Cyclic charged particle beam assist sputtering apparatus and cyclic charged particle beam assist etching apparatus

Abstract

This invention relates to a circulating charged particle beam-assisted sputtering apparatus and a circulating charged particle beam-assisted etching apparatus. The circulating charged particle beam-assisted sputtering apparatus includes: a charged particle beam source configured to irradiate the interior of a vacuum chamber with a charged particle beam; and a control module configured to control first and second pulse voltages applied to the charged particle beam source and the target material, respectively, thereby synchronizing and alternating the ion generation cycle and the target sputtering cycle. During the ion generation cycle, a preset charged particle beam bias voltage is applied to the charged particle beam source to provide a charged particle beam, and ions are generated by collisions between the charged particle beam and gas particles. During the target sputtering cycle, a preset target bias voltage is applied to the target material, thereby attracting the generated ions to the target material for sputtering, and the sputtered target particles are deposited onto a substrate. The first pulse voltage applied to the charged particle beam source and the second pulse voltage applied to the substrate are configured to be synchronized and alternate.

Description

Technical Field

[0001] This 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 in that: a charged particle beam, collectively referred to as an electron beam or an ion beam with energy, collides with gas particles to generate ions, and the generated ions are used to sputter a target material or etch a substrate. Prior Technology

[0002] As semiconductor device design rules increasingly favor micro-linewidths below 3 nm, the industry is conducting research on various thin-film evaporation processes to achieve denser microstructures, eliminate internal defects, and reduce surface roughness. Sputtering equipment is a type of PVD (Physical Vapor Deposition) thin-film evaporation equipment that uses high-energy particles, such as ions in plasma, to collide with the surface of a target material. This allows atoms or molecules sputtered from the target surface to be deposited onto the substrate to form a thin film. Common sputtering equipment includes magnetron sputtering machines and ion beam sputtering machines utilizing ion beams.

[0003] Figure 1 is a schematic diagram conceptually illustrating the structure of a conventional magnetron sputter. Referring to Figure 1, the conventional sputter or magnetron sputter 1 includes a target 100, a power supply 110 connected to the target, a substrate 120 arranged facing the target, and a chamber 130. In the conventional magnetron sputter with the above structure, an inert gas is injected into the chamber, and a plasma is generated by the dissociation of gas particles produced by the power supply applied to the target. Ions in the plasma bombard the target, resulting in sputtering. By this sputtering, target particles are deposited on the surface of the substrate facing the target. That is, capacitive plasma facing the substrate sputters the target in the opposite direction to the substrate, thereby achieving the deposition of target particles.

[0004] At this time, within the plasma in the chamber, the gas particles, ions, electrons, and activated particles that constitute the plasma are intermingled and in active motion. Therefore, the particles flying towards the substrate include not only target particles but also ions, electrons, and UV (Ultra Violet) particles escaping from the plasma surface. Furthermore, as described above, the various particles flying towards the substrate carry considerable energy and collide with the substrate surface.

[0005] If the substrate includes materials with weak bonding, such as the organic materials used in OLED displays, perovskite solar cells, perovskite semiconductors, or various materials used in 2D semiconductors, the substrate will be damaged by collisions with particles flying towards it. This damage can include ion bombardment damage, electron bombardment damage, UV damage, and heating damage caused by such particle bombardment.

[0006] In this type of damage, the greatest damage can be caused by ions with mass. Depending on the plasma conditions, these ions can carry tens to hundreds of eV of energy out of the plasma and collide with the substrate. As a result, when the substrate contains materials with low interatomic bonding forces of several to tens of eV, significant damage from collisions with these ions is unavoidable.

[0007] As mentioned above, magnetron sputtering suffers from the problem of substrate exposure to plasma, leading to damage to the thin film surface. In contrast, ion beam sputtering, where the substrate is not exposed to plasma, operates under relatively low vacuum pressure, thus yielding high-quality thin films. However, previous ion beam sputtering methods have the following problems: complexity in selecting the ion beam direction, target direction, and sputtering particle flight angle; and contamination forming within the dielectric chamber inside the ion beam source. Furthermore, during the ion beam's irradiation and flight towards the target, due to the space charge effect, it may deviate from the target and collide with the chamber walls or shield around the target, thus sputtering. Therefore, there is a possibility of accidentally sputtered material from around the target acting as a contaminant for evaporation. Additionally, in ion beam sputtering, a portion of the ion beam colliding with the target is backscattered and reflected, colliding with the substrate while still carrying energy. Therefore, although it is different from ordinary sputtering where plasma is exposed to the substrate, it can still cause damage to the substrate.

[0008] Plasma, inherently powered by a power source, exists in an unstable state containing a high amount of energy. Therefore, particles escaping from the plasma surface contain a significant amount of energy. Thus, ions carrying high-energy particles can be used for sputtering targets, and some of these high-energy particles will fly towards the substrate they are facing, effectively performing ashing, cleaning, etching, and surface modification. However, when these high-energy particles collide with weaker materials forming the substrate, damage to the substrate is inevitable. Therefore, substrates facing the plasma cannot avoid damage from collisions with plasma particles.

[0009] To avoid damage caused by particles escaping from the plasma, as described above, a facing target method is used, in which two plasma-generating targets are positioned facing each other. The facing target method is configured such that the substrate is positioned perpendicular to the sides of the two targets, thereby reducing plasma-induced damage during sputtering. However, while this method reduces some damage, plasma-induced damage still occurs.

[0010] Therefore, in order to eliminate or drastically reduce the damage to the substrate caused by plasma as described above, it is necessary to avoid the presence of plasma facing the substrate. Nevertheless, if plasma is required, it must be remote plasma that is neither facing nor exposed to the substrate. The method of remotely operating plasma from the substrate is to increase the distance from the substrate and thus spatially confine the plasma.

[0011] On the other hand, as a method for eliminating plasma, time-limited plasma methods can also be used. One method of time-limited plasma is to apply power to the target to form plasma on and off on the target surface. However, this method should be excluded because the plasma and the target bias power are no longer independent.

[0012] Another method for time-limited plasma is to irradiate an electron beam in a vacuum to form a plasma independent of the target material, and then control the plasma intermittently. However, even after controlling and eliminating the plasma, if ions in the plasma are still alive, sputtering can be performed in a plasma-free state by attracting these ions.

[0013] The method described above for intermittently generating plasma involves imparting energy not only to electrons but also to ions, thereby irradiating the space with a beam of charged particles, causing the gas in the space to ionize. If the neutralization of the ionized gas requires time, the ions can be sufficiently separated from the plasma and effectively used for sputtering a target material or etching a substrate. [Previous Technical Documents] [Patent Literature]

[0014] Korean Patent Registration Publication No. 10-0546632

[0015] Korean Patent Publication No. 10-1998-055989

[0016] Korean Patent Publication No. 10-2012-0016510

[0017] Korean Patent Registration Publication No. 10-0156144 Summary of the Invention

[0018] [The problem the invention aims to solve]

[0019] To address the problems described above, the present invention aims to provide a cyclic charged particle beam-assisted sputtering apparatus configured as follows: pulse bias voltages applied to the charged particle beam source and the target material are synchronously controlled in a cross-sectional manner; the charged particle beam is irradiated into the space within the chamber and collides with gas particles within the chamber to generate ions; sputtering and evaporation are performed using the generated ions and the target material bias voltage; thereby preventing damage to the substrate and preventing contamination of the substrate during evaporation.

[0020] Furthermore, the present invention aims to provide a cyclic charged particle beam-assisted etching apparatus configured as follows: pulse bias voltages applied to the charged particle beam source and the target are synchronously controlled in a cross-sectional manner; the charged particle beam is irradiated into the space of the chamber and collides with the gas particles in the chamber to generate ions; the generated ions are used to apply a bias voltage to the substrate for etching; thereby, the etching depth of the substrate can be precisely controlled by the low ion energy caused by the lower bias voltage. [Technical means to solve the problem]

[0021] To achieve the technical problem described above, the first aspect of the present invention, a cyclic charged particle beam-assisted sputtering apparatus, is a sputtering apparatus comprising a target and a substrate arranged facing each other at a fixed distance within a vacuum chamber. It comprises: a charged particle beam source configured to irradiate the interior of the vacuum chamber with a charged particle beam; and a control module configured to control first and second pulse voltages applied to the charged particle beam source and the target, respectively, thereby synchronizing and alternating the ion generation cycle and the target sputtering cycle. The sputtering apparatus is characterized in that: during the ion generation cycle, a pre-set charged particle beam bias voltage is applied to the charged particle beam source to irradiate the charged particle beam, and gas particle ions are generated by collisions between the charged particle beam and gas particles; during the target sputtering cycle, a pre-set target bias voltage is applied to the target, thereby attracting the generated gas particle ions to the target and sputtering the target by collision, and the sputtered target particles are deposited onto the substrate.

[0022] In the above-mentioned first-state sample of the cyclic charged particle beam assisted sputtering apparatus, the charged particle beam source can be configured as an electron beam source that provides an electron beam, and the charged particle beam can be configured as an electron beam.

[0023] In the above-mentioned first-state sample of the cyclic charged particle beam assisted sputtering apparatus, the charged particle beam source can be configured as an ion beam source that provides an ion beam, and the charged particle beam can be configured as an ion beam.

[0024] The aforementioned first-state sample of the circulating charged particle beam-assisted sputtering apparatus preferably further includes: a charged particle beam guiding module configured to generate a magnetic field or apply an additional power supply along a pre-set flight path of the charged particle beam supplied to the chamber by the charged particle beam source, thereby causing the charged particle beam to travel along the pre-set flight path; and the pre-set flight path of the charged particle beam is preferably a path that is spaced apart from the surface of the substrate and parallel to or curved with the surface of the substrate.

[0025] In the above-mentioned first-state sample of the cyclic charged particle beam assisted sputtering apparatus, the charged particle beam guiding module preferably includes an electromagnet disposed on the wall of the vacuum chamber, and the electromagnet is located at the starting point or ending point of the pre-set flight path of the charged particle beam.

[0026] In the first state of the above-mentioned cyclic charged particle beam assisted sputtering apparatus, the charged particle beam guiding module preferably further includes an electrode configured as follows: the charged particle beam is positioned at the end of a pre-set flight path of the charged particle beam to guide the charged particle beam; and when the charged particle beam is an electron beam, the electrode is preferably configured as an anode, and when the charged particle beam is an ion beam, the electrode is preferably configured as a cathode.

[0027] In the above-mentioned first-state sample of the cyclic charged particle beam assisted sputtering apparatus, the control module is preferably configured to adjust the duty cycle of the first or second pulse voltage so that the period of irradiation of the charged particle beam overlaps with part or all of the period of applying the target bias voltage, thereby increasing the sputtering and evaporation speed and having the effect of electron beam substrate irradiation.

[0028] In the above-mentioned first-state sample of the cyclic charged particle beam assisted sputtering apparatus, when the charged particle beam is an ion beam, the mass of the ions constituting the ion beam is preferably greater than the mass of the gas ionized by collision.

[0029] In the above-mentioned first-state sample of the cyclic charged particle beam assisted sputtering apparatus, the frequencies of the first and second pulse voltages applied to the charged particle beam source and the target material are preferably in the range of 0.1 to 1,000 kHz.

[0030] The second embodiment of the present invention, a cyclic charged particle beam-assisted etching apparatus, is an etching apparatus comprising a gas supply module and a substrate arranged facing each other at a fixed distance within a vacuum chamber. It includes: a charged particle beam source configured to irradiate the interior of the vacuum chamber with a charged particle beam; and a control module configured to control first and second pulse voltages applied to the charged particle beam source and the substrate, respectively, thereby synchronizing and alternating the ion generation cycle and the substrate etching cycle. The etching apparatus is characterized in that: during the ion generation cycle, a pre-set charged particle beam bias voltage is applied to the charged particle beam source to irradiate the charged particle beam, generating ions through collisions between the charged particle beam and gas particles; during the substrate etching cycle, a pre-set substrate bias voltage is applied to the substrate, thereby attracting the generated ions to the substrate for collision and etching of the substrate.

[0031] In the above-mentioned second-state cyclic charged particle beam assisted etching apparatus, the charged particle beam source can be configured as an electron beam source that provides an electron beam, and the charged particle beam can be configured as an electron beam.

[0032] In the above-mentioned second-state cyclic charged particle beam assisted etching apparatus, the charged particle beam source can be configured as an ion beam source that provides an ion beam, and the charged particle beam can be configured as an ion beam.

[0033] The second-state circulating charged particle beam assisted etching apparatus described above preferably further includes: a charged particle beam guiding module configured such that a magnetic field is formed or an additional power supply is applied along a pre-set flight path of the charged particle beam supplied to the chamber by the charged particle beam source, thereby causing the charged particle beam to travel along the pre-set flight path; and the pre-set flight path of the charged particle beam is a path that is spaced from the surface of the substrate and is parallel to or forms a curvature with the surface of the substrate.

[0034] In the above-mentioned second-state cyclic charged particle beam assisted etching device, the charged particle beam guiding module preferably includes an electromagnet disposed on the wall of the vacuum chamber, and the electromagnet is located at the starting point or ending point of the pre-set flight path of the charged particle beam.

[0035] In the second state of the above-mentioned cyclic charged particle beam assisted etching apparatus, the charged particle beam guiding module preferably further includes an electrode configured as follows: the electrode is disposed at the end of a pre-set flight path of the charged particle beam to guide the charged particle beam; and when the charged particle beam is an electron beam, the electrode is preferably configured as an anode, and when the charged particle beam is an ion beam, the electrode is preferably configured as a cathode.

[0036] In the above-mentioned second-state cyclic charged particle beam assisted etching apparatus, when the charged particle beam is an ion beam, the mass of the ions constituting the ion beam is preferably greater than the mass of the gas ionized by collision.

[0037] In the above-mentioned second-state cyclic charged particle beam assisted etching apparatus, the frequencies of the first and second pulse voltages applied to the charged particle beam source and the substrate are preferably in the range of 0.1 to 1,000 kHz. [Effects of the Invention]

[0038] The cyclic charged particle beam-assisted sputtering apparatus of the present invention, having the above-described configuration, applies synchronous first and second pulse voltages alternately and cyclically to the charged particle beam source target, thereby synchronizing and alternating the ion generation cycle and the target sputtering cycle. Therefore, ions can be generated only during the ion generation cycle by collisions between the charged particle beam irradiated by the first pulse voltage and gas particles, and the target can be sputtered only during the target sputtering cycle by ion collisions caused by the second pulse voltage. As a result, even when charged particles are irradiated into the cavity space during the ion generation cycle, no substrate bias voltage is applied and the charged particles do not collide with the substrate, thus preventing damage to the substrate.

[0039] Furthermore, the circulating charged particle beam-assisted sputtering apparatus of the present invention can generate ions with low energy of 2-3 eV by irradiating the chamber with a charged particle beam and causing it to collide with the low-pressure gas present in the chamber. Therefore, even if the ions mentioned above fly towards the substrate and collide with the substrate during the ion generation cycle before the target bias is achieved, the substrate will not be damaged due to the low energy.

[0040] Furthermore, the circulating charged particle beam-assisted sputtering apparatus of the present invention can attract low-energy ions to the target by applying a target bias voltage, thereby sputtering the target with ions. In this method of target sputtering, ions only sputter the target and cannot sputter materials in the surrounding areas outside the target. Therefore, only the target material is deposited on the substrate, thus avoiding contamination from materials other than the target material during vapor deposition.

[0041] Furthermore, the cyclic charged particle beam-assisted sputtering apparatus of the present invention can precisely adjust the speed and quantity of ion sputtering of the target by adjusting the number of ions during the ion generation cycle and adjusting the target bias voltage applied during the target sputtering cycle. Therefore, the evaporation rate of the substrate can be controlled by adjusting the number of sputtered target particles. Moreover, by adjusting the number of sputtered target particles, not only can a single atomic layer be deposited on the surface of the substrate, but also a subatomic layer can be deposited.

[0042] Furthermore, the circulating charged particle beam-assisted sputtering apparatus of the present invention can apply a magnetic field along a pre-set flight path of the charged particle beam by means of a charged particle beam path guiding module. As a result, the charged particles can fly in a straight line or a curved path along the pre-set flight path. By means of various charged particle beam guiding modules as described above, the charged particle beam can be controlled during flight to avoid or toward a target material, substrate, or electrode that avoids the target material or substrate. In this case, when using an electron beam as the charged particle beam, the electrode that avoids the target material or substrate is the anode; when using the charged particle beam as an ion beam, the electrode is the cathode.

[0043] Furthermore, the circulating charged particle beam-assisted sputtering apparatus of the present invention can adjust the duty cycles of the first and second pulse voltages applied synchronously and separately to the charged particle beam source and the target. 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 in part or all of the time during target sputtering. As a result, sputtered ions can be generated additionally or continuously, thereby increasing the sputtering evaporation rate.

[0044] Furthermore, by adjusting the duty cycle of the second pulse voltage applied to the target, a time overlap with the time of irradiation of the electron beam in the charged particle beam during the application of the second pulse voltage to the target can be generated. At this time, the electron beam is compressed by the DC(-) voltage of the target and irradiates the substrate, thus heating the film surface during sputtering and evaporation. As described above, with electron beam irradiation of the film surface, the effects of electron beam irradiation of the film can be obtained simultaneously with film evaporation. The following effects of electron beam irradiation can be listed: heat treatment effect, reduction of defects in the film, increase in density, improved epitaxial growth, and improved crystallinity.

[0045] The cyclic charged particle beam assisted etching apparatus of the present invention, having the above-described configuration, applies a first pulse voltage and a second pulse voltage alternately and cyclically to the charged particle beam source and the substrate, thereby synchronizing and alternating the ion generation cycle and the substrate etching cycle. Therefore, there is no substrate bias voltage during the ion generation cycle, and a rest period for charged particle beam irradiation can be maintained during the substrate etching cycle. As a result, even if the charged particle beam irradiates the chamber during the ion generation cycle, the charged particles do not collide with the substrate, thus preventing damage to the substrate caused by the charged particles.

[0046] Furthermore, the circulating charged particle beam-assisted etching apparatus of the present invention can irradiate the cavity with a charged particle beam, causing the charged particle beam to collide with the gas particles in the cavity to generate gas particle active species and gas particle ions that will etch the substrate, thereby generating ions with low energy of 2-3 eV. Therefore, since the energy of the gas particle ions themselves is low, the substrate will not be etched or damaged by the gas particle ions during the substrate bias rest period.

[0047] Furthermore, the cyclic charged particle beam-assisted etching apparatus of the present invention can adjust the speed and amount of ion etching of the substrate by adjusting the substrate bias voltage applied during the substrate etching cycle. The energy of the newly generated ions is low and negligible, while the energy of the ions used for etching is entirely controlled by the substrate bias voltage. Therefore, the energy of the ions used for etching can be finely controlled from several volts by the bias voltage, and thus the etching depth of the substrate can be precisely adjusted by the bias voltage volts. As a result, not only can single atomic layers of the substrate be etched, but also subatomic layers can be etched.

[0048] Furthermore, the cyclic charged particle beam assisted etching apparatus of the present invention can provide a magnetic field tunnel along a pre-set flight path of the charged particle beam by means of a charged particle beam path guiding module. As a result, the charged particles can fly in a straight line or a curve along the pre-set flight path. Consequently, during the flight of the charged particle beam, it is possible to control the beam to avoid the substrate, to face the electrode (electron beam as anode, ion beam as cathode) that avoids the substrate, or to face the substrate at a low angle.

[0049] Furthermore, the cyclic charged particle beam-assisted etching apparatus of the present invention can adjust the duty cycles of the first pulse voltage and the second pulse voltage applied synchronously and separately to the charged particle beam source and the 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 a portion or all of the substrate etching period. As a result, ions for substrate etching can be additionally or continuously generated, thereby increasing the substrate etching rate. Simple Explanation of the Diagram

[0050] Figure 1 is a schematic diagram conceptually representing the structure of a previous magnetron sputtering machine. Figure 2 is a schematic diagram illustrating that even when using the cyclic charged particle beam-assisted sputtering apparatus of the first embodiment of the present invention to control the generation of ions caused by electron beam collisions in time, the secondary generated ions can still be used for target bias sputtering. Figure 3 is a waveform diagram showing the pulse bias voltage applied to the electron beam source and the target respectively during the alternating ion generation cycle P1 and target sputtering cycle P2 in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention. Figure 4 is a schematic diagram illustrating an embodiment of the first embodiment of the present invention in which a charged particle beam path guiding module 260 is installed in a cyclic charged particle beam assisted sputtering apparatus. Figure 5 is a schematic diagram of the cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, used to illustrate the electron beam flight (a) caused by electron beam irradiation and the low-energy ion generation (b) caused by collision during the ion generation cycle P1 when the charged particle beam path guiding module 260 is installed. Figure 6 is a schematic diagram of the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, used to illustrate the process of ions colliding with the target (a) and sputtered target particles being deposited on the substrate surface during the target sputtering cycle P2 (b). Figure 7 is a schematic diagram illustrating an embodiment of the first embodiment of the present invention, which is configured with a plurality of targets and can perform co-sputtering on a large substrate by moving the substrate. Figure 8 is a schematic diagram illustrating an embodiment of the first embodiment of the present invention, which is configured to perform vapor deposition using a plurality of targets. Figure 9 is a schematic diagram illustrating an embodiment of the first embodiment of the present invention, in which an electron beam is irradiated in a direction perpendicular to the length of a large target material and a large substrate is moved to perform vapor deposition on the large substrate. Figure 10 is a graph showing the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, used to illustrate the ion survival time after electron beam irradiation ends. Figure 11 is a graph showing the changes in electron / ion flux and target bias voltage duty cycle during the application of cyclic pulse bias to the electron beam source and target in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention. Figure 12 is a schematic diagram of the cyclic charged particle beam assisted sputtering apparatus according to the second embodiment of the present invention, used to illustrate the ionization process (b) caused by the collision of the ion beam (a) irradiated by the ion beam source. Figure 13 is a graph showing the evaporation rate corresponding to the target bias voltage in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention. Figure 14 is a schematic diagram of the cyclic charged particle beam assisted sputtering apparatus of the second embodiment of the present invention, used to illustrate the vapor deposition (b) process caused by the target sputtering due to the collision (a) of the generated ions with the target material. Figure 15 shows the waveforms of the pulse bias voltages applied to the ion beam source and the target during the ion generation cycle P1 and the target sputtering cycle P2, which are synchronized with and alternate with the ion beam source and the target, in the cyclic charged particle beam assisted sputtering apparatus of the second embodiment of the present invention. Figure 16 is a schematic diagram of the cyclic charged particle beam (electron beam) assisted etching apparatus according to the third embodiment of the present invention. Figure 17 shows the waveforms of the pulse bias voltages applied to the electron beam source and the substrate respectively during the alternating ion generation cycle P1 and substrate etching cycle P2 in the cyclic charged particle beam assisted etching apparatus of the third embodiment of the present invention. Figure 18 is a schematic diagram of the cyclic charged particle beam assisted etching apparatus of the third embodiment of the present invention, used to illustrate electron beam irradiation (a) and ion generation (b) during the ion generation cycle. Figure 19 is a schematic diagram of the cyclic charged particle beam assisted etching apparatus of the third embodiment of the present invention, used to illustrate the process of ion etching of the substrate during the substrate etching cycle. Figure 20 is a schematic diagram showing the pulse bias voltages applied synchronously and alternately to the ion beam source and the substrate in the cyclic charged particle beam assisted etching apparatus of the fourth embodiment of the present invention. Figure 21 is a schematic diagram of the cyclic charged particle beam assisted etching apparatus of the fourth embodiment of the present invention, used to illustrate the ionization process (b) caused by ion beam irradiation (a) and collision. Figure 22 is a schematic diagram of the cyclic charged particle beam assisted etching apparatus of the fourth embodiment of the present invention, used to illustrate the target bias (a) and substrate etching process (b). Implementation

[0051] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the cyclic charged particle beam assisted sputtering apparatus and the cyclic charged particle beam assisted etching apparatus of the present invention will be specifically described. In the present invention, the charged particle beam can be configured as either an electron beam or an ion beam. The first embodiment of the present invention is a cyclic charged particle beam assisted sputtering (CEBAS) apparatus using an electron beam, and the second embodiment is a cyclic charged particle beam assisted sputtering (CIBAS) apparatus using an ion beam. The third embodiment of the present invention is a cyclic charged particle beam assisted etching (CEBAE) apparatus using an electron beam, and the fourth embodiment is a cyclic charged particle beam assisted etching (CIBAE) apparatus using an ion beam.

[0052] [First Embodiment: Sputtering Apparatus Assisted by Circulating Charged Particle Beam Using Electron Beam]

[0053] Figure 2 is a schematic diagram of the cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention.

[0054] Referring to FIG2, the circulating charged particle beam assisted sputtering apparatus 2 of the first embodiment of the present invention includes a chamber 200, a charged particle beam source 230 connected to a first power supply 250, a target material 210 connected to a second power supply 252, a substrate 220, and a control module 240. The circulating charged particle beam assisted sputtering apparatus 2 of the first embodiment of the present invention may further include a charged particle beam path guiding module (260 in FIG3). The circulating charged particle beam assisted sputtering apparatus of the first embodiment of the present invention is characterized in that: a first pulse and a second pulse, which are synchronous and alternate, are applied to the charged particle beam source and the target material, thereby using an electron beam to generate ions for sputtering the target material; the ions collide with the biased target material to perform sputtering deposition. Hereinafter, the constituent elements of the circulating charged particle beam assisted sputtering apparatus of the first embodiment of the present invention will be specifically described.

[0055] The chamber 200 may include a vacuum chamber capable of injecting process gas into it, and may contain a target and a substrate. A charged particle beam source may be mounted on one side. The target 210 is disposed within the chamber 200 and connected to a second power supply 252. The substrate 220 may be disposed within the chamber 200 and arranged at a fixed distance from the target 210 and facing it.

[0056] A charged particle beam source 230 is disposed on one side of the chamber 200 with its outlet facing the interior of the chamber. The charged particle beam source 230 is connected to a first power supply 250. The charged particle beam source 230 is configured to allow the charged particle beam to fly parallel to the substrate 220. The charged particle beam source of the device in the first embodiment of the present invention is configured as an electron beam source and is configured to provide an electron beam to the interior of the chamber.

[0057] The control module 240 can be configured to adjust the bias voltages applied to the charged particle beam source and the target material respectively by controlling the drive of the first power supply 250 and the second power supply 252, thereby sputtering the target material and depositing target particles onto the surface of the substrate. The control module 240 applies synchronous and alternating pulse bias voltages to the charged particle beam source and the target material respectively, thereby synchronizing and alternating the ion generation cycle P1 and the target sputtering cycle P2.

[0058] The pulsed bias voltage applied to a charged particle beam source, electron beam source, or ion beam source may include a bias voltage range with a preset voltage applied and a range without applied voltage. In this specification, the voltage within the bias voltage range applied to the pulsed bias voltage may be referred to as "charged particle beam source bias voltage," "electron beam source bias voltage," and "ion beam source bias voltage," respectively. Similarly, the pulsed bias voltage applied to a target material may also include a bias voltage range with a preset voltage applied and a range without applied voltage. In this specification, the voltage within the bias voltage range applied to the pulsed bias voltage may be referred to as "target bias voltage," and this pulsed bias voltage is applied to the target material.

[0059] In the first embodiment of the present invention, a cyclic charged particle beam-assisted sputtering apparatus applies a bias voltage to an electron beam source during an ion generation cycle P1, thereby injecting an electron beam into a cavity where it collides with gas particles and generates ions. Additionally, during a target sputtering cycle P2, a bias voltage is applied to the target, causing ions generated during the ion generation cycle P1 by the electron beam to collide with the target and sputter it. The sputtered target particles are deposited onto the surface of a substrate.

[0060] The following describes in more detail the ion generation mechanism and target sputtering mechanism in the cyclic charged particle beam assisted sputtering apparatus of the present invention.

[0061] Typically, for ion sputtering targets to be deposited, ions with mass and energy must collide with the target. In this patent, to reduce substrate damage caused by plasma, the concept of generating sputtering ions using an electron beam is realized. Therefore, the sputtering apparatus of the first embodiment of this invention can inject an electron beam into a chamber containing process gas during the ion generation cycle, causing the electron beam to collide with gas particles within the chamber, thereby generating energetic ions through the collision of the electron beam with the gas particles. The electron beam source of the sputtering apparatus of this invention can use hot electrons emitted from the surface of a tungsten filament after heating, or cold electrons extracted from the plasma generated in the chamber inside the source using various grids.

[0062] As shown in Figure 2, electrons supplied by an electron beam source possess energy and fly between the target and the substrate. During their flight, the electrons collide with the gas injected into the chamber, ionizing the gas particles. As described above, the collision between the flying electron beam and the gas can ionize the gas particles at a low pressure of approximately 10⁻⁵ to 10⁻⁴ torr. In contrast, previous sputtering apparatuses generate ions within a high-density plasma at a pressure of approximately 10³ torr, resulting in ions with extremely high energy. In comparison, the device of this invention has low pressure and low ion charge density; therefore, the ions generated by the collision with the electron beam have extremely low energy of approximately 2 to 3 eV. Typically, in order to damage one atomic layer of the substrate through ion collisions, the ion energy must be above 30 to 50 eV. Therefore, in the sputtering apparatus of the present invention, even if ions with extremely low energy of about 2 to 3 eV generated by electron beam collision fly toward the substrate and collide with the substrate, the energy is so small that it will hardly cause any damage to the substrate.

[0063] In the sputtering apparatus of the first embodiment of the present invention, during the target sputtering cycle, an electrical bias voltage of opposite polarity to the ions is applied to the target while ions are generated on the front side of the target in the chamber. Therefore, the ions are attracted to the target and collide with it. At this time, when the ions possess sufficient energy for sputtering due to the bias voltage of the target, the target particles can be sputtered through the collision between the target and the ions. As a result, the sputtered target particles are deposited onto the substrate.

[0064] Typically, inert gas particles used for sputtering are Ar, Ne, Kr, Xe, etc., which become cations with a positive charge upon collision with electrons. Therefore, in the sputtering apparatus of this invention, a negative potential is applied during the target sputtering cycle to attract ions to the target. For sputtering as described above, the negative potential applied to the target generates a repulsive force against electrons flying parallel to the surfaces of the target and substrate. Electron beams flying parallel to the substrate surface may have their flight paths bent and fly towards the substrate due to the repulsive force from the target bias voltage, thereby colliding with the substrate. As a result, the substrate may be damaged by the collision with the electron beam, or the surface of the substrate may heat up due to the collision with the electron beam.

[0065] To address this problem, the cyclic charged particle beam-assisted sputtering apparatus of the present invention adjusts the power applied to the electron beam source during the target sputtering cycle to generate an electron beam rest period, during which a negative potential is applied to the target. With this power application, no electrons are present inside the cavity P2 of the target sputtering cycle, and therefore no electrons will fly towards the substrate due to the negative potential of the target. As described above, the cyclic charged particle beam-assisted sputtering apparatus of the present invention, because the target sputtering cycle is in the electron beam rest period, prevents collisions between the substrate and electrons, thus avoiding damage to the substrate.

[0066] Figure 3 shows the waveforms of the pulse bias voltages applied to the charged particle beam source and the target respectively during the alternating ion generation cycle P1 and target sputtering cycle P2 in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention.

[0067] Referring to Figure 3, a negative bias voltage is applied to the charged particle beam source during the ion generation cycle P1, while the target maintains a ground bias voltage. This bias voltage causes the charged particle beam source to generate an electron beam that irradiates the cavity, causing gas particles within the cavity to collide with the electron beam, thus generating ions. Conversely, a negative bias voltage is applied to the target during the target sputtering cycle P2, while the charged particle beam source maintains a ground bias voltage. This bias voltage causes ions to be attracted to the target and collide with it, sputtering the target. The sputtered target particles are then deposited onto the surface of the substrate. As described above, by synchronizing and alternately applying pulsed bias voltages to the charged particle beam source and the target, the ion generation cycle P1 and the target sputtering cycle P2 are synchronized and alternately performed.

[0068] In this invention, the process of repeatedly performing ion generation cycle P1 and target sputtering cycle P2 for sputtering and evaporation is called "Cyclic Electron Beam Assist Sputtering" (CEBAS). CEBAS of this invention optimizes the frequency of the pulse bias voltage simultaneously applied to the charged particle beam source and the target, thereby not only increasing the ion yield for sputtering but also enabling sputtering and evaporation without damaging the substrate.

[0069] The sputtering apparatus of the present invention may further include a charged particle beam path guiding module 260. Figure 4 is a schematic diagram showing an embodiment of the first embodiment of the present invention in which the charged particle beam path guiding module 260 is installed in a circulating charged particle beam assisted sputtering apparatus.

[0070] During flight, electron beams repel each other due to the space charge effect. This repulsion can cause electrons to deviate from their predetermined flight path. In the sputtering apparatus of this invention, the electron beam irradiates the substrate and target in a manner that is parallel to them. However, the phenomenon that electrons may deviate from their path due to the aforementioned space charge effect and fly towards the substrate and target is possible. The charged particle beam path guiding module 260 is configured to guide the electron beam to fly in a direction parallel to the substrate and target, thereby preventing the electron beam from deviating from its predetermined flight path.

[0071] Referring to Figure 4, the charged particle beam path guiding module 260 may include an electromagnet 262 wound with a toroidal electromagnet coil (Helmholtz coil). Furthermore, the electromagnets of the charged particle beam path guiding module 260 can be respectively positioned at the start and end points of a pre-defined electron beam flight path. The electron beam flight path can be set as a path parallel to the surface of the substrate, separated by a fixed interval, or as a path parallel to the surfaces of the substrate and the target, separated by a fixed interval. Here, the start point of the electron beam flight path can be the exit of the electron beam source, and the end point of the electron beam flight path can be the opposite side wall of the chamber facing the exit of the electron beam source. Therefore, the electromagnets positioned at the start and end points of the electron beam flight path can form a magnetic field tunnel along the pre-defined electron beam flight path. An energetic electron beam irradiated by an electron beam source can be guided in the following way: by the magnetic field tunnel formed by the electromagnet of the charged particle beam path guiding module, the electron beam cannot deviate from the horizontal direction during its flight.

[0072] On the other hand, the charged particle beam path guiding module 260 may have an anode 264 on the wall of the chamber where the electron beam arrives along a pre-set electron beam flight path. Applying a (+) potential to the anode attracts the electron beam flying in the chamber, thereby helping the electron beam to fly in a straight line along the pre-set flight path.

[0073] On the other hand, the charged particle beam path guiding module can be configured together with the bias electrode, floating electrode, or electromagnet module to guide the flight path in a straight line or curve. This helps the charged particle beam fly along a pre-set flight path to avoid the substrate or target material or to approach the substrate or target material.

[0074] Figure 5 is a schematic diagram of the cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, illustrating the movement of electrons during the ion generation cycle P1 when the charged particle beam path guiding module 260 is installed. Figure 5(a) illustratively shows the path of the electron beam through the charged particle beam path guiding module. Figure 5(b) illustratively shows the generation of ions by collisions between electrons and gas particles during the flight path of the electron beam. Referring to Figure 5, during the ion generation cycle, the electron beam irradiated from the electron beam source collides with gas particles during its flight to generate ions with an energy of approximately 2-3 eV.

[0075] During the ion generation cycle, while the charged particle beam path guiding module 260 forms a magnetic field tunnel along a pre-set electron beam flight path, a negative bias voltage is applied to the electron beam source and the target is grounded. As a result, during the ion generation cycle, the electron beam is able to carry energy and be emitted, the target no longer exerts a repulsive force on the electrons, and the electrons can fly in a straight line along the path formed by the magnetic field tunnel.

[0076] Figure 6 is a schematic diagram of the cyclic charged particle beam-assisted sputtering apparatus according to the first embodiment of the present invention, illustrating the process of ion sputtering of the target and the sputtering deposition of target particles onto the substrate surface during the target sputtering cycle P2. Figure 6(a) illustratively illustrates the process of ions being attracted to the target by the attraction of the target bias voltage and sputtering the target. Figure 6(b) illustratively illustrates the process of target particles being sputtered due to collisions between ions and the target, and the sputtered target particles being deposited onto the substrate. Referring to Figure 6, during the target sputtering cycle synchronized with the ion generation cycle, if a (-) bias voltage is applied to the target, ions will sputter the target, and the sputtered target particles will be deposited onto the substrate surface.

[0077] During the target sputtering cycle P2, since no voltage is applied to the electron beam source, the electron beam irradiation is stopped. In contrast, the electron beam irradiated during the ion generation cycle is too fast and disappears instantaneously in the anode direction. Ions generated by electron beam collisions during the ion generation cycle have weight and lower energy, resulting in slower flight speeds and thus remaining in the cavity. In this state, if a (-) bias voltage of tens to thousands of volts is applied to the target, the bias voltage will exert an attractive force on the (+) ions remaining in the cavity. Attracted by the target bias voltage, the (+) ions are drawn to the target and collide with it, resulting in the sputtering of target particles. Additionally, the target particles sputtered by ions are deposited onto the surface of the substrate.

[0078] On the other hand, previous ion beam sputtering (IBD) apparatuses irradiate a target with a high-energy ion beam from plasma and sputter the target, with the sputtered target particles evaporating onto the substrate. In these previous ion beam sputtering apparatuses, during ion beam irradiation, the ion charges generate a repulsive force due to the space charge effect, causing the ion beam to diffuse. As a result, the ion beam collides not only with the target but also with the surrounding area of ​​the target, resulting in the sputtering of both the target and other materials. Therefore, previous ion beam sputtering apparatuses may cause the following problem: because materials other than the target material are also deposited onto the substrate, it can lead to substrate contamination. In contrast, the charged particle beam-assisted sputtering apparatus of the present invention is configured such that ions are attracted to the target by applying a power source to the target, thereby sputtering only the target. Therefore, the sputtering apparatus of the present invention can perform contamination-free sputtering and evaporation on the substrate by sputtering only the target material, without being contaminated by substances other than the target material.

[0079] Therefore, the charged particle beam-assisted sputtering apparatus of the present invention can perform sputtering and evaporation without substrate damage or contamination.

[0080] On the other hand, the charged particle beam-assisted sputtering apparatus of the present invention can control the sputtering rate by adjusting the pressure conditions inside the chamber. Furthermore, by controlling this sputtering rate, the charged particle beam-assisted sputtering apparatus of the present invention can perform atomic-level sputtering. The mechanism of this operation will be explained in more detail below.

[0081] Conventional sputtering apparatuses require the generation of plasma for sputtering, typically performed at pressures above approximately 10⁻³ torr. However, the charged particle beam-assisted sputtering apparatus of this invention generates sputtering ions by irradiating gas particles with an electron beam; this method can also be implemented at pressures in the range of approximately 10⁻⁴ to 10⁻¹⁰ torr. As described above, the method of generating ions by electron beam collisions in the apparatus of this invention can be performed under high vacuum, and the method of sputtering by colliding the generated ions with the target material can also be performed under high vacuum.

[0082] As the vacuum level increases, the number of gas particles inside the chamber decreases dramatically by different orders of magnitude. Therefore, as described in this invention, when an electron beam is irradiated into a high-vacuum chamber to ionize gas particles, the number of ions generated by collisions between the electron beam and the gas particles also decreases. As the number of sputtered ions decreases, the number of sputtered target particles due to collisions with ions also decreases. As a result, the number of sputtered target particles decreases, and the rate at which sputtered target particles evaporate onto the substrate also decreases. As mentioned above, by maintaining a high vacuum pressure inside the chamber, the sputtering rate of target particles can also be significantly reduced. Therefore, the charged particle beam-assisted sputtering apparatus of this invention can control not only single-atom-layer evaporation but also subatomic-layer evaporation by setting the chamber pressure to a high vacuum.

[0083] On the other hand, conventional sputtering apparatuses inject high-density process gases into the chamber, allowing these gases to easily adsorb onto the substrate surface around the adsorbed atoms. Therefore, conventional sputtering apparatuses suffer from the following problem: subsequent deposited atoms cannot connect to the adsorbed atoms, leading to partial accumulation of these atoms and the formation of island growth. However, the charged particle beam-assisted sputtering apparatus of this invention can perform excellent thin film deposition under high vacuum conditions. By eliminating the interference caused by process gas adsorption through thin film deposition under high vacuum conditions, a dense and compact atomic layer can be filled during deposition. Therefore, the charged particle beam-assisted sputtering apparatus of this invention, by performing thin film deposition under high vacuum conditions, can achieve atomic layer deposition, two-dimensional layer deposition, dense deposition, and atomically smooth deposition.

[0084] As described above, the charged particle beam-assisted sputtering apparatus of the present invention can utilize high-vacuum evaporation, allowing for control not only at lower evaporation rates but also at the layer size. With these evaporation characteristics, the charged particle beam-assisted sputtering apparatus of the present invention can be used for evaporation of materials such as nanoscale semiconductors, metal connection lines, ultra-thin barriers, low-resistivity contacts, high-power laser diodes, and EUV mirror masks. Furthermore, the charged particle beam-assisted sputtering apparatus of the present invention, with the aforementioned evaporation characteristics, can be applied to fields requiring atomic-level evaporation, such as spintronics, photonics devices, thermoelectric materials, quantum computing, electronic devices, solar cells, and superlattices.

[0085] Furthermore, the charged particle beam-assisted sputtering apparatus of the present invention can perform sputtering as follows: even when an electron beam is irradiated onto a target, ions generated by the collision of the electron beam and gas particles are attracted to the target during the target sputtering cycle. Also, in the charged particle beam-assisted sputtering apparatus of the present invention, even when the electron beam is not directed towards the target but flies parallel to it, ions generated by the collision of the electron beam and gas particles are attracted to the target during the target sputtering cycle, thus performing sputtering.

[0086] Furthermore, the charged particle beam-assisted sputtering apparatus of the present invention can arrange a plurality of targets along a pre-set flight direction of the electron beam. These plurality of targets can be arranged along the periphery of a pre-set flight space of the electron beam, or sequentially arranged along the pre-set flight direction of the electron beam. In this case, the plurality of targets can include different materials, and the bias voltage applied to each target can be controlled, thereby allowing different plurality of materials to be deposited onto the substrate, or allowing the plurality of targets to be deposited onto the substrate simultaneously. Figure 7 is a schematic diagram showing an embodiment of the first embodiment of the circulating charged particle beam-assisted sputtering apparatus of the present invention with a plurality of targets arranged. Referring to Figure 7, different plurality of targets (targets A, B, and C) can be arranged around the pre-set flight space of the electron beam.

[0087] Figure 8 is a schematic diagram illustrating an embodiment of the circulating charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, which is configured to perform vapor deposition using a plurality of targets. As shown in Figure 8, CEBAS multilayer vapor deposition or co-sputtering vapor deposition is performed using a plurality of various targets.

[0088] Figure 9 is a schematic diagram illustrating an embodiment of the first embodiment of the present invention, in which a large substrate can be moved to perform vapor deposition on the large substrate. Referring to Figure 9, an electron beam perpendicular to the length direction of a large linear target can be irradiated, thereby generating ions in front of the target. These ions can then collide with the biased target during sputtering. At this time, as shown in Figure 9, the substrate can be moved along a direction perpendicular to the length direction of the linear target to perform vapor deposition.

[0089] Furthermore, in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, the electron beam can be directly irradiated from behind the target material via the side of the target material or irradiated to the front of the target material in a manner that forms a curvature, thereby performing sputtering and evaporation by ion generated by electron beam irradiation and configuring multiple targets to sequentially perform multilayer evaporation or simultaneously evaporate multiple targets.

[0090] The frequency of the pulse bias voltage applied to the electron beam source and the target during the ion generation cycle and the target sputtering cycle in the cyclic charged particle beam assisted sputtering apparatus of the present invention will be described below.

[0091] Figure 10 is a graph illustrating the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, used to explain the ion survival period. In Figure 10, the electron beam bias (EB Bias) is the bias voltage applied to the electron beam source, the target bias (Target Bias) is the bias voltage applied to the target, and t is the ion survival time.

[0092] The first embodiment of the present invention provides a cyclic charged particle beam-assisted sputtering apparatus that alternately applies bias voltages to the electron beam source and the target, and synchronizes their cycles. Therefore, as shown in FIG10, the target bias voltage is applied synchronously with the end of the electron beam bias voltage, thereby initiating the target bias voltage during the ion generation and survival time (i.e., the ion survival time). The target bias voltage exerts an attractive force on the ions, which are attracted to the target and collide with it. In the sputtering apparatus of the present invention, the electron beam bias voltage and the target bias voltage are applied synchronously and alternately to the electron beam source and the target. Referring to FIG10, during the ion generation cycle P1, the electron beam is irradiated by the electron beam bias voltage to generate ions, which exist during the ion survival time. During the target sputtering cycle P2, the ions survive under the target bias voltage and are sputtered onto the target.

[0093] Under specific conditions where pressure exists due to gas in a vacuum, ions generated by electron collisions exist in ionic form for a fixed period of time before colliding with other particles and becoming neutralized. The ion survival time (t) refers to the time from ion generation to neutralization. As shown in Figure 10, if the ion survival time is 1 / 4 of a 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. Hereinafter, the method for setting the bias frequency in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention will be described.

[0094] The time required to neutralize Ar ions generated by electron collisions can be defined as the ion survival time (t), which is an order of magnitude lower than the working pressure typically used in sputtering equipment, i.e., P = 2 × 10⁻⁴ torr. This is based on the premise that the ions are neutralized and disappear after their first collision with other gas particles during flight at this pressure. The neutralization time t can be calculated as follows: Here, the collision cross-sectional area of ​​Ar atoms is σ = 0.36 / nm².

[0095] First, the gas density (n) can be calculated according to the following formula 1.

[0096] [Formula 1]

[0097] Here, P = 2 × torr = 2.67 × 10⁻² Pa, T = 300 K. =1.38×10-23 J / K (Boltzmann constant).

[0098] Secondly, the mean free path (λ: the average flight distance between gas particles) can be calculated according to the following formula 2.

[0099] [Formula 2]

[0100] Here, σ = 0.36 / nm2 = 0.36 × 10-18 m2.

[0101] Secondly, the average velocity of ions It can be calculated using the following formula 3.

[0102] [Formula 3]

[0103] Here, m represents the mass of the Ar ion, m = 6.63 × 10⁻²⁷ kg.

[0104] Next, the ion survival time (t), which is the time required for ion neutralization, can be calculated according to the following formula 4.

[0105] [Formula 4]

[0106] In the case shown in Figure 10, if the ion survival time t occurs within 1 / 4 of a period, the frequency is as follows. f = 1 / (4 × t) ≈ 10⁴ / s = 10 kHz

[0107] It can be as follows: Under the pressure of the vacuum chamber, i.e., P=2×10-4 torr, in order to be used efficiently for sputtering collisions before the Ar ions generated by the electron beam collisions are neutralized, the frequencies applied to the electron beam source and the target material must be alternately applied.

[0108] The frequency f is directly proportional to the gas pressure. Therefore, if the gas pressure in the vacuum is 4 times that before, i.e., P = 8 × 10⁻⁴ torr, then the frequency f is as follows. f = 10 kHz × 4 = 40 kHz

[0109] If the gas pressure in the vacuum is 10 times that before, i.e., P = 2 × 10⁻³ torr, then the frequency f is as follows. f = 10 kHz × 10 = 100 kHz

[0110] The time required for ion neutralization, calculated using the above method, i.e., the ion survival time, is based on the premise that the ion is neutralized at the first collision while traveling along the mean free path and colliding with other particles. However, if the ion fails to neutralize after a single collision with another ion, the ion neutralization time may increase by more than two times. Therefore, in the case of twice the time, i.e., at P = 2 × 10⁻⁴ torr, f = 5 kHz, and at P = 4 × 10⁻³ torr, f = 100 kHz.

[0111] Therefore, in the cyclic charged particle beam-assisted sputtering apparatus of the first embodiment of the present invention, it is known that the frequency of the cyclic pulse power in the range of 1 to 100 kHz is effectively used for damage-free thin film sputtering. Here, when the frequency of the cyclic pulse power is broadly set to include a pressure range of 10⁻⁵ to 10⁻² torr, a frequency range of 0.1 to 1000 kHz can be set.

[0112] Figure 11 is a graph showing the changes in electron / ion flux and the duty cycle of the target bias voltage during the application of cyclic pulse bias voltage to the electron beam source and the target in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention. In Figure 11, the cyclic pulse bias voltage is synchronized to the electron beam source and the target, and a set voltage (black) is applied. When the gas particles in the chamber are subjected to the pressure applied to the CEBAS device, a current will exist in the bias voltage applied by the power supply. Therefore, due to the electrical delay of the power supply, the real voltage (red) of the EB source differs from the set voltage. When the real voltage is applied to the EB source, the electron beam can have the energy of the real voltage and irradiate from the electron beam source. The electron beam flux is proportional to the electron beam energy, so the electron beam flux is expected to have the same waveform as the real voltage.

[0113] In Figure 11(a), the pulse bias voltages applied to the electron beam source and the target are set to be synchronized and alternate, and the start and end points of the electron beam bias voltage and the target bias voltage are set to coincide. In Figure 11(b), the pulse bias voltages applied to the electron beam source and the target are set to be synchronized and alternate, and the duty cycle of the target bias voltage is adjusted so that a portion of the start point of the target bias voltage overlaps with the electron beam bias voltage. In Figure 11(c), the pulse bias voltages applied to the electron beam source and the target are set to be synchronized and alternate, and the duty cycle of the target bias voltage is adjusted so that the target bias voltage is continuously applied to approximately 100%.

[0114] On the other hand, before the ions generated by electron collisions neutralize and disappear, a delay proportional to the mean free path of flight occurs. Therefore, the ion flux, as a form delayed compared to the electron flux, can be displayed as a waveform extending from the ion generation cycle P1 to the next half-cycle, i.e., the target sputtering cycle P2. During the ion generation cycle, the ionized gas ion flux continuously exists until the target sputtering cycle and plays a crucial role. When electrons disappear and only ions remain, the target bias voltage applied to the target attracts the surviving ions to the target through strong attraction. Ions carrying the energy of the target bias voltage collide with the target, sputtering the target particles onto the substrate. Ions generated by electron collisions have extremely low energy of only a few eV. Furthermore, due to the target bias voltage, ions with low energy only fly towards the target; therefore, ions only sputter the target, without concern about sputtering other materials around the target. Therefore, the sputtering apparatus of the present invention can deposit excellent thin films without damage or pollution.

[0115] On the other hand, in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, when the pulse bias is synchronously applied to the electron beam source and the target, the duty cycle of the pulse bias applied to the target can be changed.

[0116] Referring to Figures 11(b) and (c), if the duty cycle of the pulse bias voltage applied to the target is changed to increase the target bias time, the target bias voltage is also applied during the ion generation cycle of the electron beam flight. In this case, the larger the duty cycle of the target pulse bias voltage, the longer the target bias voltage is applied during the ion generation cycle. Therefore, when the target bias voltage is applied during electron beam flight, the electron beam will be repelled by the target bias voltage and fly towards the substrate, colliding with it. This produces the effect of electron beam irradiation of the substrate. As a result, as the substrate temperature rises, a heat treatment effect on the vapor-deposited material on the substrate can be expected. In summary, by increasing the duty cycle of the target bias voltage within the CEBAS, an electron beam irradiation effect can be achieved on the substrate.

[0117] As described above, by increasing the duty cycle of the target pulse bias by changing the start or end point of the synchronized target bias, the following effects can be achieved. As shown in Figure 11, if the duty cycle of the target pulse bias is increased, the application time of the target bias overlaps with the application time of the electron beam bias, thereby increasing the amount of ion flux attracted to the target. Therefore, sputtering caused by ion collisions increases, resulting in an increased evaporation rate.

[0118] Furthermore, if the duty cycle of the target's pulse bias voltage is increased, a target bias voltage will be applied during the application of the electron beam bias voltage. As a result, as electrons are pushed towards the substrate by the repulsive force of the target bias voltage, the amount of electron-substrate collisions may gradually increase. During sputtering and evaporation on the substrate, the increased electron collisions not only neutralize the build-up of ionic charges that can be generated on the surface of the evaporated film, but also induce a heating effect in the evaporated film caused by electron collisions.

[0119] As shown in Figure 11(c), in the cyclic charged particle beam assisted sputtering apparatus of the first embodiment of the present invention, by adjusting the duty cycle of the target pulse bias, the target bias can be continuously applied to approximately 100% during the application of the electron beam bias. As described above, with the continuous application of the target bias, not only are all ions generated during the ion generation cycle continuously sputtered onto the target, but electrons provided by the electron beam source also face the substrate. As a result, the evaporation rate can be increased by increasing the collision between the target and ions, and the substrate is heated by electron irradiation during the pulse cycle.

[0120] On the other hand, contrary to the curve shown in Figure 11, by adjusting the duty cycle of the pulse bias voltage of the electron beam source, a pulse bias voltage can be applied to the target material simultaneously with the application of the electron beam bias voltage. This adjustment of the duty cycle of the electron beam source's pulse bias voltage also assists the electron beam during the target sputtering cycle. As described above, when the electron beam is irradiated almost continuously in the manner shown in Figure 11(c) by adjusting the duty cycle of the electron beam source's pulse bias voltage, ion generation can be maximized to increase the evaporation rate.

[0121] The duty cycle variation described above, where the electron beam irradiation time overlaps with the target bias time, can also be applied sequentially. That is, initially, as shown in Figure 11(a), the duty cycle is maintained to prevent the electron beam from impacting the substrate, and damage-free evaporation is performed within a fixed time, thereby depositing a thin film of 10-20 nm or a fixed thickness. This initial thin film is deposited at a thickness that prevents damage that could occur in subsequent evaporation. After the initial evaporation, as shown in Figure 11(b) or (c), the duty cycle can be adjusted to deposit subsequent thin films. During the subsequent thin film evaporation, additional effects due to electron beam irradiation can be expected. Here, the effects due to electron beam irradiation can include heat treatment effects, reduction of defects in the thin film, increased density, improved epitaxial growth, and improved crystallinity.

[0122] Figure 12 is a graph showing the deposition rate measured in the cyclic charged particle beam assisted sputtering apparatus according to the first embodiment of the present invention, corresponding to the target bias voltage. The graph in Figure 12 is as follows: the charged particle beam source includes a linear electron beam, the target material is linear ITO, and the apparatus is configured as shown in Figure 10. Furthermore, the conditions at this time are as follows: TS distance is 230 mm, electron beam ICP RF power is 600 W, electron beam DC bias is -500 V, anode DC bias is +50 V, and synchronized bias frequency is 80 kHz.

[0123] <Second Embodiment: Sputtering Apparatus Assisted by Circulating Charged Particle Beams of Ion Beams>

[0124] The following describes in detail the second embodiment of the circulating charged particle beam-assisted sputtering apparatus and method of the present invention. The second embodiment of the circulating charged particle beam-assisted sputtering apparatus of the present invention is characterized in that: the charged particle beam is configured as an ion beam, and the ion beam is used to generate ions for the sputtering target.

[0125] Therefore, the configuration of the circulating charged particle beam-assisted sputtering apparatus in the second embodiment of the present invention is the same as that in the first embodiment, but there is a difference in that the charged particle beam source is configured as an ion beam source. In order to generate ions for sputtering, an electron beam is used in the first embodiment, and an ion beam is used in this embodiment.

[0126] Figure 13 is a schematic diagram of the cyclic charged particle beam-assisted sputtering apparatus according to the second embodiment of the present invention, illustrating the ionization process (b) caused by collisions of the ion beam irradiated by the ion beam source. Referring to Figure 13(a), as a bias voltage is applied to the ion beam source during the ion generation cycle P1, the ion beam with (+) bias voltage energy irradiates the chamber from the ion beam source and flies parallel to the target and substrate. Referring to Figure 13(b), during the flight of the ion beam within the chamber, it can collide with gas particles in the chamber, causing the gas particles to ionize.

[0127] Figure 14 is a schematic diagram of the cyclic charged particle beam-assisted sputtering apparatus according to the second embodiment of the present invention, illustrating the target sputtering process caused by the collision of generated ions with the target. Referring to Figure 14(a), as a bias voltage is applied to the target during the target sputtering cycle, newly generated ions due to the collision of the ion beam with gas particles are attracted to the target. Unlike the previously irradiated ions, the newly generated ions can be considered as ions with energies as low as a few eV. Referring to Figure 14(b), the ions attracted to the target can sputter the target, and the sputtered target particles are deposited on the substrate surface.

[0128] An Ar(+) ion beam, originating from one side of the chamber housing the ion beam source, must travel at a speed exceeding the Ar ionization energy required to ionize Ar gas particles within the chamber. Since the Ar ionization energy is 15.7 eV, and 1 eV of an Ar ion is 17.2 mach, the irradiated Ar(+) ion beam must reach a speed exceeding approximately 270 mach. This speed is significantly faster than the ionization speed of Ar gas atoms within the chamber (1,260 m / s), approximately 69 times faster. Therefore, even with cyclically applied pulse bias voltages to the ion beam source and target, the ions emitted from the ion beam source cannot affect the sputtering of the target; instead, newly generated ions from collisions are used for sputtering under target bias. Thus, an ion beam irradiated from the ion beam source with an energy exceeding tens of eV, sufficient to ionize gas particles through collisions, is highly effective.

[0129] Figure 15 is a graph showing the pulse bias voltages applied synchronously and alternately to the ion beam source and the target in the cyclic charged particle beam assisted sputtering apparatus of the second embodiment of the present invention. Referring to Figure 15, the sputtering apparatus of the second embodiment of the present invention alternately applies pulses to the (+) bias voltage applied to the ion beam source and the (-) bias voltage applied to the target to perform sputtering, thus enabling cyclic ion beam assisted sputtering (hereinafter referred to as "CIBAS").

[0130] The sputtering apparatus of this embodiment also includes a charged particle beam path guiding module, which enables the ion beam to form a magnetic field tunnel along a pre-set flight path, thereby preventing the ion beam from colliding with the target and substrate during flight. The configuration of the charged particle beam path guiding module is similar to that of the charged particle beam path guiding module in the first embodiment.

[0131] The charged particle beam path guiding module may include an electromagnet wound with a Helmholtz coil. Furthermore, the electromagnets of the charged particle beam path guiding module can be respectively positioned at the start and end points of a pre-defined ion beam flight path. The ion beam flight path can be configured as a path parallel to the surface of the substrate, spaced at a fixed interval, or as a path parallel to the surfaces of the substrate and the target, spaced at a fixed interval. Here, the start point of the ion beam flight path can be the exit of the ion beam source, and the end point of the ion beam flight path can be the opposite side wall of the chamber facing the exit of the ion beam source. Therefore, the electromagnets positioned at the start and end points of the ion beam flight path can form a magnetic field tunnel along the pre-defined ion beam flight path. The ion beam, possessing energy irradiated by the ion beam source, can be guided in such a way that the magnetic field tunnel formed by the electromagnets of the charged particle beam path guiding module cannot deviate from the horizontal direction during ion beam flight.

[0132] Referring to Figure 15, during the ion generation cycle P1, while the charged particle beam path guiding module forms a magnetic field tunnel along a pre-set ion beam flight path, a (+) bias voltage is applied to the ion beam source and the target is grounded. As a result, during the ion generation cycle, the ion beam can carry energy and be emitted, the target no longer repels the ion generation, and the ion beam can fly in a straight line along the path formed by the magnetic field tunnel. Furthermore, during the target sputtering cycle P2, while ions are generated on the front side of the target in the chamber, an electrical bias voltage of opposite polarity to the ions is applied to the target. Therefore, the ions are attracted to the target and collide with it. At this time, when the ions have sufficient energy for sputtering due to the target bias voltage, the target particles can be sputtered through the collision between the target and the ions. As a result, the sputtered target particles are deposited onto the substrate.

[0133] On the other hand, the charged particle beam path guiding module can have a cathode on the wall of the chamber where the ion beam arrives along a pre-set ion beam flight path. Applying a negative potential to the cathode attracts the ion beam flying in the chamber, thereby helping the ion beam to fly in a straight line along the pre-set flight path.

[0134] Since the mass of an ion beam is greater than that of an electron, the magnetic field generated by the electromagnet must be stronger than that in the first embodiment, which includes an electron beam, to guide the ion beam to fly parallel. When the ion beam energy is weak, the space charge effect causes the ions to gradually diffuse and fly due to the repulsive force between their (+) charges. Therefore, when the ion beam energy is weak, the magnetic field tunnel formed by the charged particle beam path guiding module can suppress the diffusion of the ion beam due to the space charge effect. On the other hand, when the ion beam intensity is strong, the linear motion of the ion beam is greater, and linear flight is dominant. Therefore, even without a magnetic field tunnel, the ion beam can still fly sufficiently parallel.

[0135] On the other hand, previous ion beam sputtering (IBD) devices directly sputtered and evaporated the target material by colliding the ion beam with it. The evaporation pressure of previous IBD devices was approximately 10E-4 torr, thus enabling the formation of fine evaporated films. However, since IBD sputters by irradiating the target material with an energetic ion beam, ions backscattered from the target material while being deposited onto the substrate collide with the substrate. Because these ions possess energy, they can damage the substrate. Furthermore, during the ion beam's journey towards the target, due to the space charge effect of the ions, the beam impacts not only the target but also areas outside the target. Therefore, contamination of the substrate film occurs because substances other than the target material are sputtered and evaporated onto the substrate.

[0136] As described above, the CIBAS (Cyclic Ion Beam Assist Sputtering) of the second embodiment of the present invention uses a method of applying a bias voltage to the target so that the ion beam collides with the gas in the chamber instead of directly impacting the substrate, thereby allowing additional guided ions to impact the target. The key feature is that pulsed bias voltages are applied alternately to the ion beam source and the target. Furthermore, the CIBAS of the second embodiment of the present invention overcomes the following drawbacks of previous IBDs: damage caused by backscattered ion particles colliding with the substrate, and contamination outside the sputtered and evaporated target.

[0137] Furthermore, when the mass of the irradiated ions in CIBAS is greater than the mass of the gas ionized by collisions, even after the irradiated ions collide with gas particles, the incident ion beam does not produce backscattering. Therefore, the energetic ion beam will not fly towards the substrate and cause damage. Thus, in inert gases such as He, Ne, Ar, Kr, and Xe, the heavier the irradiated gas and the lighter the ionized gas, the more favorable it is for generating damage-free thin films.

[0138] The CIBAS (Cyclic Ion Beam Assist Sputtering) of the second embodiment of the present invention has similar effects to the CEBAS of the first embodiment described above.

[0139] The circulating charged particle beam assisted sputtering apparatus of the first and second embodiments of the present invention applies a pulsed bias voltage to the target to attract ions to the target, thereby causing sputtering collisions between the ions and the target. Therefore, by adjusting the pulsed bias voltage of the target, the energy and flux of the ions colliding with the target can be significantly reduced. As a result, compared with the previous IBD method, the circulating charged particle beam assisted sputtering apparatus of the first and second embodiments of the present invention can precisely control the thickness of thin films in the nanometer, angstrom, or sub-angstrom range.

[0140] Even with target back plate cooling, previous IBD methods could not avoid target surface heating due to ion beam impacts. As the target temperature rises, the sputtering rate varies. Therefore, in multi-layer applications requiring long deposition times, the deposition rate of previous IBD methods varies over time, making it difficult to generate accurate and reproducible multilayers. However, unlike previous IBD methods, the circulating charged particle beam-assisted sputtering apparatus of the first and second embodiments of this invention reduces the ion flux of the sputtering target, thus enabling accurate and reproducible multilayers.

[0141] <Embodiment 3: Etching Device Assisted by Circulating Charged Particle Beam Using Electron Beams>

[0142] The following describes in detail the circulating charged particle beam-assisted etching apparatus and method according to the third embodiment of the present invention. The circulating charged particle beam-assisted etching apparatus of the third embodiment of the present invention is the same as the circulating charged particle beam-assisted sputtering apparatus of the first embodiment of the present invention, characterized in that: synchronous and alternating pulse bias voltages are applied to the charged particle beam source and the substrate, thereby using ions generated by collisions with the charged particle beam to etch the substrate. The bias voltage of the circulating charged particle beam-assisted etching apparatus of this embodiment can be adjusted according to the desired etching rate. In the present invention, the charged particle beam can be configured as either an electron beam or an ion beam.

[0143] Figure 16 is a schematic diagram of a circulating charged particle beam-assisted etching apparatus according to a third embodiment of the present invention. Referring to Figure 16, the circulating charged particle beam-assisted etching apparatus 3 according to the third embodiment of the present invention includes a chamber 300, a gas supply module 310, a charged particle beam source 330 connected to a first power supply 350, a substrate 320 connected to a second power supply 352, and a control module 340. The circulating charged particle beam-assisted etching apparatus 3 according to the third embodiment of the present invention may further include a charged particle beam path guiding module 360, which includes an electromagnet 362 and an anode 364. The characteristic of the circulating charged particle beam-assisted etching apparatus according to the third embodiment of the present invention is that it generates ions to etch the substrate using an electron beam. Hereinafter, the constituent elements of the circulating charged particle beam-assisted etching apparatus according to the third embodiment of the present invention will be specifically described.

[0144] The chamber 300 may include a vacuum chamber capable of injecting process gas, and may contain a gas supply module and a substrate. A charged particle beam source may be mounted on one side. The substrate 320 is disposed within the chamber 300 and connected to a second power supply 352. The gas supply module 310 is disposed within the chamber 300 and is arranged at a fixed distance from the substrate 320.

[0145] The gas supply module 310 is configured to face the substrate and can supply inert or reactive gases for the etching process to the substrate via a showering method. Alternatively, the gas supply module 310 can also supply gases to the upper part of the chamber via a fluidized bed method.

[0146] A charged particle beam source 330 is disposed on one side of the chamber 300, with its outlet facing the interior of the chamber. The charged particle beam source 330 is connected to a first power supply 350. The charged particle beam source 330 is configured to allow the charged particle beam to fly parallel to the substrate 320. In the third embodiment of the present invention, the charged particle beam source is configured as an electron beam source to provide an electron beam to the interior of the chamber.

[0147] The control module 340 is configured to control the driving 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, thereby etching the substrate. The control module 340 applies synchronous and alternating pulse bias voltages to the charged particle beam source and the substrate, thereby synchronizing and alternating the ion generation cycle P1 and the substrate etching cycle P2.

[0148] The cyclic charged particle beam-assisted etching apparatus of the third embodiment of the present invention applies a bias voltage to the electron beam source during the ion generation cycle P1, thereby generating an electron beam and injecting it into the cavity, whereby the electron beam collides with gas particles in the cavity, and ions are generated by the collision between the electron beam and the gas particles. Additionally, during the substrate etching cycle P2, a bias voltage is applied to the substrate, thereby attracting the ions generated by the electron beam to the substrate and causing them to collide with the substrate, resulting in the etching of the substrate.

[0149] Figure 17 shows the waveforms of the pulse bias voltages applied to the electron beam source and the substrate respectively during the alternating ion generation cycle P1 and substrate etching cycle P2 in the cyclic charged particle beam assisted etching apparatus of the third embodiment of the present invention.

[0150] Referring to Figure 17, a negative bias voltage is applied to the charged particle beam source during the ion generation cycle P1, while the substrate maintains a ground bias voltage. With this bias voltage applied, the charged particle beam source irradiates the cavity with an electron beam, causing gas particles within the cavity to collide with the electron beam, thus generating ions. Conversely, a negative bias voltage is applied to the substrate during the substrate etching cycle P2, while the charged particle beam source maintains a ground bias voltage. With this bias voltage applied, ions are attracted to the substrate and collide with it, etching the substrate. As described above, by synchronizing and alternately applying pulse bias voltages to the charged particle beam source and the substrate, the ion generation cycle P1 and the substrate etching cycle P2 are synchronized and alternately performed.

[0151] In this invention, the process of repeatedly performing ion generation cycle P1 and substrate etching cycle P2 to etch the substrate is called "Cyclic Electron Beam Assist Etching" (CEBAE). CEBAS of this invention can improve the ion yield for substrate etching by optimizing the frequency of the pulse bias voltage simultaneously applied to the charged particle beam source and the substrate.

[0152] The ion generation mechanism and substrate etching mechanism in the cyclic charged particle beam assisted etching apparatus of the present invention will be described in more detail below. Figure 18 is a schematic diagram of the cyclic charged particle beam assisted etching apparatus of the third embodiment of the present invention, used to illustrate the movement of electrons during the ion generation cycle. Figure 18(a) illustrates the flight path of the electron beam through the charged particle beam path guide module. Figure 18(b) illustrates the generation of ions by colliding with gas particles during the flight path of the electron beam. Referring to Figure 18, during the ion generation cycle, that is, the electron beam irradiated from the electron beam source collides with gas particles during its flight to generate ions.

[0153] During the ion generation cycle, while the charged particle beam path guiding module 360 ​​forms a magnetic field tunnel along a pre-set electron beam flight path, a negative bias voltage is applied to the electron beam source and the substrate is grounded. As a result, during the ion generation cycle, the electron beam is able to carry energy out, the substrate no longer exerts any attractive or repulsive force on the electrons, and the electrons can fly in a straight line along the path formed by the magnetic field tunnel.

[0154] Figure 19 is a schematic diagram of the cyclic charged particle beam-assisted etching apparatus according to the third embodiment of the present invention, illustrating the process of ion etching of the substrate during a substrate etching cycle. Figure 19(a) illustratively illustrates the process in which ions are attracted to the substrate by the attraction of the bias voltage applied to the substrate and collide with the substrate. Figure 19(b) illustratively illustrates the process in which the surface of the substrate is etched due to the collision between ions and the substrate. Referring to Figure 19, during the substrate etching cycle P2, which is synchronized with the ion generation cycle, if a (-) bias voltage is applied to the substrate, ions will collide with the substrate and etch the substrate surface.

[0155] During the substrate etching cycle P2, since no voltage is applied to the electron beam source, the electron beam irradiation is stopped. During the ion generation cycle P1, the irradiated electron beam travels too fast and disappears instantaneously in the anode direction. However, the ions generated by the electron beam collisions during the ion generation cycle P1 have weight and low energy, resulting in slow flight speeds and thus remaining in the cavity. The ions generated by the electron beam collisions have extremely low energy (eV). Therefore, the ions themselves have low energy and cannot etch the substrate on their own. Therefore, in the ion generation state, if a bias voltage of tens to thousands of volts (-) is applied to the substrate, the substrate bias voltage will exert an attractive force on the (+) ions remaining in the cavity. Due to the attractive force of the substrate bias voltage, the (+) ions are attracted to the substrate and collide with it, resulting in the etching of the substrate surface.

[0156] In the cyclic charged particle beam-assisted etching apparatus of the third embodiment of the present invention, the ion generation cycle and the substrate etching cycle are synchronized and alternated, thereby eliminating the heating of the substrate caused by electron collisions with the substrate. Furthermore, by adjusting the substrate bias voltage applied during the substrate etching cycle, the etching depth can be precisely controlled. Therefore, according to this embodiment, atomic layer etching (ALE) requiring 30-50 eV of energy can be performed.

[0157] Furthermore, in the cyclic charged particle beam assisted etching apparatus of the third embodiment of the present invention, the flux of ions used for etching is limited by controlling the number of pulse injections of the electron beam, thereby also controlling the depth of ALE etching.

[0158] In etching using previous ICP plasma methods, or in cases where etching is performed by applying HF, RF, or even higher frequency radio frequency bias to the substrate, the ion energy is tens to thousands of eV. When etching is performed by collisions with these high-energy ions, unexpected deep etching or uneven etching can occur, and plasma electrons can also bombard the substrate, causing it to heat up. In contrast, in the circulating charged particle beam-assisted etching apparatus of the third embodiment of this invention, ions with extremely low energies (several eV) generated by electron beam collisions are used to etch the substrate. Therefore, the etching apparatus of this invention can precisely control the etching depth by adjusting the substrate bias.

[0159] <Fourth Implementation: Etching Device Assisted by Circulating Charged Particle Beams Using Ion Beams>

[0160] The following describes in detail the fourth embodiment of the circulating charged particle beam-assisted etching apparatus and method of the present invention. The fourth embodiment of the circulating charged particle beam-assisted etching apparatus of the present invention is characterized in that the charged particle beam is configured as an ion beam, and the substrate is etched using the ion beam. Therefore, the configuration of the fourth embodiment of the circulating charged particle beam-assisted etching apparatus of the present invention is the same as that of the third embodiment, but there is a difference in that the charged particle beam source is configured as an ion beam source. In order to generate ions for substrate etching, the fourth embodiment of the circulating charged particle beam-assisted etching apparatus of the present invention uses an electron beam in the third embodiment and an ion beam in this embodiment.

[0161] Figure 20 is a schematic diagram illustrating the synchronous and alternating application of pulse bias voltages to the ion beam source and the substrate in the cyclic charged particle beam assisted etching apparatus of the fourth embodiment of the present invention. Referring to Figure 20, a (+) bias voltage is applied to the charged particle beam source during the ion generation cycle P1, while the substrate maintains a ground bias voltage. With this bias voltage applied, the charged particle beam source generates an ion beam and irradiates the chamber, causing gas particles in the chamber to collide with the ion beam, thereby generating ions. On the other hand, a (-) bias voltage is applied to the substrate during the substrate etching cycle P2, while the charged particle beam source maintains a ground bias voltage. With this bias voltage applied, ions are attracted to the substrate and collide with it to etch the substrate. As described above, by synchronizing and alternating the pulse bias voltages to the charged particle beam source and the substrate, the ion generation cycle P1 and the substrate etching cycle P2 are synchronized and alternately performed.

[0162] In this invention, the process of repeatedly performing ion generation cycle P1 and substrate etching cycle P2 to etch the substrate is called "Cyclic Ion Beam Assist Etching" (CIBAE). CIBAE of this invention can improve the ion yield for substrate etching by optimizing the frequency of the pulse bias voltage simultaneously applied to the charged particle beam source and the substrate.

[0163] Figure 21 is a schematic diagram of the cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention, illustrating the ionization process caused by ion beam collisions. Referring to Figure 21(a), as a bias voltage is applied to the ion beam source during the ion generation cycle P1, an ion beam with (+) bias voltage energy irradiates the chamber from the ion beam source and flies parallel to the substrate. Referring to Figure 21(b), during the flight of the ion beam within the chamber, it can collide with gas particles in the chamber, causing the gas particles to ionize.

[0164] Figure 22 is a schematic diagram of the cyclic charged particle beam-assisted etching apparatus according to the fourth embodiment of the present invention, used to illustrate the substrate etching process. Referring to Figure 22(a), as a (-) bias voltage 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 target material. Referring to Figure 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 voltage or adjusting the number of pulse implantations of the ion beam bias voltage.

[0165] In the cyclic charged particle beam-assisted etching apparatus of the fourth embodiment of the present invention, the ion generation cycle and the substrate etching cycle are synchronized and alternated, thereby eliminating unnecessary and uneven etching depths of the substrate caused by collisions between the emitted ion beam and the substrate. Furthermore, by adjusting the substrate bias voltage applied during the substrate etching cycle, the etching depth of the substrate can be precisely controlled. Therefore, according to this embodiment, atomic layer etching (ALE) requiring 30-50 eV can be performed.

[0166] Furthermore, in the cyclic charged particle beam assisted etching apparatus of the fourth embodiment of the present invention, the flux of ions used for etching is limited by controlling the number of pulse injections of the ion beam bias voltage, thereby also controlling the depth of ALE etching.

[0167] In etching using previous ICP plasma methods, or in cases where etching is performed by applying HF, RF, or higher frequency radio frequency bias voltages to the substrate, the ion energy is tens to thousands of eV. When etching is performed by collisions with these high-energy ions, not only does deep etching or uneven etching occur, but plasma electrons also bombard the substrate, causing it to heat up. In contrast, in the circulating charged particle beam-assisted etching apparatus of the fourth embodiment of the present invention, ions with extremely low energies (several eV) generated by ion beam collisions are used to etch the substrate. Therefore, the etching apparatus of the present invention can precisely control the etching depth by adjusting the substrate bias voltage.

[0168] In the etching apparatus of the fourth embodiment of the present invention, the ions injected from the ion beam source to generate ions in the chamber have a mass greater than that of electrons, thus carrying an impact force during collision. Therefore, when the reactive gas used for etching is formed in the form of molecules or free radicals containing multiple atoms, the ion generation process caused by ion beam collision can easily dissociate the reactive gas and achieve momentum transfer due to the impact force. As a result, the etching apparatus of the fourth embodiment of the present invention can uniformly etch the sidewalls of deep trenches by means of the directional movement of the reactive gas.

[0169] Furthermore, when the ionizing gas is a single-atom inert gas, and the mass of the irradiated ions in CIBAE is greater than the mass of the gas ionized due to collisions, no backscattering occurs even after the irradiated ions collide. Therefore, the irradiated ions will not cause uncontrolled etching of the substrate, nor will they cause uneven or unnecessary depth etching. The irradiated ion beam and the ionizing gas can include one of the inert gases He, Ne, Ar, Kr, and Xe. The heavier the irradiated ion beam and the lighter the ionizing gas, the more favorable it is for generating uniform etching depth controlled by the substrate bias voltage.

[0170] The present invention has been described above with reference to preferred embodiments, but these are merely examples and not intended to limit the invention. Those skilled in the art will recognize that various modifications and applications not illustrated above can be made without departing from 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.

[0171] 1: Magnetron sputtering machine 2: Circulating charged particle beam assisted sputtering device 3: Circulating charged particle beam assisted etching device 100: Target Material 110: Power supply 120:Substrate 130: Chamber 200: Chamber 210: Target Material 220:Substrate 230: Charged Particle Beam Source 240: Control Module 250: Power Supply 1 252: Second Power Supply 260: Charged Particle Beam Path Guiding Module 262: Electromagnet 264: Anode 300: Chamber 310: Gas supply module 320:Substrate 330: Charged Particle Beam Source 340: Control Module 350: Power Supply 1 352: Second Power Supply 360: Charged Particle Beam Path Guiding Module 362: Electromagnet 364: Anode P1: Ion formation cycle P2: Sputtering cycle of target material

Claims

1. A cyclic charged particle beam-assisted sputtering apparatus, comprising a sputtering apparatus for a target and a substrate arranged facing each other at a fixed distance within a vacuum chamber, characterized in that: a charged particle beam source configured to irradiate the interior of the vacuum chamber with a charged particle beam; and a control module configured to control first and second pulse voltages respectively applied to the charged particle beam source and the target, thereby synchronizing and alternating the ion generation cycle and the target sputtering cycle; and during the ion generation cycle, applying a preset charged particle beam bias voltage to the charged particle beam source to irradiate the charged particle beam, thereby generating gas particle ions through collisions between the charged particle beam and gas particles; and during the target sputtering cycle, applying a preset target bias voltage to the target, thereby attracting the generated gas particle ions to the target and sputtering the target by collision, wherein the sputtered target particles are deposited onto the substrate.

2. The cyclic charged particle beam assisted sputtering apparatus of claim 1, wherein the charged particle beam source is configured as an electron beam source that provides an electron beam, and the charged particle beam is an electron beam.

3. The cyclic charged particle beam assisted sputtering apparatus of claim 1, wherein the charged particle beam source is configured as an ion beam source that provides an ion beam, and the charged particle beam is an ion beam.

4. The cyclic charged particle beam-assisted sputtering apparatus of claim 1, further comprising: The charged particle beam guiding module is configured such that a magnetic field is formed or an additional power supply is applied along a pre-set flight path of the charged particle beam supplied to the chamber by the charged particle beam source, thereby causing the charged particle beam to travel along the pre-set flight path; and the pre-set flight path of the charged particle beam is a path that is separated from the surface of the substrate and is parallel to or forms a curvature with the surface of the substrate.

5. The cyclic charged particle beam assisted sputtering apparatus as claimed in claim 4, wherein the charged particle beam guiding module includes electromagnets disposed on the wall of the vacuum chamber, the electromagnets being located at the start or end point of a pre-set flight path of the charged particle beam.

6. The cyclic charged particle beam assisted sputtering apparatus of claim 4, wherein the charged particle beam guiding module further comprises an electrode configured such that it is positioned at the end of a pre-set flight path of the charged particle beam to guide the charged particle beam; and when the charged particle beam is an electron beam, the electrode is configured as an anode, and when the charged particle beam is an ion beam, the electrode is configured as a cathode.

7. The cyclic charged particle beam assisted sputtering apparatus of claim 1, wherein the control module is configured to adjust the duty cycle of the first or second pulse voltage so that the period of irradiation of the charged particle beam overlaps with part or all of the period of application of target bias voltage, thereby increasing the sputtering and evaporation speed and having the effect of electron beam substrate irradiation.

8. The cyclic charged particle beam assisted sputtering apparatus of 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. The cyclic charged particle beam assisted sputtering apparatus of claim 1, wherein the frequencies of the first and second pulse voltages applied to the charged particle beam source and the target material are respectively in the range of 0.1 to 1,000 kHz.

10. A cyclic charged particle beam-assisted etching apparatus comprising a gas supply module and an etching apparatus for a substrate arranged facing each other at a fixed distance within a vacuum chamber, the apparatus comprising: a charged particle beam source configured to irradiate the interior of the vacuum chamber with a charged particle beam; and a control module configured to control first and second pulse voltages respectively applied to the charged particle beam source and the substrate, thereby synchronizing and alternating an ion generation cycle with a substrate etching cycle; wherein, during the ion generation cycle, a preset charged particle beam bias voltage is applied to the charged particle beam source to irradiate the charged particle beam, and ions are generated by collisions between the charged particle beam and gas particles; and during the substrate etching cycle, a preset substrate bias voltage is applied to the substrate, and the generated ions collide with the substrate due to the attraction of the substrate bias voltage, thereby etching the substrate.

11. The cyclic charged particle beam assisted etching apparatus of claim 10, wherein the charged particle beam source is configured as an electron beam source that provides an electron beam, wherein the charged particle beam is an electron beam.

12. The cyclic charged particle beam assisted etching apparatus of claim 10, wherein the charged particle beam source is configured as an ion beam source that provides an ion beam, wherein the charged particle beam is an ion beam.

13. The cyclic charged particle beam-assisted etching apparatus of claim 10, further comprising: The charged particle beam guiding module is configured such that a magnetic field is formed or an additional power supply is applied along a pre-set flight path of the charged particle beam supplied to the chamber by the charged particle beam source, thereby causing the charged particle beam to travel along the pre-set flight path; and the pre-set flight path of the charged particle beam is a path that is separated from the surface of the substrate and is parallel to or forms a curvature with the surface of the substrate.

14. The cyclic charged particle beam assisted etching apparatus of claim 13, wherein the charged particle beam guiding module includes electromagnets disposed on the wall of a vacuum chamber, the electromagnets being located at the start or end point of a pre-set flight path of the charged particle beam.

15. The cyclic charged particle beam assisted etching apparatus of claim 13, wherein the charged particle beam guiding module further comprises an electrode configured to guide the charged particle beam by being disposed at the end of a pre-set flight path of the charged particle beam; and when the charged particle beam is an electron beam, the electrode is configured as an anode, and when the charged particle beam is an ion beam, the electrode is configured as a cathode.

16. The cyclic charged particle beam assisted etching apparatus of 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. The cyclic charged particle beam assisted etching apparatus of claim 10, wherein the frequencies of the first and second pulse voltages applied to the charged particle beam source and the substrate are respectively in the range of 0.1 to 1,000 kHz.

Images