Apparatus and techniques for substrate processing using independent ion and radical sources
The independent control of ion and radical beam sources in substrate processing systems addresses the challenge of controlling ion and radical concentrations, enhancing precision and flexibility in etching, deposition, and ion implantation processes.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- APPLIED MATERIALS INC
- Filing Date
- 2024-10-23
- Publication Date
- 2026-06-02
AI Technical Summary
Controlling the relative concentrations and orbital distributions of ions and radicals during substrate processing is challenging, affecting etching and deposition processes in existing systems.
A system with independent ion and radical beam sources, allowing separate control of beam composition, incidence angle, and scanning, enabling simultaneous or continuous processing of substrates with precise control over ion and radical treatments.
Enhances flexibility and precision in substrate processing, facilitating better control over reactive etching, deposition, and ion implantation, and enabling processing of complex three-dimensional structures.
Smart Images
Figure 0007869286000001 
Figure 0007869286000002
Abstract
Description
[Technical Field]
[0001] Related applications
[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 942,430, filed on 2 December 2019, entitled "APPARATUS AND TECHNIQUES FOR SUBSTRATE PROCESSING USING INDEPENDENT ION SOURCE AND RADICAL SOURCE," all of which are incorporated herein by reference.
[0002]
[0002] This disclosure relates to substrate processing, and more specifically to processing using a plurality of different sources to generate ions and radicals. [Background technology]
[0003]
[0003] Processing of substrates for forming devices such as electronic devices, optical devices, and mechanical devices often involves the use of energy 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 process. In some modifications, 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 contain 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 can contribute to etching or deposition. In particular, ions may tend to cause etching, while radicals may tend to cause deposition. However, controlling the relative concentrations of ions and radicals, and the orbitals of these species, can be difficult.
[0004]
[0004] This disclosure is provided in connection with the above considerations and other considerations. [Overview of the project]
[0005]
[0005] In one embodiment, the system may include a substrate stage for supporting a substrate, and a plurality of beam sources, each comprising an ion beam source arranged to direct an ion beam toward the substrate and a radical beam source arranged to direct a radical beam toward the substrate. In at least one embodiment, the system may include a controller configured to control the ion beam sources and the radical beam sources to operate independently of each other, and in at least one embodiment, the control includes beam composition, beam incidence angle, and relative scanning of the beam sources with respect to the substrate stage.
[0006]
[0006] In another embodiment, the method may include placing a substrate in a processing chamber and directing an ion beam from an ion beam source to the substrate. The method may further include 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 aspect, the at least one aspect including beam composition, beam incidence angle, and relative scanning of the beam source with respect to the substrate.
[0007]
[0007] In further embodiments, the processing system may include a housing, a substrate stage located within the housing, an ion beam source located within the housing for directing an ion beam to the substrate stage, and a radical beam source located within the housing for directing a radical beam to the substrate stage. In at least one embodiment, the processing system may further include a controller configured to control the ion beam source and the radical beam source to operate independently of each other, and in at least one embodiment, the control of the beam composition, the beam incidence angle, and the 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 the following: [Brief explanation of the drawing]
[0009] [Figure 1A-B] An example of a system is shown with side and schematic top views. [Figure 2] An example processing flow is shown. [Modes for carrying out the invention]
[0010]
[0011] The drawings are not necessarily to scale. The drawings are for illustrative purposes only and are not intended to represent any particular parameter of the disclosure. The drawings are intended to illustrate exemplary embodiments of the disclosure and should therefore not be considered limiting. In the drawings, similar numbers represent similar elements.
[0011]
[0012] The embodiments are described more comprehensively below with reference to the accompanying drawings, which show several embodiments. The subject matter of this disclosure can be embodied in a variety of different forms and should not be construed as being limited to the embodiments presented herein. These embodiments are provided so that this disclosure may be comprehensive and complete and so as to fully convey the scope of the subject matter to those skilled in the art. In the drawings, similar numbers refer to similar elements throughout.
[0012]
[0013] This embodiment provides novel apparatus and techniques for substrate processing. In various embodiments, substrate processing is performed using a combination of a separate ion beam source and a separate radical beam source. The radical beam source is independently tuned to the ion beam source. Radicals may include, for example, various components generated by electron-free plasma, while ions may include charged particles generated within the still 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, and carbon fluoride-based ions. Non-limiting examples of radicals may include radicals based on carbon, hydrocarbons, carbon fluoride, chlorinated hydrocarbons, hydrogen, oxygen, nitrogen, or other suitable gas species. According to various embodiments, the apparatus or system can arrange the radical beam source and the ion beam source to process the substrate continuously or simultaneously. In certain embodiments, the substrate may be processed independently by the radical beam source and the ion beam source. This processing may include etching, deposition, implantation, doping, or any suitable combination of other processing techniques related to energy particles such as ions and radicals.
[0013]
[0014] According to several embodiments, the ion beams disclosed herein may be provided as mass spectrometry ion beams or as non-mass spectrometry ion beams. In different embodiments, the ion beam may be provided as a ribbon ion beam or as a spot beam. In various embodiments, the ion beam may be provided as a focused ion beam, a collimated ion beam, or a divergent ion beam. The ion beam may be provided as a directional beam, although the average angle of incidence 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 the principal plane of the substrate, such as the main surface of a semiconductor wafer. In other embodiments, the ion beam source may be positioned to direct the ion beam off-center, i.e., at a non-zero angle of incidence with respect to the normal to the principal plane of the substrate.
[0014]
[0015] Similarly, in various embodiments, the radical beam can be directed to the substrate independently of the ion beam. Here, the angle of incidence of the radical beam may be along the normal to the substrate plane, or it may be directed to deviate from the normal to the substrate. Since the radical beam can be supplied 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 of the species provided in the ion beam containing ions.
[0015]
[0016] According to various non-limiting embodiments, the radical generator used to generate radicals for a radical beam source may be an RF plasma source, a heat source, an electron beam source, or a thermal cathode source. The radical beam source may be configured to supply 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 comprising any suitable combination of a substrate scanner, an ion beam source scanner, and a radical beam source scanner. Thus, the system can generate appropriate relative motion of the substrate with respect to the ion beam source and / or radical beam source. According to various embodiments, the scanning system may be provided by an air bearing, a Selective Compliance Assembly Robot Arm (SCARA) robot, a conventional robot, or other known scanning components.
[0017]
[0018] In various embodiments of this disclosure, the control system is provided to control the output conditions of the radical beam source and the ion beam source separately. The individual control includes adjusting the outputs of the radical beam source and the ion beam source so that a target combination of radical beam treatment and ion beam treatment can be applied to the substrate.
[0018]
[0019] In some embodiments, the substrate may be disposed within a common processing chamber where processing by both a radical beam source and an ion beam source is performed. In certain embodiments, a barrier such as a gas curtain or a partition may be provided within the processing chamber or processing station to at least partially isolate ion beam processing from radical beam processing.
[0019]
[0020] FIG. 1A shows a system 100 arranged in accordance with an embodiment of the present disclosure. The system 100 may include a plurality of beam sources including an ion beam source 104 and a radical beam source 106, and in some embodiments, the plurality of beam sources may be disposed within a common structure or housing shown as housing 102. The ion beam source 104 generates an ion beam 110 to impact a substrate 122 and may 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, a thermal cathode, an indirectly heated cathode, or other known techniques. The ion beam source 104 may further include known extraction components for extracting the ion beam 110 and directing it towards the substrate 122.
[0020]
[0021] The radical beam source 106 generates a radical beam 112 to impact the substrate 122 and can 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 heat source, an electron beam source, or a thermal cathode source.
[0021]
[0022] System 100 may further include a substrate stage 120 for supporting substrate 122, and substrate stage 120 may be disposed within a processing chamber. In the embodiment of FIG. 1A, the processing chamber is generally defined by housing 102, although other configurations are possible. A controller 150 is further provided within system 100 to control the operation of the various components of system 100 detailed below. For example, controller 150 can control ion beam source 104 and radical beam source 106 to operate independently of each other in at least one aspect. As an example, controller 150 can control the gas species supplied to ion beam source 104 and radical beam source 106 such that the beam compositions are different between ion beam source 104 and radical beam source 106. Controller 150 can control ion beam source 104 to generate the same or a different angle of incidence for ion beam 110 compared to the angle of incidence of radical beam 112. Further, controller 150 can transmit control signals to adjust the relative scanning of a beam source, such as ion beam source 104 or radical beam source 106, with respect to substrate 122.
[0022]
[0023] In different embodiments, relative scanning can be achieved using scanning components (not shown separately) of the substrate stage 120 to scan the substrate 122 while the ion beam source 104 and radical beam source 106 are stationary. In other embodiments, scanning components 130 or 132 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 may work in conjunction with the scanning components 130 and 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 may control the ion beam source 104 and the radical beam source 106 so that they scan the substrate 122 in a coordinated manner. In yet another embodiment, the ion beam source 104 may be scanned in conjunction with the simultaneous scanning of the substrate stage 120, the radical beam source 106 may be scanned in conjunction with the 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 the simultaneous scanning of the substrate stage 120.
[0023]
[0024] In various embodiments, the ion beam source 104 can generate a spot-shaped ion beam (spot beam), while in other embodiments, the ion beam source 104 can generate the ion beam 110 as a ribbon ion beam, as shown in Figure 1B. To generate a ribbon ion beam, the extraction assembly may include a rectangular and elongated extraction opening to generate an ion beam 110 having a substantially rectangular cross-section, as shown in Figure 1B. The aspect ratio (X-dimension / Y-dimension) of the extraction opening 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 can generate a radical beam 112 as a spot beam or as a ribbon radical beam, as shown in Figure 1B. According to some embodiments, the substrate 122 can be scanned (along the Y-axis of the illustrated Cartesian coordinate system) to continuously 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 rotational capability to rotate the substrate around an axis perpendicular to the main plane of the substrate stage (in the configuration of Figure 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, relative scanning can be two-dimensional rather than linear, and consists of motion in the XY plane rather than simply 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 movement in both the X and Y directions relative to a spot ion beam. Furthermore, the substrate stage 120 may be scanned with a combination of movement in both the X and Y directions relative to a spot radical beam. Furthermore, the ion beam source and / or radical source that generate the spot beam may move 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 noble gas, nitrogen, oxygen, hydrogen, hydrocarbon C y H x , halogen-containing molecules (C x F y NF x ,SCIENCE FICTION xmay include any one of them, or any combination thereof. In various embodiments, the ion beam source 104 may be biased relative to the substrate 122 at a given extraction potential, thereby generating a given ion energy for the ion beam 110. In various embodiments, the ion beam source 104 is at a given angle of incidence (θ I ) with respect to the perpendicular (Z-axis) to the main plane (X-Y) of the substrate stage 120 and the substrate 122, and the ion beam 110 can be rotatable to be directed along a trajectory forming the angle, and the plane is defined by the main surface of the substrate 122 such as the 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 neutral substances. The radicals of the radical beam 112 may include reactive radicals generated from a plasma containing a halogen-containing molecular gas (C x F y , NF x , SF x , etc.) and, in addition thereto, a mixture of other gases (noble gas, oxygen, nitrogen, hydrogen, hydrocarbon C y H x , etc.). The radical beam source 106 may include apertures to direct the radical beam 112 along a given angle of incidence with respect to the perpendicular (Z-axis). The value of the angle of incidence (θ R ) for the radical beam 112 may be set by the controller 150 to be the same as or different from the angle θ I of the ion beam 110.
[0026]
[0027] Similar to the ion beam 106, the radical beam 112 may be extended along the X-axis, as shown in Figure 1B in some embodiments. According to various embodiments of this disclosure, the radical beam source 106 may be powered and gas supplied separately from the ion beam source 104, so that the ratio of radical flux to ion flux directed to the substrate 122 in a given processing operation can be independently controlled, resulting in a process in which the direction of radicals and ions can be adjusted. Generally, the radical beam 112 may contain reactive neutral substances mainly with small amounts of ions. For example, the input gas may be CF4 (carbon tetrafluoride). Although CF4 itself is very inert (like inert argon or N2), when dissociated in the plasma (by plasma energy electrons), the parent CF4 decomposes into daughter fragments such as CF3, CF2, CF, F, and C. Here, fluorine-containing daughter fragments with open bonds are chemically reactive and useful for surface etching. In addition to generating neutral CFx radicals, similarly CFx + Although ionized radicals such as the above also exist, in various embodiments the overall flux is mainly neutral.
[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 Figure 1A, the substrate 122 is scanned horizontally (along the Y-axis) through fluxes of ions and radicals colliding at various non-zero incidence angles. However, the relative orientations of the radical beam 112 and the ion beam 110 are illustrated simply to show that the various beams can be controlled independently and various incidence angles can be defined. In other embodiments, the apparatus in Figure 1A may be oriented so that the substrate 122 is scanned vertically, and the various components shown in Figure 1A may be arranged to have the same relative orientation to one another. Accordingly, the outputs of both the ion beam source 104 and the radical beam source 106 are correspondingly colinearly oriented along the same non-zero angle with respect to the substrate scanning direction (Y-axis), making an isocentric process (allowing a spread of angles around the average non-zero incidence angle) achievable.
[0028]
[0029] As described above, in order to generate an ion beam with a non-zero incidence angle with respect to the Z axis (perpendicular to the substrate plane or scanning plane), in one embodiment, the entire ion beam source, such as the ion beam source 104, may be tilted with respect to the scanning plane (XZ plane), as shown in Figure 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, so that the individual orbits of the radicals do not deviate substantially from one another. In other words, the incidence angle (θ R The angular spread around ) can be limited to a few degrees, 10 degrees, or 20 degrees in various non-limiting embodiments.
[0030]
[0031] Therefore, by separating ion beam processing from radical beam processing, and by allowing independent control of the composition and shape of the radical beam and ion beam, system 100 provides a combination of components for increasing the flexibility of substrate processing using energy species. This configuration facilitates new capabilities, including better control of reactive ion etching, reactive deposition, and ion implantation processes, and more precise control of processing three-dimensional structures on the substrate.
[0031]
[0032] Figure 2 shows an exemplary process flow 200. In block 202, the substrate is placed in the 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 from a radical beam source separate from the ion beam source to the substrate. 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, and implantation. In block 208, the substrate is scanned with respect to the ion beam source, the radical beam source, or both, but the radical beam and 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, but the separation between the substrate and the radical beam source and ion beam source along a vertical direction such as the Z-axis is kept constant. Thus, the ion beam and radical beam may differ in beam composition, beam incidence angle, relative motion to the substrate during processing, or a combination thereof.
[0032]
[0033] This embodiment offers at least the following advantages. This embodiment allows for the separate and independent adjustment of ion and radical treatment of the substrate, thereby achieving the best process. For example, if the best ion source output is achieved at relatively low pressure and the best radical beam treatment is achieved at relatively high pressure, this embodiment allows for the fulfillment of both conditions without compromise. This embodiment has the further advantage of realizing the ability to perform substrate treatment in a common system using vastly 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 outputs of the radical beam source and the ion beam source, as in a system lacking two independent sources, the rate of radical treatment or ion beam treatment may be limited.
[0033]
[0034] While specific embodiments of the Disclosure have been described herein, the Disclosure is not limited thereto, for the Disclosure is as broad as the art allows, and this Specified Publication can be interpreted in the same way. Therefore, the above description should not be interpreted restrictively. Rather, the above description is merely illustrative of specific embodiments. Those skilled in the art will anticipate other modifications within the scope of the claims and ideas appended herein.
Claims
1. It is a system, A substrate stage for supporting the substrate, Multiple beam sources, An ion beam source is positioned to direct the ion beam toward the substrate, A radical beam source is arranged to direct the radical beam toward the substrate, Multiple beam sources equipped with, In at least one embodiment, a controller is arranged to control the ion beam source and the radical beam source to operate independently of each other. Equipped with, A system in which at least one of the embodiments includes a beam incidence angle with respect to the main plane of the substrate stage, 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.
2. The system according to claim 1, further comprising a radical generator arranged to generate radicals for the radical beam source, wherein the radical generator includes an RF plasma source, a heat source, an electron beam source, or a thermal cathode source.
3. The system according to claim 1, wherein the ion beam source is rotatable to change the angle of incidence of the ion beam with respect to the main plane of the substrate stage.
4. The system according to claim 1, wherein the radical beam source is rotatable to change the angle of incidence of the radical beam with respect to the main plane of the substrate stage.
5. The system according to claim 1, wherein the ion beam source is rotatable to change the angle of incidence of the ion beam with respect to the main plane of the substrate stage, and the radical beam source is rotatable to change the angle of incidence of the radical beam with respect to the main plane of the substrate stage.
6. It is a system, A substrate stage for supporting the substrate, Multiple beam sources, An ion beam source, positioned to direct the ion beam toward the substrate, and rotatable to change the angle of incidence of the ion beam relative to the main plane of the substrate stage, A radical beam source is arranged to direct the radical beam toward the substrate, Multiple beam sources equipped with, In at least one embodiment, a controller is arranged to control the ion beam source and the radical beam source to operate independently of each other. Equipped with, The at least one of the embodiments includes the beam incidence angle with respect to the main plane of the substrate stage, A system in which 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.
7. The system according to claim 6, wherein the radical beam source is rotatable to change the angle of incidence of the radical beam with respect to the main plane of the substrate stage.
8. The system according to claim 6, further comprising a scanning system, wherein the scanning system includes at least one of a substrate scanner, an ion beam source scanner, and a radical beam source scanner.
9. The system according to claim 6, wherein the substrate stage is located within a processing chamber, and the system further comprises a barrier extending within the processing chamber and positioned between the ion beam source and the radical beam source.
10. It is a system, A substrate stage for supporting the substrate, Multiple beam sources, An ion beam source is positioned to direct the ion beam toward the substrate, A radical beam source, positioned to direct the radical beam toward the substrate and rotatable to change the angle of incidence of the radical beam relative to the main plane of the substrate stage, Multiple beam sources equipped with, In at least one embodiment, a controller is arranged to control the ion beam source and the radical beam source to operate independently of each other. Equipped with, The at least one of the embodiments includes the beam incidence angle with respect to the main plane of the substrate stage, A system in which 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.
11. The system according to claim 10, wherein the ion beam source is rotatable to change the angle of incidence of the ion beam with respect to the main plane of the substrate stage.
12. The system according to claim 10, further comprising a scanning system, wherein the scanning system includes at least one of a substrate scanner, an ion beam source scanner, and a radical beam source scanner.
13. The system according to claim 10, wherein the substrate stage is located within a processing chamber, and the system further comprises a barrier extending within the processing chamber and located between the ion beam source and the radical beam source.