Segmented gas distribution plate for high power and high pressure process

Abstract

To provide a gas distribution plate for a substrate processing system using transformer coupled plasma.SOLUTION: A gas distribution plate includes an outer ring 210 including a stepped interface on a radially inner surface thereof, and N inner rings 220-240 (N represents an integer greater than zero). At least one of the N inner rings is circumferentially split, and includes an inner stepped interface and an outer stepped interface. An outer stepped interface of an inner ring on the radially outside of the N inner rings is placed on the inner stepped interface of the outer ring, and mates with the inner stepped interface of the outer ring. A central portion 250 includes an outer stepped interface 252 on a radially outer surface thereof, and the outer stepped interface is placed on and mates with the inner stepped interface of the inner ring on the radially inside of the N inner rings.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 966,816, filed January 28, 2020. The disclosures of the above-referenced applications are hereby incorporated by reference in their entireties.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to substrate processing systems, and more particularly to radially and circumferentially divided gas distribution plates for substrate processing systems. [Background technology]

[0003] The "Background" section provided herein is intended to provide a general background to the present disclosure. To the extent described in the "Background" section of the present disclosure, the work of the inventors named herein, as well as aspects of the present disclosure that may not be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art to the present disclosure.

[0004] Substrate processing systems may be used to etch films on substrates, such as semiconductor wafers. Substrate processing systems typically include a process chamber, a gas distribution apparatus, and a substrate support. During processing, the substrate is placed on the substrate support. Various gas mixtures may be introduced into the process chamber, and a radio frequency (RF) plasma may be used to activate chemical reactions.

[0005] Modern Microelectromechanical (MEM) processes may be performed in substrate processing systems that use transformer-coupled plasma (TCP). In these substrate processing systems, one or more coils are positioned outside the chamber. A window is positioned between the coils and the chamber. A gas mixture is supplied to the chamber. RF power is supplied to the coils, which generates a magnetic field that creates and sustains an RF plasma in the chamber.

[0006] Plasma processing is power limited due to the large thermal gradients introduced that can result in window damage. The window must be made of an inert, RF transparent material with low dielectric loss properties. In addition, the window must not corrode in response to typical etching chemistries (e.g., gas mixtures containing halogen species such as fluorine, chlorine, etc.). The window must also not outgas undesirable by-products in response to thermal and / or pressure cycles.

[0007] Given the above criteria, material choices for windows are generally limited to oxide ceramics, quartz, and some nitride ceramics. Negatives to oxide ceramics include high thermal insulation properties combined with a relatively high coefficient of thermal expansion. Oxide ceramics are prone to catastrophic failure when subjected to severe thermal gradients and / or shocks. Compared to oxide ceramics, quartz has higher dimensional stability due to its low coefficient of thermal expansion (CTE). However, quartz is silicon-based and therefore corrodes very quickly, which makes its use very expensive. Aluminum nitride offers adequate performance, but is very expensive and there are relatively few suppliers capable of producing the required large diameter blanks. Summary of the Invention

[0008] A gas distribution plate for a substrate processing system includes an outer ring including a stepped interface on its radially inner surface and N inner rings, where N is an integer greater than zero. At least one of the N inner rings is circumferentially divided and includes an inner stepped interface and an outer stepped interface. An outer stepped interface of a radially outer one of the N inner rings is configured to rest on and mate with the inner stepped interface of the outer ring. A central portion includes an outer stepped interface on its radially outer surface and the outer stepped interface is configured to rest on and mate with the inner stepped interface of a radially inner one of the N inner rings.

[0009] In other features, at least one of the N inner rings includes a plurality of gas through holes. Each of the N inner rings includes C circumferential portions, where C is an integer greater than 1. Each of the C circumferential portions includes a body having a first arcuate portion and a second arcuate portion. The first arcuate portion is radially and circumferentially offset relative to the second arcuate portion.

[0010] In other features, the first arcuate portion has an inner diameter and an outer diameter. The second arcuate portion has an inner diameter and an outer diameter. The inner diameter of the first arcuate portion is greater than the inner diameter of the second arcuate portion and less than the outer diameter of the second arcuate portion. The outer ring, the N inner rings, and the central portion are made of an RF transparent material.

[0011] In other features, the outer ring, the N inner rings, and the central portion are made of alumina. In other features, the outer ring, the N inner rings, and the central portion are made of aluminum nitride. In other features, the outer ring is made of alumina and the N inner rings and the central portion are made of aluminum nitride.

[0012] In other features, the interface surfaces of the outer ring, the N inner rings, and the central portion are polished. In other features, the second arcuate portion of the first of the C circumferential portions is below the first arcuate portion of the first of the C circumferential portions. The second arcuate portion of the first of the C circumferential portions includes a slot that defines a plenum surrounding the gas through-hole. The slot is located on a cantilevered portion of the second arcuate portion that extends from the second arcuate portion of the first of the C circumferential portions.

[0013] In other features, the gas distribution plate further includes gas through holes on a first arcuate portion of a second of the C circumferential portions, the gas through holes of the first arcuate portion of the second of the C circumferential portions being aligned with the gas through holes of the second arcuate portion of the first of the C circumferential portions when assembled.

[0014] In other features, when nested together, the outer ring, the N inner rings, and the central portion define planar upper and lower surfaces.

[0015] The substrate processing system includes a process chamber including a substrate support, a coil disposed outside the process chamber, and a gas distribution plate disposed between the process chamber and the coil.

[0016] In other features, at least one of the N inner rings includes a plurality of through holes. Each of the N inner rings includes C circumferential portions, where C is an integer greater than 1. Each of the C circumferential portions includes a body having a first arcuate portion and a second arcuate portion, where the first arcuate portion is radially and circumferentially offset relative to the second arcuate portion.

[0017] In other features, a gas distribution assembly is provided that includes a top plate and a gas distribution plate, the top plate being disposed on the gas distribution plate, and a gap exists between the top plate and the gas distribution plate for passage of gas to holes in one or more of the N inner rings.

[0018] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the disclosure.

[0019] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a functional block diagram of an example substrate processing system including a gas distribution assembly according to the present disclosure.

[0021] [Diagram 2] FIG. 2 is a perspective cross-sectional view of a radially and circumferentially segmented gas distribution plate including a stepped outer ring and one or more segmented stepped inner rings in accordance with the present disclosure.

[0022] [Figure 3A] FIG. 3A is a perspective view of the upper surface of the outer ring according to the present disclosure.

[0023] [Figure 3B] FIG. 3B is a side cross-sectional view of an outer ring according to the present disclosure.

[0024] [Figure 4A] FIG. 4A is a perspective view of an upper surface of a first portion of a first segmented stepped inner ring according to the present disclosure.

[0025] [Figure 4B]FIG. 4B is a perspective view of an upper surface of a second portion of the first segmented stepped inner ring according to the present disclosure.

[0026] [Figure 4C] FIG. 4C is a side cross-sectional view of a first portion of a first segmented stepped inner ring in accordance with the present disclosure.

[0027] [Figure 5A] FIG. 5A is a perspective view of an upper surface of a first portion of a second segmented stepped inner ring in accordance with the present disclosure.

[0028] [Figure 5B] FIG. 5B is a perspective view of the lower surface of a first portion of a second segmented stepped inner ring according to the present disclosure.

[0029] [Figure 5C] FIG. 5C is a side cross-sectional view of a first portion of a second segmented stepped inner ring in accordance with the present disclosure.

[0030] [Figure 6A] FIG. 6A is a perspective view of an upper surface of a first portion of a third segmented stepped inner ring in accordance with the present disclosure.

[0031] [Figure 6B] FIG. 6B is a perspective view of the lower surface of a first portion of a third segmented stepped inner ring according to the present disclosure.

[0032] [Figure 7A] FIG. 7A is a perspective view of an upper surface of a first portion of a fourth stepped inner ring according to the present disclosure.

[0033] [Figure 7B] FIG. 7B is a perspective view of the lower surface of a first portion of a fourth stepped inner ring according to the present disclosure.

[0034] [Figure 8]FIG. 8 illustrates a perspective cross-sectional view of another gas distribution assembly including a top plate and a split gas distribution plate in accordance with the present disclosure.

[0035] [Figure 9] FIG. 9 shows a perspective cross-sectional view of the segmented gas distribution plate of FIG.

[0036] [Figure 10] FIG. 10 shows a cross-sectional view of the gas distribution assembly showing the gas flow and gaps between the plates and adjacent interdigitated ring segments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] In the drawings, reference numbers may be reused to identify similar and / or identical elements.

[0038] Currently, microelectromechanical (MEMS) devices are produced using high etch rate processes involving high gas flows and pressures, high RF power, and high process temperatures. To achieve acceptable uniformity while maintaining high etch rates, MEMS processes are very sensitive to the location and uniformity of gas distribution. As a result, some MEMs devices are produced using substrate processing systems with TCP plasmas.

[0039] The embodiments described herein include a gas distribution assembly including a top plate and a segmented gas distribution plate. The top plate and the gas distribution plate function as RF transparent windows to allow the generated RF signal to pass through the window to the process chamber. Each of the segmented gas distribution plates according to the present disclosure is a ring assembly and includes a plurality of rings, each of which may include one or more ring segments. Examples of various ring assemblies are shown in FIGS. 1-10. At least some of the rings may be radially and / or circumferentially segmented. The ring segments mesh from the outside using continuously connected steps. In some embodiments, the ring segments have polished contact surfaces to reduce particle generation and to create an indirect path to prevent undetermined gas flow. In some embodiments, the ring segments are made of alumina (Al2O3), although other materials, such as aluminum nitride (AlN), can be used. The segmented gas distribution plate can be used at higher temperatures and higher power settings and can be subjected to higher pressures compared to unsegmented gas distribution plates made of similar materials. Gaps exist between the ring segments to allow for expansion, reduce stress, and prevent damage to the ring segments.

[0040] Ring segments formed from AlN have improved thermal conductivity and coefficient of thermal expansion compared to ring segments formed from Al2O3. As a result, a corresponding ring assembly including ring segments formed from AlN will have smaller temperature gradients, will be subject to less stress for a given operating temperature gradient, and will therefore have a more durable structure. In some embodiments, one or more of the ring segments of a ring assembly are formed from Al2O3 and one or more other ring segments are formed from AlN. In one embodiment, one or more of the radially outermost ring segments are formed from Al2O3 and one or more of the radially innermost ring segments are formed from AlN.

[0041] Splitting the gas distribution plate radially and circumferentially provides gaps between continuous segments for expansion to divert and transfer thermal energy, as opposed to creating stress points where cracks can initiate. The radial portions of the segments may include landings for through holes to control gas delivery zones, while the outermost ring segment of the outermost ring may include grooves for O-ring seals for vacuum integrity.

[0042] 1, one embodiment of a substrate processing system 110 according to the present disclosure is shown. The substrate processing system 110 includes a coil driver circuit 111. As shown, the coil driver circuit 111 includes an RF power source 112 and a tuning circuit 113. The tuning circuit 113 may be directly connected to one or more inductive transformer coupled plasma (TCP) coils 116. Alternatively, the tuning circuit 113 may be connected to one or more of the TCP coils 116 by an optional inversion circuit 115.

[0043] The tuning circuit 113 tunes the output of the RF power source 112 to a desired frequency and / or a desired phase, matches the impedance of the TCP coils 116, and splits the power between the TCP coils 116. The inverting circuit 115 is used to selectively switch the polarity of the current through one or more of the TCP coils 116. In some embodiments, the coil driver circuit 111 implements a transformer-coupled capacitively tuned (TCCT) matching network to drive the TCP coils 116. For example, a process chamber using a TCCT matching network in conjunction with a switched capacitor is shown and described in commonly assigned U.S. Patent No. 9,515,633, which is incorporated herein by reference in its entirety.

[0044] The top 124 of the processing chamber 128 includes a gas distribution assembly 121 including a top plate 123 and a segmented gas distribution plate 120 with gas through holes (shown in FIG. 2 below). A radially outermost portion of the gas distribution assembly 121 may be supported by a portion of the chamber wall or by a retainer 125 as shown. A gas plenum 127 is disposed above the segmented gas distribution plate 120 on the top plate 123. The top plate 123 and the gas distribution plate 120 are disposed between the TCP coil 116 and the processing chamber 128. In some embodiments, process gas is supplied to the gas plenum 127 using gas nozzles, gas valves, distribution plates, conduits, or the like. The processing chamber 128 further includes a substrate support (or pedestal) 132. The substrate support 132 may include an electrostatic chuck (ESC), or a mechanical chuck or other type of chuck.

[0045] Process gas is supplied to the processing chamber 128 through the gas distribution assembly 121. Gas received in the plenum 127 is distributed to holes in the divided gas distribution plate 120. RF power is supplied to the TCP coil 116. A plasma 140 is generated and maintained inside the processing chamber 128. For example, a magnetic field generated by the TCP coil 116 passes through the top plate 123 into the processing chamber 128. The magnetic field excites gas molecules in the processing chamber 128 to generate the plasma 140. The plasma 140 may be used to process (etch, deposit, clean, etc.) the exposed surface of the substrate 134. A bias may be applied to the substrate support 132 during operation using the RF power supply 150 and bias matching circuit 152 to control ion energy. For example, the TCP coil 116 may include a radially arranged inner coil and a radially arranged outer coil surrounding the inner coil.

[0046] A gas supply system 156 may be used to supply a process gas mixture to the processing chamber 128. The gas supply system 156 may include a process and inert gas source 157 (e.g., including deposition gases, etching gases, carrier gases, inert gases, etc.), a gas metering system 158 such as valves and mass flow controllers (e.g., mass flow controllers (MFCs)), and a manifold 159. For example, the gas metering system 158 and manifold 159 may be configured to supply an etching gas mixture to the processing chamber 128 during etching.

[0047] A heater / cooler 164 may be used to heat / cool the substrate support 132 to a predetermined temperature. An exhaust system 165 includes valves 166 and pumps 167 for removing reactants from the process chamber 128 by purging or evacuation.

[0048] The controller 154 may be used to control the etching process. The controller 154 monitors system parameters and controls the supply of gas mixtures, the generation, maintenance and extinguishing of plasma, the removal of reactants, etc. Additionally, the controller 154 may control various aspects, such as the coil driver circuit 111, the RF power supply 150, and the bias matching circuit 152. In some embodiments, the substrate support 132 is temperature adjustable. In one example, the temperature controller 168 may be connected to a number of heating elements 170, such as thermal control elements (TCEs), disposed within the substrate support 132. The temperature controller 168 may be used to control the number of heating elements 170 to control the temperature of the substrate support 132 and the substrate 134.

[0049] 2, the segmented gas distribution plate 200 includes a plurality of nested ring segments, at least some of which are radially and / or circumferentially segmented. The segmented gas distribution plate 200 may replace the segmented gas distribution plate 120 of FIG. 1. The segmented gas distribution plate 200 includes an outer ring 210. In some implementations, the outer ring 210 includes an annular slot 214 that extends partially or completely around a lower surface of the outer ring 210. One or more additional annular slots 214 may be located at spaced radial positions on the lower surface of the outer ring 210. The annular slot may be included and may act as a thermal choke to limit the transfer of thermal energy in adjacent regions. In some embodiments, such as the embodiments of FIGS. 8-10, the annular slot 214 is not included.

[0050] In some embodiments, one or more annular slots (or grooves) 215 may be located on the upper surface of the outer ring 210. The slots 215 may contain O-rings to provide a vacuum-tight seal between the segmented gas distribution plate 200 and a top plate, such as top plate 123 of FIG.

[0051] A first stepped inner ring 220 is disposed radially inward of and mates with the outer ring 210. The first stepped inner ring 220 rests on a stepped interface 222 defined between the first stepped inner ring 220 and the outer ring 210. In some embodiments, the first stepped inner ring 220 is circumferentially divided into two or more portions as shown at 226.

[0052] A second stepped inner ring 230 is disposed radially inward of and mates with the first stepped inner ring 220. The second stepped inner ring 230 rests on a stepped interface 232 with the first stepped inner ring. In some embodiments, the second stepped inner ring 230 is circumferentially divided into two or more portions as shown at 236. The second stepped inner ring 230 may include one or more gas through holes 238 extending from its upper surface to its lower surface.

[0053] A third stepped inner ring 240 is disposed radially inward of and mates with the second stepped inner ring 230. The third stepped inner ring 240 rests on a stepped interface 242 with the second stepped inner ring. In some embodiments, the third stepped inner ring 240 is circumferentially divided into two or more sections as shown at 246.

[0054] A central portion 250 is disposed radially inward of and mates with the third stepped inner ring 240. The central portion 250 rests on a stepped interface 252 between the third stepped inner ring. The central portion 250 is not circumferentially split. Although a single stepped outer ring, three stepped inner rings, and a central portion are shown, additional or fewer stepped inner rings may be used. While the second stepped inner ring 230 is shown to include gas through holes 238, the second stepped inner ring 230 may include additional through holes. In some embodiments, the first stepped inner ring, the third stepped inner ring, and / or the central portion may also include gas through holes (not shown). In some embodiments, the upper and lower surfaces of the segmented gas distribution plate 200 are generally flat (except for the annular slots 214).

[0055] Although segmented gas distribution plate 200 is shown to include three inner rings, gas distribution plate 200 may include one or more inner rings. Segmented gas distribution plate 200 may be formed of Al2O3 and / or AlN. In one embodiment, segmented gas distribution plate 200 may be formed of Al2O3. In another embodiment, segmented gas distribution plate 200 may be formed of AlN. In yet another embodiment, ring 210 is formed of Al2O3 and one or more of the inner rings (e.g., rings 220, 230, 240) and center portion 250 are formed of AlN.

[0056] 3A and 3B, the outer ring 210 of FIG. 2 is shown in more detail. The outer ring 210 includes an annular body 308 having a flat annular ring shape. The annular body 308 includes an upper surface 310 and a lower surface 314. The outer ring 210 further includes an annular slot 320 located on the upper surface 310. A radially inner surface of the outer ring 210 defines a stepped interface 330. In other words, the lower surface 314 extends radially inward relative to the upper surface 310 to form a step. In some embodiments, the first stepped inner ring 220 rests on the stepped interface 330.

[0057] 4A-4C, the first stepped inner ring 220 of FIG. 2 is shown in further detail. In FIG. 4A, the first stepped inner ring 220 is segmented both radially and circumferentially. Although the first stepped inner ring 220 is shown as having two circumferential segments, additional circumferential segments may be used.

[0058] The first stepped inner ring 220 includes a first circumferential portion 406 including a body 408 having an upper surface 410 and a lower surface 414. The body 408 includes a first arcuate portion 416 that rotates relative to a second arcuate portion 418. In other words, the first arcuate portion 416 and the second arcuate portion 418 have comparable but offset arcuate lengths. In some embodiments, the first arcuate portion 416 and the second arcuate portion 418 have comparable radial thicknesses. In some embodiments, an inner diameter of the first arcuate portion 416 is larger than an inner diameter of the second arcuate portion 418 and smaller than an outer diameter of the second arcuate portion 418. In some embodiments, the first arcuate portion 416 and the second arcuate portion 418 are made of a single monolithic material. In other embodiments, the first arcuate portion 416 and the second arcuate portion 418 are fabricated separately and then attached or joined together.

[0059] An end 422 of the first arcuate portion 416 extends circumferentially relative to a corresponding end 423 of the second arcuate portion 418. Similarly, an end 426 of the second arcuate portion 418 extends circumferentially relative to a corresponding end 427 of the first arcuate portion 416. In FIG. 4B, the first stepped inner ring 220 includes a second circumferential portion 440 that is similar to the first circumferential portion 406. The first arcuate portion 416 and the second arcuate portion 418 define an inner and outer stepped interface 430.

[0060] 5A-5C, the second stepped inner ring 230 of FIG. 2 is shown in further detail. In FIG. 5A, the second stepped inner ring 230 is segmented both radially and circumferentially. Although the second stepped inner ring 230 is shown as having two circumferential segments, additional circumferential segments may be used.

[0061] The second stepped inner ring 230 includes a first circumferential portion 506 including a body 508 having an upper surface 510 and a lower surface 514. The body 508 defines a first arcuate portion 516 that rotates relative to a second arcuate portion 518. In other words, the first arcuate portion 516 and the second arcuate portion 518 have similar but offset arcuate lengths. In some embodiments, the first arcuate portion 516 and the second arcuate portion 518 have similar radial thicknesses. In some embodiments, an inner diameter of the first arcuate portion 516 is greater than an inner diameter of the second arcuate portion 518 and less than an outer diameter of the second arcuate portion 518.

[0062] An end 522 of second arcuate portion 518 extends circumferentially relative to a corresponding end 523 of first arcuate portion 516. Similarly, an end 526 of first arcuate portion 516 extends circumferentially relative to a corresponding end 527 of second arcuate portion 518. First arcuate portion 516 and second arcuate portion 518 define inner and outer stepped interfaces 530.

[0063] The second stepped inner ring 230 includes a plurality of through holes 532. One or both of the ends 522 and 526 (the cantilevered portions thereof) may include slots 528 that define a plenum around one or more of the through holes 532. In FIG. 5B, the second stepped inner ring 230 includes a second circumferential portion 540 (shown inverted) that is similar to the first circumferential portion 506.

[0064] 6A-6B, the third stepped inner ring 240 of FIG. 2 is shown in further detail. In FIG. 6A, the third stepped inner ring 240 is segmented both radially and circumferentially. Although the third stepped inner ring 240 is shown as having two circumferential segments, additional circumferential segments may be used.

[0065] The third stepped inner ring 240 includes a first circumferential portion 606 including a body 608 having an upper surface 610 and a lower surface 614. The body 608 defines a first arcuate portion 616 that rotates relative to a second arcuate portion 618.

[0066] The body 608 defines a first arcuate portion 616 that rotates relative to a second arcuate portion 618. In other words, the first arcuate portion 616 and the second arcuate portion 618 have similar but offset arcuate lengths. In some embodiments, the first arcuate portion 616 and the second arcuate portion 618 have similar radial thicknesses. In some embodiments, an inner diameter of the first arcuate portion 616 is greater than an inner diameter of the second arcuate portion 618 and less than an outer diameter of the second arcuate portion 618.

[0067] An end 622 of the first arcuate portion 616 extends circumferentially relative to a corresponding end 623 of the second arcuate portion 618. An end 626 of the second arcuate portion 618 extends circumferentially relative to a corresponding end 627 of the first arcuate portion 616. In FIG. 6B, the second stepped inner ring 230 includes a second circumferential portion 640 (shown inverted) similar to the first circumferential portion 606. The first arcuate portion 616 and the second arcuate portion 618 define inner and outer stepped interfaces 630.

[0068] 7A-7B, central portion 250 of FIG. 2 is shown in further detail. Central portion 250 includes a body 708 having an upper surface 710 and a lower surface 714. An upper portion 722 of body 708 has a cylindrical shape and a first diameter. A lower portion 724 of body 708 has a cylindrical shape and a second diameter that is smaller than the first diameter.

[0069] 8 shows a gas distribution assembly 800 including a top plate 802 and a segmented gas distribution plate 804. The gas distribution assembly 800 may replace the gas distribution assembly 121 of FIG. 1. The top plate 802 includes a centrally located plenum 806 for receiving gas having a central hole 808. Gas received in the plenum 806 is directed through the central hole 808 and distributed between the top plate 802 and the segmented gas distribution plate 804 to one or more rings 810 of the segmented gas distribution plate 804.

[0070] Ring 810 may include a support ring 820, one or more inner (or middle) rings (three middle rings 822, 824, 826 are shown as examples), and a central portion (or stepped circular plug) 828. Stepped interfaces 830, 832, 834 exist between rings 820, 822, 824, 826. Stepped interface 836 exists between ring 826 and central portion 828. Ring 820 supports ring 822, which in turn supports ring 824. Ring 824 supports ring 826, which in turn supports central portion 828. Each of the middle rings may be divided and may include ring segments. Exemplary ring segments 840, 842, 844, 846, 848, 850, 852, 854 are shown for rings 822, 824, 826. In FIG. 8, ring segments 840 , 842 , 844 , 846 , 848 , 850 , 852 , 854 are shown as being visible through top plate 802 , but in reality are not visible through top plate 802 .

[0071] Ring 820 does not include an annular slot (e.g., slot 214 in FIG. 2 ), but does include an annular groove 860 into which an O-ring (not shown) can be placed to provide an annular vacuum seal between the top plate 802 and the divided gas distribution plate 804.

[0072] Top plate 802 and segmented gas distribution plate 804 may be formed from Al2O3 and / or (AlN). In one embodiment, top plate 802 and segmented gas distribution plate 804 are formed from Al2O3. In another embodiment, top plate 802 and segmented gas distribution plate 804 are formed from AlN. In yet another embodiment, top plate 802 and ring 820 are formed from Al2O3, and one or more middle rings (e.g., rings 822, 824, 826) and center portion 828 are formed from AlN.

[0073] The gas distribution assembly 800 is described further below with respect to Figures 9-10. Figure 9 shows a segmented gas distribution plate 804. The segmented gas distribution plate 804 includes rings 820, 822, 824, 826 and a central portion 828. The ring 820 includes an annular groove 860. The rings 820, 822, 824, 826 include ring segments, such as ring segments 840, 842, 844, 846, 848, 850, 852, 854. Circular interfaces 900, 902, 904 are shown between the rings 820, 822, 824, 826. A circular interface 906 is shown between the ring 826 and the central portion 828. Radially extending interfaces 910 , 912 , 914 , 916 , 918 , 920 , 922 are shown between the ring segments of rings 822 , 824 , 826 .

[0074] Ring segments 848, 850 and other ring segments of middle ring 824 may include gas holes 920, some of which are shown. Although the ring segments of middle ring 824 are shown as having gas holes, ring segments of rings 822, 826 may include gas holes. Gas is received at the holes and passes into the corresponding processing chambers.

[0075] 10 illustrates a gas distribution assembly 800 showing the gas flow and gaps between the plates 802, 804 and the interdigitated ring segments. The top plate 802 includes a plenum 806 and a central hole 808. The segmented gas distribution plate 804 includes rings 820, 822, 824, 826 and a central portion 828, which include annular interfaces 830, 832, 834, 836.

[0076] A small gap G1 exists between (i) top plate 802 and (ii) rings 824, 826 and central portion 828. Gap G1 may be provided via a circular recess in top plate 802. Additionally or alternatively, rings 824, 826 and central portion 828 may be shorter than rings 820, 822 to provide gap G1. The area between plates 802, 804 associated with gap G1 may extend laterally across central portion 828, ring 826, and a portion of ring 824, radially inward, and upward to hole 1000.

[0077] In the example shown, gas is received in plenum 806, passes vertically through holes 808, and distributes radially through gap G1 to holes in ring 824 (e.g., holes 1000 or holes 920 in FIG. 9 ), passes vertically through the holes, and enters the processing chamber. This is indicated by arrows 1002. In one embodiment, gap G1 is between 0.011 inches (i.e., about 0.28 millimeters) and 0.023 inches (i.e., about 0.58 millimeters). In another embodiment, gap G1 is equal to or about 0.017 inches (i.e., about 0.43 millimeters). In the example shown, there is no gap between ring 822 and top plate 802, although a gap may be present if ring 822 includes gas holes.

[0078] Annular interfaces 830, 832, 834, 836 each include an upper vertical portion 1010, 1012, 1014, 1016, a central horizontal portion 1020, 1022, 1024, 1026, and a lower vertical portion 1030, 1032, 1034, 1036. The upper vertical portions 1010, 1012, 1014, 1016 may have the same gap size, referred to as G2 in FIG. 10. The lower vertical portions 1030, 1032, 1034, 1036 may have the same gap size, referred to as G3 in FIG. 10. Although G2 and G3 are only shown for interface 824, the gaps in the vertical portions of interfaces 830, 832, and 836 may also be referred to as G2 and G3. In one embodiment, the gaps G2, G3 are each between 0.010 inches (i.e., about 0.25 mm) and 0.025 inches (i.e., about 0.61 mm). In another embodiment, the gaps G2 and G3 are equal to or about 0.013 inches (i.e., about 0.33 mm). The gaps G2 and G3 of the vertical portions 1010, 1012, 1014, 1016, 1030, 1032, 1034, 1036 are provided to account for the expansion of the rings 820, 822, 824, 826, and the central portion 828. Each of the central horizontal portions 1020, 1022, 1024, 1026 does not have a gap because the corresponding central portion or inner ring rests on the corresponding outer ring.

[0079] In one embodiment, the mating surfaces of the rings 820, 822, 824, 826 and central portion 828 associated with the annular interfaces 830, 832, 834, 836 are polished to provide a gas seal. The gas seal is provided to prevent gas from passing between the rings 820, 822, 824, 826 and / or between the ring 826 and central portion 828.

[0080] The segmented gas distribution plate is resistant to damage caused by extreme heat input without resorting to compromises such as quartz or expensive materials such as nitride ceramics. The segmented gas distribution plate is a passive, maintenance free device and can be fabricated by conventional methods. The use of a segmented gas distribution plate made from aluminum oxide reduces initial costs as well as extending the life of the gas distribution plate under harsh process conditions. A segmented gas distribution plate made from aluminum nitride provides improved durability.

[0081] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure can be embodied in various forms. Thus, while the disclosure includes specific examples, other modifications will become apparent upon study of the drawings, the specification, and the following claims, and the true scope of the disclosure should not be so limited. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of the disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of these features described with respect to any embodiment of the disclosure may be implemented in any of the other embodiments and / or combined with features of any of the other embodiments, even if the combinations are not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more of the embodiments with one another remain within the scope of the disclosure.

[0082] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms including "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Unless expressly described as "direct," when a relationship between a first element and a second element is described in the disclosure above, the relationship may be a direct relationship where there are no other intervening elements between the first element and the second element, but it may also be an indirect relationship where one or more intervening elements exist (either spatially or functionally) between the first element and the second element. As used herein, the phrases "at least one of A, B, and C" and "at least one of A, B, or C" should be interpreted to mean a logical non-exclusive OR (A OR B OR C), and not to mean "at least one of A, at least one of B, and at least one of C."

[0083] In some implementations, the controller is part of a system that may be part of the embodiments described above. Such systems may include semiconductor processing equipment, including processing tool(s), chamber(s), processing platform(s), and / or specific processing components (wafer pedestal, gas flow system, etc.). These systems may be integrated with electronics for controlling pre-, during, and post-processing operations of semiconductor wafers or substrates. The electronics may be referred to as a "controller" that may control various components or subparts of the system(s). The controller may be programmed to control any process disclosed herein, including delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, fluid delivery settings, position and operation settings, wafer transfer to and from tools and other transport tools and / or load locks connected or interfaced with the particular system, depending on the processing requirements and / or type of system.

[0084] Broadly speaking, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software to receive instructions, issue instructions, control operations, enable cleaning operations, and enable endpoint measurements. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0085] In some implementations, the controller may be part of or coupled to a computer that is embedded in, coupled to, or networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or all or part of a fab host computer system, which may enable remote access of wafer processing. The computer may enable remote access to the system to monitor the current progress of a fabrication operation, examine the history of past fabrication operations, examine trends or performance indicators from multiple fabrication operations, modify parameters of a current process, set up processing steps following a current process, or start a new process. In some embodiments, a remote computer (e.g., a server) may provide a process recipe to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows for entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some embodiments, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool with which the controller is configured to interface or control. Thus, as discussed above, the controller may be distributed, such as by comprising one or more individual controllers networked together and operating toward a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes may be one or more integrated circuits on the chamber in communication with one or more remotely located integrated circuits (e.g., at the platform level or as part of a remote computer) that combine to control the process in the chamber.

[0086] Without being limited thereto, exemplary systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0087] As described above, depending on the process steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to and from wafer containers to and from tool locations and / or load ports within a semiconductor manufacturing factory.

Claims

1. 1. A gas distribution plate for a substrate processing system, comprising: an outer ring including a stepped interface on a radially inner surface thereof; N inner rings, N is an integer greater than zero, At least one of the N inner rings is circumferentially divided and includes an inner stepped interface and an outer stepped interface; N inner rings, the outer stepped interface of a radially outer one of the N inner rings being configured to rest on and mate with the inner stepped interface of the outer ring; a central portion including an outer stepped interface on a radially outer surface of the central portion, the outer stepped interface configured to rest on and mate with the inner stepped interface of a radially inner one of the N inner rings.

2. The gas distribution plate of claim 1 , wherein at least one of the N inner rings includes a plurality of gas through holes.

3. 3. The gas distribution plate of claim 2, wherein the outer ring, the N inner rings, and the central portion, when nested together, define planar upper and lower surfaces.

4. 2. The gas distribution plate of claim 1, wherein N=2.

5. 2. The gas distribution plate of claim 1, wherein N=3.

6. 2. The gas distribution plate of claim 1, the N inner rings each include C circumferential portions, where C is an integer greater than 1; each of the C circumferential portions includes a body having a first arcuate portion and a second arcuate portion; The first arcuate portion is radially and circumferentially offset relative to the second arcuate portion.

7. 7. The gas distribution plate of claim 6, wherein C=2.

8. 7. The gas distribution plate of claim 6, the first arcuate portion has an inner diameter and an outer diameter; the second arcuate portion has an inner diameter and an outer diameter; The gas distribution plate, wherein the inner diameter of the first arcuate portion is greater than the inner diameter of the second arcuate portion and less than the outer diameter of the second arcuate portion.

9. 7. The gas distribution plate of claim 6, the second arcuate portion of a first circumferential portion of the C circumferential portions is below the first arcuate portion of the first circumferential portion of the C circumferential portions; the second arcuate portion of the first of the C circumferential portions includes a slot defining a plenum surrounding a gas through hole; A gas distribution plate, the slot being located on a cantilevered portion of the second arcuate portion that extends from the second arcuate portion of the first of the C circumferential portions.

10. 10. The gas distribution plate of claim 9, further comprising a gas through hole on a first arcuate portion of a second of the C circumferential portions; a gas distribution plate, wherein the gas through holes of the first arcuate portion of the second circumferential portion of the C circumferential portions are aligned with the gas through holes of the second arcuate portion of the first circumferential portion of the C circumferential portions when assembled.

11. 10. The gas distribution plate of claim 1, wherein the outer ring, the N inner rings, and the central portion are made of an RF transparent material.

12. 10. The gas distribution plate of claim 1, wherein the outer ring, the N inner rings, and the central portion are made of alumina.

13. 10. The gas distribution plate of claim 1, wherein the outer ring, the N inner rings, and the central portion are made of aluminum nitride.

14. 2. The gas distribution plate of claim 1, the outer ring is made of alumina; The gas distribution plate, wherein the N inner rings and the central portion are made of aluminum nitride.

15. 2. The gas distribution plate of claim 1, wherein interface surfaces of the outer ring, the N inner rings, and the center portion are polished.

16. 1. A gas distribution assembly comprising: An upper plate; The gas distribution plate according to claim 1, the top plate is disposed on the gas distribution plate; A gas distribution assembly, wherein a gap exists between the top plate and the gas distribution plate for the passage of gas to holes in one or more of the N inner rings.

17. 1. A substrate processing system, comprising: a processing chamber including a substrate support; a coil disposed outside the processing chamber; 13. A substrate processing system comprising: the gas distribution plate of claim 1 disposed between the processing chamber and the coil.

18. 20. The substrate processing system of claim 17, wherein at least one of the N inner rings includes a plurality of through holes.

19. 20. The substrate processing system of claim 17, wherein N=2.

20. 20. The substrate processing system of claim 17, the N inner rings each include C circumferential portions, where C is an integer greater than 1; each of the C circumferential portions includes a body having a first arcuate portion and a second arcuate portion; The first arcuate portion is radially and circumferentially offset relative to the second arcuate portion.

21. 21. The substrate processing system of claim 20, wherein C=2.

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