Methods of ion implantation and deposition of materials and etching and processing workpieces

Abstract

A method of ion implantation and deposition of materials and etching and processing workpieces using a processing system having an auxiliary plasma source positioned proximate to the workpiece for use with an ion beam. The auxiliary plasma source is used to generate ions and radicals that drift toward the workpiece and can form a film. Then, the ion beam is used to provide energy so that the ions and radicals can process the workpiece. In addition, various applications of the system are disclosed. For example, the system can be used for a variety of processes including deposition, implantation, etching, pre-treatment, and post-treatment. By positioning the auxiliary plasma source proximate to the workpiece, processes that were previously not possible can be performed. In addition, two different processes, such as cleaning and implantation or implantation and passivation, can be performed without removing the workpiece from the end station.

Description

[0001] This invention is a divisional application of the invention patent application filed on June 12, 2019, with application number 201980041813.6 and title "Processing System and Ion Implantation and Deposition Material and Method for Etching and Processing Workpiece". Technical Field

[0002] The embodiments in this specification relate to semiconductor processing methods using inline surface-engineered sources, and more specifically, to ion and radical sources used in conjunction with ion beams in close proximity to a workpiece. Particularly, it relates to a method for ion implantation and deposition of materials, and for etching and processing workpieces. Background Technology

[0003] The fabrication of semiconductor devices involves multiple discrete and complex processes. One such process is an implantation process that embeds dopant material into a workpiece. Another process is a deposition process that deposits material onto the workpiece. Yet another process is an etching process in which material is removed from the workpiece.

[0004] To guide ions along a desired path, a beamline system with multiple components (such as electrodes, mass analyzers, quadrupole lenses, and acceleration / deceleration stages) is used. Much like optical systems, beamline systems manipulate ions by bending their paths and focusing them.

[0005] In some embodiments, a ribbon ion beam is generated. A ribbon ion beam is an ion beam whose width is much greater than its height. In other words, the aspect ratio of the ribbon ion beam (defined as the width of the ribbon ion beam measured at the workpiece divided by its height) can be very high, for example, greater than 20. In some embodiments, the width of the ribbon beam is wider than the diameter of the workpiece being processed.

[0006] Over the years, ion implantation machines have become highly sophisticated tools, incorporating the use of energy filters, collimators, scanning systems, and more recently, the use of molecular ion sources and the ability to implant at both low and high temperatures. As memory and logic architectures continue to scale and complex structures such as gate-all-around become possible, there is a growing desire to control and modify near-surface processes similar to ion implantation. These near-surface processes can include native oxide cleaning, surface passivation, neo-damage engineering to reduce defect rates, beam distributions from surface-gradient to traditionally typical receding distributions, and selective treatment where the ion beam itself acts as a catalyst for surface reactions.

[0007] Therefore, it would be beneficial to have a semiconductor processing system and method that forms an infeed surface engineering source close to the workpiece to perform near-surface processes on the workpiece together with an ion beam. Summary of the Invention

[0008] This specification discloses a system with an auxiliary plasma source positioned close to a workpiece and used in conjunction with an ion beam. The auxiliary plasma source generates ions and radicals that drift toward the workpiece and can form a film. The ion beam then provides energy, enabling the ions and radicals to process the workpiece. Furthermore, various applications of the system are disclosed. For example, the system can be used for various processes including deposition, implantation, etching, pretreatment, and post-treatment. By positioning the auxiliary plasma source close to the workpiece, processes previously impossible can be performed. Furthermore, two different processes, such as cleaning and implantation or implantation and passivation, can be performed without removing the workpiece from the terminal station.

[0009] According to one embodiment, a semiconductor processing system is disclosed. The semiconductor processing system includes: an ion source for generating an ion beam; and an auxiliary plasma source disposed close to a workpiece, the auxiliary plasma source having an exit aperture oriented to emit ions and free radicals toward the workpiece. In some embodiments, the ion source is a component of a beamline implantation system. In some embodiments, the auxiliary plasma source includes a housing, an antenna disposed within the housing, and a radio frequency (RF) power supply communicating with the antenna. In other embodiments, the auxiliary plasma source includes a housing, an antenna disposed outside the housing and close to a wall of the housing, and an RF power supply communicating with the antenna. In some embodiments, the exit aperture is oriented such that the free radicals and ions are guided toward the workpiece at a location where the ion beam impacts the workpiece. In other embodiments, the exit aperture is oriented such that the free radicals and ions are guided toward the workpiece in a direction parallel to the ion beam. In some embodiments, the auxiliary plasma source is biased such that the ions are attracted to the workpiece. In some embodiments, the system includes a terminal station in which the workpiece is disposed, wherein the auxiliary plasma source is disposed in the terminal station. In some embodiments, the terminal station is provided with a heater. In some embodiments, the terminal station is provided with a plasma diffuser electron gun separate from the auxiliary plasma source.

[0010] According to another embodiment, a method for implanting ions of a desired species into a workpiece is disclosed. The method includes: generating plasma in an auxiliary plasma source using a gas comprising the desired species, wherein the auxiliary plasma source is located near the workpiece, and wherein ions and radicals from the plasma are emitted from the auxiliary plasma source and travel toward the workpiece; and knocking the ions and radicals from the auxiliary plasma source into the workpiece using an ion beam generated using an ion source different from the auxiliary plasma source. In some embodiments, the ion beam comprises an inert species. In some embodiments, the ions and radicals from the plasma are directed toward the workpiece at the location where the ion beam impacts the workpiece. In some embodiments, the ions and radicals form a film on the surface of the workpiece at the location where the ion beam impacts the workpiece. In some embodiments, the desired species comprises molecules containing a Group III, Group IV, or Group V element.

[0011] According to another embodiment, a method for processing a workpiece is disclosed. The method includes: generating plasma in an auxiliary plasma source using a gas comprising etching species, wherein the auxiliary plasma source is located near the workpiece in a terminal station, wherein ions and free radicals from the plasma are emitted from the auxiliary plasma source and react with a native oxide layer on the surface of the workpiece; heating the workpiece after the reaction, wherein the heat causes the native oxide layer on the workpiece to sublimate; and performing an additional process on the workpiece using an ion beam generated using an ion source different from the auxiliary plasma source, wherein the workpiece remains located in the terminal station. In some embodiments, the etching species is selected from the group consisting of ammonia and NF3. In some embodiments, the workpiece is scanned such that a portion of the workpiece is exposed to the plasma and subsequently to heat. In some embodiments, the generation and heating are repeated until the surface of the workpiece is cleaned.

[0012] According to another embodiment, a method for etching a workpiece is disclosed. The method includes: generating plasma in an auxiliary plasma source using a gas comprising an etching species, wherein the auxiliary plasma source is located close to the workpiece, and wherein ions and free radicals from the plasma are ejected from the auxiliary plasma source toward a portion of the workpiece and form a film on said portion of the workpiece; and using an ion beam to provide energy for etching the workpiece, the ion beam being generated using an ion source different from the auxiliary plasma source. In some embodiments, the etching species includes halogens. In some embodiments, the etching species includes CF4 and oxygen. In some embodiments, the etching species includes hydrogen, and a native oxide layer is etched. In some embodiments, the ion beam includes an inert gas. In some embodiments, the ion beam is directed to said portion of the workpiece while the film is being generated. In some embodiments, the ion beam is directed to said portion of the workpiece after the film has been generated.

[0013] According to other embodiments, a method for depositing material on a workpiece is disclosed. The method includes: generating plasma in an auxiliary plasma source using a processing gas, wherein the auxiliary plasma source is located close to the workpiece, and wherein ions and radicals from the plasma are ejected from the auxiliary plasma source toward a portion of the workpiece and form a film on said portion of the workpiece; and using an ion beam to provide energy to deposit the material on the workpiece, the ion beam being generated using an ion source different from the auxiliary plasma source. In some embodiments, the processing gas includes CH4, and the ion beam includes a Group IV element. In some embodiments, a more box-like profile is produced than that produced by using the ion beam alone.

[0014] According to another embodiment, a method for processing a workpiece is disclosed. The method includes: guiding ions toward the workpiece using an ion beam; generating plasma in an auxiliary plasma source using a processing gas, wherein the auxiliary plasma source is located near the workpiece in a terminal station, wherein ions and free radicals from the plasma are emitted from the auxiliary plasma source and react with the surface of the workpiece; and heating the workpiece after the reaction, wherein the heat repairs damage caused by the ion beam on the surface of the workpiece. In some embodiments, the ion beam is used to implant ions into the workpiece. In some embodiments, the workpiece is scanned such that a portion of the workpiece is exposed to the plasma and subsequently to heat. In some embodiments, the workpiece is heated to a temperature between 100°C and 500°C. In some embodiments, the processing gas comprises a hydrogen / nitrogen mixture. In some embodiments, the entire workpiece is processed by the ion beam prior to generation and heating. In some embodiments, a first portion of the workpiece is processed by the ion beam while a second portion reacts with the plasma. Attached Figure Description

[0015] For a better understanding of this specification, refer to the accompanying drawings incorporated herein for reference, in which:

[0016] Figure 1 This is a representative view of a wire implantation system for generating ribbon ion beams, which can be used with an incoming surface-engineered source according to one embodiment.

[0017] Figure 2 An example is shown. Figure 1 The terminal station shown.

[0018] Figure 3A An example is shown. Figure 2 The auxiliary plasma source is shown.

[0019] Figure 3B An illustration according to another embodiment Figure 2 The auxiliary plasma source is shown.

[0020] Figure 4A An example is shown. Figure 2 The configuration of the terminal station shown.

[0021] Figure 4B An illustration according to another embodiment Figure 2 The configuration of the terminal station shown.

[0022] Figure 5 Showing the use Figure 4A Ion implantation at the terminal station shown.

[0023] Figure 6A representative flow chart of a pretreatment process is shown.

[0024] Figure 7 A representative flow chart of a post-processing procedure is shown.

[0025] Figure 8 A semiconductor processing system using an incoming surface-engineered source is shown according to another embodiment. Detailed Implementation

[0026] Figure 1 A wire ion implantation system is shown according to one embodiment, which can be used with an incoming surface engineering source. The wire ion implantation system can be used to process workpieces using a ribbon ion beam.

[0027] The beam ion implantation system includes an ion source 100, which includes a plurality of chamber walls defining an ion source chamber. In some embodiments, the ion source 100 may be an RF ion source. In this embodiment, an RF antenna may be disposed against a dielectric window. This dielectric window may form part or all of one of the chamber walls. The RF antenna may contain a conductive material, such as copper. An RF power supply communicates electrically with the RF antenna. The RF power supply may supply an RF voltage to the RF antenna. The power supplied by the RF power supply may be between 0.1 kW and 10 kW, and may be at any suitable frequency, for example, between 1 MHz and 100 MHz. Furthermore, the power supplied by the RF power supply may be pulsed.

[0028] In another embodiment, a cathode is disposed within the ion source chamber. A filament is positioned behind the cathode and is excited to emit electrons. These electrons are attracted to the cathode, which in turn emits electrons into the ion source chamber. This cathode may be referred to as an indirectly heated cathode (IHC) because it is indirectly heated by electrons emitted from the filament.

[0029] Other embodiments may also exist. For example, plasma can be generated in different ways (e.g., via a Bernas ion source, a capacitively coupled plasma (CCP) source, a microwave ion source, or an electron-cyclotron-resonance (ECR) ion source). The method of plasma generation is not limited to this specification.

[0030] A chamber wall, referred to as an extraction plate, includes an extraction opening. The extraction opening may be an opening through which ions 1 generated in the ion source chamber are extracted and guided toward workpiece 10. Workpiece 10 may be a silicon wafer, or another wafer suitable for semiconductor manufacturing, such as GaAs, GaN, or GaP. The extraction opening may be of any suitable shape. In some embodiments, the extraction opening may be elliptical or rectangular, wherein a dimension referred to as the width (x-dimension) of the ellipse or rectangle may be much larger than a second dimension referred to as the height (y-dimension).

[0031] An extraction optics 110 is disposed outside and near the extraction opening of the ion source 100. In some embodiments, the extraction optics 110 includes one or more electrodes. Each electrode may be a single conductive component in which an opening is provided. Alternatively, each electrode may consist of two conductive components spaced apart to form an opening between the two components. The electrodes may be metals, such as tungsten, molybdenum, or titanium. One or more of the electrodes may be electrically connected to ground. In some embodiments, an electrode power supply may be used to apply a bias voltage to one or more of the electrodes. The electrode power supply may be used to apply a bias voltage to one or more of the electrodes relative to the ion source to attract ions via the extraction opening. The extraction opening is aligned with an opening in the extraction optics such that ions 1 pass through both openings.

[0032] Downstream of the extraction optics 110 may be a first quadrupole lens 120. The first quadrupole lens 120 cooperates with other quadrupole lenses in the system to focus ions 1 into an ion beam.

[0033] Downstream of the first quadrupole lens 120 is a mass analyzer 130. The mass analyzer 130 uses a magnetic field to guide the path of the extracted ions 1. This magnetic field influences the ion's flight path according to its mass and charge. A mass resolution device 150 with a resolution aperture 151 is located at the output or distal end of the mass analyzer 130. By appropriately selecting the magnetic field, only those ions 1 with the selected mass and charge will be guided through the resolution aperture 151. Other ions will strike the mass resolution device 150 or the wall of the mass analyzer 130 and will not travel further in the system.

[0034] A second quadrupole lens 140 may be provided between the output of the mass analyzer 130 and the mass resolution device 150.

[0035] Collimator 180 is positioned downstream of mass resolution device 150. Collimator 180 receives ions 1 passing through resolution aperture 151 and generates a band-shaped ion beam formed by multiple parallel or nearly parallel sub-beams. The output or distal end of mass analyzer 130 is spaced at a fixed distance from the input or proximal end of collimator 180. Mass resolution device 150 is positioned in the space between these two components.

[0036] A third quadrupole lens 160 may be provided between the input of the quality resolution device 150 and the collimator 180. A fourth quadrupole lens 170 may also be provided between the input of the quality resolution device 150 and the collimator 180.

[0037] In some embodiments, the quadrupole lens may be located in other positions. For example, the third quadrupole lens 160 may be located between the second quadrupole lens 140 and the quality resolution device 150. Additionally, in some embodiments, one or more of the quadrupole lenses may be omitted.

[0038] Downstream of the collimator 180 may be an acceleration / deceleration stage 190. The acceleration / deceleration stage 190 may be referred to as an energy purity module. The energy purity module is a beamline lens assembly configured to independently control the deflection, deceleration, and focusing of the ion beam. For example, the energy purity module may be a vertical electrostatic energy filter (VEEF) or an electrostatic filter (EF).

[0039] Ions 1 are emitted as ion beam 191 from the acceleration / deceleration stage 190 and enter the terminal station 200. Ion beam 191 can be a strip-shaped ion beam. Workpiece 10 is disposed in the terminal station 200.

[0040] Therefore, the beamline ion implantation system includes multiple components terminating at terminal station 200. As described above, these components include an ion source 100; extraction optics 110; quadrupole lenses 120, 140, 160, and 170; a mass analyzer 130; a mass resolution device 150; a collimator 180; and an acceleration / deceleration stage 190. It should be noted that the beamline ion implantation system may not include one or more of these components.

[0041] Furthermore, although the above disclosure describes a strip-shaped ion beam with a width much greater than its height, other embodiments are possible. For example, a scanning spot beam may enter terminal station 200. The scanning spot beam is an ion beam that is typically circular in shape and is scanned laterally to produce the same effect as the strip-shaped ion beam.

[0042] The system can be controlled using controller 195. Controller 195 has a processing unit and an associated memory device. This memory device contains instructions that, when executed by the processing unit, enable the system to perform the functions described herein. This memory device can be any non-transitory storage medium, including non-volatile memory such as flash read-only memory (FLASH ROM), electrically erasable read-only memory, or other suitable means. In other embodiments, the memory device can be volatile memory, such as random access memory (RAM) or dynamic random access memory (DRAM). In some embodiments, controller 195 can be a general-purpose computer, an embedded processor, or a specially designed microcontroller. Actual implementations of controller 195 are not limited to this specification.

[0043] Figure 2 A terminal station 200 according to one embodiment is shown. As described above, a workpiece 10 is disposed in the terminal station 200. An ion beam 191 enters the terminal station 200 and is guided toward the workpiece 10. The workpiece 10 may be held by a pressure plate 210. The pressure plate 210 may be rotatable about an axis perpendicular to the front surface of the pressure plate 210. The pressure plate 210 may also be rotatable about an axis 211 parallel to the front surface of the pressure plate 210. In addition, the pressure plate 210 may be rotatable linearly along direction 212. Of course, the pressure plate 210 may not have all of these capabilities.

[0044] A plasma diffuser electron gun 220 may be disposed in the terminal station 200 and near the ion beam 191. The plasma diffuser electron gun 220 is used to emit low-energy electrons to reduce space charge bursts and neutralize the workpiece 10. It is particularly important to note that the plasma diffuser electron gun 220 is used only to emit a net negative charge flux in the form of electrons from plasma formed by rare or non-reactive gases, and not from other plasma species (such as atomic or molecular radicals derived from molecular dissociation). In other words, the plasma diffuser electron gun 220 uses an inert gas (e.g., xenon) to emit electrons. The plasma diffuser electron gun 220 is not intended to alter the properties of the workpiece 10.

[0045] In one embodiment, the plasma diffuser electron gun 220 may include a plasma chamber 221 having a substantially metal-free inner surface. A radio frequency coil 222 may be disposed within the plasma chamber 221 to directly excite the gas enclosed within the chamber, thereby generating and sustaining the desired plasma. The plasma chamber 221 may have an elongated exit opening 223 on one side, through which plasma can flow out of the plasma chamber 221 and combine with ions from the ion beam 191. A series of magnets 224 may be disposed around the plasma chamber 221 to contain and control the plasma generated within the plasma chamber 221. Specifically, the magnets 224 may be positioned outside the walls of the plasma chamber 221, and the magnetic field of each magnet 224 extends through the walls of the plasma chamber 221.

[0046] More specifically, the interior of the plasma chamber 221 may be made of a non-metallic conductive material such as graphite or silicon carbide (SiC). A feed gas pipe may be disposed in the sidewall of the plasma chamber 221, through which one or more gaseous substances can be supplied to the plasma chamber 221. The gaseous substances may include inert gases such as xenon (Xe), argon (Ar), or krypton (Kr). The gas pressure is typically maintained in the range of 1 mTorr to 50 mTorr.

[0047] The radio frequency (RF) coil 222 may have an elongated shape extending substantially through the center of the plasma chamber 221. One end of the RF coil 222 may be connected to an RF power source, which may inductively couple RF power into the plasma chamber 221. The RF power may operate at typical frequencies (e.g., 2 MHz, 13.56 MHz, and 27.12 MHz). The RF coil 222 may be completely enclosed within the plasma chamber 221. In the sidewall of the plasma chamber, an exit aperture 223 is positioned to allow the generated plasma flow to contact the ion beam 191. For a strip-shaped ion beam, the exit aperture 223 may cover substantially the bandwidth.

[0048] According to one embodiment, it is desirable to form a plasma bridge between the plasma from the plasma diffuser electron gun 220 and the ion beam 191 that passes just outside the plasma chamber 221. As described above, the plasma chamber 221 may include a series of magnets 224 (e.g., permanent magnets or electromagnets) arranged to contain and control the plasma generated within the plasma chamber 221. The characteristics of these magnets 224 may also be arranged to control the characteristics of the plasma as it exits the plasma chamber 221 via the exit opening 223.

[0049] In other embodiments, the plasma diffuse electron gun 220 may be a Bernas-type ion source, in which a filament is used to generate thermionic emission. A gas, such as argon, is introduced into the plasma chamber. The emitted electrons excite plasma within the plasma chamber. Electrons from the plasma are then extracted from the plasma chamber via an exit opening.

[0050] In other words, the plasma diffuse electron gun 220 can be constructed in various ways, and its implementation is not limited to this specification.

[0051] Therefore, electrons from the plasma diffuser electron gun 220 can be confined by a magnetic field to guide their path toward the ion beam 191. In some embodiments, the plasma diffuser electron gun 220 may not be used.

[0052] An auxiliary plasma source 270 is provided within the terminal station 200. Unlike the plasma diffuser electron gun 220, the auxiliary plasma source 270 is used to emit ions and / or free radicals into a region near the workpiece 10 via one or more emission openings 275. Free radicals are known to be molecular or atomic species with unpaired valence electrons. Therefore, free radicals are generally highly reactive. Free radicals are typically generated by dissociating larger molecules in the auxiliary plasma source 270. In some embodiments, the auxiliary plasma source 270 is positioned within 30 cm of the workpiece 10; however, other embodiments are possible. Although the auxiliary plasma source 270 is shown as cylindrical, it should be understood that this is merely illustrative and the auxiliary plasma source 270 can be of any shape.

[0053] In some embodiments, a heater 240 may also be provided in the terminal station 200. The heater 240 may be located near the auxiliary plasma source 270, such that the heater 240 and the auxiliary plasma source 270 are positioned on the same side of the ion beam 191. The heater 240 may be any suitable device, including a heat lamp, a light-emitting diode (LED), or a resistive heater. Although Figure 2 An auxiliary plasma source 270 is shown positioned between the ion beam 191 and the heater 240; however, other configurations are possible. For example, the heater 240 may be positioned between the ion beam 191 and the auxiliary plasma source 270. In another embodiment, the heater 240 and the auxiliary plasma source 270 may be positioned on opposite sides of the ion beam 191.

[0054] exist Figure 3AIn one embodiment shown, the auxiliary plasma source 270 includes a housing 231, which may be cylindrical, but other shapes are also possible. The housing 231 may be constructed of aluminum or some other suitable material. An antenna 232 is provided within the housing 231 and may be surrounded by a protective shield 233. The antenna 232 may be constructed of a conductive material (e.g., metal) and may be U-shaped. The antenna 232 is coated with or coaxially within the protective shield 233, which may be a ceramic material to protect the antenna 232 from the plasma 274 generated within the auxiliary plasma source 270. The housing 231 includes one or more exit openings 275 through which the plasma 274 exits from the auxiliary plasma source 270 and enters the terminal station 200. In operation, processing gas is introduced into the volume defined by the housing 231. An RF power supply 235 is used to excite the antenna 232. This energy generates plasma 274 within the auxiliary plasma source 270. Next, plasma 274 is emitted from auxiliary plasma source 270 via one or more exit openings 275.

[0055] Figure 3B An auxiliary plasma source 270 according to another embodiment is shown. In this embodiment, the auxiliary plasma source 270 has an antenna 252 disposed outside a housing 251. An RF power supply 255 is used to excite the antenna 252. For example, the wall near the antenna 252 may be a dielectric material, allowing energy from the antenna 252 to pass through the wall and enter the volume defined by the housing 251. Processing gas is introduced into this volume and, when excited, generates plasma 274. The plasma 274 is then emitted from the auxiliary plasma source 270 via one or more exit openings 275.

[0056] Other types of devices can be used for the auxiliary plasma source 270. For example, an indirect-heated cathode (IHC) ion source can be used. Alternatively, a Berners source can be used. In another embodiment, an inductively coupled plasma (ICP) source or a capacitively coupled plasma (CCP) source can be used. Therefore, the auxiliary plasma source 270 is not limited to... Figures 3A to 3B As shown in the image.

[0057] In some embodiments (e.g.) Figure 4A In the embodiment shown, the auxiliary plasma source 270 can be oriented such that one or more exit openings 275 emit plasma 274 toward a location on the workpiece 10 where the ion beam 191 strikes the workpiece 10. In this way, the ion beam 191 and the plasma 274 cooperate to process the workpiece 10. For example, ions and radicals in the plasma 274 can deposit on the workpiece 10 in the area exposed to the ion beam 191. (See reference...) Figure 2As needed, the terminal station 200 may include a plasma diffuser electron gun 220 and / or a heater 240.

[0058] Figure 4B A terminal station 200 according to another embodiment is shown. In this embodiment, an auxiliary plasma source 270 is oriented such that one or more exit openings 275 are directly opposite the workpiece 10. Thus, the flow formed by the plasma 274 is parallel to the ion beam 191. (See reference...) Figure 2 As needed, the terminal station 200 may include a plasma diffuser electron gun 220 and / or a heater 240.

[0059] exist Figures 4A to 4B In the illustrated embodiment, a processing gas may be introduced into an auxiliary plasma source 270. For example, an antenna may be excited using an RF power supply. The energy in the antenna ionizes the processing gas within the auxiliary plasma source 270, forming plasma 274. This plasma 274 is then emitted toward the workpiece 10 via the one or more exit openings 275. In some embodiments, a voltage difference may exist between the auxiliary plasma source 270 and the workpiece 10. For example, the auxiliary plasma source 270 may be applied a positive bias voltage relative to the workpiece 10. In some embodiments, the auxiliary plasma source 270 may be applied a positive bias voltage relative to the workpiece 10 ranging from 0V to 5000V. In some embodiments, the auxiliary plasma source 270 may be applied a positive bias voltage relative to the workpiece 10 ranging from 0V to 500V. In this embodiment, positive ions within the auxiliary plasma source 270 are accelerated toward the workpiece 10. Alternatively, the auxiliary plasma source 270 may be applied a negative bias voltage relative to the workpiece 10. In this embodiment, positive ions within the auxiliary plasma source 270 are repelled to some extent by the workpiece 10. In other embodiments, the auxiliary plasma source 270 may be at the same potential as the workpiece 10, such that the flux of ions and radicals from the auxiliary plasma source 270 only drifts through the one or more exit openings 275.

[0060] exist Figure 4A In the illustrated embodiment, as the pressure plate 210 moves upward along direction 212, a portion of the workpiece 10 is exposed to the ion beam 191 and plasma 274 from the auxiliary plasma source 270. Following this exposure, said portion of the workpiece 10 can then be heated by the heater 240.

[0061] exist Figure 4B In the embodiment shown, workpiece 10 is first treated by ion beam 191 and then by plasma 274 as it moves upward. After exposure to ion beam 191 and plasma 274, workpiece 10 may then undergo heat treatment by heater 240.

[0062] The use of heat after treatment by ion beam 191 and / or plasma 274 can have beneficial applications.

[0063] It should be noted that it is possible to Figures 4A to 4B The configuration shown employs any type of auxiliary plasma source. Therefore, the choice of the type and orientation of the auxiliary plasma source 270 is a design decision based on the process being performed and other considerations.

[0064] The flow rate of the process gas into the auxiliary plasma source 270 and the energy applied by the antenna are the determining factors for the number of free radicals and ions extracted from the auxiliary plasma source 270. In some embodiments, for process control, the process gas is diluted with an inert gas to maintain plasma or reduce the number of free radicals and ions of the desired species.

[0065] Although it was explained in conjunction with ion implantation Figure 1 However, it should be understood that the terminal station 200 can be used with any semiconductor processing system. Semiconductor processing systems with surface-engineered sources have been described; various applications of such semiconductor processing systems will be explained.

[0066] In one embodiment, using Figure 4A The configuration shown Figure 1 The semiconductor processing system shown can be used to perform ion implantation processes. As described above, Figure 4A The terminal station shown guides plasma 274 from auxiliary plasma source 270 toward the location where ion beam 191 impacts the workpiece 10. In this way, while interacting with the surface of the workpiece 10, there is also an interaction between ion beam 191 and plasma 274.

[0067] In this embodiment, it is desirable to implant a target species into workpiece 10. For example, the target species may be a Group III, Group IV, or Group V element. For example, in one embodiment, arsenic may be the desired species. The desired species is introduced into auxiliary plasma source 270. The desired species may be introduced in the form of molecules containing the target species. This desired species is stimulated to form plasma 274. Figure 5 As shown, plasma 274 diffuses toward the location where ion beam 191 impacts workpiece 10. Ions and free radicals from plasma 274 can be deposited on the surface of workpiece 10, for example, in the form of film 277. Gases such as argon, xenon, or krypton are introduced into ion source 100 (see [reference]). Figure 1The gas is used to generate an ion beam 191. In some embodiments, the gas may be an inert species defined as a Group VIII element, such as neon, argon, xenon, or krypton. The ion beam 191 collides with ions and radicals from plasma 274 near the workpiece 10 or deposited as a film 277 on the workpiece 10. These collisions transfer most of the energy of the ions from the ion beam 191 to the ions and radicals from plasma 274. This allows the ions and radicals from plasma 274 to acquire the velocity required to penetrate the surface of the workpiece 10. Thus, the energy of the ions in the ion beam 191 is imparted to the ions and radicals from plasma 274. This allows the ions and radicals in film 277 to be driven into the workpiece 10. In this embodiment, the ion beam 191 is used to knock in ions and radicals from plasma 274. Therefore, unlike conventional ion implanters, the ions in ion source 100 are used to provide energy to drive in ions and radicals generated in an auxiliary plasma source 270 in terminal station 200.

[0068] Therefore, in this embodiment, the ion beam 191 is used to provide energy, while the auxiliary plasma source 270 is used to supply the desired species. Although the above description uses inert gases and arsenic, these are purely illustrative and this specification is not limited to this embodiment. The ion beam 191 can be made of any ion species. In some embodiments, certain species, such as inert elements or Group IV elements, can be used such that the ion beam does not affect the conductivity of the silicon wafer. The target species can be any desired species, including Group III elements (e.g., boron and gallium) and Group V elements (e.g., phosphorus and arsenic). In some embodiments, Group III and Group V elements can be combined with other elements to form molecules, such as BF3, AsH3, PH3, and other molecules.

[0069] In another embodiment, the semiconductor processing system described herein can be used to perform the etching process. Specifically, the use of an auxiliary plasma source 270 allows for the generation of more chemically active free radicals near the workpiece. In this case, the auxiliary plasma source 270 is used to generate ions of etching chemicals (e.g., Group VII elements and molecules containing these elements), free radicals, and metastable neutrons. These ions and metastable neutrons are emitted from the auxiliary plasma source 270 and drift toward the workpiece 10. Because the ions from the auxiliary plasma source 270 have low energy, these ions are deposited on or near the surface of the workpiece 10.

[0070] In one particular embodiment, a halogen-containing gas is introduced into an auxiliary plasma source 270 to generate ions. Low-energy ions and free radicals emitted from the auxiliary plasma source 270 can form a thin film on the surface of the workpiece 10. Using the energy provided by the ion beam 191, this thin film reacts with the workpiece 10 to etch it. In some embodiments, the ion beam 191 may include an inert gas such as argon. In one embodiment, using… Figure 4A The illustrated embodiment guides the ion beam 191 toward a portion of the workpiece 10 while forming the film. In another embodiment, using... Figure 4B The illustrated embodiment is used to guide the ion beam 191 toward a portion of the workpiece 10 after the membrane has been formed.

[0071] In another specific embodiment, CF4 and oxygen are ionized and dissociated in an auxiliary plasma source 270. An ion beam 191 containing an inert gas (e.g., argon) is used to etch the surface of the workpiece 10.

[0072] In yet another specific embodiment, a native oxide layer may be formed on the surface of workpiece 10. This native oxide layer can be etched by ionizing hydrogen in an auxiliary plasma source 270. An ion beam containing an inert gas (e.g., argon) is used to etch the native oxide from the surface of workpiece 10.

[0073] In another embodiment, it can be used Figures 1 to 4B The semiconductor processing system shown is used for deposition. The material to be deposited can be ionized in an auxiliary plasma source 270. The material can be a dopant or a material used as a coating for the workpiece 10. Ions and radicals from the material are emitted from the auxiliary plasma source 270 and drift toward the workpiece 10, wherein the ions and radicals are deposited on the surface of the workpiece 10.

[0074] In one particular embodiment, the processing gas may be CH4, while the ion beam 191 includes a Group IV element, such as carbon. This allows for a more box-like distribution in the workpiece 10. In contrast, using the ion beam 191 alone produces a regressive distribution.

[0075] Therefore, in applications where both the ion beam 191 and the auxiliary plasma source 270 are used simultaneously, the ion beam 191 can be used to perform at least one of the two functions.

[0076] First, the ion beam 191 can supply the energy required to drive ions or free radicals from the auxiliary plasma source 270 toward and into the workpiece 10. One example of this is using the ion beam 191 to knock ions from the plasma 274 into the workpiece 10, such as... Figure 5 As shown in the image.

[0077] Secondly, the ion beam 191 can supply additional species to promote or induce chemical reactions at the surface of the workpiece 10. This can be achieved in several ways. First, the ion beam 191 can weaken the bonds in the underlying workpiece 10, making the surface of the workpiece 10 react with the deposited layer. Second, the ion beam 191 can incorporate the deposited layer into the underlying workpiece 10 to facilitate further reactions. Third, the ion beam 191 can release or volatilize newly formed compounds created from the deposited layer and the workpiece 10. The sputtering yield of this newly formed compound can be much higher than the sputtering yield of the ion beam 191 alone on the workpiece 10. For example, in an etching process, CF4 and oxygen radicals react with silicon nitride on the surface of the workpiece 10 to produce CF4+. x Polymer-type materials. The resulting SiF... x C y The compound volatilizes when exposed to the energy of the ion beam 191.

[0078] In another embodiment, the auxiliary plasma source 270 and the ion beam 191 may not be used simultaneously. For example, the workpiece 10 may be processed by one of these sources first and then by the other source at a later time.

[0079] For example, in one embodiment, an auxiliary plasma source is used to provide pretreatment of the workpiece 10. Figure 6 The flowchart of this process is shown in the figure. In this embodiment, since the ion beam 191 is inactive during pretreatment, it can be used... Figure 4A or Figure 4B The illustrated embodiment. First, as shown in process 500, ion beam 191 is disabled. One or more etching species (e.g., ammonia (NH3) and NF3) are introduced into auxiliary plasma source 270, as shown in process 510. Auxiliary plasma source 270 generates ions and other free radicals. These ions and free radicals are emitted from auxiliary plasma source 270 and drift toward workpiece 10, where they react with the silicon oxide layer of workpiece 10, as shown in process 520. Workpiece 10 is scanned such that the portions of workpiece 10 exposed to ions and free radicals are then heated by heater 240, as shown in process 530. The heat serves to sublimate the reacted silicon oxide on the surface of workpiece 10, as shown in process 540. This process is repeated until the surface of workpiece 10 is cleaned. Thereafter, workpiece 10 can be subjected to another process by ion beam 191, as shown in process 550. Advantageously, workpiece 10 remains in terminal station 200 throughout the pretreatment and the second process shown in process 550. In other words, workpiece 10 does not leave the terminal station between pretreatment and the second process.

[0080] In another embodiment, the process described above can be performed without placing the workpiece 10 on the pressure plate 210. In this embodiment, the process serves to clean the pressure plate 210.

[0081] In another embodiment, an auxiliary plasma source 270 is used in the post-processing of workpiece 10. For example, post-processing can be used to passivate the surface of workpiece 10 or restore damage caused by the ion implantation process. Figure 7 The flowchart illustrates this process. First, as described above, workpiece 10 is treated using ion beam 191. Next, a processing gas is introduced into auxiliary plasma source 270, as shown in process 610. The processing gas may include a hydrogen / nitrogen mixture. Ions and radicals from auxiliary plasma source 270 are directed toward the surface of workpiece 10, as shown in process 620. At a temperature, for example, between 100°C and 500°C, workpiece 10 is scanned through heater 240, as shown in process 630. It has been shown that damage recovery is effective at lower temperatures using a synthesis gas, and this is known as plasma annealing. Passivation occurs by reacting hydrogen or nitrogen radicals with dangling bonds on the surface, as shown in process 640.

[0082] In one embodiment, Figure 7 The post-processing shown is performed while ion beam 191 is disabled. In another embodiment, it can be used... Figure 4B The embodiment shown is used to perform post-processing. Specifically, the workpiece 10 is implanted using an ion beam 191. As the workpiece 10 moves upward along direction 212, the implanted portion is then exposed to processing gas from an auxiliary plasma source 270. Subsequently, the implanted portion is heated. Therefore, in this embodiment, the workpiece 10 is implanted using an ion beam 191 and post-processed during a single scan of the workpiece 10. In other words, one portion (a first portion) of the workpiece is exposed to the ion beam, while a second portion of the workpiece, different from the first portion, is exposed to the plasma.

[0083] Therefore, this specification describes a semiconductor processing system in which ion and radical sources are incorporated into a terminal station 200. Traditionally, significant effort has been made to ensure that ions or radicals are not introduced into the terminal station 200. Specifically, the plasma diffuse electron gun 220 is designed to ensure that electrons are primarily emitted into the terminal station 200. This semiconductor processing system intentionally introduces ions and radicals into the terminal station 200. In some embodiments, these ions and radicals are introduced simultaneously with the use of the ion beam 191 to perform applications that would otherwise be impossible.

[0084] While the above disclosure describes the use of the auxiliary plasma source 270 with a beam ion implantation system, other embodiments are possible. For example, Figure 8This example is illustrated. In this figure, the semiconductor processing system includes an ion source chamber 700 comprised of multiple chamber walls 701. In some embodiments, one or more of these chamber walls 701 may be constructed of a dielectric material such as quartz. An RF antenna 710 may be disposed on the outer surface of a first dielectric wall 702. The RF antenna 710 may be powered by an RF power supply 720. Energy delivered to the RF antenna 710 is radiated within the ion source chamber 700 to ionize the feed gas introduced via a gas inlet 730. In other embodiments, the gas is ionized in different ways (e.g., by using an interthermal cathode (IHC), a capacitively coupled plasma source, an inductively coupled plasma source, a Berners-Stokes source, or any other plasma generator).

[0085] A chamber wall, referred to as an extraction plate 740, includes an extraction opening 745 through which ions can exit from the ion source chamber 700. The extraction plate 740 may be constructed of a conductive material (e.g., titanium, tantalum, or another metal). The width of the extraction plate 740 may exceed 300 mm. Furthermore, the extraction opening 745 may be wider than the diameter of the workpiece 10. In some embodiments, an extraction optics 750 (e.g., an electrode) may be provided outside the extraction opening 745 to accelerate ions generated within the ion source chamber 700 toward the workpiece 10.

[0086] A pressure plate 760 is located outside the ion source chamber 700 near the extraction opening 745. The workpiece 10 is placed on the pressure plate 760.

[0087] In some embodiments, the auxiliary plasma source 270 may be as described in reference to Figure 3A As described above. In other embodiments, the auxiliary plasma source 270 may be as described in reference to... Figure 3B As described above. Furthermore, the exit aperture 275 of the auxiliary plasma source 270 can be as follows: Figure 4A or Figure 4B It is oriented as shown in the diagram.

[0088] In some embodiments, a plasma diffuse electron gun 220 may be used. The plasma diffuse electron gun 220 functions as described above.

[0089] Usable Figure 8 The configuration shown is used to perform all the processes described in this document.

[0090] The semiconductor processing system and method described in this article have many advantages.

[0091] In implantation using knock-in, the implantation depth can be more precisely controlled. Furthermore, when implanting molecules such as AsH3, knock-in allows for better control of the hydrogen ion depth. Additional benefits associated with knock-in exist. First, the straggle from implanted ions is reduced due to energy absorption by the deposited film. This is beneficial in applications such as source / drain extension, where lateral straggle can cause short-channel effects below the gate. Second, the resulting dopant distribution becomes surface-peaked, resulting in surface-peaked carrier concentrations. This is beneficial in applications such as contacts, where near-surface contact is consumed by silicide processes and low contact resistance in this region is desired. Third, approaching ions can sputter the deposited film onto adjacent fin structures, thereby improving fin sidewall doping.

[0092] In etching, using an auxiliary plasma source 270 allows the removal of the native oxide layer at the same terminal station as the subsequent process. An additional benefit of this configuration in etching and deposition applications is the ability to process or produce thicker films while maintaining low energy through continuous processes. Low energy can be useful in preventing unwanted sputtering or undesirable damage to underlying layers.

[0093] In continuous operation scenarios, using an auxiliary plasma source 270 at the terminal station eliminates the need to transport the workpiece after the pretreatment cleaning process. This also reduces the amount of time between cleaning and the process (i.e., deposition, implantation, etching). For example, if the application is sensitive to the native oxide layer, reducing the time between cleaning the workpiece surface and subjecting the workpiece to the desired process minimizes the regrowth of the native oxide layer.

[0094] The scope of this specification is not limited to the specific embodiments described herein. In fact, upon reading the foregoing description and accompanying drawings, it will be apparent to those skilled in the art that various other embodiments and modifications of this specification, besides those described herein, are also readily apparent. Therefore, these other embodiments and modifications are intended to fall within the scope of this specification. Furthermore, although this specification has been set forth in a particular context and in a particular setting for a particular purpose, those skilled in the art will recognize that the utility of this specification is not limited thereto and that it can be advantageously practiced for any number of purposes and in any number of settings. Therefore, the foregoing claims should be understood in light of the full scope and spirit of this specification as described herein.

Claims

1. A method for implanting ions of a desired species into a workpiece, comprising: Plasma is generated using a gas comprising the desired species within an auxiliary plasma source, wherein the auxiliary plasma source is located in a terminal station near the workpiece, and wherein ions and free radicals from the plasma are emitted from the auxiliary plasma source and travel toward the workpiece; and Ion beams are used to knock ions and radicals from the auxiliary plasma source into the workpiece. The ion beams are generated using an ion source different from the auxiliary plasma source, and the ion source and the auxiliary plasma source are operated simultaneously.

2. The method of claim 1, wherein the ion beam comprises an inert species.

3. The method of claim 1, wherein the ions and radicals from the plasma are guided at the location where the ion beam impacts the workpiece.

4. The method according to claim 3, wherein the ions and the free radicals form a film at the location on the surface of the workpiece where the ion beam impacts the workpiece.

5. The method of claim 1, wherein the desired species comprises a molecule containing a Group III element, a Group IV element, or a Group V element.

6. A method for etching a workpiece, comprising: Plasma is generated in an auxiliary plasma source using a gas containing etching species, wherein the auxiliary plasma source is located in a terminal station close to the workpiece, and wherein ions and free radicals from the plasma are ejected from the auxiliary plasma source toward a portion of the workpiece and form a film on said portion of the workpiece. as well as An ion beam is used to provide energy to etch the workpiece. The ion beam is generated using an ion source different from the auxiliary plasma source, which is operated simultaneously with the auxiliary plasma source.

7. The method of claim 6, wherein the etching species comprises halogen.

8. The method of claim 6, wherein the etching species comprises CF4 and oxygen.

9. The method of claim 6, wherein the etch species comprises hydrogen, and the native oxide layer is etched.

10. The method of claim 6, wherein the ion beam comprises an inert gas.

11. The method of claim 6, wherein the ion beam is guided to the portion of the workpiece while the membrane is being generated.

12. The method of claim 6, wherein the ion beam is directed to the portion of the workpiece after the membrane has been produced.

13. A method for depositing material on a workpiece, comprising: Plasma is generated in an auxiliary plasma source using a processing gas, wherein the auxiliary plasma source is located in a terminal station close to the workpiece, and wherein ions and free radicals from the plasma are ejected from the auxiliary plasma source toward a portion of the workpiece and form a film on said portion of the workpiece. as well as An ion beam is used to provide energy to deposit the material on the workpiece. The ion beam is generated using an ion source different from the auxiliary plasma source, which is operated simultaneously with the auxiliary plasma source.

14. The method of claim 13, wherein the processing gas comprises CH4 and the ion beam comprises a group IV element.

15. A method for processing a workpiece, comprising: Ion beams are used to direct ions toward the workpiece; Plasma is generated using a processing gas within an auxiliary plasma source, wherein the auxiliary plasma source is located near the workpiece in a terminal station, and ions and free radicals from the plasma are emitted from the auxiliary plasma source and react with the surface of the workpiece; and Following the reaction, the workpiece is heated, wherein the heat repairs damage caused by the ion beam on the surface of the workpiece, a first portion of the workpiece being treated by the ion beam while a second portion of the workpiece reacts with the plasma. The ion beam is generated using an ion source different from the auxiliary plasma source, and both the ion source and the auxiliary plasma source are operated simultaneously.

16. The method of claim 15, wherein the ion beam is used to implant ions into the workpiece.

17. The method of claim 15, wherein the workpiece is scanned such that a portion of the workpiece is exposed to the plasma, and the portion of the workpiece is subsequently exposed to heat after being exposed to the plasma.

18. The method of claim 15, wherein the workpiece is heated to a temperature between 100°C and 500°C.

19. The method of claim 15, wherein the processing gas comprises a mixture of hydrogen and nitrogen.

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