Device and method for measuring the chucking force

Abstract

A chucking force measuring device and method for measuring electrostatic attraction between a substrate and a heater are provided. The chucking force measuring device comprises: a chamber; a heater fixing part installed within the chamber and to which a heater to be tested is fixed; and a measuring unit installed within the chamber and to measure the chucking force between the substrate and the heater to be tested while lifting a substrate placed on the heater to be tested upward.

Description

Technology Field

[0001] The present invention relates to a chucking force measuring device and method for measuring the chucking force between a substrate and a heater. Background Technology

[0002] When manufacturing semiconductor or display devices, various processes such as photolithography, etching, ashing, ion implantation, thin film deposition, and cleaning are performed. In this process, plasma is used in the etching or cleaning process. Plasma refers to an ionized gaseous state composed of ions, electrons, radicals, etc., generated by high temperatures, strong electric fields, or high-frequency electromagnetic fields. Ions or radicals contained in the plasma collide with or react with a substrate, thereby enabling the etching or cleaning process of the substrate. The problem to be solved

[0003] Meanwhile, when a substrate is placed on a heater and a plasma process is performed, static electricity may accumulate on the substrate. However, if this static electricity is not removed to ground through the heater, an electrostatic attraction may occur between the substrate and the heater. In particular, even with the same type of heater, the magnitude of the electrostatic attraction between the substrate and the heater may vary due to design tolerances. If the electrostatic attraction is large, a sticking phenomenon occurs where the substrate does not detach easily from the heater, resulting in damage to the substrate. If the sticking phenomenon occurs, particles may be generated or the substrate may be damaged.

[0004] The problem that the present invention aims to solve is to provide a chucking force measuring device that measures the electrostatic attraction between a substrate and a heater.

[0005] Another problem that the present invention aims to solve is to provide a chucking force measuring device that measures the electrostatic attraction between a substrate and a heater.

[0006] The problems of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0007] One aspect of the chucking force measuring device of the present invention for achieving the above objective comprises: a chamber; a heater fixing part installed within the chamber and to which a heater to be tested is fixed; and a measuring unit installed within the chamber and measuring the chucking force between the substrate and the heater to be tested while lifting a substrate placed on the heater to be tested upward.

[0008] An electrostatic charge of a preset size is applied to the above substrate, and an electrostatic attraction is generated between the above substrate and the heater under test.

[0009] The above measuring unit includes a load cell connected to the substrate to measure the pulling force of the substrate, and a driving unit connected to the load cell and moving the load cell in an up-and-down direction.

[0010] The substrate placed on the heater under test is lifted upward, and the value measured at the point where the substrate is separated from the heater under test is determined as the chucking force.

[0011] It further includes a control unit that compares the chucking force with a reference value and determines whether the heater under test is a good product based on the comparison result.

[0012] One aspect of the method for measuring a chucking force according to the present invention for achieving the above other objectives is to fix a heater to be tested onto a heater fixing part, place a substrate to which static electricity of a predetermined size is applied onto the heater to be tested, and measure the chucking force between the substrate and the heater to be tested while lifting the substrate placed on the heater to be tested upward.

[0013] The substrate placed on the heater under test is lifted upward, and the value measured at the point where the substrate is separated from the heater under test is determined as the chucking force.

[0014] It further includes comparing the above chucking force with a reference value and determining whether the heater under test is a good product based on the comparison result.

[0015] The heater under test, which is determined to be a good product, is installed in a substrate processing device that processes a substrate using plasma, wherein the substrate processing device has a dielectric plate containing quartz located above the processing space where the heater under test is installed and radiates microwaves into the processing space, and a liner containing quartz located on the side of the processing space.

[0016] Lifting the substrate placed on the heater under test upwards is carried out at a speed of 1 cm / s or less.

[0017] Specific details of other embodiments are included in the detailed description and drawings. Brief explanation of the drawing

[0018] FIG. 1 illustrates a chucking force measuring device according to some embodiments of the present invention. FIG. 2 is a flowchart illustrating a method for measuring chucking force according to some embodiments of the present invention. Figure 3 is a drawing to explain S93 of Figure 2. Figure 4 is a flowchart for explaining the steps after S93 of Figure 2. FIG. 5 is a cross-sectional view illustrating an exemplary substrate processing apparatus in which a heater determined to be a good product is installed. Specific details for implementing the invention

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The advantages and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0020] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used to facilitate the description of the relationship between one element or component and another, as illustrated in the drawings. Spatially relative terms should be understood as encompassing different orientations of the element during use or operation, in addition to the orientations illustrated in the drawings. For example, if an element illustrated in the drawings is flipped, the element described as "below" or "beneath" of another element may be placed "above" of that other element. Therefore, the exemplary term "below" may encompass both the lower and upper directions. Elements may also be oriented in other directions, and accordingly, spatially relative terms may be interpreted according to the orientation.

[0021] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In describing with reference to the attached drawings, identical or corresponding components are given the same reference number regardless of the drawing symbols, and redundant descriptions thereof will be omitted.

[0023] FIG. 1 illustrates a chucking force measuring device according to some embodiments of the present invention.

[0024] Referring to FIG. 1, a chucking force measuring device (1) according to some embodiments of the present invention is a device for measuring the chucking force between a substrate (W) and a heater (20) to be tested, and is intended to select a good heater (see 210 in FIG. 5) to be installed in a substrate processing device (see 400 in FIG. 5).

[0025] This chucking force measuring device (1) includes a chamber (10), a heater fixing part (25), a measuring unit (35), a control part (50), etc.

[0026] The heater fixing part (25) is installed on one side (e.g., the bottom surface) of the chamber (10). The heater to be tested (20) is fixed on the heater fixing part (25). The fixing method may be a physical method of connection such as a bolt / nut connection or a snap connection, but is not limited thereto. Since the heater to be tested (20) must be separated from the heater fixing part (25) after the chucking force measurement is completed, any connection method that is detachable is possible.

[0027] The measuring unit (35) is installed within the chamber (10) and, for example, may be installed on one side wall of the chamber (10) as illustrated. The measuring unit (35) measures the chucking force between the substrate (W) and the heater under test (20) while being connected to the substrate (W) placed on the heater fixing part (25) and lifting the placed substrate (W) upward.

[0028] Electrostatic charge of a preset size is applied to the substrate (W). Depending on the measurement method, the measurer can apply electrostatic charge to the substrate (W). For example, electrostatic charge can be applied to the substrate (W) using an ESC gun. An ESC gun is a device capable of generating electrostatic charge proportional to the voltage size by adjusting the voltage size.

[0029] Since static electricity is applied to the substrate (W), an electrostatic attraction is generated between the substrate (W) and the heater under test (20). If the electrostatic attraction is small, the substrate (W) and the heater under test (20) can be easily separated as the measuring unit (35) moves upward. On the other hand, if the electrostatic attraction is small, the substrate (W) and the heater under test (20) are not easily separated as the measuring unit (35) moves upward.

[0030] This measuring unit (35) includes a load cell (30) and a driving unit (40).

[0031] The load cell (30) is connected to the substrate (W) and measures the force pulling the substrate (W). The load cell (30) is a type of sensor capable of measuring physical quantities such as force or load. When a force is applied to the load cell (30), an electrical signal corresponding to the force is generated, and the electrical signal is interpreted to display the result in a weight unit (e.g., kg). In some embodiments of the present invention, the load cell (30) may be an S-shaped or beam-shaped load cell capable of measuring pulling force, but is not limited thereto.

[0032] The drive unit (40) is connected to the load cell (30) and moves the load cell (30) in an up-and-down direction. The drive unit (40) may be hydraulic, magnetic levitation, mechanical, etc., and any method capable of moving the load cell (30) is possible.

[0033] The control unit (50) controls the operation of the measurement unit (35) and determines whether the heater under test (20) is a good product based on the chucking force measured by the measurement unit (35). For example, the control unit (50) can compare the measured chucking force with a reference value and determine whether the heater under test is a good product based on the comparison result. The chucking force may be the maximum value among the values ​​(weights) measured by the load cell while lifting the substrate (W) placed on the heater under test (20) upward.

[0034] Hereinafter, a method for measuring chucking force according to some embodiments of the present invention will be described using FIGS. 2 to 4.

[0035] FIG. 2 is a flowchart for explaining a chucking force measurement method according to some embodiments of the present invention. FIG. 3 is a diagram for explaining S93 of FIG. 2. FIG. 3 shows the value measured by the load cell of FIG. 1. FIG. 4 is a flowchart for explaining the steps after S93 of FIG. 2.

[0036] First, referring to FIGS. 1 and 2, the heater to be tested (20) is fixed onto the heater fixing part (25) (S91). As described above, the heater to be tested (20) is connected to the heater fixing part (25) in a detachable manner.

[0037] Next, a substrate (W) to which static electricity of a preset size has been applied is placed on the heater (20) to be tested (S92). For example, after applying static electricity of a preset size to the substrate (W) using an ESC gun, the substrate (W) is placed on the heater (20) to be tested.

[0038] Next, the substrate (W) placed on the heater (20) under test is lifted upward, and the chucking force between the substrate (W) and the heater (20) under test is measured (S93).

[0039] Specifically, referring to FIGS. 1 and FIGS. 3, at time t0, the measuring unit (35) begins to lift the substrate (W) placed on the heater under test (20) upward. The lifting force exerted by the measuring unit (35) begins to increase from 0. Accordingly, the weight (w) measured by the load cell (30) also begins to increase from 0. In order to prevent damage to the substrate (W) and to increase the accuracy of the measurement, the lifting of the substrate (W) upward can be carried out considerably slowly. For example, the lifting of the substrate (W) placed on the heater under test (20) upward can be carried out at a speed of 1 cm / s or less.

[0040] After time t0, the measuring unit (35) continues to pull the substrate (W) upward (or, by applying a greater force). That is, from time t0 to time t1, the force with which the measuring unit (35) pulls the substrate (W) continues to increase. Therefore, it can be seen in FIG. 3 that the weight (w) measured by the load cell (30) from time t0 to time t1 also continues to increase.

[0041] Even if the measuring unit (35) pulls the substrate (W) upward, if the force pulling the substrate (W) does not reach a specific value (i.e., a threshold value), the substrate (W) is not separated from the heater under test (20). At the point when the force pulling the substrate (W) becomes greater than the electrostatic attraction between the heater under test (20) and the substrate (W), the heater under test (20) and the substrate (W) are separated. At time t1, the heater under test (20) and the substrate (W) are separated. At the point when the heater under test (20) and the substrate (W) are separated, the weight (w) measured by the load cell (30) shows a maximum value as CF. The chucking force becomes CF, which is the value at the point when the heater under test (20) and the substrate (W) are separated.

[0042] Immediately after time t1, since the substrate (W) has moved away from the electrostatic attraction with the heater under test (20), the weight (w) measured by the load cell (30) decreases to C1 and then stabilizes at C2. Here, weight C2 may be the weight of the substrate (W) itself.

[0043] Next, referring to FIG. 4, the measured chucking force is compared with a reference value (S94).

[0044] If the chucking force is smaller than the reference value, it is determined to be a good product (S95). The heater (20) determined to be a good product is installed in a substrate processing device (see FIG. 5) (S96).

[0045] Alternatively, if the chucking force is greater than the reference value, it is determined to be a defective product (S99).

[0046] For example, let's assume the reference value is 300g. If the measured chucking force (i.e., the weight measured by the load cell (30) at the point when the substrate (W) and the heater under test (20) are separated) is 250g, the heater under test (20) is determined to be a good product.

[0047] Conversely, if the measured chucking force is 1 kg, the heater (20) under test is determined to be defective.

[0048] Due to design tolerances, the chucking force may vary even for heaters (20) of the same type.

[0049] By using the chucking force measuring device / method according to some embodiments of the present invention, the chucking force that may occur between the substrate (W) and the heater (20) can be measured in advance before installation in the substrate processing device, thereby allowing the heater (20) that may cause problems to be excluded in advance. Therefore, it is possible to prevent the sticking phenomenon in which the substrate does not detach easily from the heater from occurring. Since the phenomenon does not occur, particles are not generated and the substrate is not damaged.

[0050] FIG. 5 is a cross-sectional view illustrating an exemplary substrate processing apparatus in which a heater determined to be a good product is installed.

[0051] Referring to FIG. 5, the substrate processing device performs process processing on a substrate (W) using plasma. The substrate processing device includes a process chamber (100), a substrate support unit (200), a gas supply unit (300), a microwave application unit (400), an antenna (500), a wave plate (600), etc.

[0052] A process chamber (100) has a processing space (101) formed inside, and the processing space (101) is provided as a space where a processing process is performed. The process chamber (100) includes a body (110) and a cover (120).

[0053] The body (110) has an open top surface and a space is formed inside. A groove (112) into which a flange (920) is inserted is formed in the inner wall of the body (110).

[0054] The cover (120) is placed on the top of the body (110) and seals the open upper surface of the body (110). The inner lower portion of the cover (120) is stepped so that the upper space has a larger radius than the lower space.

[0055] A substrate inlet (not shown) may be formed on one side wall of the process chamber (100). The substrate inlet (not shown) is provided as a passage through which a substrate (W) can enter and exit the process chamber (100). The substrate inlet is opened and closed by an opening and closing member, such as a door.

[0056] An exhaust hole (102) is formed on the bottom surface of the process chamber (100). The exhaust hole (102) is connected to an exhaust line (131). Through exhaust via the exhaust line (131), the interior of the process chamber (100) can be maintained at a pressure lower than atmospheric pressure. Additionally, reaction byproducts generated during the process and gases remaining inside the processing space (101) can be discharged to the outside through the exhaust line (131).

[0057] A substrate support unit (200) supports a substrate (W) within a processing space (101). The substrate support unit (200) includes a heater (210), a lift pin (not shown), a heating unit (220), and a support shaft (230).

[0058] The heater (210) is provided as a disc having a predetermined thickness and a radius larger than that of the substrate (W). A substrate providing groove on which the substrate (W) is placed may be formed on the upper surface of the heater (210). According to an embodiment, the heater (210) is not provided with a configuration for fixing the substrate (W), and the substrate (W) may be provided to the process in a state where it is placed on the heater (210), but is not limited thereto.

[0059] A plurality of lift pins are provided and are located in each of the pin holes (not shown) formed in the heater (210). The lift pins move up and down along the pin holes to load a substrate (W) onto the heater (210) or unload a substrate (W) placed on the heater (210).

[0060] A heating unit (220) is provided inside the heater (210). The heating unit (220) is provided as a spiral-shaped coil and can be embedded inside the heater (210) at uniform intervals. The heating unit (220) is connected to an external power source (not shown) and generates heat by resisting the current applied from the external power source. The generated heat is transferred to the substrate (W) through the heater (210) and heats the substrate (W) to a predetermined temperature.

[0061] The support shaft (230) is located at the bottom of the heater (210) and supports the heater (210). The heater (210) may be provided to be movable up and down by a driving member (not shown).

[0062] The gas supply unit (300) supplies process gas into the processing space (101) of the process chamber (100). The gas supply unit (300) can supply process gas into the process chamber (100) through a gas supply hole (105) formed in the side wall of the process chamber (100). The gas supply hole (105) may be provided in multiple numbers.

[0063] The microwave application unit (400) applies microwaves to the antenna (500). The microwave application unit (400) includes a microwave generator (410), a first waveguide (420), a second waveguide (430), a phase converter (440), and a matching network (450).

[0064] The microwave generator (410) generates microwaves.

[0065] The first waveguide (420) is connected to the microwave generator (410) and has a passage formed inside. Microwaves generated from the microwave generator (410) are transmitted along the first waveguide (420) to the phase converter (440).

[0066] The second waveguide (430) includes an outer conductor (432) and an inner conductor (434).

[0067] The outer conductor (432) extends downward in a vertical direction from the end of the first waveguide (420), and a passage is formed inside. The upper end of the outer conductor (432) is connected to the lower end of the first waveguide (420), and the lower end of the outer conductor (432) is connected to the upper end of the cover (120).

[0068] The inner conductor (434) is located within the outer conductor (432). The inner conductor (434) is provided as a cylindrical rod, and its longitudinal direction is arranged parallel to the vertical direction. The upper end of the inner conductor (434) is inserted and fixed to the lower end of the phase converter (440). The inner conductor (434) extends downward, and its lower end is located inside the process chamber (100). The lower end of the inner conductor (434) is fixedly coupled to the center of the antenna (500). The inner conductor (434) is positioned perpendicular to the upper surface of the antenna (500). The inner conductor (434) may be provided by sequentially coating a first plating film and a second plating film onto a copper rod. According to one embodiment, the first plating film may be made of nickel (Ni) and the second plating film may be made of gold (Au). Microwaves are mainly propagated to the antenna (500) through the first plating film.

[0069] The microwave, whose phase has been changed in the phase converter (440), is transmitted to the antenna (500) side along the second waveguide (430).

[0070] A phase converter (440) is provided at the point where the first waveguide (420) and the second waveguide (430) are connected, and changes the phase of the microwave. The phase converter (440) may be provided in a cone shape with a pointed bottom. The phase converter (440) propagates the microwave transmitted from the first waveguide (420) to the second waveguide (430) in a mode-converted state. The phase converter (440) can convert the microwave from TE mode to TEM mode.

[0071] A matching network (450) is provided to the first waveguide (420). The matching network (450) matches the microwave propagating through the first waveguide (420) to a predetermined frequency.

[0072] The antenna (500) is provided in the shape of a plate. The antenna (500) is positioned on the upper part of the substrate support unit (200). For example, the antenna (500) may be provided as a thin disc. The antenna (500) is positioned to face the heater (210). A plurality of slots (501) are formed in the antenna (500). The slots (501) may be provided in an 'X' shape. Alternatively, the shape and arrangement of the slots may be varied. A plurality of slots (501) are combined with each other to form a plurality of ring shapes.

[0073] The wave plate (600) is located on the upper part of the antenna (500) and is provided as a disc having a predetermined thickness. The wave plate (600) may have a radius corresponding to the inner side of the cover (120). The wave plate (600) is provided as a dielectric material such as alumina or quartz. Microwaves propagated vertically through the inner conductor (434) propagate radially through the wave plate (600). The wavelength of the microwaves propagated through the wave plate (600) is compressed and resonated.

[0074] The dielectric plate (700) transmits microwaves from the antenna (500) to the processing space (101). The dielectric plate (700) is provided on the upper surface of the processing space (101). That is, the dielectric plate (700) is located below the antenna (500) and is provided as a disc having a predetermined thickness. The dielectric plate (700) is provided as a dielectric material such as quartz. The bottom surface of the dielectric plate (700) is provided as a concave surface that is indented inward. The bottom surface of the dielectric plate (700) may be located at the same height as the bottom of the cover (120). The side of the dielectric plate (700) is stepped so that the top has a larger radius than the bottom. The top of the dielectric plate (700) is placed on the stepped bottom of the cover (120). The bottom of the dielectric plate (700) has a smaller radius than the bottom of the cover (120) and maintains a predetermined distance from the bottom of the cover (120). Microwaves are radiated into the process chamber (100) through the dielectric plate (700). The process gas supplied into the process chamber (100) is excited into a plasma state by the electric field of the radiated microwaves. According to an embodiment, the dielectric plate (600), antenna (500), and dielectric plate (700) can be in close contact with each other.

[0075] A liner (900) is installed on the side of the processing space (101), that is, on the inner wall of the process chamber (100). The liner (900) prevents the inner wall of the process chamber (100) from being damaged by plasma. The liner (900) may be provided with a dielectric material such as quartz. The liner (900) includes a body (910) and a flange (920).

[0076] The body (910) has a ring shape facing the inner wall of the process chamber (100). A through hole (912) is formed in the body (910) so as to face the gas supply holes (105). Process gas injected from the gas supply holes (105) flows into the process chamber (100) through the through hole (912).

[0077] The flange (920) is provided to extend from the outer wall of the body (910) to the inside of the wall of the process chamber (100). The flange (920) is provided in a ring shape that wraps around the perimeter of the body (910). The flange (920) may be provided on the top of the liner (900).

[0078] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0079] 1: Chucking force measuring device 20: Heater under test 25: Heater fixing part 30: Load cell 40: Driving unit 35: Measuring unit

Claims

Claim 1 A chucking force measuring device comprising: a chamber; a heater fixing part installed within the chamber and to which a heater to be tested is fixed; and a measuring unit installed within the chamber and measuring a chucking force between a substrate and a heater to be tested while lifting a substrate placed on the heater to be tested upward, wherein the measuring unit includes a load cell connected to the substrate to measure a pulling force on the substrate, and a driving part connected to the load cell and to move the load cell in an up-and-down direction. Claim 2 A chucking force measuring device according to claim 1, wherein static electricity of a preset size is applied to the substrate, and an electrostatic attraction is generated between the substrate and the heater under test. Claim 3 delete Claim 4 A chucking force measuring device according to claim 1, wherein a value measured at the point when the substrate placed on the heater under test is separated from the heater under test is determined as the chucking force by starting to lift the substrate upward. Claim 5 A chucking force measuring device according to claim 4, further comprising a control unit that compares the chucking force with a reference value and determines whether the heater under test is a good product based on the comparison result. Claim 6 A method for measuring a chucking force, wherein a heater to be tested is fixed on a heater fixing part, a substrate to which static electricity of a preset size is applied is placed on the heater to be tested, and the chucking force between the substrate and the heater to be tested is measured by a measuring unit while lifting the substrate placed on the heater to be tested upward, wherein the measuring unit includes a load cell connected to the substrate to measure the pulling force of the substrate, and a driving part connected to the load cell and moving the load cell in an up-and-down direction. Claim 7 A chucking force measurement method according to claim 6, wherein a substrate placed on the heater under test is lifted upward, and a value measured at the point when the substrate is separated from the heater under test is determined as the chucking force. Claim 8 A chucking force measurement method according to claim 7, further comprising comparing the chucking force with a reference value and determining whether the heater under test is a good product based on the comparison result. Claim 9 A chucking force measurement method according to claim 8, wherein the heater under test determined to be a good product is installed in a substrate processing device that processes a substrate using plasma, wherein the substrate processing device has a dielectric plate containing quartz located above the processing space where the heater under test is installed and radiates microwaves into the processing space, and a liner containing quartz located on the side of the processing space. Claim 10 In claim 6, the method for measuring chucking force, wherein lifting the substrate placed on the heater under test upward proceeds at a speed of 1 cm / s or less.

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