gas outlet, processing, for example, a substrate placed in the processing chamber.

[0064] As shown in Figure 8, process 800 may include a gas inlet configured to allow gas to flow into the cavity and a gas outlet configured to allow gas and / or plasma to flow from the cavity into the processing chamber (block 804). Furthermore, as shown in Figure 8, process 800 includes a remote plasma device positioned close to the RF source, with a first conductor, a second conductor and a dielectric layer sized and arranged around an enclosure, and resonating at an RF frequency sufficient to generate plasma in the cavity (block 806).

[0065] In the embodiment, the plasma further includes radicals (block 808). In the embodiment, the remote plasma apparatus further includes a grounding element or other structure adjacent to the gas outlet, suitable for preventing at least some of the ions from flowing out of the gas outlet. The gas flowing out of the gas outlet contains radicals generated in the cavity (block 810).

[0066] Figure 8 shows an exemplary block of process 800. However, in some embodiments, process 800 may include more blocks, fewer blocks, different blocks, or blocks in different arrangements than those shown in Figure 8. Additionally or alternatively, two or more blocks of process 800 may be executed in parallel.

[0067] The above applies to embodiments of the present disclosure, but it is possible to create other embodiments and further embodiments of the present disclosure without departing from the basic scope of the present disclosure.

Claims

1. A remote plasma device, The enclosure surrounding the cavity, The first conductor surrounds the first part of the enclosure, A second conductor surrounding the second part of the enclosure, wherein the first part of the enclosure and the second part of the enclosure overlap by an amount equal to the overlap, and the first and second conductors are discontinuous in the circumferential direction. A dielectric layer is placed between the first conductor and the second conductor to separate them, A gas inlet configured to allow gas to flow into the cavity, A remote plasma device with a gas outlet located at the bottom of the enclosure and configured to release gas from the cavity.

2. The remote plasma apparatus according to claim 1, wherein the first and second parts are different.

3. The remote plasma apparatus according to claim 1, wherein the surface area of ​​the first conductor is substantially equal to the surface area of ​​the second conductor.

4. The remote plasma apparatus according to claim 1, wherein the enclosure comprises a top having an enclosure circumference and enclosure height and a plurality of side walls, the cavity is formed within the plurality of side walls and top, and each of the first conductor and the second conductor is a C-shaped metal sheet having a conductor length of about 99% or less of the enclosure circumference and a conductor height of about 50% or more of the enclosure height.

5. The remote plasma apparatus according to claim 1, wherein the first conductor is helical, including a plurality of windings arranged around the first part of the enclosure.

6. The remote plasma apparatus according to claim 1, wherein the first conductor and the second conductor are electrically connected at one location.

7. The remote plasma apparatus according to claim 1, wherein the first conductor includes a metal sheet disposed on the outer surface of the enclosure, the dielectric layer includes a sheet of dielectric material disposed on the outer surface of the first conductor and on the outer surface of the enclosure, and the second conductor is a metal sheet disposed on the outer surface of the dielectric layer.

8. The remote plasma device according to claim 7, wherein at least one of the first conductor and the second conductor is provided with at least one through hole and / or nonlinear edge, and is sized and arranged to reduce or eliminate eddy currents induced in the remote plasma device during use.

9. A remote plasma apparatus according to any one of claims 1 to 8, wherein the first conductor, the second conductor and the dielectric layer are sized to resonate at an RF frequency in the range of about 400 kHz to 10,000 GHz and are arranged around an enclosure.

10. The remote plasma device according to claim 9, comprising one or more capacitors electrically communicating between a first conductor and a second conductor, wherein the remote plasma device resonates at an RF frequency in the range of approximately 400 kHz to 10,000 GHz.

11. A remote plasma apparatus according to any one of claims 1 to 8, wherein the second conductor is movable relative to the first conductor and the amount of overlap is changed.

12. The remote plasma apparatus according to any one of claims 1 to 8, wherein the gas inlet comprises a plurality of inlet conduits sized and arranged to guide the gas flow into the cavity in an inflow direction opposite to the outflow direction of the gas flow flowing out of the cavity through the gas outlet.

13. The remote plasma apparatus according to any one of claims 1 to 8, wherein the gas inlet comprises a first plurality of inlet conduits having dimensions and arrangements to guide a gas flow into a cavity, and a second plurality of inlet gas conduits having dimensions and arrangements to guide a gas flow around the cavity into a processing chamber in which the remote plasma apparatus is installed.

14. A remote plasma apparatus according to any one of claims 1 to 8, comprising a gas distribution plate covering a gas outlet, wherein the gas distribution plate includes a plurality of holes arranged through it.

15. The remote plasma apparatus according to claim 14, wherein the gas distribution plate is grounded.

16. The enclosure comprises an upper end, one or more side walls forming a cavity inside, and an open lower end that can engage with the processing chamber, and the enclosure has an enclosure circumference and enclosure height. The first conductor is positioned on a first portion of the enclosure and includes a metal sheet in contact with the outer surface of one or more side walls. The dielectric layer includes a sheet of dielectric material disposed on the outer surface of the first conductor and on the outer surface of one or more side walls. The second conductor is positioned on the second part of the enclosure and includes a metal sheet in contact with the outer surface of the dielectric layer. Each of the first and second conductors independently has a conductor length of approximately 99% or less of the enclosure circumference and a conductor height of approximately 50% or more of the enclosure height. The first and second parts of the enclosure are different. The first conductor, the second conductor, and the dielectric layer are sized to resonate at RF frequencies in the range of approximately 400 kHz to 10,000 GHz and are positioned around the enclosure. The gas inlet comprises a first set of inlet conduits sized and arranged to guide the gas flow into the cavity, and a second set of inlet gas conduits sized and arranged to guide the gas flow around the cavity into a processing chamber where a remote plasma device is installed. The remote plasma apparatus according to claim 1, wherein the gas outlet located at the bottom of the enclosure is provided with a gas distribution plate having a plurality of holes through it.

17. The remote plasma device according to claim 16, comprising one or more capacitors electrically connected between a first conductor and a second conductor so that the remote plasma device resonates at an RF frequency in the range of approximately 400 kHz to 10,000 GHz.

18. A plasma processing chamber, A chamber surrounding the processing volume, A substrate support configured to support the substrate within the processing volume during use, A first RF source configured to supply RF energy at a predetermined frequency, A plasma processing chamber comprising a remote plasma apparatus coupled to a chamber and a first RF source, wherein the remote plasma apparatus is the remote plasma apparatus according to any one of claims 1 to 8, and the first conductor, dielectric layer and second conductor at least partially form a capacitor having a resonant frequency close to a predetermined frequency, and when placed in the enclosure, the remote plasma apparatus forms an electromagnetic field within the enclosure suitable for forming radicals from a gas.

19. The plasma processing chamber according to claim 18, wherein the gas outlet of the remote plasma device is directly attached to the lid, side, or bottom of the chamber, and the gas outlet is located at a distance of approximately 30.5 cm or less from the chamber.

20. One or more electrodes, A plasma processing chamber according to claim 18, comprising a second RF source coupled to one or more electrodes, wherein the one or more electrodes and the second RF source are configured to generate plasma within the processing volume of the chamber, and the second RF source has a different frequency from the first RF source.

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