Apparatus and techniques for substrate processing using independent ion source and radical source

Abstract

To provide substrate processing, and more specifically, processing using multiple different sources to generate ions and radicals.SOLUTION: A system 100 may include a substrate stage 120 to support a substrate 122, and a plurality of beam sources. The plurality of beam sources may include: an ion beam source 104 arranged to direct an ion beam to the substrate; and a radical beam source 106 arranged to direct a radical beam to the substrate. The system may include a controller 150 configured to control the ion beam source and the radical beam source to operate independently of one another, in at least one aspect. The at least one aspect includes beam composition, a beam angle of incidence, and relative scanning of a beam source with respect to the substrate.SELECTED DRAWING: Figure 1A-B

Description

[Technical field]

[0001] Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 942,430, entitled "APPARATUS AND TECHNIQUES FOR SUBSTRATE PROCESSING USING INDEPENDENT ION SOURCE AND RADICAL SOURCE," filed December 2, 2019, the entire contents of which are incorporated herein by reference.

[0002] This disclosure relates to substrate processing, and more particularly, to processing that uses multiple different sources to generate ions and radicals. [Background technology]

[0003]

[0003] Processing of substrates to form devices, such as electronic, optical, mechanical, etc., often involves the use of energetic species such as ions and radicals. In known etching or deposition systems, for example, a substrate may be exposed to a processing plasma to perform a given deposition or etching step. In some variations, a processing ion beam may be extracted from the plasma and directed toward the substrate. In particular, the processing plasma or processing ion beam may include excited species in the form of ions and radicals. Both ions and radicals may affect the properties of the substrate during processing. For example, both ions and radicals may contribute to etching or deposition. In particular, ions may tend to cause etching, while radicals may tend to cause deposition. However, it may be difficult to control the relative concentrations of ions and radicals, and the trajectories of these species.

[0004]

[0004] It is with respect to these considerations and others that the present disclosure is provided. Summary of the Invention

[0005] In one embodiment, the system may include a substrate stage for supporting a substrate, and a plurality of beam sources, the plurality of beam sources including an ion beam source arranged to direct an ion beam to the substrate and a radical beam source arranged to direct a radical beam to the substrate. The system may include a controller configured to control the ion beam source and the radical beam source to operate independently of each other in at least one aspect, the at least one aspect including beam composition, beam incidence angle, and relative scanning of the beam source with respect to the substrate stage.

[0006] In another embodiment, a method may include providing a substrate in a process chamber and directing an ion beam from an ion beam source to the substrate. The method may further include directing a radical beam to the substrate from a radical beam source separate from the ion beam source, the ion beam differing from the radical beam in at least one manner, the at least one manner including beam composition, beam incidence angle, and relative scanning of the beam source with respect to the substrate.

[0007] In a further embodiment, the processing system may include a housing, a substrate stage disposed within the housing, an ion beam source disposed within the housing for directing an ion beam to the substrate stage, and a radical beam source disposed within the housing for directing a radical beam to the substrate stage. The processing system may further include a controller configured to control the ion beam source and the radical beam source to operate independently of one another in at least one aspect, including beam composition, beam incidence angle, and relative scanning of the beam source with respect to the substrate stage.

[0008]

[0008] The accompanying drawings illustrate exemplary approaches of the present disclosure, including practical applications of the principles of the present disclosure, such as: [Brief description of the drawings]

[0009] [Figure 1A-B] 1A and 1B show side and schematic top views of an exemplary system. [Diagram 2] 1 shows an exemplary process flow. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010]

[0011] The drawings are not necessarily to scale. The drawings are merely representational and are not intended to represent specific parameters of the present disclosure. The drawings are intended to illustrate exemplary embodiments of the present disclosure and therefore should not be considered limiting of the scope. In the drawings, like numbers represent like elements.

[0011]

[0012] The present embodiments will be described more fully below with reference to the attached drawings in which several embodiments are shown. The subject matter of the present disclosure can be embodied in various different forms and should not be construed as being limited to the embodiments presented herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art. In the drawings, like numbers refer to like elements throughout.

[0012]

[0013] The present embodiments provide novel apparatus and techniques for substrate processing. In various embodiments, a combination of a separate ion beam source and a separate radical beam source is utilized to perform substrate processing. The radical beam source is independently adjustable relative to the ion beam source. Radicals may include, for example, various components generated by an electron-free plasma, while ions may include charged particles generated in an electron-free plasma. Non-limiting examples of ions include inert gas ions, hydrogen ions, oxygen ions, nitrogen ions, reactive ions, carbon-based ions, hydrocarbon-based ions, fluorocarbon-based ions, and the like. Non-limiting examples of radicals may include radicals based on carbon, hydrocarbon, fluorocarbon, chlorinated hydrocarbon, hydrogen, oxygen, nitrogen, or other suitable gas species. According to various embodiments, an apparatus or system may be arranged with a radical beam source and an ion beam source to process a substrate sequentially or simultaneously. In certain embodiments, a substrate may be independently processed by a radical beam source and an ion beam source. The processing may include any suitable combination of etching, deposition, implantation, doping, or other processing techniques involving energetic particles such as ions and radicals.

[0013]

[0014] According to some embodiments, the ion beams disclosed herein may be provided as mass analyzed ion beams or non-mass analyzed ion beams. In different embodiments, the ion beams may be provided as ribbon ion beams or as spot beams. In various embodiments, the ion beams may be provided as focused, collimated, or diverging ion beams. The ion beams may be provided as directional beams, but the average incidence angle of the ion beam may be fixed or adjustable. In some embodiments, the ion beam source may be positioned to direct the ion beam along a perpendicular (normal) to a major plane of a substrate, such as a major surface of a semiconductor wafer. In other embodiments, the ion beam source may be positioned to direct the ion beam off-normal, i.e., at a non-zero incidence angle to the normal to the major plane of the substrate.

[0014]

[0015] Similarly, in various embodiments, a radical beam can be directed to the substrate independently from the ion beam, where the angle of incidence of the radical beam can be along the normal to the substrate plane or can be directed off-normal to the substrate. Because the radical beam can be provided from a radical beam source separate from the ion beam source, the chemical species directed to the substrate, i.e., the radical species, can be controlled independently relative to the species provided in the ion beam, including the ions.

[0015]

[0016] According to various non-limiting embodiments, the radical generator used to generate radicals for the radical beam source may be an RF plasma source, a thermal source, an electron beam source, or a thermal cathode source. The radical beam source may be configured to provide the radical beam as a spot beam, or alternatively as a ribbon radical beam.

[0016]

[0017] According to various non-limiting embodiments, the apparatus or system disclosed herein may include a scanning system comprised of any suitable combination of a substrate scanner, an ion beam source scanner, and a radical beam source scanner. Thus, the system may generate a suitable relative motion of the substrate with respect to the ion beam source and / or the radical beam source. According to various embodiments, the scanning system may be arranged with an air bearing, a Selective Compliance Assembly Robot Arm (SCARA) robot, or a conventional robot, or other known scanning components.

[0017]

[0018] In various embodiments of the present disclosure, a control system is provided to separately control the output conditions of the radical beam source and the ion beam source, including adjusting the output of the radical beam source and the ion beam source, so that a targeted combination of radical and ion beam treatments can be applied to the substrate.

[0018]

[0019] In some embodiments, the substrate may be placed in a common processing chamber where processing by both the radical beam source and the ion beam source occurs, In certain embodiments, a barrier such as a gas curtain or partition may be provided in the processing chamber or processing station to at least partially isolate the ion beam processing from the radical beam processing.

[0019]

[0020] 1A shows a system 100 arranged according to an embodiment of the present disclosure. The system 100 may include multiple beam sources, including an ion beam source 104 and a radical beam source 106, and in some embodiments, the multiple beam sources may be arranged in a common structure or housing, shown as a housing 102. The ion beam source 104 may generate an ion beam 110 for bombarding a substrate 122 to perform a given substrate processing operation. The ion beam source 104 may include an ion chamber, such as a processing chamber, and the plasma is generated by known methods, including RF excitation, thermal cathode, indirectly heated cathode, or other known techniques. The ion beam source 104 may further include known extraction components for extracting and directing the ion beam 110 to the substrate 122.

[0020]

[0021] The radical beam source 106 can generate the radical beam 112 for bombarding the substrate 122 to process the substrate 122 independently of the processing of the substrate 122 performed by the ion beam 110. According to some non-limiting embodiments, the radical beam source 106 may incorporate or be coupled to a radical generator (not shown separately) arranged to generate radicals for the radical beam source 106. The radical generator is an RF plasma source, a thermal source, an electron beam source, or a thermal cathode source.

[0021]

[0022] The system 100 may further include a substrate stage 120 for supporting a substrate 122, which may be disposed within a processing chamber. In the embodiment of FIG. 1A, the processing chamber is generally defined by a housing 102, although other configurations are possible. A controller 150 is further provided within the system 100 to control the operation of various components of the system 100, which are described in more detail below. For example, the controller 150 may control the ion beam source 104 and the radical beam source 106 to operate independently of each other in at least one aspect. As an example, the controller 150 may control the gas species supplied to the ion beam source 104 and the radical beam source 106 such that the beam composition is different between the ion beam source 104 and the radical beam source 106. The controller 150 may control the ion beam source 104 to generate the same or a different angle of incidence for the ion beam 110 compared to the angle of incidence for the radical beam 112. Additionally, the controller 150 may send control signals to adjust the relative scanning of a beam source, such as the ion beam source 104 or the radical beam source 106 , with respect to the substrate 122 .

[0022]

[0023] In different embodiments, the relative scanning can be achieved using a scanning component (not shown separately) of the substrate stage 120 to scan the substrate 122 while the ion beam source 104 and the radical beam source 106 are stationary. In other embodiments, the scanning component 130 or the scanning component 132, respectively, can be used to move or scan the ion beam source 104, the radical beam source 106, or both beam sources relative to the substrate 122 while the substrate stage is stationary. In particular, in some implementations, the controller 150 can cooperate with the scanning component 130 and the scanning component 132 to generate independent motion of the ion beam source 104 and the radical beam source 106 relative to each other. In other implementations, the controller 150 can control the ion beam source 104 and the radical beam source 106 such that they scan in coordination with each other relative to the substrate 122. In yet another embodiment, the ion beam source 104 may be scanned in conjunction with a simultaneous scanning of the substrate stage 120, the radical beam source 106 may be scanned in conjunction with a simultaneous scanning of the substrate stage 120, or both the ion beam source 104 and the radical beam source 106 may be scanned in conjunction with a simultaneous scanning of the substrate stage 120.

[0023]

[0024] In various embodiments, the ion beam source 104 may generate a spot-shaped ion beam (spot beam), while in other embodiments, the ion beam source 104 may generate the ion beam 110 as a ribbon ion beam, as shown in FIG. 1B. To generate a ribbon ion beam, the extraction assembly may include a rectangular and elongated extraction aperture to generate the ion beam 110 with a substantially rectangular cross-section, as shown in FIG. 1B. The aspect ratio (X-dimension / Y-dimension) of the extraction aperture and the ion beam may be 2 / 1, 3 / 1, 5 / 1, 10 / 1, 50 / 1 or more, according to various non-limiting embodiments. Similarly, the radical beam source 106 may generate the radical beam 112 as a spot beam or as a ribbon radical beam, as shown in FIG. 1B. According to some embodiments, the substrate 122 may be scanned (along the Y-axis of the illustrated Cartesian coordinate system) to successively expose the same area of ​​the substrate 122 to the ion beam 110 and the radical beam 112. In particular, the substrate stage 120 may be provided with a rotation capability to rotate the substrate around an axis perpendicular to the main plane of the substrate stage (in the configuration of FIG. 1A, the main plane is represented by the XY plane, and the normal is represented by the Z axis). In the case of a spot beam system, the relative scanning may be two-dimensional rather than linear, consisting of a motion in the XY plane, rather than simply a motion along the Y axis. For example, the substrate stage 120 may be scanned in a scanning plane (e.g., the XY plane) with a combination of both X- and Y-direction movements relative to the spot-shaped ion beam. Furthermore, the substrate stage 120 may be scanned with a combination of both X- and Y-direction movements relative to the spot-shaped radical beam. Furthermore, the ion beam source generating the spot beam and / or the radical source generating the spot beam may be moved in both the X- and Y-directions relative to the substrate stage 120.

[0024]

[0025] In various non-limiting embodiments, the ion beam source 104 may be a gas such as a noble gas, nitrogen, oxygen, hydrogen, a hydrocarbon C y H x , halogen-containing molecules (C x F y , N.F. x ,SCIENCE FICTION xetc.), or any combination thereof. In various implementations, the ion beam source 104 may be biased with respect to the substrate 122 at a given extraction potential, thereby producing a given ion energy for the ion beam 110. In various implementations, the ion beam source 104 may be biased with respect to the substrate 122 at a given angle of incidence (θ 100 ) with respect to a normal (Z axis) to the major plane (XY) of the substrate stage 120 and substrate 122. I ), the plane being defined by a major surface of the substrate 122, such as a wafer surface. The value of this angle of incidence may range from 0 degrees (i.e., the beam trajectory is along the Z-axis) to 85 degrees in various non-limiting embodiments.

[0025]

[0026] In various embodiments, the radical beam 112 may include neutrals. The radicals in the radical beam 112 may be either halogen-containing molecular gas (C x F y , N.F. x ,SCIENCE FICTION x etc.), plus other gases (noble gases, oxygen, nitrogen, hydrogen, hydrocarbons C y H x The reactive radicals may be generated from a plasma containing a mixture of radicals and a mixture of oxygen and water. The radical beam source 106 may include an aperture to direct the radical beam 112 along a given angle of incidence with respect to the normal (Z-axis). The angle of incidence (θ R ) is determined by the angle θ I may be set by the controller 150 to be the same as or different from the angle of the ion beam 110.

[0026]

[0027] Similar to the ion beam 106, the radical beam 112 may be elongated along the X-axis as shown in FIG. 1B in some embodiments. According to various embodiments of the present disclosure, the radical beam source 106 may be powered and gassed separately from the ion beam source 104, allowing independent control of the ratio of radical and ion fluxes directed to the substrate 122 in a given processing run, resulting in a process with tunable radical and ion directionality. In general, the radical beam 112 may contain primarily reactive neutrals with a small amount of ions. For example, the input gas may be CF4 (carbon tetrafluoride). CF4 itself is very inert (like inert argon or N2), but when dissociated in a plasma (by plasma-energy electrons), the parent CF4 breaks down into daughter fragments such as CF3, CF2, CF, F, C, etc. The fluorine-containing daughter fragments, which now have open bonds, are chemically reactive and useful for etching surfaces. In addition to generating neutral CFx radicals, CFx + Although there are additional ionized radicals such as, the total flux is primarily neutral in various embodiments.

[0027]

[0028] In various embodiments, the substrate 122 may be scanned along the Y-axis of the illustrated Cartesian coordinate system, where the main substrate surface is positioned parallel to the XY plane during scanning. In the illustration of FIG. 1A, the substrate 122 scans horizontally (along the Y-axis) through a flux of ions and radicals impinging at various non-zero angles of incidence. However, the relative orientation of the radical beam 112 and the ion beam 110 is illustrated merely to show that the various beams can be independently controlled and various angles of incidence can be defined. In other embodiments, the apparatus of FIG. 1A may be oriented such that the substrate 122 scans vertically, and the various components shown in FIG. 1A may be arranged to have the same relative orientation with respect to each other. Accordingly, the outputs of both the ion beam source 104 and the radical beam source 106 are correspondingly collinearly directed along the same non-zero angle with respect to the substrate scanning direction (Y-axis), making it possible to achieve an isocentric process (allowing for angular spread around the average non-zero angle of incidence).

[0028]

[0029] As mentioned above, to generate an ion beam at a non-zero angle of incidence with respect to the Z axis (normal to the substrate plane or scan plane), in one embodiment, the entire ion beam source, such as ion beam source 104, may be tilted with respect to the scan plane (XZ plane), as suggested in FIG. 1A.

[0029]

[0030] The radical beam source 106 may include a nozzle structure or other similar configuration to achieve collimation of the radical beam 112. This allows the radical flux from the radical beam 112 to define an average incidence angle, such that the individual trajectories of the radicals do not substantially deviate from each other. In other words, the incidence angle (θ R ) may be limited to a few degrees, 10 degrees, or 20 degrees in various non-limiting embodiments.

[0030]

[0031] Thus, by separating ion beam processing from radical beam processing, and allowing independent control of the composition and shape of the radical and ion beams, system 100 provides a combination of components for increased flexibility in substrate processing with energetic species. This configuration facilitates new capabilities including better control of reactive ion etch processing, reactive deposition processing, ion implantation processing, and more precise control of processing of three-dimensional structures in substrates.

[0031]

[0032] FIG. 2 illustrates an exemplary process flow 200. In block 202, a substrate is provided in a processing chamber. In block 204, an ion beam is directed from an ion beam source to the substrate. The ion beam source may be coupled to generate any suitable species of ions and may be movable to adjust the angle of incidence of the ion beam to the substrate. In block 206, a radical beam is directed to the substrate from a radical beam source separate from the ion beam source. In particular, the radical beam source may be used together with the ion beam source in processing the substrate for operations such as etching, deposition, implantation, etc. In block 208, the substrate is scanned relative to the ion beam source, the radical beam source, or both, while the radical beam and the ion beam are directed to the substrate. For example, during scanning of the substrate, the substrate may be scanned along a horizontal direction, such as the Y axis, while the separation between the substrate and the radical beam source and the ion beam source along a vertical direction, such as the Z axis, is kept constant. Thus, the ion beam and the radical beam may differ in beam composition, beam incidence angle, relative motion with respect to the substrate being processed, or a combination thereof.

[0032]

[0033] This embodiment provides at least the following advantages: It allows the ion and radical processing of the substrate to be adjusted separately and independently to achieve the best process. For example, if the best ion source output is achieved at a relatively low pressure and the best radical beam processing is achieved at a relatively high pressure, this embodiment allows both of these conditions to be met without compromise. This embodiment has the further advantage of realizing the ability to perform substrate processing in a common system using widely different types of sources (e.g., RF-based radical sources and thermal cathode-based ion sources are available). A further advantage of this embodiment is the ability to match the output of the radical beam source and the ion beam source; in systems lacking two independent sources, the radical or ion beam processing may be rate limited.

[0033]

[0034] Although specific embodiments of the present disclosure have been described herein, the present disclosure is not limited thereto, because the present disclosure is as broad as the art will permit, and the present specification can be interpreted in the same manner. Therefore, the above description should not be construed as limiting. Instead, the above description is merely an illustration of specific embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

1. 1. A system comprising: a substrate stage for supporting the substrate; A plurality of beam sources, an ion beam source positioned to direct an ion beam at the substrate; a radical beam source positioned to direct a radical beam towards the substrate; a plurality of beam sources, In at least one embodiment, a controller configured to control the ion beam source and the radical beam source to operate independently of each other. Equipped with The system, wherein the at least one aspect includes a beam composition, a beam incidence angle, and a relative scan of the beam source with respect to the substrate.

2. The system of claim 1 , wherein the substrate stage comprises a scanner that scans the substrate relative to at least one of the ion beam source and the radical beam source.

3. an ion beam source scanner for scanning the ion beam source relative to the substrate; The system of claim 1 further comprising:

4. a radical beam source scanner for scanning the radical beam source relative to the substrate; The system of claim 1 further comprising:

5. a radical source scanner for scanning the radical beam source relative to the substrate; The system of claim 1 further comprising:

6. a radical source scanner for scanning the radical beam source relative to the substrate; The system of claim 1 further comprising:

7. an ion source scanner for scanning the ion beam source relative to the substrate; and a radical source scanner for scanning the radical beam source relative to the substrate; The system of claim 2 further comprising:

8. The system of claim 1 , wherein the ion beam source is configured to generate a ribbon ion beam and the radical beam source is configured to generate a ribbon radical beam.

9. 10. The system of claim 1, further comprising a radical generator positioned to generate radicals for the radical beam source, the radical generator comprising an RF plasma source, a thermal source, an electron beam source, or a thermal cathode source.

10. 10. The system of claim 1, further comprising a scanning system, the scanning system including at least one of a substrate scanner, an ion beam source scanner, and a radical beam source scanner, the scanning system including at least one of an air bearing component, a linear scanner, and a robot.

11. The system of claim 1 , wherein the ion beam source is rotatable relative to a major plane of the substrate stage.

12. The system of claim 1 , wherein the radical beam source is rotatable relative to a major plane of the substrate stage.

13. The system of claim 7 , wherein the radical beam source and the ion beam source are rotatable relative to a major plane of the substrate stage.

14. 10. The system of claim 1, wherein the substrate stage is disposed within a processing chamber, the system further comprising a barrier extending into the processing chamber and disposed between the ion beam source and the radical beam source.

15. Providing a substrate in a processing chamber; directing an ion beam from an ion beam source toward the substrate; directing a radical beam from a radical beam source separate from the ion beam source to the substrate, the ion beam differing from the radical beam in at least one manner, the at least one manner including beam composition, beam incidence angle, and relative scanning of the beam source with respect to the substrate; The method includes:

16. 16. The method of claim 15, wherein the ion beam and the radical beam perform a set of processing steps on the substrate including etching the substrate, depositing material on the substrate, implanting species into the substrate, or any combination thereof.

17. 16. The method of claim 15, wherein at least one of the ion beam and the radical beam is directed to the substrate at a non-zero angle of incidence relative to a normal to a major plane of the substrate.

18. 16. The method of claim 15, wherein a scanning procedure is performed to scan the substrate relative to the ion beam source, relative to the radical beam source, or relative to the ion beam source and the radical beam source.

19. 20. The method of claim 18, wherein the scanning procedure is performed along a scan plane parallel to a main plane of the substrate, and wherein the scanning procedure is performed two-dimensionally within the scan plane.

20. 1. A processing system comprising: housing, a substrate stage disposed within the housing; an ion beam source disposed within the housing for directing an ion beam to the substrate stage; a radical beam source disposed within the housing for directing a radical beam to the substrate stage; and In at least one embodiment, a controller configured to control the ion beam source and the radical beam source to operate independently of each other. wherein the at least one aspect includes a beam composition, a beam incidence angle, and a relative scan of a beam source with respect to the substrate stage.

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