Cyclic charged particle beam–assisted sputtering device and cyclic charged particle beam–assisted etching device

Abstract

The present invention relates to a cyclic charged particle beam–assisted sputtering device and a cyclic charged particle beam–assisted etching device. The cyclic charged particle beam-assisted sputtering device comprises: a charged particle beam source configured to emit a charged particle beam to an interior of a vacuum chamber; and a control module configured to control first and second pulse voltages respectively applied to the charged particle beam source and a target such that an ion generation cycle and a target sputtering cycle are synchronized so as to be alternately performed. In the ion generation cycle, a preset charged particle beam bias is applied to the charged particle beam source to provide a charged particle beam, and ions are generated by collision between the charged particle beam and gas particles. In the target sputtering cycle, a preset target bias is applied to the target such that the generated ions are attracted toward the target to sputter the target, and sputtered target particles are deposited on a substrate. The first pulse voltage applied to the charged particle beam source and the second pulse voltage applied to the substrate are synchronized so as to be alternately applied.

Description

Cyclic charged particle beam-assisted sputtering device and cyclic charged particle beam-assisted etching device

[0001] The present invention relates to a sputtering apparatus and an etching apparatus using a charged particle beam, and more specifically, to a cyclic charged particle beam-assisted sputtering apparatus and a cyclic charged particle beam-assisted etching apparatus characterized by generating ions by colliding a charged particle beam, collectively referred to as an electron beam having energy or an ion beam having energy, with gas particles, and sputtering a target or etching a substrate using the generated ions.

[0002] In response to the evolution of semiconductor device design rules toward increasingly finer linewidths of 3 nm or less, research on various thin film deposition processes is underway to make the microstructure of thin films constituting these fine linewidths denser, to eliminate defects within the film, and to reduce surface roughness. A sputtering device is a PVD (Physical Vapor Deposition) thin film deposition apparatus that allows high-energy particles, such as ions in a plasma, to collide with the surface of a target, and to deposit atoms or molecules ejected from that surface onto the surface of a substrate to form a thin film. Conventional sputtering equipment includes magnetron sputters and ion beam sputters using ion beams.

[0003] FIG. 1 is a schematic diagram conceptually illustrating the structure of a conventional Magnetron Sputter. Referring to FIG. 1, a conventional Sputter or Magnetron Sputter (1) comprises a target (100), a power source (110) connected to the target, a substrate (120) positioned to face the target, and a chamber (130). In a conventional Magnetron Sputter having the aforementioned structure, an inert gas is injected into the chamber, and plasma is generated by the dissociation of gas particles produced by the power source applied to the target, and ions within this plasma strike the target to cause sputtering. Through this sputtering, deposition of target particles occurs on the surface of the substrate facing the target. That is, a capacitive plasma facing the substrate sputters the target from the opposite direction of the substrate, thereby depositing target particles.

[0004] At this time, the plasma inside the chamber is in a state where gas particles, ions, electrons, and active particles are actively moving together. Therefore, the particles flying toward the substrate include not only target particles but also ions, electrons, and UV (Ultra Violet) that have escaped from the plasma surface. Furthermore, these various particles flying toward the substrate carry significant energy and collide with the substrate surface.

[0005] If the substrate is composed of materials with weak bonding, such as organic materials used in OLED displays, organic materials in perovskite solar cells, perovskite semiconductor organic materials, or various materials used in 2D semiconductors, the substrate is damaged by collisions with particles flying toward the substrate. Here, the damage to the substrate may include ion bombardment damage, electron bombardment damage, UV damage, and heating damage caused by collisions with these particles.

[0006] Among these types of damage, the greatest damage can be caused by ions with mass. Depending on the plasma conditions, ions with mass escape the plasma with energies ranging from tens to hundreds of eV and collide with the substrate. Consequently, if the substrate is composed of a material with low interatomic bonding forces of several to tens of eV, significant damage resulting from collisions with ions cannot be avoided.

[0007] As mentioned above, magnetron sputtering has the problem that the substrate is exposed to plasma, causing damage to the thin film surface. In contrast, ion beam sputtering, in which the substrate is not exposed to plasma, is conducted at a relatively low vacuum pressure compared to the magnetron sputtering process, allowing for the production of high-quality thin films. However, conventional ion beam sputtering presents problems such as the complexity of selecting the ion beam direction, target direction, and the flight angle of the sputtered particles, as well as contamination occurring within the dielectric chamber inside the ion beam source. Furthermore, while the ion beam is irradiated toward the target and flies, it deviates from the target due to the space charge effect, colliding with the chamber walls or shields surrounding the target and sputtering them. Consequently, unintended sputtered materials surrounding the target may be deposited as contaminants. Additionally, in ion beam sputtering, a portion of the ion beam that collides with the target is reflected by backscattering and strikes the substrate while retaining energy. Therefore, even though it is not the same as general sputtering where plasma is exposed to the substrate, this also causes substrate damage.

[0008] Since plasma is fundamentally an unstable state containing a large amount of energy supplied by a power source, particles emitted from the plasma surface also contain a large amount of energy. Therefore, among the high-energy particles emitted from the plasma, ions sputter the target, and some of the high-energy particles emitted from the plasma surface fly toward the facing substrate and can be usefully utilized for ashing, cleaning, etching, and surface modification. However, as high-energy particles collide with the weak material constituting the substrate, damage to the substrate is inevitably entailed. Therefore, the substrate facing the plasma cannot avoid damage caused by collisions with particles emitted from the plasma.

[0009] In order to avoid damage caused by particles emitted from the plasma, a facing target method is sometimes used, in which two targets generating plasma are positioned facing each other. The facing target method is configured to reduce plasma damage during the sputtering process by placing the substrate in a vertical lateral direction relative to the two targets. However, although this method reduces some of the damage, damage caused by the plasma still occurs.

[0010] Therefore, to eliminate or drastically reduce substrate damage caused by such plasma, there must be no plasma directly facing the substrate. Nevertheless, if plasma must be used, it must be a remote plasma that neither faces the substrate nor is exposed toward it. The method of operating plasma remotely from the substrate is to spatially confine the plasma by increasing the distance from the substrate.

[0011] Meanwhile, as a method to eliminate plasma, a method of time-limiting the plasma can be used. One method of time-limiting the plasma is to power the target to turn the plasma formed on the target surface on and off. However, this method should be excluded because the plasma and the target bias power are not already in an independent relationship.

[0012] Another method for temporally limiting plasma is to irradiate a vacuum with an electron beam to create a plasma independent of the target, and then intermittently control this plasma. However, with this method, even if the ions within the plasma remain alive after being controlled to dissipate, sputtering would become possible without plasma by attracting these ions.

[0013] One method to intermittently generate such a plasma is to energize not only electrons but also ions, and then irradiate the space with a beam of these charged particles to ionize the gas in space. If time is required for the ionized gas to be neutralized, these ions can be sufficiently separated from the plasma and utilized independently to sputter a target or etch a substrate.

[0014] To solve the aforementioned problems, the present invention aims to provide a cyclic charged particle beam assisted sputtering apparatus configured to prevent not only damage to the substrate but also contamination deposition on the substrate by alternately synchronizing and controlling pulse biases applied to a charged particle beam source and a target, irradiating the charged particle beam into the space within the chamber to generate ions by colliding with gas particles within the chamber, and using the generated ions to sputter and deposit with a target bias.

[0015] In addition, the present invention aims to provide a cyclic charged particle beam assisted etching apparatus configured to precisely control the etching depth of a substrate with low ion energy due to a low bias voltage by synchronizing and controlling pulse biases applied to a charged particle beam source and a target alternately, irradiating the charged particle beam into the space within the chamber to generate ions by colliding with gas particles within the chamber, and using the generated ions to apply a bias to the substrate for etching.

[0016] To achieve the aforementioned technical objectives, a cyclic charged particle beam assist sputtering apparatus according to the first aspect of the present invention comprises: a sputtering apparatus having a target and a substrate arranged facing each other at a certain distance apart within a vacuum chamber, and a charged particle beam source configured to irradiate a charged particle beam into the interior of the vacuum chamber; and a control module configured to control first and second pulse voltages applied to the charged particle beam source and the target, respectively, so that the ion generation cycle and the target sputtering cycle are synchronized and proceed alternately. The sputtering apparatus described above is characterized by applying a pre-set charged particle beam bias to a charged particle beam source during the ion generation cycle to irradiate a charged particle beam, and generating ions of gas particles through collisions between the charged particle beam and gas particles, and by applying a pre-set target bias to a target during the target sputtering cycle to attract the generated gas particle ions to the target and collide with it to sputter the target, and depositing the sputtered target particles onto a substrate.

[0017] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, the charged particle beam source is composed of an electron beam source that provides an electron beam, and the charged particle beam may be composed of an electron beam.

[0018] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, the charged particle beam source is composed of an ion beam source that provides an ion beam, and the charged particle beam may be composed of an ion beam.

[0019] The cyclic charged particle beam assist sputtering apparatus according to the first aspect described above further comprises a charged particle beam guidance module configured to form a magnetic field or apply additional power along a preset flight path of a charged particle beam supplied into a chamber by a charged particle beam source so that the charged particle beam travels along a preset flight path; and preferably, the preset flight path of the charged particle beam is spaced apart from the surface of the substrate and is a path that is parallel to or forms a curvature of the surface of the substrate.

[0020] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, the charged particle beam guidance module preferably comprises electromagnets disposed on the walls of a vacuum chamber located at the starting point or the end point of a preset flight path of the charged particle beam.

[0021] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, the charged particle beam guidance module further comprises an electrode configured to guide the charged particle beam by being positioned at the end of a preset flight path of the charged particle beam, wherein, if the charged particle beam is an electron beam, the electrode is configured as an anode, and if the charged particle beam is an ion beam, the electrode is configured as a cathode.

[0022] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, it is preferable that the control module is configured to adjust the duty of the first or second pulse voltage so that some or all of the cycle in which the charged particle beam is irradiated and the cycle in which the target bias is applied overlap, thereby improving the sputtering deposition rate and having the effect of irradiating the substrate with the electron beam.

[0023] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, when the charged particle beam is an ion beam, it is preferable that the mass of the ions constituting the ion beam is greater than the mass of the gas ionized by collision.

[0024] In the cyclic charged particle beam assist sputtering apparatus according to the first sun described above, it is preferable that the frequencies of the first and second pulse voltages applied to the charged particle beam source and the target, respectively, are in the range of 0.1 to 1,000 kHz.

[0025] A cyclic charged particle beam-assisted etching apparatus according to a second aspect of the present invention comprises: a gas supply module and a substrate arranged facing each other at a certain distance apart within a vacuum chamber; a charged particle beam source configured to irradiate a charged particle beam into the interior of the vacuum chamber; and a control module configured to control first and second pulse voltages applied to the charged particle beam source and the substrate, respectively, so that the ion generation cycle and the substrate etching cycle are synchronized and proceed alternately. The aforementioned etching apparatus is characterized in that, during the ion generation cycle, a charged particle beam bias is applied to the charged particle beam source to irradiate a charged particle beam, and ions are generated by the collision between the charged particle beam and gas particles; and during the substrate etching cycle, a substrate bias is applied to the substrate, so that the generated ions are attracted to the substrate and collide with it to etch the substrate.

[0026] In the cyclic charged particle beam assist etching apparatus according to the second sun described above, the charged particle beam source is composed of an electron beam source that provides an electron beam, and the charged particle beam may be composed of an electron beam.

[0027] In the cyclic charged particle beam assist etching apparatus according to the second sun described above, the charged particle beam source is composed of an ion beam source that provides an ion beam, and the charged particle beam may be composed of an ion beam.

[0028] The cyclic charged particle beam assist etching apparatus according to the second aspect described above further comprises a charged particle beam guidance module configured to form a magnetic field along a preset flight path of a charged particle beam supplied into a chamber by a charged particle beam source or to apply additional power so that the charged particle beam travels along a preset flight path; wherein the preset flight path of the charged particle beam is preferably a path that is spaced apart from the surface of the substrate but is parallel to or forms a curvature of the surface of the substrate.

[0029] In the cyclic charged particle beam assist etching apparatus according to the second aspect described above, the charged particle beam guidance module preferably comprises electromagnets disposed on the walls of a vacuum chamber located at the starting point or the end point of a preset flight path of the charged particle beam.

[0030] In the cyclic charged particle beam assist etching apparatus according to the second sun described above, the charged particle beam guidance module further comprises an electrode configured to guide the charged particle beam by being positioned at the end of a preset flight path of the charged particle beam; wherein, if the charged particle beam is an electron beam, the electrode is configured as an anode, and if the charged particle beam is an ion beam, the electrode is configured as a cathode.

[0031] In the cyclic charged particle beam assist etching apparatus according to the second sun described above, when the charged particle beam is an ion beam, it is preferable that the mass of the ions constituting the ion beam is greater than the mass of the gas ionized by collision.

[0032] In the cyclic charged particle beam assist etching apparatus according to the second sun described above, it is preferable that the frequencies of the first and second pulse voltages applied to the charged particle beam source and the substrate, respectively, are in the range of 0.1 to 1,000 kHz.

[0033] The cyclic charged particle beam assisted sputtering device according to the present invention, having the configuration described above, can synchronize the ion generation cycle and the target sputtering cycle by cyclically applying a first pulse voltage and a second pulse voltage, which are synchronized with the charged particle beam source and the target, respectively, thereby allowing the ion generation cycle and the target sputtering cycle to proceed alternately. Accordingly, ions can be generated by colliding with gas particles through irradiation of the charged particle beam by the first pulse voltage only during the ion generation cycle, and sputtering can be performed by ion collision with the target by the second pulse voltage only during the target sputtering cycle. As a result, even if charged particles are irradiated into the space within the chamber during the ion generation cycle, the charged particles do not collide with the substrate because there is no substrate bias, thus preventing damage to the substrate.

[0034] In addition, the cyclic charged particle beam-assisted sputtering device according to the present invention can generate ions having a low energy of 2 to 3 eV by irradiating a charged particle beam into a chamber and colliding with a low-pressure gas present in the chamber to ionize it. Therefore, even if such ions fly toward a substrate and collide with the substrate during the ion generation cycle before biasing the target, no damage to the substrate occurs due to the low energy.

[0035] In addition, the cyclic charged particle beam-assisted sputtering apparatus according to the present invention can sputter the target by attracting low-energy ions to the target by applying a target bias. By sputtering the target in this manner, the ions sputter only the target, and the material in the surrounding region other than the target is not sputtered. Therefore, since only the target material is deposited on the substrate, contamination deposition by materials other than the target does not occur.

[0036] In addition, the cyclic charged particle beam-assisted sputtering apparatus according to the present invention can precisely control the speed and amount of ions sputtering the target by controlling the number of ions during the ion generation cycle and controlling the target bias applied during the target sputtering cycle. Accordingly, the deposition rate of the substrate can be controlled by controlling the number of sputtered target particles. Furthermore, by controlling the number of sputtered target particles, it is possible to deposit not only a single atomic layer but also a sub-atomic layer on the surface of the substrate.

[0037] In addition, the cyclic charged particle beam assisted sputtering device according to the present invention is equipped with a charged particle beam path guidance module, thereby enabling the application of a magnetic field along a preset flight path of the charged particle beam. As a result, the charged particles can fly in a straight line or in a curve along the preset flight path. By providing various charged particle beam guidance modules in this manner, it is possible to control the charged particle beam to avoid or face a target or substrate during flight, or to face an electrode that avoids the target or substrate. In this case, when an electron beam is used as the charged particle beam, the electrode that avoids the target or substrate will be the anode, and when an ion beam is used as the charged particle beam, the aforementioned electrode will be the catode.

[0038] In addition, the cyclic charged particle beam assisted sputtering device according to the present invention can adjust the duty cycles of a first pulse voltage and a second pulse voltage, which are applied to the charged particle beam source and the target, respectively, in synchronization. In particular, by adjusting the duty cycle of the first pulse voltage applied to the charged particle beam source, the charged particle beam can be irradiated during part or the entire duration while the target is sputtered. As a result, additional or continuous ions to be sputtered can be generated, thereby increasing the speed of sputtering deposition.

[0039] In addition, by adjusting the duty cycle of the second pulse voltage applied to the target, an overlap period may be created between the time when the electron beam of the charged particle beam is irradiated and the time when the second pulse voltage of the target is applied. At this time, since the electron beam is irradiated onto the substrate by being pushed by the DC (-) voltage of the target, the surface of the thin film can be heated during sputtering deposition. In this way, as the electron beam is irradiated onto the surface of the thin film, the effect of electron beam irradiation on the thin film can be obtained simultaneously with the deposition of the thin film. Examples of electron beam irradiation effects include heat treatment effects, reduction of defects within the thin film, increase in density, improvement of epi growth, and improvement of crystallinity.

[0040] The cyclic charged particle beam assisted etching apparatus according to the present invention, having the configuration described above, can synchronize the ion generation cycle and the substrate etching cycle and proceed alternately by alternately applying a first pulse voltage to the charged particle beam source and a second pulse voltage to the substrate. Accordingly, there is no substrate bias during the ion generation cycle, and a rest period for the charged particle beam irradiation can be maintained during the substrate etching cycle. As a result, even if the charged particle beam is irradiated into the chamber during the ion generation cycle, the charged particles do not collide with the substrate, so damage to the substrate caused by the charged particles is not caused.

[0041] In addition, the cyclic charged particle beam-assisted etching apparatus according to the present invention can generate ions having a low energy of 2 to 3 eV by generating gas particle active species and gas particle ions to etch a substrate through collision between the charged particle beam and gas particles in the chamber while irradiating a charged particle beam into the chamber. Therefore, since the self-energy of the gas particle ions is low, substrate etching or substrate damage caused by the gas particle ions does not occur during the substrate bias rest period.

[0042] In addition, the cyclic charged particle beam-assisted etching apparatus according to the present invention can adjust the speed and amount of etching of the substrate by ions by controlling the substrate bias applied during the substrate etching cycle. The energy of the newly generated ions themselves is small and can be ignored, and the energy of the ions used for etching is entirely controlled by the substrate bias. Therefore, since the energy of the ions used for etching can be finely controlled from a few volts by the bias, the etching depth of the substrate can be precisely controlled by the bias volt, and as a result, it is possible to etch not only a single atomic layer of the substrate but also a sub-atomic layer.

[0043] In addition, the cyclic charged particle beam-assisted etching apparatus according to the present invention is equipped with a charged particle beam path guidance module, thereby providing a magnetic field tunnel along a preset flight path of the charged particle beam. As a result, the charged particles can fly in a straight line or a curve along the preset flight path. Consequently, it is possible to control the charged particle beam to avoid the substrate during flight, to head toward the electrode (anode for electron beams, cathode for ion beams) at the location where it avoids the substrate, or to head toward the substrate at a low angle.

[0044] In addition, the cyclic charged particle beam assisted etching device according to the present invention can adjust the duty cycles of a first pulse voltage and a second pulse voltage, which are respectively applied in synchronization with a charged particle beam source and a substrate. By adjusting the duty cycle of the first pulse voltage applied to the charged particle beam source, the charged particle beam can be additionally irradiated during part or the entire period while the substrate is being etched. As a result, additional or continuous ions to be etched on the substrate can be generated, thereby increasing the speed of substrate etching.

[0045] Figure 1 is a schematic diagram conceptually illustrating the structure of a conventional Magnetron Sputter.

[0046] FIG. 2 is a schematic diagram illustrating that by using a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, even if the generation of ions by electron beam collision is controlled in time, the ions generated secondarily can be used in target bias sputtering.

[0047] FIG. 3 is a waveform diagram illustrating pulse biases applied to an electron beam source and a target, respectively, during alternating ion generation cycles (P1) and target sputtering cycles (P2) in a cyclic charged particle beam assisted sputtering apparatus according to a first embodiment of the present invention.

[0048] FIG. 4 is a schematic diagram illustrating an embodiment of a cyclic charged particle beam assisted sputtering device according to the first embodiment of the present invention, in which a charged particle beam path guidance module (260) is installed.

[0049] FIG. 5 is a schematic diagram illustrating electron beam flight (a) by electron beam irradiation and low-energy ion generation (b) by collision therewith during an ion generation cycle (P1) while the charged particle beam path guidance module (260) is mounted in a cyclic charged particle beam assisted sputtering device according to the first embodiment of the present invention.

[0050] FIG. 6 is a schematic diagram illustrating the process (b) in which ions collide with a target (a) and sputtered target particles are deposited on a substrate surface during a target sputtering cycle (P2) in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention.

[0051] FIG. 7 is a schematic diagram illustrating an embodiment of a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, wherein a plurality of targets are arranged and Co-sputter deposition on a large substrate is possible by moving the substrate.

[0052] FIG. 8 is a schematic diagram illustrating an embodiment configured to deposit using a plurality of targets in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention.

[0053] FIG. 9 is a schematic diagram illustrating an embodiment in which deposition on a large substrate is achieved by irradiating an electron beam in a direction perpendicular to the length of a large target and moving the large substrate in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention.

[0054] FIG. 10 is a graph illustrating the ion survival time after electron beam irradiation is finished in a cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention.

[0055] FIG. 11 is a graph showing the pattern of Electron / Ion flux and the duty cycle of Target bias voltage while a Cyclic pulse bias is applied to an electron beam source and a target in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention.

[0056] FIG. 12 is a schematic diagram illustrating the ionization process (b) by collision of an ion beam (a) irradiated from an ion beam source in a cyclic charged particle beam assisted sputtering apparatus according to a second embodiment of the present invention.

[0057] FIG. 13 is a graph showing the deposition rate according to the target bias in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention.

[0058] FIG. 14 is a schematic diagram illustrating the deposition (b) process by target sputtering by collision (a) between generated ions and a target in a cyclic charged particle beam-assisted sputtering apparatus according to a second embodiment of the present invention.

[0059] FIG. 15 is a waveform diagram illustrating pulse biases applied to an ion beam source and a target, respectively, during an ion generation cycle (P1) and a target sputtering cycle (P2) that are synchronized with each other and alternately applied to the ion beam source and the target, in a cyclic charged particle beam assisted sputtering apparatus according to a second embodiment of the present invention.

[0060] FIG. 16 is a schematic diagram illustrating a cyclic charged particle beam (electron beam) assisted etching apparatus according to a third embodiment of the present invention.

[0061] FIG. 17 is a waveform diagram illustrating pulse biases applied to an electron beam source and a substrate, respectively, during alternating ion generation cycles (P1) and substrate etching cycles (P2) in a cyclic charged particle beam assisted etching apparatus according to a third embodiment of the present invention.

[0062] FIG. 18 is a schematic diagram illustrating electron beam irradiation (a) and ion generation (b) during an ion generation cycle in a cyclic charged particle beam-assisted etching apparatus according to a third embodiment of the present invention.

[0063] FIG. 19 is a schematic diagram illustrating the process of ions etching a substrate during a substrate etching cycle in a cyclic charged particle beam-assisted etching apparatus according to a third embodiment of the present invention.

[0064] FIG. 20 is a schematic diagram illustrating pulse biases that are synchronized and alternately applied to an ion beam source and a substrate in a cyclic charged particle beam-assisted etching apparatus according to a fourth embodiment of the present invention.

[0065] FIG. 21 is a schematic diagram illustrating the process of ion beam irradiation (a) and ionization by collision (b) in a cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention.

[0066] FIG. 22 is a schematic diagram illustrating a target bias (a) and a substrate etching process (b) in a cyclic charged particle beam-assisted etching apparatus according to a fourth embodiment of the present invention.

[0067] Hereinafter, a cyclic charged particle beam assist sputtering apparatus and a cyclic charged particle beam assist etching apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. In the present invention, the charged particle beam may be composed of either an electron beam or an ion beam. The first embodiment of the present invention is a cyclic charged particle beam assist sputtering (CEBAS) apparatus using an electron beam, and the second embodiment of the present invention is a cyclic charged particle beam assist sputtering (CIBAS) apparatus using an ion beam. The third embodiment of the present invention is a cyclic charged particle beam assist etching (CEBAE) apparatus using an electron beam, and the fourth embodiment of the present invention is a cyclic charged particle beam assist etching (CIBAE) apparatus using an ion beam.

[0068]

[0069] [First Embodiment: Cyclic Charged Particle Beam Assisted Sputtering Device Using an Electron Beam]

[0070] FIG. 2 is a schematic diagram illustrating a cyclic charged particle beam assisted sputtering apparatus according to a first embodiment of the present invention.

[0071] Referring to FIG. 2, a cyclic charged particle beam assisted sputtering apparatus (2) according to a first embodiment of the present invention comprises a chamber (200), a charged particle beam source (230) connected to a first power source (250), a target (210) connected to a second power source (252), a substrate (220), and a control module (240). The cyclic charged particle beam assisted sputtering apparatus (2) according to a first embodiment of the present invention may further comprise a charged particle beam path guidance module (260 in FIG. 3). The cyclic charged particle beam assisted sputtering apparatus according to a first embodiment of the present invention is characterized by generating ions to sputter a target using an electron beam by applying a first pulse and a second pulse that alternate with each other and are synchronized with the charged particle beam source and the target, and causing the ions to collide with a biased target to perform sputtering deposition. Hereinafter, the components of the cyclic charged particle beam assist sputtering device according to the first embodiment of the present invention will be described in detail.

[0072] The chamber (200) may be configured as a vacuum chamber into which process gas can be injected, and a target and a substrate may be placed therein, and a charged particle beam source may be mounted on one side. The target (210) is placed inside the chamber (200) and is connected to a second power source (252). The substrate (220) is placed inside the chamber (200) but may be placed facing the target (210) while being spaced apart by a certain distance.

[0073] A charged particle beam source (230) is positioned on one side of the chamber (200), and the outlet of the charged particle beam source is positioned to face the interior of the chamber. The charged particle beam source (230) is connected to a first power source (250). The charged particle beam source (230) may be positioned so that the charged particle beam can fly parallel to the substrate (220). The charged particle beam source of the device according to the first embodiment of the present invention is composed of an electron beam source and is configured to provide an electron beam into the interior of the chamber.

[0074] The control module (240) is configured to control the operation of the first power supply (250) and the second power supply (252) to adjust the bias voltage applied to the charged particle beam source and the target, respectively, thereby sputtering the target to deposit target particles on the surface of the substrate. By applying pulse-shaped biases that are synchronized and alternate to the charged particle beam source and the target, the ion generation cycle (P1) and the target sputtering cycle (P2) can be synchronized and proceed alternately.

[0075] Pulse biases applied to a charged particle beam source, an electron beam source, and an ion beam source may consist of a bias section where a preset voltage is applied and a section where no voltage is applied. In this specification, the voltages applied during the bias sections of the pulse bias applied to the charged particle beam source, the electron beam source, and the ion beam source are referred to as "charged particle beam source bias," "electron beam source bias," and "ion beam source bias," respectively. Additionally, the pulse bias applied to the target also consists of a bias section where a preset voltage is applied and a section where no voltage is applied. In this specification, the voltage applied during the bias sections of the pulse bias applied to the target is referred to as "target bias."

[0076] A cyclic charged particle beam assisted sputtering device according to the first embodiment of the present invention injects an electron beam into a chamber by applying a bias to an electron beam source during an ion generation cycle (P1), thereby causing a collision between the electron beam and gas particles in the chamber, and generates ions through the collision between the electron beam and the gas particles. Then, during a target sputtering cycle (P2), by applying a bias to a target, the ions generated by the collision of the electron beam during the ion generation cycle (P1) collide with the target to sputter the target, and the sputtered target particles are deposited on the surface of a substrate.

[0077] Hereinafter, the ion generation mechanism and target sputtering mechanism in the cyclic charged particle beam-assisted sputtering device according to the present invention will be described in more detail.

[0078] Generally, for ions to sputter a target, ions possessing mass and energy must collide with the target. In this patent, the idea of ​​generating ions to be sputtered using an electron beam is implemented to reduce damage to the substrate caused by plasma. Accordingly, the sputtering apparatus according to the first embodiment of the present invention can generate ions with energy by injecting an electron beam into a chamber containing process gas during the ion generation cycle, causing the electron beam to collide with gas particles inside the chamber, and by the collision between the electron beam and the gas particles. The electron beam source of the sputtering apparatus according to the present invention may use hot electrons emitted from the surface of a filament by heating a W filament, or may use cold electrons extracted from the plasma through a plurality of grids by creating plasma in a chamber inside the source.

[0079] As shown in Fig. 2, electrons supplied by an electron beam source fly between the target and the substrate with energy. During the flight of the electrons, they collide with the gas injected into the chamber, ionizing the gas particles. Due to the collision between the flying electron beam and the gas in this manner, the gas particles are approximately 10 -5 torr ~ 10 -4Ionization can be performed at a low pressure of torr. In this regard, since ions are formed in a high-density plasma generated at a pressure of about 10³ torr in conventional sputtering devices, the generated ions have very high energy. In contrast, since the device according to the present invention has low pressure and low ion charge density, the ions generated by collision with the electron beam have very low energy of about 2 to 3 eV. Typically, in order to cause damage to one atomic layer of a substrate by ion collision, the energy of the ions must be 30 to 50 eV or higher. Therefore, in the sputtering device according to the present invention, even if ions with very low energy of about 2 to 3 eV generated by electron beam collision fly toward the substrate and collide with it, almost no damage is caused to the substrate because the energy is low.

[0080] In the sputtering apparatus according to the first embodiment of the present invention, during the target sputtering cycle, an electrical bias of opposite polarity to the ions is applied to the target while ions are generated on the front surface of the target within the chamber, and accordingly, the ions are attracted to the target and collide with the target. At this time, if the ions have sufficient energy to be sputtered by the bias voltage of the target, target particles can be sputtered by the collision between the target and the ions, and as a result, the sputtered target particles are deposited on a substrate.

[0081] Typically, inert gas particles used in sputtering are Ar, Ne, Kr, Xe, etc., which become positively charged cations upon collision with electrons. Accordingly, in the sputtering apparatus according to the present invention, a negative potential is applied to the target to attract ions during the target sputtering cycle. The negative potential applied to the target for sputtering exerts a repulsive force on electrons flying parallel to the surfaces of the target and the substrate. The electron beam flying parallel to the substrate surface has its flight path bent by the repulsive force with the target bias and flies toward the substrate, thereby potentially colliding with the substrate. As a result, the substrate is damaged by the collision of the electron beam, or the surface of the substrate is heated by the collision of the electron beam.

[0082] To solve this problem, the cyclic charged particle beam assisted sputtering device according to the present invention controls the power applied to the electron beam source during the target sputtering cycle to create an electron beam resting period, and applies a (-) potential to the target during the electron beam resting period. Due to this power application, there are no electrons inside the chamber during the target sputtering cycle (P2), so there are no electrons flying to the substrate due to the (-) potential of the target. In this way, the cyclic charged particle beam assisted sputtering device according to the present invention ensures that the electron beam is in a resting period during the target sputtering cycle, thereby preventing collisions between the substrate and electrons and thus preventing damage to the substrate.

[0083] FIG. 3 is a waveform diagram illustrating pulse biases applied to a charged particle beam source and a target, respectively, during alternating ion generation cycles (P1) and target sputtering cycles (P2) in a cyclic charged particle beam assisted sputtering apparatus according to a first embodiment of the present invention.

[0084] Referring to FIG. 3, during the ion generation cycle (P1), a (-) bias is applied to the charged particle beam source while the target maintains a ground bias. By applying this bias, the charged particle beam source generates an electron beam and irradiates it into the chamber, causing a collision between the gas particles in the chamber and the electron beam, and generates ions through the collision between the gas particles and the electron beam. Meanwhile, during the target sputtering cycle (P2), a (-) bias is applied to the target while the charged particle beam source maintains a ground bias. By applying this bias, ions are attracted to the target, collide with the target, and sputter the target, and the sputtered target particles are deposited on the surface of the substrate. In this way, by synchronizing pulse biases to the charged particle beam source and the target and applying them alternately, the ion generation cycle (P1) and the target sputtering cycle (P2) can be synchronized and proceed alternately.

[0085] In the present invention, the process of sputtering deposition by repeating the ion generation cycle (P1) and the target sputtering cycle (P2) is referred to as 'Cyclic Electron Beam Assist Sputtering' (CEBAS). CEBAS according to the present invention can increase the yield of ions used for sputtering by optimizing the frequency of synchronizing the pulse biases applied to the charged particle beam source and the target, and can also perform sputtering deposition without damage to the substrate.

[0086] The sputtering device according to the present invention may further include a charged particle beam path guidance module (260). FIG. 4 is a schematic diagram illustrating an embodiment in which a charged particle beam path guidance module (260) is installed in a cyclic charged particle beam assist sputtering device according to the first embodiment of the present invention.

[0087] While the electron beam is in flight, electrons generate a repulsive force against each other due to the space charge effect. Due to this repulsive force, the electrons may deviate from a preset flight path. In the sputtering device according to the present invention, the electron beam is irradiated to fly parallel to the substrate and the target, but due to the aforementioned space charge effect, it may deviate from the path and fly toward the substrate and the target. The charged particle beam path guidance module (260) is configured so that the electron beam can fly along a direction parallel to the substrate and the target, thereby preventing the electron beam from deviating from a preset flight path.

[0088] Referring to FIG. 4, the charged particle beam path guidance module (260) may include an electromagnet (262) made by winding a ring-shaped electromagnet coil (Helmholtz coil). The electromagnet of the charged particle beam path guidance module (260) may be placed at the start and end points of a preset electron beam flight path, respectively. The electron beam flight path may be set as a path parallel to the surface of the substrate while being spaced at a certain distance from the surface of the substrate, or as a path parallel to the surfaces of the substrate and the target while being spaced at a certain distance from the substrate and the target. Here, the start point of the electron beam flight path may be the exit of the electron beam source, and the end point of the electron beam flight path may be the wall opposite the chamber facing the exit of the electron beam source. Accordingly, the electromagnets placed at the start and end points of the electron beam flight path may form a magnetic field tunnel along the preset electron beam flight path. An electron beam with energy irradiated from an electron beam source can be guided so as not to deviate from the horizontal direction during electron beam flight by a magnetic field tunnel formed by electromagnets of a charged particle beam path guidance module.

[0089] Meanwhile, the charged particle beam path guidance module (260) may further be provided with an anode (264) on the wall of the chamber where the electron beam reaches according to a preset electron beam flight path. By applying a (+) potential to the anode to attract the electron beam flying within the chamber, it can help the electron beam fly in a straight line according to the preset flight path.

[0090] Meanwhile, the charged particle beam path guidance module can be deployed with a bias electrode, a floating electrode, or an electromagnet module to guide a straight or curved flight path. These can assist the flight of the charged particle beam along a preset flight path to avoid or towards a substrate or target.

[0091] FIG. 5 is a schematic diagram illustrating the movement of electrons during an ion generation cycle (P1) in a cyclic charged particle beam assisted sputtering apparatus according to a first embodiment of the present invention, with a charged particle beam path guidance module (260) installed. FIG. 5 (a) exemplarily shows the path of the electron beam flying by the charged particle beam path guidance module. FIG. 5 (b) exemplarily shows that ions are generated by the collision of electrons and gas particles during the flight path of the electron beam. Referring to FIG. 5, during the ion generation cycle, the electron beam irradiated from the electron beam source collides with gas particles while flying to generate ions having an energy of about 2 to 3 eV.

[0092] During the ion generation cycle, a magnetic field tunnel is formed along a preset electron beam flight path using a charged particle beam path guidance module (260), and a (-) bias is applied to the electron beam source and the target is biased to ground. As a result, during the ion generation cycle, the electron beam is emitted with energy, the target does not create a repulsive force against the electron, and the electron is able to fly in a straight line along the path where the magnetic field tunnel is formed.

[0093] FIG. 6 is a schematic diagram illustrating the process in which ions sputter a target and target particles are sputtered and deposited on a substrate surface during a target sputtering cycle (P2) in a cyclic charged particle beam-assisted sputtering apparatus according to a first embodiment of the present invention. FIG. 6(a) exemplarily shows the process in which ions are attracted to the target by the attractive force of the target bias and sputter the target. FIG. 6(b) exemplarily shows the process in which target particles are sputtered by collision between ions and the target, and the sputtered target particles are deposited on the substrate. Referring to FIG. 6, during a target sputtering cycle synchronized with the ion generation cycle, when a (-) bias is applied to the target, ions sputter the target, and the sputtered target particles are deposited on the surface of the substrate.

[0094] During the target sputtering cycle (P2), no voltage is applied to the electron beam source, so the irradiation of the electron beam is stopped. The electron beam irradiated during the ion generation cycle moves too fast and disappears towards the anode in an instant. In contrast, the ions generated by the collision of the electron beam during the ion generation cycle have weight and low energy, so their flight speed is slow and they remain in the space within the chamber. In this state, if a negative bias of about tens to thousands of volts is applied to the target, the target bias exerts an attractive force on the positive ions remaining in the chamber. Due to the attractive force of the target bias, the positive ions are pulled toward the target and collide with it, and as a result, the target particles are sputtered. Then, the target particles sputtered by the ions are deposited on the surface of the substrate.

[0095] Meanwhile, in a conventional Ion Beam Sputter Deposition (IBD) device, a high-energy ion beam within the plasma is irradiated toward a target to sputter the target, and the sputtered target particles are deposited on a substrate. In such a conventional IBD device, repulsion occurs between ion charges due to the space charge effect while the ion beam is irradiated, causing the ion beam to spread out. As a result, the ion beam collides not only with the target but also with the surrounding region of the target, potentially sputtering materials other than the target. Consequently, in a conventional IBD device, the deposition of materials other than the target material on the substrate can lead to the problem of contaminant deposition on the substrate. In contrast, the charged particle beam-assisted sputtering device according to the present invention is configured to sputter only the target by attracting ions to the target through the application of power to the target. Accordingly, the sputtering device according to the present invention can perform contamination-free sputtering deposition on a substrate by sputtering only the target.

[0096] Accordingly, the charged particle beam-assisted sputtering device according to the present invention can perform sputtering deposition without substrate damage or substrate contamination.

[0097] Meanwhile, the charged particle beam-assisted sputtering device according to the present invention can control the sputtering deposition rate by adjusting the pressure conditions within the chamber. Furthermore, through this control of the deposition rate, the charged particle beam-assisted sputtering device according to the present invention enables atomic-level deposition. The mechanism of this operation will be explained in more detail below.

[0098] Conventional sputtering devices must generate plasma for sputtering, typically about 10 -3The plasma generation process is carried out at a pressure of torr or higher. However, the charged particle beam-assisted sputtering device according to the present invention generates ions to be sputtered by irradiating gas particles with an electron beam, and this method is approximately 10 -4 ~ 10 -10 It is possible to implement this even at pressures in the torr range. As such, the method of generating ions by electron beam collision used in the device according to the present invention is not only possible in a high vacuum, but sputtering by colliding the generated ions with a target is also possible in a high vacuum.

[0099] As the vacuum increases, the number of gas particles inside the chamber decreases rapidly in a different order. Therefore, when gas particles are ionized by irradiating an electron beam into a chamber in a high vacuum state as in the present invention, the number of ions generated by the collision between the electron beam and the gas particles also decreases. As the number of ions to be sputtered decreases, the number of target particles sputtered by collision with ions also decreases. As a result, the number of sputtered target particles decreases, and thus the rate at which the sputtered target particles are deposited on the substrate can also be reduced. In this way, by maintaining the pressure inside the chamber at a high vacuum, the sputtering deposition rate of target particles can be drastically reduced. Accordingly, the charged particle beam-assisted sputtering device according to the present invention enables control capable of depositing not only single atomic layers but also sub-atomic layers by setting the pressure inside the chamber to a high vacuum.

[0100] Meanwhile, in conventional sputtering devices, high-density process gases are injected into the chamber, so the process gases can easily be adsorbed to the left and right sides of the adatoms deposited on the substrate surface. Consequently, conventional sputtering devices suffer from the problem that subsequent deposited atoms cannot extend to the sides of the adatoms, causing them to partially accumulate and form an island growth pattern. However, the charged particle beam-assisted sputtering device according to the present invention enables the deposition of excellent thin films under a high vacuum. By performing thin film deposition under a high vacuum, interference caused by process gas adsorption is eliminated, and as a result, deposition can be achieved by densely filling the atomic layer. Therefore, by performing thin film deposition under a high vacuum, the charged particle beam-assisted sputtering device according to the present invention enables the deposition of atomic layers, 2D layers, dense deposition, and atomically smooth deposition.

[0101] As described above, the charged particle beam-assisted sputtering device according to the present invention utilizes high vacuum deposition to control not only a low deposition rate but also layer control. The charged particle beam-assisted sputtering device according to the present invention, having these deposition characteristics, can be used for the deposition of nano-scale semiconductors, metal connection lines, ultra-thin barriers, low resistivity contacts, high-power laser diodes, reticle EUV mirrors, etc. Furthermore, the charged particle beam-assisted sputtering device according to the present invention, having the aforementioned deposition characteristics, can be applied to spintronics, photonics devices, thermoelectrics, quantum computing, electronic devices, solar cells, super lattices, etc., where atomic-level deposition is required.

[0102] In addition, the charged particle beam-assisted sputtering device according to the present invention can sputter by attracting ions generated by the collision between the electron beam and gas particles to the target during the target sputtering cycle, even when the electron beam is irradiated toward the target. Furthermore, in the charged particle beam-assisted sputtering device according to the present invention, sputtering can be performed by attracting ions generated by the collision between the electron beam and gas particles to the target during the target sputtering cycle, even when the electron beam is not directed toward the target but flies parallel to the target.

[0103] In addition, the charged particle beam assisted sputtering device according to the present invention can arrange a plurality of targets along a preset flight direction of the electron beam. The plurality of targets may be arranged along the perimeter of the preset flight space of the electron beam or arranged sequentially along the preset flight direction of the electron beam. At this time, by composing the plurality of targets with different materials and controlling the bias applied to each target, it is possible to selectively deposit a plurality of different materials on a substrate or to deposit a plurality of targets simultaneously. FIG. 7 is a schematic diagram illustrating an embodiment in which a plurality of targets are arranged in a cyclic charged particle beam assisted sputtering device according to the first embodiment of the present invention. Referring to FIG. 7, a plurality of different targets (Target A, B, C) may be arranged around the perimeter of the preset flight space of the electron beam.

[0104] FIG. 8 is a schematic diagram illustrating an embodiment configured to deposit using a plurality of targets in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention. As shown in FIG. 8, a CEBAS multilayer can be deposited or co-sputter deposition can be performed using a plurality of targets.

[0105] FIG. 9 is a schematic diagram illustrating an embodiment in which deposition on a large substrate is realized by moving the large substrate in a cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention. Referring to FIG. 9, an electron beam perpendicular to the length direction of a large linear target can be irradiated onto the large linear target, thereby generating ions on the front surface of the target, and the ions can sputter and collide with the biased target. At this time, deposition can be performed while moving the substrate in a direction perpendicular to the length direction of the linear target as shown in FIG. 9.

[0106] In addition, in the cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, an electron beam is irradiated from the rear of a target through the side of the target to the front in a straight line or at a curvature, and sputter deposition is performed by ion generation by electron beam irradiation, and multiple targets can be arranged to sequentially deposit a multi-layer or deposit multiple targets simultaneously.

[0107] Hereinafter, the frequencies of pulse biases applied to an electron beam source and a target during an ion generation period and a target sputtering period in a cyclic charged particle beam assisted sputtering apparatus according to the present invention will be described.

[0108] FIG. 10 is a graph illustrating the survival period of ions in a cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention. In FIG. 10, electron beam bias (EB Bias) is a bias applied to the electron beam source, Target Bias is a bias applied to the target, and t is the ion survival time.

[0109] A cyclic charged particle beam assisted sputtering device according to the first embodiment of the present invention alternately applies bias to an electron beam source and a target, while synchronizing their cycles. Accordingly, as shown in FIG. 10, by applying a target bias synchronized with the time when the electron beam bias ends, the target bias can be started during the time that ions are generated and survive (i.e., ion survival time). The target bias exerts an attractive force on the ions, and due to this attractive force, the ions are pulled toward the target and collide with the target. In the sputtering device according to the present invention, the electron beam bias and the target bias are synchronized and alternately applied to the electron beam source and the target. Referring to FIG. 10, during the ion generation cycle (P1), an electron beam is irradiated by the electron beam bias to generate ions, and the generated ions exist during the ion survival time. During the target sputtering cycle (P2), the ions surviving by the target bias sputter the target.

[0110] Under specific conditions where pressure from gas in a vacuum exists, ions generated by electron collisions fly for a certain period of time and exist as ions until they are neutralized by collision with other particles. The ion survival time (t) refers to the time from when an ion is generated until it is neutralized. As shown in Fig. 10, if the ion survival time during one cycle is 1 / 4 cycle, the bias frequency (f) can be expressed as f(frequency) = 1 / 4t. Therefore, the bias frequency applied by CEBAS can be calculated using t. Below, a method for setting the bias frequency in a cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention is described.

[0111] Let t be the ion survival time for the Ar ions generated by electron collisions to be neutralized, and set the pressure P = 2×10⁻⁶, which is one order of lower than the working pressure typically used in sputtering devices. -4 Assuming that at this pressure torr, the ion is neutralized and disappears upon its first collision with another gas particle during flight, the neutralization time t can be calculated as follows. Here, the collision cross-section of an Ar atom σ = 0.36 / nm 2 am.

[0112] First, the gas density (n) can be calculated according to Equation 1 below.

[0113] [Formula 1]

[0114]

[0115] Here, P = 2 × tor = 2.67 × 10 -2 Pa,T= 300K, = 1.38×10 -23 It is J / K (Boltzmann constant).

[0116] Next, the Mean Free Path (λ: average flight distance between gas particles) can be calculated according to Equation 2 below.

[0117] [Formula 2]

[0118]

[0119] Here, σ = 0.36 / nm 2 = 0.36 × 10⁻⁶ -18 m 2 am.

[0120] Next, the average speed of ions It can be calculated according to Formula 3 below.

[0121] [Formula 3]

[0122]

[0123] Here, m is the mass of the Ar ion, m = 6.63 × 10⁻⁶-27 It is kg.

[0124] Next, the ion survival time (t), which is the time it takes for the ion to be neutralized, can be calculated according to Equation 4 below.

[0125] [Equation 4]

[0126]

[0127] In the situation of Fig. 10, if the ion survival time t is 1 / 4 of a cycle, the frequency is as follows.

[0128] f = 1 / (4 × t) ≈ 10 4 / s = 10kHz

[0129] This means the pressure in the vacuum chamber is P = 2 × 10 -4 In a situation of torr, this can be described as the frequency that must be alternately applied to the electron beam source and the target in order to efficiently utilize the Ar ions generated by electron beam collisions for sputtering collisions before they are neutralized.

[0130] Since frequency f is proportional to gas pressure, the gas pressure in a vacuum is four times the original pressure, i.e., P = 8 × 10⁻⁶ -4 If torr, the frequency f is as follows.

[0131] f = 10kHz × 4 = 40kHz

[0132] The gas pressure in a vacuum is 10 times the existing pressure, i.e., P = 2 × 10⁻⁶ -3 If torr, the frequency f is as follows.

[0133] f = 10kHz × 10 = 100kHz

[0134] The time required for an ion to be neutralized, i.e., the ion survival time, calculated by the aforementioned method, is a value calculated on the premise that the ion is neutralized upon the first collision when it travels along the mean free path and collides with another particle. However, if the ion is not neutralized after a single collision with another ion, the time required for neutralization can increase by more than double. Therefore, in the case of double the time, P = 2×10⁻¹⁰ -4 At torr, f = 5kHz, and P = 4×10 -3 f becomes 100kHz at torr.

[0135] Therefore, it can be seen that in the cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention, the frequency of the cyclic pulse power can be effectively used for the sputter deposition of a damage-free thin film in the range of 1 to 100 kHz. Here, the pressure range is 10 -5 ~ 10 -2 If the frequency of the cyclic pulse power is set broadly to include up to torr, it can be set to a frequency range of 0.1 to 1000 kHz.

[0136] FIG. 11 is a graph illustrating the pattern of Electron / Ion flux and the duty cycle of Target bias voltage while a Cyclic pulse bias is applied to an electron beam source and a target in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention. In FIG. 11, the set voltage (black) is applied to the electron beam source and the target by synchronizing the Cyclic pulse biases. When gas particles in the chamber have pressure applied by the CEBAS device, the bias voltage applied from the power has current, so the real voltage (red) of the EB source appears different from the set voltage value due to the electrical delay of the power supply. If the real voltage is applied to the EB source, the electron beam is irradiated from the electron beam source with the energy of the real voltage, and since the electron beam flux is proportional to the electron beam energy, the electron beam flux can be expected to have the same waveform as the real voltage.

[0137] In FIG. 11 (a), the pulse bias applied to the electron beam source and the target is set to be synchronized and alternate with each other, such that the start and end points of the electron beam bias and the target bias coincide. In FIG. 11 (b), the pulse bias applied to the electron beam source and the target is set to be synchronized and alternate with each other, such that the duty cycle of the target bias is adjusted so that the start point of the target bias partially overlaps with the electron beam bias. In FIG. 11 (c), the pulse bias applied to the electron beam source and the target is set to be synchronized and alternate with each other, such that the duty cycle of the target bias is adjusted so that the target bias is continuously applied at nearly 100%.

[0138] Meanwhile, ions generated by electron collisions are delayed by a time proportional to the time they travel along the mean free path until they are neutralized and disappear. Therefore, the ion flux is delayed compared to the electron flux and can be represented as a waveform that extends beyond the ion generation cycle (P1) to the next half-cycle, the target sputtering cycle (P2). The gas ion flux generated during the ion generation cycle remains and plays an important role until the target sputtering cycle. When electrons disappear and only ions remain, the target bias applied to the target attracts the living ions to the target with a strong attractive force. Ions colliding with the target with the energy of the target bias sputter the target, and the sputtered target particles are deposited on the substrate. Ions generated by electron collisions possess only very low energy of a few eV. Furthermore, due to the target bias, low-energy ions fly only toward the target, so the ions sputter only the target, and there is no risk of sputtering other materials around the target. Therefore, the sputtering device according to the present invention can deposit an excellent thin film that is damage-free and contamination-free.

[0139] Meanwhile, in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, when pulse biases are synchronized and applied to an electron beam source and a target, the duty of the pulse bias applied to the target can be changed.

[0140] Referring to Figures 11 (b) and (c), if the duty of the pulse bias applied to the target is varied to increase the target bias time, the target bias is applied even during the ion generation cycle in which the electron beam flies. At this time, as the duty of the pulse bias of the target is increased, the time during which the target bias is applied during the ion generation cycle becomes longer. Consequently, the target bias is applied while the electron beam is flying, and the electron beam receives a repulsive force from the target bias, flies toward the substrate, and collides with the substrate. This results in the effect of irradiating the substrate with an electron beam. As a result, as the temperature of the substrate rises, a heat treatment effect on the substrate deposition material can be expected. In conclusion, by increasing the duty of the target bias during CEBAS, an electron beam irradiation effect on the substrate can be created.

[0141] As described above, by changing the start or end point of the synchronized target bias to increase the duty of the target pulse bias, the following effects can be obtained. As illustrated in FIG. 11, increasing the duty of the target pulse bias causes the time during which the target bias is applied to overlap with the time during which the electron beam bias is applied, thereby increasing the amount of ion flux attracted to the target. Consequently, sputtering caused by ion collisions is increased, and as a result, the deposition rate can be increased.

[0142] In addition, if the duty cycle of the pulse bias of the target is increased, the target bias is applied while the electron beam bias is applied. As a result, as electrons are pushed toward the substrate by the repulsive force of the target bias, the amount of electron collisions with the substrate can gradually increase. As the electron collisions increase while sputtering deposition is taking place on the substrate, not only can the build-up of ionic charges that may occur on the surface of the deposited thin film be neutralized, but the electron collisions can also induce a heating effect on the deposited thin film.

[0143] As illustrated in FIG. 11(c), in a cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention, by adjusting the duty of the pulse bias of the target, the target bias can be continuously applied at nearly 100% while the electron beam bias is applied. As the target bias is continuously applied in this way, all ions generated during the ion generation cycle continuously sputter the target, and electrons provided from the electron beam source are directed toward the substrate. As a result, the collision between the target and ions is increased, thereby improving the deposition rate, and electrons are irradiated onto the substrate during the pulse cycle to heat the substrate.

[0144] Meanwhile, contrary to the graph shown in Fig. 11, by adjusting the duty of the pulse bias of the electron beam source, the electron beam bias can be applied to the target while applying the electron beam bias. By adjusting the duty of the pulse bias of the electron beam source in this way, the electron beam can be assisted even during the target sputtering cycle. In this manner, by adjusting the duty of the pulse bias of the electron beam source to irradiate the electron beam almost continuously in the form of Fig. 11 (c), ion generation can be maximized and the deposition rate can be increased.

[0145] Changes in duty cycles that cause the electron beam irradiation time and target bias time to overlap can also be applied sequentially. That is, initially, as shown in FIG. 11 (a), the duty cycle is maintained to prevent the electron beam from striking the substrate, thereby performing damage-free deposition for a certain period to deposit a thin film of 10 to 20 nm or a constant thickness. This initial thin film is deposited with a thickness that prevents damage that may occur during subsequent deposition. Following the initial deposition, a subsequent thin film can be deposited by adjusting the duty cycle as shown in FIG. 11 (b) or (c). During the subsequent thin film deposition, additional effects from electron beam irradiation can be expected. Here, effects from electron beam irradiation include heat treatment effects, reduction of defects within the thin film, increase in density, improvement of epitaxial growth, and improvement of crystallinity.

[0146] FIG. 12 is a graph showing the deposition rate according to the target bias in a cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention. The graph in FIG. 12 is a graph measured in a state where the charged particle beam source is configured as a linear electron beam, the target is Linear ITO, and the equipment is configured in the form shown in FIG. 10. The conditions at this time are as follows: the TS distance is 230 mm, the Electron Beam ICP RF power is 600 W, the Electron Beam DC Bias is -500 V, the Anode DC Bias is +50 V, and the Synchronized Bias Frequency is 80 kHz.

[0147] <2nd Embodiment: Cyclic Charged Particle Beam-Assisted Sputtering Device Using an Ion Beam>

[0148] Hereinafter, a cyclic charged particle beam-assisted sputtering apparatus and a method according to a second embodiment of the present invention will be described in detail. The cyclic charged particle beam-assisted sputtering apparatus according to the second embodiment of the present invention is characterized in that the charged particle beam is composed of an ion beam, and ions to be sputtered on a target are generated using the ion beam.

[0149] Accordingly, the cyclic charged particle beam-assisted sputtering device according to the second embodiment of the present invention is configured identically to that of the first embodiment, but differs in that the charged particle beam source is configured as an ion beam source. In order to generate ions used for sputtering, an electron beam is used in the first embodiment, whereas an ion beam is used in this embodiment.

[0150] FIG. 13 is a schematic diagram illustrating the ionization process by collision of an ion beam irradiated from an ion beam source in a cyclic charged particle beam-assisted sputtering apparatus according to a second embodiment of the present invention. Referring to FIG. 13 (a), as a bias is applied to the ion beam source during the ion generation cycle (P1), an ion beam having (+) bias energy is irradiated from the ion beam source into the chamber and flies parallel to the target and the substrate. Referring to FIG. 13 (b), while the ion beam flies in the chamber, it can collide with gas particles in the chamber and ionize the gas particles.

[0151] FIG. 14 is a schematic diagram illustrating the target sputtering process by collision between generated ions and a target in a cyclic charged particle beam-assisted sputtering apparatus according to a second embodiment of the present invention. Referring to FIG. 14 (a), as a bias is applied to the target during the target sputtering cycle, newly generated ions are attracted to the target by collision between the ion beam and gas particles. Unlike the previously irradiated ions, the newly generated ions can be described as having low energy, with an energy of several eV. Referring to FIG. 14 (b), the ions attracted to the target sputter the target, and the sputtered target particles can be deposited on the surface of a substrate.

[0152] The speed at which an ion beam composed of Ar(+) ions travels from one side of a chamber equipped with an ion beam source to the opposite cathode must exceed the Ar ionization energy capable of colliding with and ionizing Ar gas particles inside the chamber. Therefore, since the Ar ionization energy is 15.7 eV and 1 eV of an Ar ion is 17.2 mach, the speed of the irradiated Ar(+) ion beam must exceed approximately 270 mach. This speed is significantly faster than the speed of 1,260 m / s at which Ar gas atoms inside the chamber are ionized and travel by collision, and is approximately 69 times faster. Therefore, it can be seen that even if pulse bias is applied cyclically to the ion beam source and the target, the ions emitted from the ion beam source cannot affect the sputtering of the target, and sputtering occurs with the target bias due to the newly created ions by collision. Therefore, the energy of the ion beam irradiated from the ion beam source is sufficiently effective if it is tens of eV or more, which is sufficient to collide with and ionize gas particles.

[0153] FIG. 15 is a graph illustrating pulse biases that are applied alternately to an ion beam source and a target in synchronization with each other in a cyclic charged particle beam assist sputtering apparatus according to a second embodiment of the present invention. Referring to FIG. 15, the sputtering apparatus according to the second embodiment of the present invention performs sputtering by alternately applying pulses of a (+) bias applied to an ion beam source and a (-) bias applied to a target, thereby enabling cyclic ion beam assist sputtering (hereinafter referred to as 'CIBAS').

[0154] The sputtering apparatus according to the present embodiment is also equipped with a charged particle beam path guidance module so that the ion beam can fly without colliding with the target and the substrate by forming a magnetic field tunnel along a preset flight path. The configuration of the charged particle beam path guidance module is similar to that of the charged particle beam path guidance module of the first embodiment.

[0155] The charged particle beam path guidance module may include an electromagnet formed by winding a ring-shaped electromagnet coil (Helmholtz coil). Furthermore, the electromagnet of the charged particle beam path guidance module may be positioned at the start and end points of a preset ion beam flight path, respectively. The ion beam flight path may be set as a path parallel to the surface of the substrate while spaced at a certain distance from the surface of the substrate, or as a path parallel to the surfaces of the substrate and the target while spaced at a certain distance from the substrate and the target. Here, the start point of the ion beam flight path may be the exit of the ion beam source, and the end point of the ion beam flight path may be the wall opposite the exit of the ion beam source. Accordingly, the electromagnets positioned at the start and end points of the ion beam flight path can form a magnetic field tunnel along the preset ion beam flight path. An ion beam with energy irradiated from an ion beam source can be guided by a magnetic field tunnel formed by electromagnets of a charged particle beam path guidance module so as not to deviate from a preset flight path during ion beam flight.

[0156] Referring to FIG. 15, during the ion generation cycle (P1), a magnetic field tunnel is formed along a preset ion beam flight path using a charged particle beam path guidance module, and a (+) bias is applied to the ion beam source and the target is biased to ground. As a result, during the ion generation cycle, the ion beam is emitted with energy, the target does not generate a repulsive force against the ion, and the ion beam is able to fly in a straight line along the path where the magnetic field tunnel is formed. Then, during the target sputtering cycle (P2), while ions are generated on the front surface of the target inside the chamber, an electrical bias with a polarity opposite to that of the ion is applied to the target, and accordingly, the ion is attracted to the target and collides with the target. At this time, if the ion has sufficient energy to be sputtered by the bias voltage of the target, the target particles can be sputtered by the collision between the target and the ion, and as a result, the sputtered target particles can be deposited on the substrate.

[0157] Meanwhile, the charged particle beam path guidance module may further be equipped with a cathode on the wall of the chamber where the ion beam reaches according to a preset ion beam flight path. By applying a negative potential to the cathode to attract the ion beam flying within the chamber, it can help the ion beam fly in a straight line according to the preset flight path.

[0158] Since the mass of an ion beam is greater than that of an electron, the strength of the magnetic field generated by the electromagnet must be stronger than that of the first embodiment composed of an electron beam to guide the parallel flight of the ion beam. When the energy of the ion beam is weak, due to the space charge effect, a phenomenon occurs where the beam spreads out as it flies through space due to the repulsion between the positive charges of the ions. Therefore, when the energy of the ion beam is weak, the phenomenon of the ion beam spreading out due to the space charge effect can be contained through the magnetic field tunnel formed by the charged particle beam path guidance module. On the other hand, when the intensity of the ion beam is high, the momentum in the linear direction of the ion beam is large and linear flight is dominant; thus, the ion beam can sufficiently perform parallel flight even without a magnetic field tunnel.

[0159] Meanwhile, conventional Ion Beam Sputter Deposition (IBD) devices deposit by sputtering the target by directly colliding an ion beam with it. Conventional IBDs can form fine deposited thin films because the deposition pressure is approximately 10⁻⁴ torr. However, as IBDs irradiate the target with an energetic ion beam to sputter, the sputtered target particles are deposited on the substrate, while ions backscattered from the target collide with the substrate. At this time, since the ions colliding with the substrate carry energy, there is a problem of causing damage to the substrate. Furthermore, while the ion beam is traveling toward the target, due to the space charge effect of the ion charge, the ion beam strikes not only the target but also regions outside the target. As a result, materials other than the target are sputtered and deposited on the substrate, leading to contamination deposition on the substrate thin film.

[0160] As described above, CIBAS (Cyclic Ion Beam Assist Sputtering) according to the second embodiment of the present invention uses a method of biasing the target so that ions additionally induced by colliding with the gas inside the chamber strike the target, rather than the ion beam directly striking the substrate, and is characterized by alternately applying pulse bias to the ion beam source and the target. Furthermore, CIBAS according to the second embodiment of the present invention can overcome the disadvantages of conventional IBD, such as damage caused by backscattered ion particles colliding with the substrate and contaminants located outside the target being sputtered and deposited.

[0161] Furthermore, in CIBAS, the greater the mass of the irradiated ions compared to the mass of the gas ionized by collision, the less backscattered the incident ion beam becomes after colliding with gas particles; thus, the energetic particles do not fly off to the substrate and cause damage. Therefore, among inert gases such as He, Ne, Ar, Kr, and Xe, it is advantageous to produce damage-free thin films when the irradiated ion beam is heavier and the ionized gas is lighter.

[0162] CIBAS (Cyclic Ion Beam Assist Sputtering) according to the second embodiment of the present invention has an effect almost similar to CEBAS according to the first embodiment described above.

[0163] The cyclic charged particle beam-assisted sputtering device according to the first and second embodiments of the present invention applies a pulse bias to a target to attract ions to the target, thereby causing sputtering collisions between the ions and the target. Accordingly, by adjusting the pulse bias of the target, the energy and flux of the ions colliding with the target can be sufficiently reduced. As a result, the cyclic charged particle beam-assisted sputtering device according to the first and second embodiments of the present invention can precisely control thin films of nano, angstrom, or sub-angstrom thickness more than the conventional IBD method.

[0164] In conventional IBDs, heating of the target surface due to ion beam collisions cannot be avoided even if the target back plate is cooled. If the temperature of the target rises, the sputtering rate of the target changes. Therefore, when depositing multi-layers that require a long deposition time, the deposition rate of the conventional IBD changes over time, and as a result, it becomes difficult to produce multi-layers of accurate and repeatable thickness. However, unlike conventional IBDs, the cyclic charged particle beam assisted sputtering device according to the first and second embodiments of the present invention can lower the ion flux sputtering the target, thereby enabling the accurate and repeatable implementation of multi-layers.

[0165]

[0166] < Third Embodiment: Cyclic Charged Particle Beam Assisted Etching Device Using an Electron Beam >

[0167] Hereinafter, a cyclic charged particle beam-assisted etching apparatus and a method according to a third embodiment of the present invention will be described in detail. Similar to the cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention, the cyclic charged particle beam-assisted etching apparatus according to the third embodiment of the present invention is characterized by etching a substrate using ions generated through collision with a charged particle beam by applying pulse biases that alternate with each other and are synchronized with a charged particle beam source and a substrate. The cyclic charged particle beam-assisted etching apparatus according to this embodiment can adjust the bias according to a desired etching rate. In the present invention, the charged particle beam may be composed of either an electron beam or an ion beam.

[0168] FIG. 16 is a schematic diagram illustrating a cyclic charged particle beam assisted etching apparatus according to a third embodiment of the present invention. Referring to FIG. 16, the cyclic charged particle beam assisted etching apparatus (3) according to the third embodiment of the present invention comprises a chamber (300), a gas supply module (310), a charged particle beam source (330) connected to a first power source (350), a substrate (320) connected to a second power source (352), and a control module (340). The cyclic charged particle beam assisted etching apparatus (3) according to the third embodiment of the present invention may further comprise a charged particle beam path guidance module (360). The cyclic charged particle beam assisted etching apparatus according to the third embodiment of the present invention is characterized by generating ions to etch the substrate using an electron beam. Hereinafter, the components of the cyclic charged particle beam assisted etching apparatus according to the third embodiment of the present invention will be described in detail.

[0169] The chamber (300) may be configured as a vacuum chamber capable of injecting process gas, and a gas supply module and a substrate may be placed inside it, and a charged particle beam source may be mounted on one side. The substrate (310) is placed inside the chamber (300) and is connected to a second power source (352). The gas supply module (310) is placed inside the chamber (300) but may be positioned to face the substrate (320) while being spaced apart by a certain distance.

[0170] The gas supply module (310) is positioned to face the substrate and can supply an inert gas or a reactive gas used in the etching process toward the substrate by showering. Meanwhile, the gas supply module (310) may also be supplied from the top of the chamber by a flowing bed method.

[0171] A charged particle beam source (330) is positioned on one side of the chamber (300), and the outlet of the charged particle beam source is positioned to face the interior of the chamber. The charged particle beam source (330) is connected to a first power source (350). The charged particle beam source (330) may be positioned so that the charged particle beam flies parallel to the substrate (320). The charged particle beam source of the device according to the third embodiment of the present invention is composed of an electron beam source and is configured to provide an electron beam into the interior of the chamber.

[0172] The control module (340) is configured to etch the substrate by controlling the operation of the first power supply (350) and the second power supply (352) to adjust the bias voltages applied to the charged particle beam source and the substrate, respectively. By applying pulse-shaped biases that are synchronized and alternate to the charged particle beam source and the substrate, the ion generation cycle (P1) and the substrate etching cycle (P2) can be synchronized and proceed alternately.

[0173] A cyclic charged particle beam-assisted etching apparatus according to the third embodiment of the present invention generates an electron beam by applying a bias to an electron beam source during an ion generation cycle (P1), injects the electron beam into a chamber to cause a collision between the electron beam and gas particles in the chamber, and generates ions through the collision between the electron beam and the gas particles. Then, during a substrate etching cycle (P2), by applying a bias to a substrate, the ions generated by the electron beam are attracted to the substrate and collide with the substrate, and as a result, the substrate is etched.

[0174] FIG. 17 is a waveform diagram illustrating pulse biases applied to a charged particle beam source and a substrate, respectively, during alternating ion generation cycles (P1) and substrate etching cycles (P2) in a cyclic charged particle beam assisted etching apparatus according to a third embodiment of the present invention.

[0175] Referring to FIG. 17, during the ion generation cycle (P1), a (-) bias is applied to the charged particle beam source while the substrate maintains a ground bias. By applying this bias, the charged particle beam source irradiates an electron beam into the chamber, causes a collision between the gas particles in the chamber and the electron beam, and generates ions through the collision between the gas particles and the electron beam. Meanwhile, during the substrate etching cycle (P2), a (-) bias is applied to the substrate while the charged particle beam source maintains a ground bias. By applying this bias, ions are attracted to the substrate and collide with it to etch the substrate. In this way, by synchronizing pulse biases between the charged particle beam source and the substrate and applying them alternately, the ion generation cycle (P1) and the substrate etching cycle (P2) can be synchronized and proceed alternately.

[0176] In the present invention, the process of etching a substrate by repeating an ion generation cycle (P1) and a substrate etching cycle (P2) is referred to as 'Cyclic Electron Beam Assist Etching' (CEBAE). CEBAE according to the present invention can increase the yield of using ions for substrate etching by optimizing the frequency that synchronizes the pulse biases applied to the charged particle beam source and the substrate.

[0177] Hereinafter, the ion generation mechanism and the substrate etching mechanism in the cyclic charged particle beam-assisted etching apparatus according to the present invention will be described in more detail. FIG. 18 is a schematic diagram illustrating the movement of electrons during the ion generation cycle in the cyclic charged particle beam-assisted etching apparatus according to the third embodiment of the present invention. FIG. 18 (a) exemplarily shows the path along which an electron beam flies by means of a charged particle beam path guidance module. FIG. 18 (b) exemplarily shows that ions are generated by the collision between electrons and gas particles during the flight path of the electron beam. Referring to FIG. 18, during the ion generation cycle, that is, while the electron beam irradiated from the electron beam source flies, it collides with gas particles to generate ions.

[0178] During the ion generation cycle, a magnetic field tunnel is formed along a preset electron beam flight path using a charged particle beam path guidance module (360), and a (-) bias is applied to the electron beam source and the substrate is biased to ground. As a result, during the ion generation cycle, the electron beam is emitted with energy, the substrate does not generate any attractive or repulsive force against the electron, and the electron is able to fly in a straight line along the path where the magnetic field tunnel is formed.

[0179] FIG. 19 is a schematic diagram illustrating the process of ions etching a substrate during a substrate etching cycle in a cyclic charged particle beam-assisted etching apparatus according to a third embodiment of the present invention. FIG. 19 (a) exemplarily shows the process in which ions are attracted to the substrate by an attractive force due to a bias applied to the substrate and collide with the substrate. FIG. 19 (b) exemplarily shows the process in which the surface of the substrate is etched by the collision between the ions and the substrate. Referring to FIG. 19, during a substrate etching cycle (P2) synchronized with the ion generation cycle, when a (-) bias is applied to the substrate, ions collide with the substrate and etch the surface of the substrate.

[0180] During the substrate etching cycle (P2), voltage is not applied to the electron beam source, so the irradiation of the electron beam is stopped. The electron beam irradiated during the ion generation cycle (P1) moves too fast and disappears towards the anode in an instant. However, the ions generated by the collision of the electron beam during the ion generation cycle (P1) have weight and low energy, so their flight speed is slow and they remain in the space within the chamber. The ions generated by the collision of the electron beam have very low energy of several eV. Therefore, the ions generated by the collision of the electron beam have low energy of their own and cannot etch the substrate on their own. Therefore, when a negative bias of about tens to thousands of volts is applied to the substrate while the ions are generated, the substrate bias exerts an attractive force on the positive ions remaining in the chamber. Due to the attractive force of the substrate bias, the positive ions are pulled to the substrate and collide with it, and as a result, the surface of the substrate is etched.

[0181] In a cyclic charged particle beam-assisted etching apparatus according to the third embodiment of the present invention, the ion generation cycle and the substrate etching cycle are synchronized and alternate with each other, thereby eliminating heating of the substrate caused by electron collisions with the substrate. In addition, by adjusting the substrate bias applied during the substrate etching cycle, the depth of etching can be precisely controlled. Accordingly, according to this embodiment, atomic layer etching ('ALE') requiring 30 to 50 eV of energy can be performed.

[0182] In addition, in the cyclic charged particle beam assisted etching apparatus according to the third embodiment of the present invention, the depth of ALE etching can be controlled by controlling the number of electron beam pulse injections to limit the flux of ions to be used for etching.

[0183] In conventional etching using ICP plasma, or in addition to this, etching is performed by applying HF, RF, or a faster frequency RF bias to the substrate, and the energy of the ions is approximately tens to thousands of eV. When etching is performed through collisions with ions having such high energy, not only is unintended deep etching or non-uniform etching occurring, but the electrons of the plasma also strike the substrate, causing heating of the substrate. In contrast, the cyclic charged particle beam-assisted etching apparatus according to the third embodiment of the present invention etches the substrate using ions having a very low energy of several eV generated by the collision of an electron beam. Therefore, the etching apparatus according to the present invention can precisely control the etching depth by adjusting the substrate bias.

[0184]

[0185] < 4th Embodiment: Cyclic Charged Particle Beam Assisted Etching Device Using an Ion Beam >

[0186] Hereinafter, a cyclic charged particle beam-assisted etching apparatus and a method according to the fourth embodiment of the present invention will be described in detail. The cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention is characterized in that the charged particle beam is composed of an ion beam and the substrate is etched using the ion beam. Accordingly, the cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention is configured identically to that of the third embodiment, except that the charged particle beam source is composed of an ion beam source. In order to generate ions used for substrate etching, the cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention uses an electron beam in the third embodiment, and an ion beam in this embodiment.

[0187] FIG. 20 is a schematic diagram illustrating pulse biases that are applied alternately to an ion beam source and a substrate in synchronization with each other in a cyclic charged particle beam-assisted etching apparatus according to a fourth embodiment of the present invention. Referring to FIG. 20, during the ion generation cycle (P1), a (+) bias is applied to the charged particle beam source while the substrate maintains a ground bias. By applying this bias, the charged particle beam source generates an ion beam and irradiates it into the chamber, causes a collision between the ion beam and gas particles in the chamber, and generates ions through the collision between the gas particles and the ion beam. Meanwhile, during the substrate etching cycle (P2), a (-) bias is applied to the substrate while the charged particle beam source maintains a ground bias. By applying this bias, ions are attracted to the substrate and collide with the substrate to etch the substrate. In this way, by synchronizing pulse biases between the charged particle beam source and the substrate and applying them alternately, the ion generation cycle (P1) and the substrate etching cycle (P2) can be synchronized and proceed alternately.

[0188] In the present invention, the process of etching a substrate by repeating an ion generation cycle (P1) and a substrate etching cycle (P2) is referred to as 'Cyclic Ion Beam Assist Etching' (CIBAE). CIBAE according to the present invention can perform an etching process by increasing the yield of ions used for substrate etching by optimizing the frequency that synchronizes the pulse biases applied to the charged particle beam source and the substrate.

[0189] FIG. 21 is a schematic diagram illustrating the ionization process by collision of an ion beam in a cyclic charged particle beam-assisted etching apparatus according to a fourth embodiment of the present invention. Referring to FIG. 21 (a), as a bias is applied to the ion beam source during the ion generation cycle, an ion beam having (+) bias energy is irradiated from the ion beam source into the chamber and flies parallel to the substrate. Referring to FIG. 21 (b), the ion beam flying in the chamber can collide with gas particles in the chamber and ionize the gas particles.

[0190] FIG. 22 is a schematic diagram illustrating a substrate etching process in a cyclic charged particle beam-assisted etching apparatus according to a fourth embodiment of the present invention. Referring to FIG. 22 (a), when a negative bias is applied to the substrate during the substrate etching cycle, ions generated by the collision of the ion beam and gas particles are attracted to the substrate. Referring to FIG. 22 (b), the ions attracted to the substrate etch the substrate. At this time, the etching depth of the substrate can be controlled by adjusting the substrate bias or by adjusting the number of pulse injections of the ion beam bias.

[0191] In a cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention, by synchronizing the ion generation cycle and the substrate etching cycle so that they alternate with each other, unnecessary and non-uniform depth etching of the substrate caused by collision between the irradiated ion beam and the substrate can be eliminated. In addition, by adjusting the substrate bias applied during the substrate etching cycle, the depth of etching of the substrate can be precisely controlled. Accordingly, according to this embodiment, atomic layer etching ('ALE') requiring energy of 30 to 50 eV can be performed.

[0192] In addition, in the cyclic charged particle beam assisted etching apparatus according to the fourth embodiment of the present invention, the depth of ALE etching can be controlled by limiting the flux of ions to be used for etching by controlling the number of pulse injections of the ion beam bias.

[0193] In conventional etching using ICP plasma, or in addition to this, etching is performed by applying HF, RF, or a faster frequency RF bias to the substrate, and the energy of the ions is approximately tens to thousands of eV. When etching is performed through collisions with ions having such high energy, not only does deep etching occur or non-uniform etching take place, but the electrons of the plasma also strike the substrate, causing heating of the substrate. In contrast, the cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention etches the substrate using ions having a very low energy of several eV generated by the collision of the ion beam. Therefore, the etching apparatus according to the present invention can precisely control the etching depth by adjusting the substrate bias.

[0194] In the etching apparatus according to the fourth embodiment of the present invention, ions injected from an ion beam source for ion generation within the chamber have mass compared to electrons and can collide with an impact force. Therefore, when the reactive gas for etching is in the form of a molecule or radical in which a large number of atoms are bonded, the ion generation process by ion beam collision can easily dissociate the reactive gas, and momentum transfer due to the impact force can occur. As a result, the etching apparatus according to the fourth embodiment of the present invention can perform uniform etching on the side walls of a deep trench by the directional movement of the reactive gas.

[0195] In addition, when the ionizing gas is a single-atom inert gas, the greater the mass of the ions irradiated in CIBAE than the mass of the gas ionized by collision, the less the irradiated ions are backscattered after collision. Therefore, the irradiated ions not only do not create uncontrolled etching on the substrate, but they also do not create non-uniform or unnecessary depth etching on the substrate. The irradiating ion beam and the ionizing gas can be composed of one of the inert gases He, Ne, Ar, Kr, or Xe. Among these, the heavier the irradiating ion beam and the lighter the ionizing gas, the more advantageous it is for the ionized gas to create uniform etching of depth controlled by the substrate bias.

[0196] Although the present invention has been described above with reference to preferred embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the invention. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. A sputtering apparatus comprising a target and a substrate arranged facing each other at a certain distance apart within a vacuum chamber, A charged particle beam source configured to irradiate a charged particle beam into the interior of the above vacuum chamber; and A control module configured to control first and second pulse voltages applied to the charged particle beam source and the target, respectively, so that the ion generation cycle and the target sputtering cycle are synchronized and proceed alternately with each other; During the ion generation cycle, a charged particle beam is irradiated by applying a preset charged particle beam bias to a charged particle beam source, and ions of gas particles are generated by the collision between the charged particle beam and gas particles. A cyclic charged particle beam assist sputtering apparatus characterized by applying a target bias preset to the target during the target sputtering cycle, so that the generated gas particle ions are attracted to the target and collide with it to sputter the target, and the sputtered target particles are deposited on a substrate.

2. A cyclic charged particle beam assisted sputtering device according to claim 1, wherein the charged particle beam source is composed of an electron beam source that provides an electron beam, and the charged particle beam is an electron beam.

3. A cyclic charged particle beam assisted sputtering device according to claim 1, wherein the charged particle beam source is composed of an ion beam source that provides an ion beam, and the charged particle beam is an ion beam.

4. In claim 1, the cyclic charged particle beam-assisted sputtering device is, A charged particle beam guidance module further comprising: a charged particle beam guidance module configured to form a magnetic field along a preset flight path of a charged particle beam supplied into a chamber by a charged particle beam source or to apply additional power so that the charged particle beam proceeds along a preset flight path; A cyclic charged particle beam assisted sputtering device characterized in that the preset flight path of the charged particle beam is spaced apart from the surface of the substrate, but is parallel to or forms a curvature with respect to the surface of the substrate.

5. In paragraph 4, the charged particle beam guidance module is, A cyclic charged particle beam assisted sputtering device characterized by comprising electromagnets disposed on the walls of a vacuum chamber located at the start or end point of a preset flight path of a charged particle beam.

6. In paragraph 4, the charged particle beam guidance module is, Further comprising an electrode configured to be placed at the end of a preset flight path of a charged particle beam to guide the charged particle beam; When the charged particle beam is an electron beam, the electrode is composed of an anode, and A cyclic charged particle beam assisted sputtering device characterized in that, when the charged particle beam is an ion beam, the electrode is composed of a cathode.

7. In paragraph 1, the control module is, A cyclic charged particle beam-assisted sputtering apparatus characterized by adjusting the duty cycle of the first or second pulse voltage to configure the period during which the charged particle beam is irradiated and the period during which the target bias is applied to overlap, thereby improving the sputtering deposition rate and having an electron beam substrate irradiation effect.

8. A cyclic charged particle beam assisted sputtering apparatus according to claim 1, wherein, when the charged particle beam is an ion beam, the mass of the ions constituting the ion beam is greater than the mass of the gas ionized by collision.

9. A cyclic charged particle beam assisted sputtering apparatus according to claim 1, characterized in that the frequencies of the first and second pulse voltages applied to the charged particle beam source and the target, respectively, are in the range of 0.1 to 1,000 kHz.

10. An etching apparatus comprising a gas supply module and a substrate arranged facing each other at a certain distance apart within a vacuum chamber, A charged particle beam source configured to irradiate a charged particle beam into the interior of the above vacuum chamber; and A control module configured to control first and second pulse voltages applied to the charged particle beam source and the substrate, respectively, so that the ion generation cycle and the substrate etching cycle are synchronized and proceed alternately with each other; During the ion generation cycle, a charged particle beam is irradiated by applying a preset charged particle beam bias to a charged particle beam source, and ions are generated by the collision between the charged particle beam and gas particles. A cyclic charged particle beam-assisted etching apparatus characterized by applying a pre-set substrate bias to the substrate during a substrate etching cycle, and etching the substrate by causing the generated ions to collide with the substrate due to the attractive force of the substrate bias.

11. A cyclic charged particle beam assisted etching apparatus according to claim 10, wherein the charged particle beam source is composed of an electron beam source that provides an electron beam, and the charged particle beam is an electron beam.

12. A cyclic charged particle beam assisted etching apparatus according to claim 10, wherein the charged particle beam source is composed of an ion beam source that provides an ion beam, and the charged particle beam is an ion beam.

13. In Clause 10, the cyclic charged particle beam-assisted etching device is, A charged particle beam guidance module further comprising: a charged particle beam guidance module configured to form a magnetic field along a preset flight path of a charged particle beam supplied into a chamber by a charged particle beam source or to apply additional power so that the charged particle beam proceeds along a preset flight path; A cyclic charged particle beam-assisted etching apparatus characterized in that the preset flight path of the charged particle beam is spaced apart from the surface of the substrate, but is parallel to or forms a curvature with respect to the surface of the substrate.

14. In Clause 13, the charged particle beam guidance module is, A cyclic charged particle beam assisted etching apparatus characterized by comprising electromagnets disposed on the walls of a vacuum chamber located at the start or end point of a preset flight path of a charged particle beam.

15. In Clause 13, the charged particle beam guidance module is, Further comprising an electrode configured to be placed at the end of a preset flight path of a charged particle beam to guide the charged particle beam; When the charged particle beam is an electron beam, the electrode is composed of an anode, and A cyclic charged particle beam assisted etching apparatus characterized in that, when the charged particle beam is an ion beam, the electrode is configured as a cathode.

16. A cyclic charged particle beam-assisted etching apparatus according to claim 10, wherein, when the charged particle beam is an ion beam, the mass of the ions constituting the ion beam is greater than the mass of the gas ionized by collision.

17. A cyclic charged particle beam-assisted etching apparatus according to claim 10, characterized in that the frequencies of the first and second pulse voltages applied to the charged particle beam source and the substrate, respectively, are in the range of 0.1 to 1,000 kHz.

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