Static electricity control device for semiconductor processing system

Abstract

This embodiment relates to a technique for easily adjusting the static electricity level required by a substrate according to a semiconductor process by injecting static electricity onto the substrate or removing pre-formed static electricity. The static electricity control device of the semiconductor processing system according to the present embodiment is configured to inject static electricity onto a substrate disposed within a vacuum chamber or to remove static electricity formed on the substrate, and includes a charged particle generator disposed at an upper portion of the vacuum chamber and generating VUV (Vacuum Ultraviolet Ray) and generating charged particles including positive ions and electrons as a result of the VUV reacting with a process gas within the vacuum chamber; a grid disposed below the charged particle generator and having a number of holes for selectively passing types of charged particles downward according to an input voltage; a substrate support disposed below the grid, on whose upper surface the substrate is disposed, the substrate support made of a conductive material and for guiding the charged particles that have passed through the grid toward the substrate at a predetermined density according to an input bias voltage; and a static electricity control controller configured to supply a pulse-type voltage to at least one of the grid and the substrate support to control static electricity of the substrate, and the grid and the substrate support are disposed to have a distance therebetween that is within four times the free travel distance of the process gas according to environmental conditions of the vacuum chamber.

Description

[Technical field]

[0001] The present technology generally relates to a technology for injecting static electricity onto a substrate or removing static electricity formed on a substrate, thereby easily adjusting the static electricity level required by the substrate in accordance with a semiconductor process. [Background technology]

[0002] Recently, as integration in the semiconductor industry increases, the size and area of ​​semiconductor devices are becoming smaller.

[0003] As a result, the size of patterns and the thickness of thin films forming the patterns of semiconductor devices are decreasing, and factors that did not have a significant impact in the past are now emerging as important factors in the development of semiconductor devices. One of these factors is static electricity formed on a substrate, and therefore processes for controlling static electricity formed on a substrate are being used.

[0004] During the deposition, etching, or substrate cleaning processes that use plasma in semiconductor manufacturing, static electricity is generated on the substrate. If this voltage is excessively large or if the substrate is charged and then suddenly discharged, it can cause deformation of the pattern due to phenomena such as arcing.

[0005] In addition, static electricity formed on the substrate is mainly generated by the use of deionized water, charge transfer from charged plastic materials, induction charging, or charges during processes using plasma.

[0006] In order to prevent the generation of such static electricity, positive charges (ions) or negative charges (electrons) are pre-charged (injected) into the substrate's insulator (thin film) several to several tens of nm deep before the pattern formation process, cleaning process, or plasma treatment process, and are used to adjust fine patterns such as local pattern uniformity and local edge placement errors during multiple patterning processes, and to adjust (trade-off) static electricity generated during other processes. This is called a static electricity charger.

[0007] Meanwhile, static electricity on substrates is mainly generated during photoprocessing and cleaning processes that use rotational motion, and it is known that the most static electricity is concentrated in the center due to the difference in centrifugal force. That is, during the photo resist coating process, as the wafer rotates at high speed, the concentration of air flow in the center of the substrate is more than three times higher than that at the periphery, so static electricity is formed around the center where the centrifugal force is relatively weak. Static electricity caused by the strong electric field formed in the center of the substrate is charged inside the multi-layer insulating film, or on the surface of the wafer and the photoresist pattern formed on the surface.

[0008] For this reason, a method is required to efficiently remove the static electricity formed on the substrate, and a device that removes the static electricity that has already been generated on the substrate or that is generated during the process is called a static electricity discharger.

[0009] FIG. 1A illustrates a shape in which electrostatic voltages of −50 V, −30 V, and −10 V appear from the center of the substrate 1 to the outer periphery.

[0010] However, as shown in FIG. 1A, when the substrate 1 is charged with a high voltage centered on the center thereof, in the region corresponding to the center of the substrate in FIG. 1B (the region where the static electricity voltage is -50V in FIG. 1A), the charge is not only charged to the surface of the substrate 1, such as an insulator such as P / R (Photo Resist) or oxide, but also to a certain depth D of the substrate surface, which may result in a state in which neutralization by ions having low kinetic energy is impossible.

[0011] In addition, the electrostatic voltage charged to the substrate varies depending on various variables such as the type of process, material, and pattern shape, and is generally formed between -100V and +100V.

[0012] For example, as shown in FIG. 1B, a charging voltage of 100V or less is formed on a substrate 1 on which an insulating film in a fine circuit of 10nm or a pattern P having an aspect ratio of 5 or more is formed. However, since the width of the pattern is narrow, it is difficult to remove the static electricity accumulated inside the thin film due to the self-neutralization effect between the positive and negative ions generated by the ionizer and the reduced collision of ions due to the low electromotive force caused by the low voltage difference between the substrate and the ions. Summary of the Invention [Problem to be solved by the invention]

[0013] Conventionally, static electricity on a board was removed using an ionizer. However, in the method using an ionizer, as shown in Figure 2, if static electricity is charged to a board at 1000V, it takes 1 to 2 seconds to reduce this to 100V using a soft X-ray ionizer, but if an initial charging voltage of less than 100V is formed, it takes a long time to reduce the charging voltage below that level.

[0014] In general, the ion density of an ionizer is 10 6 Considering this, charging also occurs inside the silicon oxide layer under the PR in the substrate, and the ion density is 10 8 In the above cases, the static electricity formed inside the substrate 1 cannot be removed using a conventional ionizer.

[0015] One of the problems to be solved by the present technology is to provide a static electricity control device for a semiconductor processing system that can accurately and quickly inject static electricity onto a substrate or easily remove static electricity formed on a substrate by a simple method of controlling voltages applied to a grid and a substrate support. [Means for solving the problem]

[0016] The static electricity control device of the semiconductor processing system according to the present embodiment is a static electricity control device for injecting static electricity onto a substrate disposed in a vacuum chamber or removing static electricity formed on the substrate, and includes a charged particle generator disposed in an upper portion of the vacuum chamber and generating VUV (Vacuum Ultraviolet Ray) and generating charged particles including positive ions and electrons as the VUV reacts with a process gas in the vacuum chamber; a grid disposed below the charged particle generator and having a number of holes for selectively passing the charged particles downward according to an input voltage; a substrate support disposed below the grid, on whose upper surface the substrate is placed, for guiding the charged particles that have passed through the grid toward the substrate at a preset density according to an input bias voltage; and a static electricity control controller for supplying a pulse-type voltage to at least one of the grid and the substrate support to control static electricity of the substrate, and the grid and the substrate support are disposed to have a distance therebetween that is within four times the free travel distance of the process gas according to environmental conditions of the vacuum chamber.

[0017] In one aspect of this embodiment, the static electricity adjustment controller applies a bias voltage to the substrate support so that the bias voltage is higher than the voltage applied to the grid by a certain level or more in a static electricity injection mode, and applies a bias voltage to the substrate support so that the voltage applied to the grid and the bias voltage applied to the substrate support are within a preset similarity range in a static electricity removal mode.

[0018] In one aspect of this embodiment, the static electricity adjustment controller adjusts a pulse period applied to the grid and the substrate support to adjust a voltage level.

[0019]

[0020] In one aspect of this embodiment, the charged particle generator includes one or more VUV lamps that emit VUV light.

[0021]

[0022] In one aspect of this embodiment, a beam generator that emits a line-shaped ion beam through a side of the vacuum chamber is additionally provided below the VUV lamp, and charged particles due to the reaction between the VUV and the process gas and charged particles due to the reaction between the ion beam and the process gas are simultaneously generated, thereby increasing the charged particle density.

[0023]

[0024] In one aspect of this embodiment, the charged particle generator includes a plasma generator that generates plasma, and a separation plate below the plasma generator that transmits only VUV, and generates charged particles by reaction between the VUV generated in the plasma generator and the process gas.

[0025]

[0026] In one aspect of this embodiment, the plasma generator includes at least one microplasma device that generates plasma using a power source in the range of 10 to 200 W in a vacuum environment in which the volume of a vacuum chamber is in the range of 500 to 1000 cc.

[0027]

[0028] In one aspect of this embodiment, the static electricity adjustment controller adjusts at least one of the type of process gas injected into a vacuum chamber of a microplasma device or a plasma power source to adjust static electricity of the substrate.

[0029]

[0030] In one aspect of this embodiment, the plasma generator includes a number of microplasma devices, and the static electricity adjustment controller adjusts static electricity of the substrate by individually controlling the type of process gas or the plasma power source injected into the vacuum chamber of each microplasma device.

[0031]

[0032] In one aspect of this embodiment, the plasma generator includes a number of microplasma devices, the separation plates are arranged in one-to-one correspondence with each of the microplasma devices, and the static electricity adjustment controller adjusts static electricity on the substrate by individually controlling the type of process gas or the plasma power source injected into the vacuum chamber of each of the microplasma devices, and each of the separation plates includes a lens having a different divergence angle.

[0033]

[0034] In one aspect of this embodiment, the grid and substrate support are of a multi-zone type in which multiple regions are electrically isolated, and the static electricity adjustment controller individually supplies voltages of different levels to each region of the grid and substrate support.

[0035]

[0036] In one aspect of this embodiment, the static electricity adjustment controller applies voltages to each region of the grid and the substrate support so as to inject static electricity into a certain portion of the substrate and remove static electricity from other portions of the substrate.

[0037]

[0038] In one aspect of this embodiment, the grid includes an upper grid and a lower grid disposed below the upper grid, and the electrostatic regulation controller supplies voltages of different levels to the upper grid and the lower grid.

[0039]

[0040] In one aspect of this embodiment, the diameter of the holes formed in the lower grid is set to be different from the diameter of the holes formed in the upper grid, and the electrostatic adjustment controller applies a first level of negative voltage to the lower grid to induce ions between the lower grid and the substrate toward the upper grid through the holes in the lower grid, and then applies a negative voltage greater than the first level to the upper grid to cause the ions flowing in through the lower grid to collide with a lower surface of the upper grid to generate secondary electrons, thereby releasing higher density electrons toward the substrate through the holes in the lower grid.

[0041]

[0042] In one aspect of this embodiment, the aperture ratio of the holes in the center of the grid is higher than the aperture ratio of the holes in the peripheral region.

[0043]

[0044] In one aspect of this embodiment, a distance adjustment unit is further provided for moving the grid and the substrate support up and down within the vacuum chamber, and the static electricity adjustment control unit controls the distance adjustment unit to change the position of at least one of the grid or the substrate support to the upper or lower side based on the process gas free path distance calculated according to the environmental conditions of the vacuum chamber.

[0045]

[0046] In one aspect of the present embodiment, the grid surface is coated or sputtered with a film containing a carbon component, such as carbon, CNT, or glassy carbon, to prevent the generation of an arc.

[0047]

[0048] In one aspect of this embodiment, the grid surface is provided with a silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), silicon nitride (Si 3 N4 ) or a thin oxide film is coated or sputtered to prevent arcing. Effect of the Invention

[0049] The present technology provides the advantage of being able to accurately and quickly inject static electricity onto a substrate and easily remove static electricity formed on the substrate, thereby minimizing the defect rate in the semiconductor manufacturing process and enabling the manufacture of more reliable semiconductor devices.

[0050] [Brief description of the drawings]

[0051] [Figure 1] 1 is a diagram for explaining problems with removing static electricity from a semiconductor;

[0052] [Diagram 2] 1 is a diagram illustrating static electricity removal characteristics of a natural drop type using an ionizer.

[0053] [Diagram 3] 1 is a schematic diagram of a semiconductor processing system including a static electricity control device according to a first embodiment;

[0054] [Figure 4] 4 is a diagram illustrating a configuration of a charged particle generator illustrated in FIG. 3;

[0055] [Diagram 5] 4 is a diagram illustrating a multi-zone structure of the grid and the substrate support illustrated in FIG. 3;

[0056] [Figure 6] 4 is a diagram illustrating a dual grid structure of the grid illustrated in FIG. 3;

[0057] [Figure 7]4 is a graph showing experimental results of static electricity injection and removal depending on the distance between the grid and the substrate support illustrated in FIG. 3.

[0058] [Figure 8] 4 is a diagram illustrating an operation of the static electricity control device of the semiconductor processing system illustrated in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] The embodiments described in the present invention and the configurations illustrated in the drawings are merely preferred embodiments of the present invention and do not fully express the technical ideas of the present invention, so the scope of the present invention should not be interpreted as being limited by the embodiments and drawings described in the present text. In other words, since the embodiments can be modified in various ways and can have various forms, the scope of the present invention should be understood to include equivalents that can realize the technical ideas. In addition, the objectives or effects presented in the present invention do not mean that a specific embodiment must include all of them or must include only such effects, so the scope of the present invention should not be understood as being limited thereby.

[0060] All terms used herein, unless otherwise defined, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as meanings consistent with the context of the relevant art, and should not be interpreted as having ideal or overly formal meanings not expressly defined in the present invention.

[0061]

[0062] FIG. 3 is a schematic diagram illustrating a semiconductor processing system including a static electricity control apparatus according to a first embodiment of the present invention.

[0063] Referring to FIG. 3, the semiconductor processing system according to the present invention includes a charged particle generator 100 disposed at the upper inside of a vacuum chamber C in which a substrate 10 is disposed, a grid 200 and a substrate support 300 disposed in sequence below the charged particle generator 100, and a static electricity adjustment controller 400 which generates charged particles in the vacuum chamber C through the charged particle generator 100, and controls a voltage applied to the grid 200 and the substrate support 300 to adjust the density of the charged particles emitted toward the substrate 10 through the grid 200, thereby injecting static electricity onto the substrate 10 or removing static electricity formed on the substrate 10.

[0064] In addition, the electrostatic adjustment controller 400 may further include a distance adjustment unit 500 for adjusting the distance between the grid 200 and the substrate support 300 by adjusting the position of at least one of the grid 200 and the substrate support 300 up or down under the control of the static electricity adjustment controller 400 .

[0065] That is, in this embodiment, charged particles generated in the vacuum chamber C are selectively transmitted through the grid 200, and a bias voltage is applied to the substrate support 300 supporting the substrate 10, thereby inducing the charged particles that have passed through the grid 200 toward the substrate 10, thereby injecting static electricity onto the substrate 10 or neutralizing (removing) static electricity formed on the substrate 10.

[0066]

[0067] Next, this embodiment will be described in more detail.

[0068] The vacuum chamber C is equipment for performing a semiconductor process on the substrate 10, and includes a vacuum forming unit for maintaining the inside of the chamber in a vacuum state and a gas supplying unit for supplying gas into the chamber, both of which are not shown.

[0069] In this case, the vacuum forming unit may include a vacuum pump for discharging the material in the chamber to the outside of the chamber, a vacuum gauge for detecting the degree of vacuum inside the chamber, a valve for switching on and off the inflow and outflow of the material, and a pipe for connecting each component. The vacuum forming unit may preferably be configured to maintain the degree of vacuum inside the chamber at 10-1 ~10 -4 Maintain at Torr.

[0070] The gas supply unit can supply different gases depending on the process. Helium (He), nitrogen (N 2 ), and argon (Ar), and other gases can be provided, and the flow rate of the gas can be set to 10 to 1000 sccm.

[0071] The charged particle generator 100 is an apparatus that generates VUV (Vacuum Ultraviolet Ray) and reacts the VUV with a process gas to generate charged particles including positive ions and electrons. The charged particle generator 100 includes at least one of a VUV lamp and a plasma generator, and can generate charged particles including electrons and ions by additionally generating a line-shaped ion beam, a large-area electron beam, etc. using plasma.

[0072] FIG. 4 illustrates an example of the configuration of the charged particle generator 100.

[0073] 4A, the charged particle generator 100 may include a VUV lamp 110 disposed above the vacuum chamber C, and a beam generator 120 for emitting a large-area beam (B), i.e., an ion beam or an electron beam, from the side of the vacuum chamber C into the vacuum chamber C below the VUV lamp 110. A plurality of VUV lamps 110 may be disposed. That is, the VUV lamp 110 generates and irradiates VUV light having a wavelength band of 110 nm to 400 nm into the vacuum chamber C. The VUV reacts with the process gas in the vacuum chamber C to decompose the gas particles, generating charged particles including positive ions and electrons.

[0074] The beam generator 120 dissociates the process gas in the vacuum chamber C through an ion beam or an electron beam to generate additional positive ions and electrons, thereby increasing the density of electrons and positive ions emitted toward the grid 200. The configuration of the beam generator 120 for generating a line-shaped beam is disclosed in Korean Patent Nos. 10-1911542, 10-1989847, 10-1998774, and 10-2118604, all of which are patents owned by the inventor of the present application, and detailed description thereof will be omitted as they are incorporated herein by reference.

[0075] 4B, the charged particle generator 100 includes a plasma generator 130 disposed inside a vacuum chamber C. The plasma generator 130 generates charged particles including positive ions and electrons by reacting VUV formed into plasma with a process gas.

[0076] A VUV lamp 140 may be additionally disposed below the plasma generator 130, emitting VUV from the side of the vacuum chamber C into the vacuum chamber C. In this case, a plurality of VUV lamps 140 may be disposed on both sides of the vacuum chamber C, as shown in FIG. 4B.

[0077] The electrons excited by the plasma generated by the plasma generator 130 fall back to the ground state and emit light having an energy corresponding to the difference in energy between the excited state and the ground state to the outside. The wavelength band of the light thus generated is an ultraviolet band that can dissociate the gas provided by the gas supplier to form negatively charged particles and / or positively charged particles.

[0078] The plasma generator 130 may be an inductively coupled plasma (ICP) generator or a capacitively coupled plasma (CCP). The electrical signal supplied to the plasma generator 130 may be a pulse or a continuous wave (CW). For example, the ultraviolet ray band may be classified into near ultraviolet ray (NEAR UV, 300nm to 380nm), far ultraviolet ray (FAR UV, 200nm to 300nm), and vacuum ultraviolet ray (VUV, 70nm to 200nm) having a wavelength shorter than that of the far ultraviolet ray band, and the plasma generator 130 of the present invention may generate ultraviolet ray in the vacuum ultraviolet ray (VUV) band.

[0079] The plasma generating unit 130 may be a micro plasma source that generates plasma using a DC, RF, or pulse power source in the range of 10 to 200 W in an environment where the volume of the vacuum chamber is in the range of 500 to 1000 cc. The micro plasma source includes a separate vacuum chamber for forming plasma, and includes a means for performing gas injection and gas exhaust processing, vacuum processing, and power supply processing in the vacuum chamber under the control of the static electricity adjustment control unit 400.

[0080] At this time, the micro plasma source is composed of one of atmospheric pressure plasma devices using ICP, CCP, TCP, hollow cathode, or DBD, and generates plasma using various process gases including oxygen, nitrogen, argon, and helium.

[0081] Compared to VUV lamps, which usually require a preheating time of about 30 seconds and cannot adjust the output of the light source, microplasma sources have the advantage of being able to freely turn plasma on / off since the volume of the vacuum chamber is in the range of 500~1000cc, making it easy to change process conditions and having a short plasma turn-on time. When using a microplasma source, it is possible to prevent deterioration of thin film properties, which would otherwise be required for the process time required for multi-layered semiconductor thin films, as well as to inject and remove static electricity on the substrate more quickly and adaptively.

[0082] In addition, in the present invention, as shown in Fig. 4(C), the plasma generator 130 can be composed of a plurality of microplasma sources. In Fig. 4(C), first to third microplasma sources 131, 132, and 133 are illustrated.

[0083] In the embodiment illustrated in FIG. 4(C), the first to third micro plasma sources 131, 132, and 133 are each implemented on an independent vacuum chamber, and the static electricity adjustment control unit 400 can be configured to individually control the vacuum environment, type of process gas, and plasma power source of the first to third micro plasma sources 131, 132, and 133 to perform different static electricity injection or removal processes on different regions of the substrate 10.

[0084] That is, when more static electricity is formed at the center of the substrate 10 than at the periphery, the static electricity adjustment controller 400 can set the pressure or power of the microplasma source corresponding to the corresponding position differently from the pressure or power of the microplasma source at other positions. This allows for a more precise static electricity adjustment process compared to a VUV lamp that cannot adjust the wavelength band of the VUV light output.

[0085] In addition, the wavelength of the VUV generated by the microplasma source is 58.4 nm when helium gas is used as the process gas, 130.5 nm when oxygen gas is used as the process gas, and 104.8 nm when argon gas is used as the process gas. Therefore, the static electricity control controller 400 can select the desired VUV wavelength by varying or mixing the types of process gases supplied to the vacuum chambers of the first to third microplasma sources 131, 132, and 133, and thereby can set the static electricity level injected or removed on the substrate 10 differently for each region. For example, helium gas can be used when the band gap energy of the semiconductor thin film formed on the substrate 10 is large, and nitrogen gas can be used when the band gap energy is small.

[0086] In addition, the static electricity adjustment control unit 400 can selectively operate only the microplasma source at a position corresponding to an area of ​​the substrate 10 where static electricity adjustment is required.

[0087] Also, depending on the use environment including the type of substrate to be subjected to static electricity adjustment, the first to third microplasma sources 131, 132, and 133 may be implemented as different types of atmospheric pressure plasma devices using ICP, CCP, TCP, hollow cathode, and DBD.

[0088] On the other hand, in order to utilize the VUV wavelength generated by the plasma, as shown in FIG. 4B, MgF 2 Glass, CaF 2 A glass separator 150 is provided to block the positive ions, electrons, and active species generated in the plasma generator 130 from being emitted downward, and is configured to transmit only VUV. At this time, charged particles generated by the reaction between the VUV generated in the plasma generator 130 and the process gas and charged particles generated by the reaction between the VUV emitted from the VUV lamp and the process gas are generated simultaneously.

[0089] The separation plate 150 may be provided with an optical filter coating portion that selectively transmits only VUV light to emit light of 10 to 20 mm in size downward, and may be configured to have a desired divergence angle of the VUV light emitted downward using a concave lens or a convex lens. When the separation plate 150 is embodied in the embodiment illustrated in FIG. 4C, the separation plate 150 may be disposed (151, 152, 153) below the first to third microplasma sources 131, 132, 133, respectively, and may have different divergence angles. For example, a convex lens may be provided below the first and third microplasma sources 131, 133, and a concave lens may be provided below the second microplasma source 132. Of course, it is also possible to configure one separation plate 150 to have lenses having different divergence angles corresponding to each microplasma source, as in the embodiment illustrated in FIG. 4B.

[0090] In addition, a light diffusion plate (not shown) can be disposed in front of the VUV lamp 140 to diffuse the VUV light into the vacuum chamber C.

[0091] Meanwhile, the grid 200 is formed in a plate shape made of a conductive material, and has a number of fine holes formed therein for discharging charged particles flowing in from above to below. Considering that the electrostatic charging voltage of the substrate 10 is always higher at the center than at the outside after processing, it is preferable that the aperture ratio of the fine holes in the center of the grid 200 is 10% or more higher than the surrounding area, and the fine holes may be in a circular, diamond, or other shape with a diameter set in the range of 1 to 10 mm.

[0092] The grid 200 selectively emits charged particles toward the substrate 10 according to a voltage supplied through the static electricity adjustment controller 400 .

[0093] In addition, as illustrated in FIG. 5, the grid 200 is configured as a multi-zone type in which a plurality of regions are electrically separated, and each region is supplied with a different voltage V1 , V 2 , V 3 In this case, considering that the center of the substrate 10 has a higher static electricity voltage than the outside thereof, the voltage supplied to the center of the grid 200 can be set higher than that of the periphery (V 1 >V 2 >V 3 That is, a higher density of charged particles can be supplied to the center of the substrate 10.

[0094] The multi-zone type grid 200 is prepared by preparing a circular or square graphite or metal plate with a thickness of 5 mm to 10 mm, which is divided into multiple zones, and laminating a 50 μm to 100 μm polyimide and a 20 to 100 μm copper (Cu) film on the metal plate or graphite. Then, the copper (Cu) film is patterned on both sides and etched, and the metal plate or graphite is patterned so that it is electrically separated. Then, a number of holes are formed with a diameter of 1 to 10 mm, and the insides of the holes are plated. At this time, it is preferable that the holes have an opening rate of 50% or more of the metal plate (meatal plate) or graphite surface, and the insides of the holes can be subjected to 20 μm electroless plating and 30 μm electrolytic plating.

[0095] The grid 200 has a film containing carbon components such as carbon, CNT, and glassy carbon on the upper surface, DLC (diamond like carbon), silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), silicon nitride (Si 3 N 4), oxide-based thin film, etc., may be coated or sputtered to a thickness of 100 to 1000 nm to prevent the occurrence of arcs. This can prevent defects such as distortion, shrinkage, and LER (line edge roughness) of ultra-fine patterns of several nm in size formed on the substrate 10 caused by arcs generated on the surface of the grid 200 due to a partial concentration phenomenon caused by the concentration phenomenon of ions and electrons on the top of the grid 200.

[0096] 6, the grid 200 may have a dual grid structure including an upper grid 210 and a lower grid 220. At this time, the upper grid 210 and the lower grid 220 are supplied with different voltages (V g1 , V g2 That is, the upper grid 210 is supplied with a voltage of, for example, 50 to 100 V so that the grid alone can induce the electric charge inside the vacuum chamber C, and the lower grid 220 is supplied with a voltage of 300 to 500 V so that the electric charge that has entered the grid hole has sufficient kinetic energy to be discharged to the substrate below.

[0097] In the dual grid structure, when the electric charge between the charged particle generator 100 and the grid 200 collides with the surface of the grid 200, it is guided to the grid hole by the low voltage of the upper grid 210, so that it is possible to prevent phenomena such as ARC from occurring on the upper part of the grid. g The charges are more widely distributed through the holes of the upper grid 210 and the lower grid 220 that are spaced apart from each other, so that the uniformity of the charges discharged toward the substrate 10 can be improved.

[0098] In addition, the grid 200 having the dual grid structure may be implemented by setting the grid hole diameter of the lower grid 220 to be 10 to 20% or more smaller than the grid hole diameter of the upper grid 210 to generate additional secondary electrons within the grid 200, thereby increasing the density of charges emitted toward the substrate 10.

[0099] That is, the upper grid 210 serves as a cathode that emits secondary electrons and is made of aluminum or anodized Al, Carbon, CNT, or other materials. When a negative voltage of -50 to -150V is applied to the lower grid 220, ions formed between the lower grid 220 and the substrate 10 are provided to the upper grid 210, and when a larger negative voltage, for example, a voltage of -200 to -1000V, is applied to the upper grid 210, the ions collide with the lower surface of the upper grid (cathode) to generate secondary electrons. Accordingly, the ions formed between the lower grid 220 and the substrate 10 by the VUV are supplied to the upper grid 210. 3 cm 2 By simultaneously emitting electrons of about 100 nm and secondary electrons additionally generated inside the grid 200 toward the substrate 10, the electron density applied to the substrate 10 is about 100 nm. 6 ~10 8 cm 2 This results in higher process efficiency.

[0100] As shown in Fig. 6B, the lower surface of the upper grid 210 may be configured to have roughness to broaden the direction of movement of secondary electrons and improve uniformity. The generation of secondary electrons through such a dual grid structure does not generate radicals having chemical properties, making it possible to perform a process that does not damage the substrate 10. In particular, the electron beam can inject high density electrons into a specific location in a short time during static electricity injection, minimizing physical impact on the substrate 10.

[0101] Meanwhile, the substrate support 300 is formed in a plate shape made of a dielectric or conductive material and provides kinetic energy to the charges emitted from the grid 200 by the bias voltage supplied from the static electricity adjustment controller 400 so that the charges move toward the substrate 10 at a preset density.

[0102] In this case, the substrate support 300 is divided into a number of regions, and the static electricity adjustment controller 400 may be configured as shown in FIG 5. In the case where the grid 200 is divided into regions and each region is supplied with a voltage individually, the substrate support 300 may be divided into the same region as the grid 200 and each region of the grid 200 may be supplied with a bias voltage with the same polarity and voltage difference. Also, only the grid 200 may be divided into a number of regions, and the substrate support 200 may not be divided into a number of regions. The grid 200 and the substrate support 200 may be divided into regions having different shapes, and when the static electricity adjustment level is different for each region, the voltages applied to the grid 200 and the substrate support 300 may have different voltage differences for each region. Accordingly, static electricity injection and static electricity removal processes may be performed simultaneously for different regions of the substrate 10.

[0103] In addition, a rotating unit 310 for rotating the substrate support 300 may be additionally provided below the substrate support 300, and the rotating unit 310 rotates the substrate support 300 at 1 to 30 RPM during the static electricity adjustment process under the control of the static electricity adjustment controller 400.

[0104] In addition, in this embodiment, it is preferable that the distance between the grid 200 and the substrate 10 is set to within four times the free travel distance of the process gas according to the internal environmental conditions of the vacuum chamber C.

[0105] At this time, the process gas free path length (λ) can be calculated by the following Equation 1.

[0106]

number

[0107] where K is the Boltzmann constant, T is the temperature, P is the pressure, and D is the process gas particle diameter.

[0108] The inventors conducted an electrostatic charging experiment using a 300 mm silicon wafer by using a turbo vacuum pump in a chamber of a general semiconductor manufacturing device, which is 330 mm (diameter) x 150 mm (height). As a result, when the distance between the grid 200 and the substrate 10 is arranged to deviate from the free path distance (10 mm) by a certain amount or more and a bias power supply is not supplied to the substrate support 300, the electrostatic charging of the 300 mm silicon.SiO 2 When using a 100nm deposition wafer, the process conditions were pressure 30mtorr, 5sccm, distance between substrate and grid 100mm, and grid voltage +250V. After 30 seconds, the substrate 10 voltage was +80 volts, which was significantly different from the expected voltage of -10V.

[0109] In contrast, under the same process conditions as above, when the distance between the substrate 10 and the grid 200 was set to 10 mm, which is the free path distance due to the process gas and pressure, and a bias voltage of 200 V was supplied to the substrate 10, the voltage of the substrate 10 was induced to the desired −10 V. This confirmed that the distance between the substrate 10 and the grid 200 and the bias voltage to the substrate support 300 are important variables in controlling static electricity on the substrate 10.

[0110] Also, as shown in Fig. 7, it was confirmed that the efficiency of static electricity injection and removal was shown to satisfy a certain range even when the distance between the grid 200 and the substrate 10 was increased to 40 mm, which is four times the free path distance (10 mm) in the process gas environment. In Fig. 7, (A) shows the experimental results for the static electricity injection process, and as a result of measurement using Semilab's QC 3000e system, it was confirmed that the same static electricity voltage was maintained on the substrate 10 under the above-mentioned process gas conditions up to the distance between the grid 200 and the substrate 10 being 40 mm, which is four times the free path distance (10 mm) in the process gas environment.

[0111] In FIG. 7, (B) shows the experimental results for the static electricity removal process. Measurements were taken using Semilab's QC 3000e system. Under the process gas conditions described above, static electricity is removed and the static electricity voltage converges to "0" when the distance between the grid 200 and the substrate 10 is up to 40 mm, which is four times the free path distance (10 mm) in the process gas environment, but static electricity is re-generated at distances greater than this.

[0112] It was confirmed that the efficiency of electrostatic injection and removal due to the free path distance of electrons and cations is influenced by the difference in size of molecules compared to the process gas, or the selective extraction of electrons or cations above the grid where ions and electrons are formed due to the grid voltage, the bias electric field of the substrate support, and the rapid vacuum pumping effect.

[0113] Meanwhile, the static electricity adjustment controller 400 controls the voltage supplied to each device so that ions or electrons are supplied to the substrate 10 at a desired density, thereby injecting static electricity onto the substrate or removing static electricity formed on the substrate 10. The static electricity adjustment controller 400 adjusts the power supply level by adjusting the pulse period when power is supplied to the grid 200 and the substrate support 300.

[0114] In the static electricity injection mode, the static electricity adjustment controller 400 supplies voltage so that the voltage difference between the grid 200 and the substrate support 300 is at least twice, for example, at least 2.5 times. That is, the bias voltage applied to the substrate support 300 is set to be at least 2.5 times higher than the voltage applied to the grid 200.

[0115] In addition, the static electricity adjustment controller 400 performs voltage supply so that the voltage difference between the grid 200 and the substrate support 300 is within a preset similar range, for example, the same, in the static electricity removal mode.

[0116] In addition, the static electricity adjustment controller 400 supplies power such as DC, DC Pulse, or reverse pulse, AC, or RF to the grid 200 and the substrate support 300. When supplying a voltage in the form of a pulse, the static electricity adjustment controller 400 supplies voltage so that the grid 200 and the substrate support 300 are synchronized with each other, thereby increasing the efficiency of static electricity injection and removal.

[0117] In addition, since the density of ions and electrons may change due to changes in the gas flow rate, vacuum level, pumping speed, etc. within the vacuum chamber C, and fine adjustment of the density is not possible with a DC power supply, the static electricity adjustment controller 400 adjusts the pulse on / off period or polarity of the pulse-type power supply applied to the grid 200 and the substrate support 300 to more accurately adjust the static electricity voltage, thereby preventing overshooting from occurring on the substrate 10.

[0118] That is, when a bias voltage is supplied to the substrate support 300, the charged particles that pass through the grid 200 are accelerated toward the substrate 10 by electrical attraction, and the charged particles accelerated toward the substrate 10 charge the substrate 10 with static electricity or neutralize the static electricity formed on the substrate 10.

[0119] When removing static electricity using electrons, the movement speed of electrons is faster than that of cations, so a negative (-) overcharge phenomenon, i.e., excessive static electricity may occur in the insulating thin film on the surface of the substrate 10. Therefore, the static electricity adjustment controller 400 may increase or decrease the bias voltage to the substrate support 300 in a stepped manner.

[0120] In addition, the static electricity adjustment controller 400 adjusts the voltage level of the voltage supplied to the grid 200 or the substrate support 300 at regular time intervals (several seconds) during static electricity injection, or interrupts the supply of voltage and sets an automatic neutralization time at regular intervals, thereby preventing overcharging of the surface without affecting the extremely fine patterns of several nanometers formed on the surface of the substrate 10.

[0121]

[0122] Next, the operation of the static electricity control apparatus of the semiconductor processing system having the above-mentioned configuration will be described with reference to FIG.

[0123] First, a substrate 10 having an insulating film formed thereon is placed on a substrate support 300 provided in a vacuum chamber C. At this time, the insulating film formed on the surface of the substrate 10 is formed of SiO 2 using plasma or an atomic layer deposition method. 2 , Si 3 N 4 The material may be polysilicon, doped oxide, etc., and the thickness may vary from 10 nm to 200 nm.

[0124] Next, the static electricity adjustment control unit 400 calculates the free path distance of the process gas corresponding to the environmental conditions of the vacuum chamber using Equation 1 (ST100). At this time, various information including temperature, pressure, and size of the process gas molecules for calculating the free path distance of the process gas may be input in advance by an administrator.

[0125] Then, the static electricity adjustment control unit 400 controls the distance adjustment unit 500 to adjust the position of at least one of the grid 200 or the substrate support 300 upward or downward so that the distance between the grid 200 and the substrate 10 is within four times the process gas free travel distance calculated in step ST100 (ST200).

[0126] In this state, the static electricity adjustment control unit 400 supplies process gases to the inside of the vacuum chamber C under preset environmental conditions to set up a vacuum environment.

[0127] In addition, the static electricity adjustment control unit 400 generates VUV through the charged particle generation unit 100, and generates charged particles such as positive ions and electrons through a reaction between the VUV and the process gas. Generally, the ion density by the VUV has a large deviation depending on the pressure, but it is about 10 3 ~10 4 / cm 2 On the other hand, the static electricity capacity required for the substrate 10 is about 10 8 ~10 9 cm 2 However, electrostatic injection requires a long process time. The ion density is increased to 10 by additionally using a line beam shaped ion beam using plasma. 6 ~10 7 cm 2 4A, when a line-shaped beam is emitted from the side of the vacuum chamber C, no radicals having chemical properties are generated in the vacuum chamber C, so the static electricity injection process can be performed without damaging the substrate 10. By shortening the process time, the time that the VUV contacts the insulating film can be minimized, which not only reduces changes in the insulating properties of the insulating film but also improves productivity.

[0128] In the above state, when the static electricity injection mode is set by the administrator (ST300), the static electricity adjustment controller 400 applies a preset voltage to the grid 200 and the substrate support 300, but supplies a bias voltage applied to the substrate support 300 that is at least twice as high as the voltage applied to the grid 200 (ST400). At this time, the voltage applied to the grid 200 is set higher than the voltage applied to the grid 200 in the static electricity removal mode, and a pulse-type voltage can be applied to at least one of the grid 200 and the substrate support 300.

[0129] In addition, in step ST300, the administrator sets the electrostatic voltage to be injected into the substrate 10, and the electrostatic adjustment control unit 400 calls up pre-stored voltage information to be supplied to the grid 200 and the substrate support 300 corresponding to the electrostatic voltage requested by the administrator, and supplies the corresponding power to the grid 200 and the substrate support 300 accordingly.

[0130] In other words, when the distance between the grid 200 and the substrate support 300 is set within four times the free travel distance of the process gas, the charged particles generated in the charged particle generator 100 selectively pass through the fine holes due to the voltage of the grid 200 and move toward the substrate 10, and the charged particles are emitted toward the substrate 10 at a higher density due to the high voltage applied to the substrate support 300.

[0131] Meanwhile, when the distance between the grid 200 and the substrate support 300 is adjusted to within four times the free travel distance of the process gas (ST200), and the static electricity removal mode is set by the administrator (ST500), the static electricity adjustment controller 400 applies a preset voltage to the grid 200 and the substrate support 300, but sets the voltage applied to the grid 200 and the bias voltage applied to the substrate support 300 to be the same or within a similar range (ST600). Here, a pulse-type voltage may be applied to at least one of the grid 200 and the substrate support 300.

[0132] At this time, in step ST500, the administrator sets the static electricity removal voltage for the substrate 10, and the static electricity adjustment control unit 400 calls up voltage information to be supplied to the grid 200 and the substrate support 300 that has been pre-stored to correspond to the static electricity removal voltage requested by the administrator, and supplies the corresponding power to the grid 200 and the substrate support 300 accordingly.

[0133] That is, the static electricity on the surface of the substrate is removed in the same manner as in the static electricity injection process, but the static electricity embedded inside the multilayer film of the substrate 10 is neutralized by passing through the multilayer film with 100 nm to 200 nm VUV having energy larger than the band gap of each insulating film and separating the static electricity into pairs of holes and electrons, while the static electricity on the upper part of the substrate 10 is neutralized by using electrons and ions formed by VUV, electron beam, and ion beam. For example, the VUV energy in the 120 nm wavelength band is 10.33 eV, the silicon energy is 1.1 eV, and the SiO 2 The energy is 9 to 10 eV.

[0134] Meanwhile, in the present invention, when the grid 200 and the substrate support 300 have a multi-zone structure, the static electricity adjustment control unit 400 can control the grid 200 and the substrate support 300 to inject static electricity into certain parts of the substrate 10 and remove static electricity from other parts of the substrate 10 by supplying different voltages corresponding to static electricity injection and static electricity removal to each region of the grid 200 and the substrate support 300.

Claims

1. 2. A static electricity control device for a semiconductor processing system for injecting static electricity onto a substrate disposed in a vacuum chamber or removing static electricity formed on the substrate, a charged particle generator disposed in an upper portion of the inside of the vacuum chamber, generating VUV (Vacuum Ultraviolet Ray) and generating charged particles including positive ions and electrons by reacting the VUV with a process gas inside the vacuum chamber; a grid having a number of holes disposed under the charged particle generator and selectively passing the charged particles therethrough in response to an input voltage; a substrate support disposed under the grid, the substrate being positioned on an upper surface of the substrate support, and guiding the charged particles passing through the grid toward the substrate at a preset density by an input bias voltage; a static electricity control controller for controlling static electricity of the substrate by supplying a pulse-type voltage to at least one of the grid and the substrate support; The grid and the substrate support are disposed at a distance apart from each other that is within four times the free travel distance of a process gas under environmental conditions of a vacuum chamber.

2. The static electricity adjustment control unit is 2. The static electricity control device of claim 1, wherein in the static electricity injection mode, a bias voltage applied to the substrate support is higher than a voltage applied to the grid by a predetermined level or more, and in the static electricity removal mode, the voltage applied to the grid and the bias voltage applied to the substrate support are within a predetermined similarity range.

3. The static electricity adjustment control unit is 3. The electrostatic control device of claim 2, further comprising a step of controlling a period of a pulse applied to the grid and the substrate support to control a voltage level.

4. The charged particle generator includes:

2. The static electricity conditioning device of claim 1, comprising one or more VUV lamps for emitting VUV light.

5. Below the VUV lamp, 5. The electrostatic control device of claim 4, further comprising a beam generator for emitting a line-shaped ion beam through a side of the vacuum chamber, and for simultaneously generating charged particles due to a reaction between the VUV and the process gas and charged particles due to a reaction between the ion beam and the process gas, thereby increasing the charged particle density.

6. 2. The static electricity control device of claim 1, wherein the charged particle generating unit comprises a plasma generator for generating plasma, and a separation plate below the plasma generator that transmits only VUV, and generates the charged particles by a reaction between the VUV generated in the plasma generator and a process gas.

7. 7. The static electricity control device for a semiconductor processing system according to claim 6, wherein the plasma generator comprises at least one microplasma device that generates plasma using a power source in the range of 10 to 200 W in a vacuum environment in which the volume of a vacuum chamber is in the range of 500 to 1000 cc.

8. The static electricity adjustment control unit is 8. The static electricity control device for a semiconductor processing system according to claim 7, wherein the static electricity of the substrate is controlled by controlling at least one of the type of process gas injected into the vacuum chamber of the microplasma device and a plasma power source.

9. the plasma generator includes a number of microplasma devices; 9. The static electricity control device of claim 7 or 8, wherein the static electricity control controller controls the type of process gas or the plasma power source injected into the vacuum chamber of each microplasma device to control static electricity of the substrate.

10. the plasma generator includes a number of microplasma devices; The separation plates are arranged in one-to-one correspondence with each of the microplasma devices, The static electricity adjustment control unit adjusts the static electricity of the substrate by individually controlling the type of process gas injected into the vacuum chamber of each microplasma device or the plasma power source.

9. The electrostatic control device of claim 7, wherein each of the separation plates further comprises a lens having a different divergence angle.

11. 2. The electrostatic conditioning device of claim 1, wherein the grid and the substrate support are of a multi-zone type in which a number of regions are electrically isolated from each other, and the electrostatic conditioning controller individually supplies voltages of different levels to each region of the grid and the substrate support.

12. 12. The static electricity control device of claim 11, wherein the static electricity control controller applies voltages to each region of the grid and the substrate support so as to inject static electricity into a certain portion of the substrate and remove static electricity from other portions of the substrate.

13. The grid includes an upper grid and a lower grid disposed below the upper grid, 2. The electrostatic conditioning apparatus of claim 1, wherein the electrostatic conditioning controller supplies voltages of different levels to the upper grid and the lower grid.

14. a diameter of a hole formed in the lower grid is set to be different from a diameter of a hole formed in the upper grid, 14. The static electricity control device of claim 13, wherein the static electricity control controller applies a negative voltage of a first level to the lower grid to induce ions between the lower grid and the substrate toward the upper grid through the holes in the lower grid, and then applies a negative voltage higher than the first level to the upper grid to cause the ions flowing in through the lower grid to collide with a lower surface of the upper grid to generate secondary electrons, thereby discharging higher density electrons toward the substrate through the holes in the lower grid.

15. 14. The static electricity control device of claim 1, 11, or 13, wherein a hole aperture ratio in the center portion of the grid is higher than a hole aperture ratio in a peripheral region.

16. A distance adjustment unit is further provided for vertically moving the grid and the substrate support in the vacuum chamber, 2. The static electricity control device of claim 1, wherein the static electricity control controller controls the distance adjustment unit to change the position of at least one of the grid or the substrate support to an upper or lower position based on a process gas free path distance calculated according to environmental conditions of the vacuum chamber.

17. 2. The static electricity control device of claim 1, wherein the grid surface is coated or sputtered with a film containing a carbon component, such as carbon, CNT, or glassy carbon, to prevent the generation of arcs.

18. The grid surface is coated with silicon oxide (SiO ２ ), aluminum oxide (Al ２ O ３ ), silicon nitride (Si ３ N ４ 2. The static electricity control device for a semiconductor processing system according to claim 1, wherein the generation of arcs is prevented by coating or sputtering one of a thin oxide film.

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