Electrostatic Removing Device for Semiconductor Substrate

Abstract

The present invention relates to an apparatus for neutralizing static electricity formed on a semiconductor substrate and a pattern located on the semiconductor substrate using VUV light, and more specifically, to a technology for easily removing static electricity embedded within a thin film on a large-area semiconductor substrate by expanding the range of VUV light irradiated onto the semiconductor substrate. The electrostatic removal device for a semiconductor substrate according to the present invention is an electrostatic removal device for a semiconductor substrate that removes static electricity formed on a semiconductor substrate arranged inside a vacuum chamber by irradiating the semiconductor substrate with VUV (Vacuum Ultraviolet Ray) light, and is characterized in that it includes a VUV generator that is arranged above the vacuum chamber and has a VUV lamp that emits narrowband VUV light inside the vacuum chamber, and a light diffusion unit that is arranged below the VUV generator and diffuses the incident VUV light into a wideband and outputs it to the semiconductor substrate located below.

Description

Technical Field

[0001] The present invention relates to an apparatus for neutralizing static electricity formed on a semiconductor substrate and a pattern located on the semiconductor substrate using VUV light. More specifically, the present invention relates to a technique for expanding the range of VUV light irradiated on the semiconductor substrate side so as to easily remove static electricity (Embedded) embedded in a thin film on a large-area semiconductor substrate.

[0002]

Background Art

[0003] Recently, as the integration of the semiconductor industry increases, the size of semiconductor elements tends to decrease. As a result, the size of patterns forming semiconductor elements and the thickness of thin films are decreasing, and factors that have not significantly affected in the past are tending to emerge as important elements in semiconductor element development. One of these elements is static electricity formed on the substrate.

[0004] The causes of static electricity formed on a semiconductor substrate include the use of deionized water from which ions have been removed, charge transfer from a charged plastic material, or induction charge.

[0005] Such static electricity on a semiconductor substrate is mainly generated in a photolithography process or a cleaning process using rotational motion, and it is known that the most static electricity concentrates in the central part due to the difference in centrifugal force. That is, in the high-speed rotation of a wafer in a photoresist coating process, the concentration of the air flow in the central part of the substrate is more than three times higher than that of the outer periphery, and static electricity is formed mainly around the central part where the centrifugal force is relatively weak. In particular, static electricity due to a strong electric field formed in the central part is charged into the photoresist pattern formed inside and on the surface of the multilayer film on the wafer.

[0006] FIG. 1(A) illustrates the shape in which electrostatic voltages of -50V, -30V, and -10V appear from the central portion of the semiconductor substrate 1 toward the outer periphery side.

[0007] However, as shown in FIG. 1(A), when the center of the semiconductor substrate 1 is charged at a high voltage, in the region corresponding to the central portion of the substrate in FIG. 1(B) (the region where the electrostatic voltage is -50V in FIG. 1(A)), not only the surface of the semiconductor substrate 1 such as a photoresist pattern (PR, Photo Resist) or an oxide film which is an insulator, but also charges are charged to a certain depth D from the substrate surface, and a state may occur in which neutralization by ions having low kinetic energy is impossible. Such an electrostatic voltage charged on the semiconductor substrate has many variables such as the type of process, materials, and pattern shape, and is generally formed between -200V and +200V.

[0008] In relation to this, Patent Document 1 (Korean Registered Patent No. 10-1698273) and Patent Document 2 (Korean Published Patent No. 10-2004-0040106) disclose configurations for removing static electricity of a semiconductor substrate using an ionizer.

[0009] For example, as shown in FIG. 1(B), when a charge voltage of 100V or less is formed on the semiconductor substrate 1 such that an insulating film within a fine circuit of 10 nm or less or a pattern P having an aspect ratio of "5" or more is formed, the pattern width becomes narrow, and due to the self-neutralization effect between cations and anions generated by the ionizer and the low electromotive force due to the low voltage difference between the semiconductor substrate and the ions, reducing the collision of ions, it is difficult to remove the static electricity accumulated inside the thin film on the substrate.

[0010] Also, reducing the static electricity filled in the semiconductor substrate at 1000V to within 100V with a soft X-ray ionizer requires a decay time within 1 to 2 seconds. However, when an initial charge voltage of 100V or less is formed, it takes a long time to reduce the charge voltage to below the desired voltage.

[0011] In addition, the ionizer generates ultraviolet rays to remove static electricity on the substrate. However, the divergence angle of the ultraviolet rays emitted from the lamp of the ionizer is very small, about ±7°, and for removing static electricity from a large-area semiconductor substrate, a very long separation distance is required between the ionizer and the semiconductor substrate. That is, not only is there a problem that the size of the vacuum chamber for performing the static electricity removal process of the semiconductor substrate must be designed larger corresponding to the semiconductor substrate area, but also, since the energy of the ultraviolet rays rapidly decreases according to the irradiation distance, a long static electricity removal time is required for removing static electricity above a certain level filled in the semiconductor substrate.

[0012] In addition, generally considering that the ion density of the ionizer is 10 6 when considering that the ion density inside the oxide film under the photoresist in the semiconductor substrate is 10 8 or more, the static electricity formed on the semiconductor substrate cannot be removed using a conventional ionizer.

[0013] In such a case, there may be a method of generating a high-density plasma of 10 9 or more in the vacuum chamber to remove the static electricity of the semiconductor substrate.

[0014] However, in the case of the vacuum chamber configuration, a problem may occur in that the ion beam is further charged over the entire surface due to the self-bias and plasma uniformity according to the plasma type. Also, on the semiconductor substrate, fine circuits may be formed in a non-uniform pattern, and static electricity of different voltages can be charged for each part according to the characteristics of the pattern. That is, depending on the part of the semiconductor substrate, a static electricity voltage of -100 to +100 V can be distributed.

[0015] Therefore, when ions are uniformly supplied to the substrate, ions of the same intensity are emitted onto the semiconductor substrate over the entire surface of the substrate, and thus, in a region where a voltage level higher than the static electricity voltage generated on the semiconductor substrate is applied, overcharging may further occur.

[0016] Furthermore, when charges are filled inside the oxide film and / or the pattern, ions must be provided with high energy to neutralize the static electricity. However, if the substrate is irradiated with reactive radicals and / or reactive ions at high energy, there is a possibility of colliding with the substrate and the pattern formed on the surface of the substrate, causing damage.

[0017] In particular, in the case of a semiconductor substrate with an ultra-fine structure with a pattern of 10 nm or less, the performance and yield of semiconductor elements will be more affected by charges due to cations, anions, or electrons.

Summary of the Invention

Problems to be Solved by the Invention

[0018] Here, the present invention has been created in view of the above circumstances. By expanding the narrow-area VUV light generated from a VUV generator through a diffractive optical element and irradiating it onto the semiconductor substrate side, the area of the vacuum chamber does not need to be expanded, and static electricity formed on a large-area semiconductor substrate can be easily neutralized. The technical objective is to provide an electrostatic removal device for a semiconductor substrate.

[0019] Also, according to the present invention, different voltages are supplied to a plurality of electrode regions in mutually separated and different regions, and VUV light corresponding to the electrostatic voltage formed on the semiconductor substrate is emitted to the semiconductor substrate through holes formed on the electrode regions, so that charged static electricity embedded (Embedded) inside the thin film on the semiconductor substrate can be accurately and quickly removed in a short time. Another technical objective is to provide an electrostatic removal device for a semiconductor substrate.

Means for Solving the Problems

[0020] According to one aspect of the present invention for achieving the above object, in an electrostatic removal device for a semiconductor substrate that irradiates a semiconductor substrate disposed inside a vacuum chamber with VUV (Vacuum Ultraviolet Ray) light to remove electrostatic charges embedded in a thin film on the semiconductor substrate, a VUV generator disposed above the vacuum chamber and equipped with a VUV lamp that emits narrow-band VUV light inside the vacuum chamber, and a light diffusing unit disposed below the VUV generator, which diffuses the incident VUV light over a wide band and outputs it to the semiconductor substrate located below, are provided, and an electrostatic removal device for a semiconductor substrate is characterized by being configured to include these components.

[0021] Also, according to another aspect of the present invention for achieving the above object, in an electrostatic removal device for a semiconductor substrate that irradiates a semiconductor substrate disposed inside a vacuum chamber with VUV light to remove electrostatic charges formed on the semiconductor substrate, a plasma generator disposed above the vacuum chamber, which forms plasma by reacting with a process gas to emit VUV light inside the vacuum chamber, and a light diffusing unit disposed below the plasma generator, which diffuses the incident VUV light over a wide band and outputs it to the semiconductor substrate located below, are provided, and an electrostatic removal device for a semiconductor substrate is characterized by being configured to include these components.

[0022] Also, an electrostatic removal device for a semiconductor substrate is provided, characterized in that the light diffusing unit is a beam splitter.

[0023] Also, an electrostatic removal device for a semiconductor substrate is provided, characterized in that the light diffusing unit is composed of a metal mesh or a metal plate formed with a plurality of holes.

[0024] Also, an electrostatic removal device for a semiconductor substrate is provided, characterized in that the light diffusing unit has a multi-lens array structure in which a plurality of microlenses are arranged on a substrate made of one of MgF2, CaF2, LiF, or sapphire.

[0025] Also, below the light diffusing portion, a grid plate having a structure in which a central electrode region of a certain size disposed in the central portion and one or more peripheral electrode regions having one or more bands are disposed around the central electrode region and the electrode regions are separated is further disposed and configured. The electrode regions are formed of a metal material with a plurality of holes formed therein, and different voltages are supplied to each electrode region. An electrostatic removal device for a semiconductor substrate is provided.

[0026] Also, inside the vacuum chamber, a separation plate that separates an upper space and a lower space with reference to the light diffusing portion is further provided and configured. The light diffusing portion is formed on the separation plate. An electrostatic removal device for a semiconductor substrate is provided.

[0027] Also, in the upper space and the lower space of the vacuum chamber, a vacuum setting portion for setting the vacuum state of the space is respectively provided and configured. The degree of vacuum in the upper space is set higher than the degree of vacuum in the lower space. An electrostatic removal device for a semiconductor substrate is provided.

[0028] Also, the substrate support base is made of a metal material, and a positive (+) or negative (-) bias voltage is supplied. However, in order to induce electrons to the semiconductor substrate 1 side, a positive (+) bias voltage is supplied, and in order to induce ions to the semiconductor substrate 1 side, a negative (-) bias voltage is supplied. An electrostatic removal device for a semiconductor substrate is provided.

[0029] Also, on the upper side of the vacuum chamber, a plurality of VUV generators that emit VUV at regular intervals are disposed. The light diffusing portion expands and outputs a large number of VUV lights emitted from the VUV generators to the entire surface of the semiconductor substrate. An electrostatic removal device for a semiconductor substrate is provided.

[0030] In addition, a plurality of plasma generators that emit VUV at regular intervals are arranged above the vacuum chamber. The light diffusion unit expands and outputs a large number of VUV lights emitted from the VUV generators to the entire surface of the semiconductor substrate. Each of the plasma generators is configured to emit VUV in different bands by reacting with different process gases. There is provided an electrostatic removal device for a semiconductor substrate characterized by this.

[0031] Also, a rotating means for rotating the substrate support while VUV light is emitted from the VUV generator is provided and configured below the substrate support for supporting the semiconductor substrate. The light diffusion unit is composed of at least one light diffusion module that is eccentrically located from the center of the semiconductor substrate. There is provided an electrostatic removal device for a semiconductor substrate characterized by this.

[0032]

Advantages of the Invention

[0033] According to the present invention, the output range of VUV irradiated from the inside of the vacuum chamber to the semiconductor substrate side is expanded, and the static electricity formed on a large-area semiconductor substrate can be easily neutralized without expanding the area of the vacuum chamber.

[0034] In addition, by adjusting the power applied to the grid plate so as to correspond to the static electricity charged on the semiconductor substrate and adjusting the amount of VUV light irradiated to the semiconductor substrate side, the static electricity charged differently on the semiconductor substrate can be accurately removed, minimizing the defective rate in the semiconductor manufacturing process. Of course, a more reliable semiconductor element can be manufactured.

Brief Description of the Drawings

[0035]

Figure 1

[0036]

Figure 2

[0037]

Figure 3

[0038]

Figure 4

[0039]

Figure 5

[0040]

Figure 6

[0041]

Figure 7

[0042]

Figure 8

[0043]

Figure 9

Embodiments for Carrying Out the Invention

[0044] The embodiments described in the present invention and the configurations shown in the drawings are merely preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, the scope of the rights of the present invention should not be construed as being limited by the embodiments and drawings described in the text. That is, since the embodiments can be variously modified and can have various forms, the scope of the rights of the present invention should be understood to include equivalents that can implement the technical idea. Also, since the objects and effects presented in the present invention do not mean that a specific embodiment should include all of them or should include only such effects, the scope of the rights of the present invention should not be understood to be limited thereby.

[0045] All terms used in this specification shall have the same meaning as commonly understood by those having ordinary knowledge in the field to which the present invention pertains, unless otherwise defined. Terms defined in commonly used dictionaries should be construed to be consistent with the meaning in the context of the related art and should not be construed to have an ideal or overly formal meaning not clearly defined in the present invention.

[0046]

[0047] FIG. 2 is a diagram schematically showing an electrostatic removal device for a semiconductor substrate according to a first embodiment of the present invention.

[0048] Referring to FIG. 2, in the electrostatic removal device for a semiconductor substrate according to the present invention, a VUV generator 100 is disposed above a vacuum chamber CM in which a semiconductor substrate 1 is disposed. Inside the vacuum chamber CM, a light diffusion unit 200 that expands and outputs the emission range of VUV emitted from the VUV generator 100 is disposed. Below the light diffusion unit 200, the semiconductor substrate 1 is disposed on the upper surface of a substrate support base 10. And the devices disposed inside the vacuum chamber CM are controlled via a control device (not shown).

[0049] The VUV generator 100 can consist of a VUV (Vacuum Ultraviolet Ray) ionizer. The VUV ionizer generates VUV light with a wavelength in the 110 nm to 400 nm band inside the vacuum chamber CM. The VUV light reacts with the process gas inside the vacuum chamber CM to decompose gas particles, generating cations and electrons while irradiating the semiconductor substrate 1 side. At this time, the VUV ionizer emits VUV, which is light energy greater than the band-gap of the thin film, to the thin film with accumulated static electricity on the lower side of the substrate, forming electron-hole pairs inside the thin film, thereby neutralizing the static electricity embedded on the semiconductor substrate 1.

[0050] At this time, the VUV ionizer emits VUV inside the vacuum chamber CM through a deuterium lamp. The light divergence area of the VUV emitted through the deuterium lamp is about 10 mm × 10 mm, and the light divergence angle is about ±7°.

[0051] The light diffusing unit 200 expands and outputs the divergence angle of the VUV emitted from the VUV generator 100 and can consist of a diffractive optical element (DOE, Diffractive Optical Element).

[0052] The DOE is an optical element that diffuses the optical path using the diffraction phenomenon caused by the structure inside or on the surface of the lens. It is manufactured using Fresnel Lens, Binary Optics, Fresnel Zone Plate, Hybrid Lens, etc., and there are elements such as Beam Shaping, Dlite Beam Splitter, Transmission Grating Random Dot Generation. In particular, a diffractive spot beam splitter can be used, and such a beam splitter can consist of MgF2, CaF2, LiF, or sapphire.

[0053] Further, the light diffusing part 200 can be composed of a board made of a metal material having a plurality of holes. For example, as shown in FIG. 3(A), the metal board can be made of a mesh of a metal material, that is, a metal mesh, or a metal plate having a certain thickness and formed with a plurality of holes H.

[0054] The metal board reflects the VUV emitted from the VUV generator 100 by the metal material and emits it downward while diffusing it to the surroundings through the holes. For example, the light reflectivity of the metal board has a reflectivity of 70 - 80% in the 120 nm wavelength band in the case of aluminum (Al) polished with UV.

[0055] Further, the light diffusing part 200 can be composed of a multi - lens array structure in which a plurality of lenses are arranged.

[0056] As shown in FIG. 3(B), the multi - lens array is formed by arranging a large number of microlenses L on a substrate I, forming a pattern with photoresist on the substrate I made of one of MgF2, CaF2, LiF or sapphire, and then forming the microlens array using plasma such as ICP. At this time, a 2 μm microlens array with a size of 20 mm × 20 mm whose light width is expanded by 5 times or more is arranged in the central part of the substrate I, and the distance from the semiconductor substrate 1 is arranged within 100 mm. As a result of the experiment, considering the pump - out time during the 300 mm wafer process, etc., it was confirmed that there is an effect that the efficiency increases by 30% or more without rotating the semiconductor substrate 1. Considering the size of the semiconductor substrate 1, this means that static electricity can be removed with only one VUV lamp compared to a structure where three or more VUV lamps had to be arranged conventionally, and when using a plurality of them, an over - dose caused by VUV generated partially can be prevented.

[0057] The light diffusing part 200 with such a structure expands the light in a narrow band range with a size of 10 mm × 10 mm emitted from the VUV generator 100, for example, to a wide band range with a size of 300 nm × 300 mm and emits it downward.

[0058] Then, the VUV emitted to the semiconductor substrate 1 through the light diffusing part 200 penetrates into the SiO2 layer of the semiconductor substrate 10 and generates holes and electrons in the oxide, thereby removing the charges stored in the film, that is, static electricity.

[0059] At this time, since the VUV emitted from the VUV generator 100 is severely attenuated in energy depending on the internal vacuum degree of the vacuum chamber CM, it is preferable to set the vacuum degree of the vacuum chamber CM where the VUV is emitted to 10 -4 Torr to minimize the energy attenuation of the VUV.

[0060] Also, it is preferable to minimize the distance between the VUV generator 100 and the light diffusing part 200 to minimize the VUV energy attenuation emitted from the VUV generator 100.

[0061] Also, as shown in FIG. 4, the light diffusing part 200 can be disposed at the central portion of the separation plate 300 that separates the internal space of the vacuum chamber CM.

[0062] The separation plate 300 supports the light diffusing part 200 so that it is located inside the vacuum chamber CM, and while being in contact with the inner surface of the vacuum chamber CM, seals its inscribed portion in a vacuum to separate the inside of the vacuum chamber CM into an upper space S1 and a lower space S2 with the light diffusing part 200 as a reference.

[0063] At this time, the upper space S1 and the lower space S2 of the vacuum chamber CM may be respectively provided with vacuum forming parts 21 and 22 for injecting gas into the space to adjust the vacuum state. These vacuum forming parts 21 and 22 include a gas injection port for injecting gas into the space inside and a gas discharge port for discharging gas to the outside of the vacuum chamber, and the vacuum degrees of the upper space S1 and the lower space S2 can be set to be different.

[0064] For example, in the present invention, the upper space S1 of the vacuum chamber CM is set to a vacuum degree of 10 -4 Torr in consideration of the VUV energy attenuation characteristics emitted from the VUV generator 100, and the lower space S2 of the vacuum chamber CM can be set to 10 -2 Torr.

[0065] Also, different process gases can be injected into the upper space S1 and the lower space S2 of the vacuum chamber CM.

[0066] Further, the substrate support 10 provided inside the vacuum chamber CM is made of a metal material, and a certain level of bias voltage can be supplied to the substrate support 10. This is for the electrons and ions generated by the VUV light flowing into the semiconductor substrate 1 side to reach the lower film of the semiconductor substrate 1 while having a directionality. To induce electrons to the semiconductor substrate 1 side, a positive (+) bias voltage is supplied, and to induce ions to the semiconductor substrate 1 side, a negative (-) bias voltage is supplied. At this time, the bias voltage is set in the range of 1V to ±200V.

[0067]

[0068] On the other hand, in consideration of the fact that a pattern having an aspect ratio of a certain level or more is formed on the upper surface of the semiconductor substrate 1 to be electrostatically removed, the present invention can be configured to have a structure in which the optical path of VUV is vertically emitted to the semiconductor substrate 1 side.

[0069] For this purpose, as shown in FIG. 5, the present invention can be further configured by arranging a grid plate 400 having a plurality of holes formed on the lower side of the light diffusing portion 200. At this time, the grid plate 400 is arranged at a position having a separation distance within 100 mm from the semiconductor substrate 1, the size is set to be the same as or larger than the semiconductor substrate 1, and is configured in the same shape as the semiconductor substrate 1, for example, a circular or square shape.

[0070] The grid plate 400 is formed in a plate shape of a metal material having a thickness of 1 to 10 mm and includes a plurality of holes having a diameter of 0.1 to 5 mm. The aperture ratio of the entire holes can be set to 60% or more of the grid plate area, and it can be configured in a structure of a metal mesh or a metal plate provided with holes (see Fig. 3(A)).

[0071] That is, the grid plate 400 changes the optical path so that the upper VUV is reflected from the hole wall surface and is emitted to the semiconductor substrate 1 side while being incident on the semiconductor substrate 1, thereby improving the VUV penetration efficiency into the thin film formed with static electricity on the semiconductor substrate 1.

[0072] Such a grid plate 400 has a structure in which a central electrode region of a certain size arranged in the central portion and one or more peripheral electrode regions having one or more bands are arranged around the central electrode region, and the electrode regions are separated from each other.

[0073] For example, as shown in Fig. 6, the grid plate 400 can be configured such that a plurality of circular electrode regions LX having a certain area in an elliptical or concentric shape with different diameters are arranged in an annular shape separated by a certain distance in the outer direction with respect to the same center point.

[0074] At this time, each electrode region LX is arranged on the insulating plate I and is arranged to be electrically insulated from each other by the insulating plate I. The holes H formed on each electrode region penetrate through the insulating plate I. Here, the wall surface of the hole H of the insulating plate I can be coated with a metal substance such as aluminum (Al) or copper (Cu).

[0075] This is formed by forming the electrode regions according to the pattern characteristics that the static voltage formed on the semiconductor substrate 1 due to the semiconductor process characteristics is the highest at the central portion of the semiconductor substrate 1 and decreases toward the outside.

[0076] At this time, the electrode region in the central portion of the grid plate 400 may be configured in a disk shape having a constant area, and may be configured to form more holes H than the strip-shaped electrode region on the outside thereof. The diameter of the holes can be set to a size of 0.1 to 5 mm.

[0077] In the present invention, different voltages can be supplied to each electrode region LX of the grid plate 400. At this time, the amount of light is adjusted so as to neutralize different levels of electrostatic voltages formed in different regions formed on the semiconductor substrate 1 corresponding to the electrostatic voltage formed on the semiconductor substrate 1. For example, the voltage V1 of the electrode region LX in the central portion can be set to be the largest, and the voltage of the electrode region LX can be set to gradually decrease toward the outside thereof (V2 > V3 > V4 ···).

[0078]

[0079] On the other hand, in the above embodiment, a semiconductor process system including one VUV ionizer 700 in the central portion of the vacuum chamber CM has been described. However, as shown in FIG. 7, the present invention can also be applied to a semiconductor process system including two or more VUV ionizers 110 and 120 that output VUV at different positions above the vacuum chamber CM. FIG. 6 illustrates the shape in which the first and second VUV generators 110 and 120 are arranged.

[0080] At this time, as shown in FIG. 7(A), the light diffusing portion may be configured such that the first and second light diffusing portions 210 and 220 are arranged so as to correspond one-to-one to the positions corresponding to the first and second VUV generating portions 110 and 120.

[0081] Further, as shown in FIG. 7(B), the light diffusing portion may be composed of one light diffusing portion 200 having a size corresponding to the entire size of the first and second VUV generating portions 110 and 120.

[0082] At this time, a rotating means 500 for rotating the substrate support table 10 may be further provided on the lower surface of the substrate support table 10, and by rotating the substrate support table 10 while VUV light is generated by the electrostatic elimination process, the semiconductor substrate 1 can be rotated at a constant speed.

[0083] In the structure provided with the rotating means 500 in this way, the center of the light diffusing portion 200 may be eccentric from the center C of the semiconductor substrate 1 as shown in FIG. 7(A), and the diameter of the light diffusing portion 200 may be larger than or equal to the radius of the semiconductor substrate 1. Therefore, although the diameter of the light diffusing portion 200 is smaller than the diameter of the semiconductor substrate 10, when the semiconductor substrate 1 rotates, VUV is provided to the entire surface of the semiconductor substrate 1.

[0084] Also, even in a structure in which the light diffusing portion 200 includes a plurality of light diffusing portions 210 and 220, each of the light diffusing portions 210 and 220 may have a diameter smaller than the radius of the semiconductor substrate 1, and as shown in FIG. 8(B), each of the light diffusing portions 210 and 220 may be eccentric from the center C of the semiconductor substrate 1. At this time, the plurality of light diffusing portions 210 and 220 may be arranged so that there is no portion where VUV is not provided to the semiconductor substrate 1 when the semiconductor substrate 1 rotates, and may be arranged so that a larger amount of VUV trapped in the central portion of the semiconductor substrate 1 is irradiated.

[0085]

[0086] On the other hand, in the present invention, the electrostatic charge trapped in the semiconductor substrate 1 is removed using VUV emitted through the VUV ionizer 100. However, by providing a plasma generator instead of the VUV generator in the structures shown in FIGS. 1, 4, 5, and 7 to generate VUV, it can be configured to remove the electrostatic charge (Embedded) embedded in the thin film of the semiconductor substrate 1. FIG. 9 illustrates a structure including a plurality of plasma generators 700.

[0087] In one embodiment, the plasma generator 700 is a capacitively coupled plasma (CCP) forming device. Plasma is formed by providing RF, DC, high-frequency or low-frequency electrical signals to two separated metal electrodes located within the device. In one embodiment, the electrical signal provided to the plasma forming unit 110 can be a pulse or a continuous wave (CW).

[0088] In other embodiments, the plasma generator 700 is an inductively coupled plasma (ICP) forming device. A magnetic field is generated by passing a current through a coil located within the device, and the inductively coupled plasma forming device forms plasma from the thus-formed magnetic field. In one embodiment, the electrical signal provided to the plasma forming unit 110 is a pulse or a continuous wave (CW), and a signal in a band of 1 MHz or higher can be provided.

[0089] In still other embodiments, the plasma generator 700 can be a microwave providing device, and can provide an electrical signal in the RF band to an ultraviolet forming vacuum chamber to generate plasma. In one embodiment, the frequency of the electrical signal provided to the plasma generator is 2.45 GHz or higher, and a pulse or a continuous wave can be provided. The plasma forming unit 110 preferably forms plasma as illustrated and forms pulse-time-modulated plasma.

[0090] That is, electrons excited by the plasma formed by the plasma generator 700 return to the ground state again and emit light having energy corresponding to the energy difference between the excited state and the ground state to the outside. The wavelength band of the light thus formed can be the infrared region, the visible light region, and the ultraviolet region, but in this embodiment, ultraviolet light in the vacuum ultraviolet (VUV) band is formed in order to neutralize charges trapped in the semiconductor substrate and / or the pattern formed on the semiconductor substrate.

[0091] In addition, the plasma generator 700 is set such that the VUV wavelength band emitted to the outside is different according to the type of process gas used in the plasma source. Since the static electricity formed on the semiconductor substrate 1 can be different for each region, in the present invention, the VUV wavelength band emitted from the plasma generator 700 can be set to be different according to the different static electricity levels formed at different positions on the semiconductor substrate 1.

[0092] For example, the first plasma generator at a position corresponding to a region with a low static electricity level formed on the semiconductor substrate 1 forms plasma with argon (Ar) and emits VUV light in a wavelength band of 104.4 nm. The second plasma generator at a position corresponding to a region with a high static electricity level forms plasma with oxygen O2 and can emit VUV light in a wavelength band of 130.5 nm.

[0093] Thereby, it is possible to prevent the VUV light from penetrating into the insulating film due to the high-frequency VUV light and changing the film characteristics on the semiconductor substrate 1 in the region with a low static electricity level.

Claims

1. An electrostatic elimination device for a semiconductor substrate, which irradiates a semiconductor substrate disposed inside a vacuum chamber with VUV (Vacuum Ultraviolet Ray) light to remove electrostatic charges (Embedded) embedded inside a thin film on the semiconductor substrate. A VUV generator disposed above the vacuum chamber and equipped with a VUV lamp that emits VUV light with a narrow area inside the vacuum chamber. An electrostatic elimination device for a semiconductor substrate, characterized in that it includes a light diffusing part disposed below the VUV generator, which diffuses the incident VUV light and outputs it to the semiconductor substrate located below.

2. An electrostatic elimination device for a semiconductor substrate, which irradiates a semiconductor substrate disposed inside a vacuum chamber with VUV light to remove electrostatic charges formed on the semiconductor substrate. A plasma generator disposed above the vacuum chamber, which reacts with a process gas to form plasma and emits VUV light inside the vacuum chamber. An electrostatic elimination device for a semiconductor substrate, characterized in that it includes a light diffusing part disposed below the plasma generator, which diffuses the incident VUV light and outputs it to the semiconductor substrate located below.

3. The electrostatic elimination device for a semiconductor substrate according to claim 1 or claim 2, characterized in that the light diffusing part is a beam splitter.

4. The electrostatic elimination device for a semiconductor substrate according to claim 1 or claim 2, characterized in that the light diffusing part is composed of a metal mesh or a metal plate formed with a plurality of holes.

5. The light diffusing part is made of MgF ２ , CaF ２ , LiF or sapphire, and is characterized in that it has a multi-lens array structure in which a plurality of microlenses are arranged on a substrate made of one of these materials. The electrostatic removing device for a semiconductor substrate according to claim 1 or claim 2.

6. Below the light diffusing part, a grid plate having a structure in which a central electrode region of a certain size disposed in the central part and one or more peripheral electrode regions having one or more belts are disposed around the central electrode region and the electrode regions are separated is further disposed. The electrostatic elimination device for a semiconductor substrate according to claim 1 or claim 2, characterized in that the electrode regions are formed with a plurality of holes in a metal material, and different voltages are supplied to each electrode region.

7. The inside of the vacuum chamber is further configured to include a separation plate that separates an upper space and a lower space with reference to the light diffusing part. The electrostatic elimination device for a semiconductor substrate according to claim 1 or claim 2, characterized in that the light diffusing part is formed on the separation plate.

8. The upper space and the lower space of the vacuum chamber are each provided with a vacuum setting unit for setting the vacuum state of the space, The electrostatic removal device for a semiconductor substrate according to claim 7, wherein the degree of vacuum in the upper space and the degree of vacuum in the lower space are set to be different.

9. The electrostatic removal device for a semiconductor substrate further includes a substrate support table for supporting the substrate, The substrate support table is made of a metal material, and a positive (+) or negative (−) bias voltage is supplied. However, In order to induce electrons to the semiconductor substrate 1 side, a positive (+) bias voltage is supplied, and in order to induce ions to the semiconductor substrate 1 side, a negative (−) bias voltage is supplied. The electrostatic removal device for a semiconductor substrate according to claim 1 or claim 2, characterized in that.

10. A plurality of VUV generators that emit VUV are arranged at regular intervals above the vacuum chamber, The light diffusing unit expands and outputs a large number of VUV lights emitted from the VUV generator to the entire surface of the semiconductor substrate. The electrostatic removal device for a semiconductor substrate according to claim 1, characterized in that.

11. A plurality of plasma generators that emit VUV are arranged at regular intervals above the vacuum chamber, The light diffusing unit expands and outputs a large number of VUV lights emitted from the plasma generator to the entire surface of the semiconductor substrate. However, Each of the plasma generators is configured to react with different process gases and emit VUV in different bands. The electrostatic removal device for a semiconductor substrate according to claim 2, characterized in that.

12. A rotating means for rotating the substrate support table while VUV light is emitted from a VUV generator is provided below the substrate support table for supporting the semiconductor substrate, The light diffusing unit is composed of at least one light diffusing module that is eccentrically located from the center of the semiconductor substrate. The electrostatic removal device for a semiconductor substrate according to claim 10 or claim 11, characterized in that.

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