Apparatus for processing substrate and method for processing substrate

Abstract

The invention provides an apparatus for processing a substrate and a method for processing a substrate. The apparatus for processing a substrate includes: a chamber providing a processing space; a substrate supporting unit disposed in the processing space; a gas supply unit that introduces a gas into the processing space; a plasma source providing energy, the plasma source exciting the gas introduced into the processing space with a plasma; a discharge unit that discharges the atmosphere in the treatment space out of the treatment space; and a laser emitting unit disposed above the support unit and emitting a laser beam to the substrate placed on the support unit, in which the laser emitting unit includes: a laser source generating the laser beam; and a digital micromirror device (DMD) unit, the DMD unit being a light modulation unit that modulates the laser beam generated from the laser source, in which the DMD unit includes: a micromirror set to be rotatable; and a plate-type substrate on which these micromirrors are mounted.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10 - 2023 - 0197495, filed with the Korean Patent Office on December 29, 2023, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present invention relates to an apparatus and a method for processing a substrate, and more particularly, to an apparatus and a method for processing a substrate using plasma. Background art

[0004] Plasma can be used in the processing process of a substrate. For example, plasma can be used in an etching process, a deposition process, or a dry cleaning process. Plasma is formed by a very high temperature, a strong electric field, or a high - frequency (RF) electromagnetic field, and plasma refers to an ionized gas state composed of ions, electrons, free radicals, etc. The dry cleaning process, ashing process, or etching process using plasma is performed through the reaction or collision of ions or radiation particles contained in the plasma with the substrate.

[0005] In addition, for manufacturing semiconductor devices, various heat treatments, such as modification and annealing, are repeatedly performed on semiconductor wafers. In addition, as semiconductor devices experience higher density, multi - layering, and greater integration, the specifications of semiconductor devices become increasingly difficult each year. Therefore, it is necessary to improve the uniformity and film thickness within the surface of various heat - treated semiconductor wafers.

[0006] In the process of processing a substrate using plasma, a method of initiating a reaction and removing a thin film by heating the entire substrate is used. In particular, a method of heating the substrate by emitting a laser beam to the substrate is used to perform an atomic layer etching (ALE) process. However, in the related art, when heating the substrate by emitting a laser beam to the entire area of the substrate, it is impossible to transfer thermal energy differently to each area of the substrate, and the heat is uniformly transferred to the entire area of the substrate. Therefore, there is a problem that it is difficult to perform asymmetric etching and selective etching of a local area even when the thickness of the thin film of the substrate is different in each area. Summary of the invention

[0007] Accordingly, an object of the present invention is to provide an apparatus and a method for processing a substrate, which can effectively process the substrate.

[0008] In addition, an object of the present invention is to provide an apparatus for processing a substrate and a method for processing a substrate, which can adjust the heat for each local area of heating the substrate and adjust the etching amount.

[0009] In addition, an object of the present invention is to provide an apparatus for processing a substrate and a method for processing a substrate, which can perform etching by selectively heating the substrate, so as to form a uniform thin film on the substrate.

[0010] The object of the present invention is not limited thereto, and those skilled in the art can clearly understand other objects not stated herein from the following description.

[0011] The present invention provides an apparatus for processing a substrate. The apparatus for processing a substrate includes: a chamber that provides a processing space; a substrate support unit disposed in the processing space; a gas supply unit that introduces gas into the processing space; a plasma source that provides energy, and the plasma source uses plasma to excite the gas introduced into the processing space; an exhaust unit that exhausts the atmosphere in the processing space from the processing space; and a laser emitting unit disposed above the support unit and emitting a laser beam to a substrate placed on the support unit, wherein the laser emitting unit includes: a laser source that generates the laser beam; and a Digital Micro-mirror Device (DMD) unit that is an optical modulation unit for modulating the laser beam generated from the laser source, wherein the DMD unit includes: micromirrors that are arranged to be rotatable; and a board substrate on which the micromirrors are mounted.

[0012] In one embodiment, the laser emitting unit may further include an imaging unit that adjusts the laser beam modulated by the DMD unit and emits the laser beam to the substrate corresponding to the area where the laser beam is emitted.

[0013] In one embodiment, the laser emitting unit may further include a beam shaper that converts the type of the laser beam generated by the laser source, and the beam shaper may convert the type of the laser beam and then transmit the laser beam to the DMD unit.

[0014] In one embodiment, the apparatus may further include: a window disposed on top of the chamber; an upper electrode stacked on the window; a lower electrode disposed lower than the substrate; and a high-frequency power supply connected to any one or more of the upper electrode and the lower electrode, wherein the upper electrode may be a transparent electrode, and the laser emission unit may be disposed above the window.

[0015] In one embodiment, the window may be made of quartz material.

[0016] In one embodiment, the apparatus may further include a control unit, wherein the control unit may control each of the micromirrors of the DMD unit to selectively switch between an on state and an off state, such that the thermal energy required for each region of the substrate can be transmitted by emitting the laser beam onto the substrate. In the on state, each of the micromirrors reflects the laser beam onto the substrate, and in the off state, each of the micromirrors dumps the laser beam.

[0017] In one embodiment, the control unit may perform control to execute a removal step, in which the gas supply unit introduces a process gas into the processing space, the plasma source excites the introduced process gas using plasma, and then the laser emission unit heats the substrate by emitting the laser beam onto the substrate.

[0018] In one embodiment, in the removal step, the laser emission unit may emit the laser beam onto the entire region of the substrate, and the DMD unit may form different emission patterns of the laser beam emitted onto each local region in the local region of the substrate, thereby selectively adjusting the heat of each region in the region of the substrate being heated.

[0019] In one embodiment, in the removal step, the emission pattern of the laser beam may be formed by reflecting the thickness data of each region in the region of the substrate.

[0020] In addition, the present invention provides a method for processing a substrate. In this method for processing a substrate, the substrate is set to be supported on a substrate support unit, which includes a lower electrode located in a chamber providing a processing space and disposed in the chamber. The method performs a removal step in which a process gas is introduced into the processing space, the process gas is excited by plasma by applying high-frequency power, and a laser emission unit heats the substrate by emitting a laser beam toward the substrate. Wherein, the removal step includes: a laser modulation step: forming an emission pattern by modulating the laser beam by means of an optical modulation unit included in the laser emission unit; and a laser emission step: emitting the laser beam modulated by the optical modulation unit toward the substrate.

[0021] In one embodiment, the optical modulation unit may be a digital micromirror device (DMD) unit, and the DMD unit may form different emission patterns of the laser beam emitted to each local area in a local area of the substrate, thereby selectively adjusting the heat of each area in the area heating the substrate.

[0022] In one embodiment, the DMD unit may include micromirrors that are set to be rotatable, and in the laser modulation step, the emission pattern may be formed by selectively switching between an on state and an off state by adjusting the direction in which each of these micromirrors reflects the laser beam. In the on state, each of these micromirrors reflects the laser beam to the substrate, and in the off state, each of these micromirrors dumps the laser beam.

[0023] In one embodiment, the laser beam modulated by the DMD unit may be adjusted to correspond to the size of the substrate and then emitted by the laser emission unit to the substrate, and in the removal step, the emission pattern may be formed by reflecting the thickness data of each area in the area of the substrate.

[0024] In one embodiment, the method may perform: a modification step: processing the substrate by introducing a processing gas into the processing space and exciting the processing gas by plasma; and a first purification step: before the removal step, introducing a purification gas into the processing space and discharging the processing space, and the method may perform a second purification step: after the removal step, introducing a purification gas into the processing space and discharging the processing space; and the modification step, the first purification step, the removal step, and the second purification step may be sequentially performed.

[0025] In one embodiment, the laser beam can be transmitted to the substrate through an upper electrode disposed on the top of the chamber; the upper electrode can include a window made of quartz and a transparent electrode stacked on the window; and the high-frequency power can be applied to any one or more of the transparent electrode and the lower electrode.

[0026] Furthermore, the present invention provides an apparatus for processing a substrate. The apparatus for processing a substrate includes: a chamber that provides a processing space; a substrate support unit disposed in the processing space; a gas supply unit that introduces gas into the processing space; a plasma source that provides energy and uses plasma to excite the gas introduced into the processing space; an exhaust unit that exhausts the atmosphere in the processing space from the processing space; a window disposed on the top of the chamber; an upper electrode stacked on the window; a lower electrode disposed lower than the substrate; a high-frequency power supply connected to any one or more of the upper electrode and the lower electrode; and a laser emitting unit disposed above the window and emitting a laser beam to the substrate placed on the support unit, wherein the laser emitting unit includes: a laser source that generates the laser beam; a digital micromirror device (DMD) unit that is an optical modulation unit for modulating the laser beam generated from the laser source; an imaging unit that adjusts the laser beam modulated by the DMD unit and emits the laser beam to the substrate corresponding to the area where the laser beam is emitted; and a beam shaper that converts the type of the laser beam generated from the laser source, wherein the DMD unit includes: micromirrors that are arranged to be rotatable; and a plate substrate on which the micromirrors are mounted, and the upper electrode is a transparent electrode.

[0027] In one embodiment, the apparatus may further include a control unit, wherein the control unit can control each of the micromirrors of the DMD unit to selectively switch between an on state and an off state, so that the thermal energy required for each area of the substrate can be transmitted by emitting the laser beam to the substrate. In the on state, each of the micromirrors reflects the laser beam to the substrate, and in the off state, each of the micromirrors dumps the laser beam.

[0028] In one embodiment, the control unit may perform control to execute: a modification step in which the gas supply unit introduces a first process gas into the processing space and excites the introduced first process gas with plasma by controlling the plasma source, thereby processing the substrate; a first purification step in which the gas supply unit introduces a third process gas into the processing space and discharges the processing space by controlling the discharge unit; a removal step in which the gas supply unit introduces a second process gas into the processing space, excites the introduced second process gas with plasma by controlling the plasma source, and then the laser emission unit heats the substrate by emitting a laser beam toward the substrate; and a second purification step in which the gas supply unit introduces the third process gas into the processing space and discharges the processing space by controlling the discharge unit, and the modification step, the first purification step, the removal step, and the second purification step may be sequentially executed.

[0029] In one embodiment, in the removal step, the laser emission unit may emit the laser beam toward the entire area of the substrate, and the DMD unit may form different emission patterns of the laser beam emitted toward each local area in the local area of the substrate, thereby selectively adjusting the heat of each area in the area where the substrate is heated.

[0030] In one embodiment, in the removal step, the emission pattern of the laser beam may be formed by reflecting the thickness data of each area in the area of the substrate.

[0031] According to an embodiment of the present invention, a substrate can be effectively processed.

[0032] In addition, according to an embodiment of the present invention, the heating amount and etching amount of each local area in the local area of the substrate can be adjusted.

[0033] In addition, according to an embodiment of the present invention, etching can be performed by selectively heating the substrate, thereby forming a uniform thin film on the substrate.

[0034] The effects of the present invention are not limited to the above effects, and those skilled in the art will clearly understand the effects not stated above from the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 An apparatus for processing a substrate according to an embodiment of the present invention is shown.

[0036] Figure 2 is schematically shown Figure 1 a view of the configuration of the laser emission module.

[0037] Figure 3 is a graph showing the distribution of light output from a laser source, and Figure 4 is a graph showing the distribution of light that has passed through a beam shaper.

[0038] Figure 5 is a view schematically showing the appearance of an optical modulation device.

[0039] Figure 6 is a view showing light output from the optical modulation device.

[0040] Figure 7 is a view showing that the light output from the optical modulation device is removed at an optical dumper.

[0041] Figure 8 is a view for explaining the principle of light removal at the optical dumper.

[0042] Figure 9 is a view for explaining the emission pattern of light output from an optical modulation unit.

[0043] Figure 10 is a view showing the execution of an ALE process and showing the state of the apparatus when performing an adsorption process (as a usage example of the apparatus for processing a substrate).

[0044] Figure 11 is a view showing the state of the apparatus when performing Figure 10 a modification step.

[0045] Figure 12 is a view showing the state of the apparatus when performing Figure 10 a first purification step.

[0046] Figure 13 is a view showing the state of the apparatus when performing Figure 10 a removal step.

[0047] Figure 14 shows Figure 10 an embodiment of the emission pattern of a laser beam modulated in a laser modulation step.

[0048] Figure 15 is a view showing the state of the apparatus when performing Figure 10 a second purification step.

[0049] The various features and advantages of the non-limiting exemplary embodiments of this specification can become apparent by reading the detailed description in conjunction with the accompanying drawings. The drawings are for illustrative purposes only and should not be construed as limiting the scope of the claims. Unless explicitly stated, the drawings are not considered to be drawn to scale. For clarity, various dimensions in the figures may be exaggerated. Detailed Description

[0050] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. The exemplary embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that the exemplary embodiments may be embodied in many different forms and that specific details should not be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0051] The terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" may be intended to include the plural forms. The terms "comprises", "comprising", "including", and "having" are inclusive and thus specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. Unless explicitly identified as the order of execution, the method steps, processes, and operations described herein should not be construed as necessarily being performed in the particular order discussed or illustrated. It should also be understood that additional or alternative steps may be employed.

[0052] When an element or layer is referred to as being "on another element or layer", "joined to another element or layer", "connected to another element or layer", or "coupled to another element or layer", the element or layer can be directly on, joined to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. In contrast, when an element is referred to as being "directly on another element or layer", "directly joined to another element or layer", "directly connected to another element or layer", or "directly coupled to another element or layer", there can be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" relative to "directly between", "adjacent" relative to "directly adjacent", etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0053] Although the terms first, second, third, etc. may be used herein to describe different elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, and / or section from another region, layer, or section. When used herein, unless the context clearly indicates otherwise, terms such as "first", "second", and other numerical terms do not imply an order or sequence. Thus, without departing from the teachings of the exemplary embodiments, a first element, first component, first region, first layer, or first section discussed below may be referred to as a second element, second component, second region, second layer, or second section.

[0054] For ease of description, spatial relative terms such as "inner", "outer", "beneath", "below", "under", "above", "over", etc. may be used herein to describe the relationship of one element or feature to another or other elements or features, as illustrated. Spatial relative terms are intended to cover different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as "beneath" or "below" another element or feature will then be oriented "above" the other element or feature. Thus, the exemplary term "below" can cover both an above and a below orientation. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatial relative descriptors used herein are interpreted accordingly.

[0055] When the terms "same" or "identical" are used in the description of the exemplary embodiments, it should be understood that there may be some imprecision. Thus, when an element or value is referred to as being the same as another element or value, it should be understood that the element or value is the same as other elements or values within the manufacturing or operating tolerance range (e.g., ±10%).

[0056] When the terms "about" or "substantially" are used in connection with a numerical value, it should be understood that the associated numerical value includes manufacturing or operational tolerances around the stated numerical value (e.g., ±10%). In addition, when the words "generally" and "substantially" are used in connection with a geometry, it should be understood that precision of the geometry is not required, but the latitude of the shape is within the scope of the present disclosure.

[0057] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments belong. It should also be understood that terms (including those defined in common dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0058] In the following, reference Figures 1 to 15 is made to describe embodiments of the present invention.

[0059] Figure 1 An apparatus for processing a substrate according to an embodiment of the present invention is shown.

[0060] An apparatus 1000 for processing a substrate may include a process chamber 510, a support unit 200, a gas supply unit 400, a plasma source 300, and a laser emission unit 100. The apparatus 1000 for processing a substrate processes the substrate W using plasma.

[0061] The process chamber 510 has an internal space 501 for performing a process therein. A discharge hole 503 is formed through the bottom of the process chamber 510. The discharge hole 503 is connected to a discharge line in which a pump 720 is installed. Reaction by-products generated during the process and gases remaining in the internal space 501 are discharged through the discharge hole 503 by the discharge pressure applied by the pump 720. In addition, during the discharge process, the pressure in the internal space 501 of the process chamber 510 is reduced to a desired pressure. The pump 720 may be a vacuum pump.

[0062] An opening (not shown) is formed through one side of the process chamber 510. The opening (not shown) serves as a passage through which the substrate W is loaded into and unloaded from the process chamber 510. The opening (not shown) is opened and closed by a door assembly (not shown).

[0063] The support unit 200 is positioned in the lower region of the internal space 501. The support unit 200 may include an electrostatic chuck (ESC). The ESC holds the substrate W using electrostatic force. Differently, the support unit 200 may use various methods such as mechanical clamping to support the substrate W. The support unit 200 may include a metal lower electrode 210. The lower electrode 210 may be made of aluminum. The lower electrode 210 may be arranged in a plate shape. In addition, a channel may be formed in the support unit 200. The channel is set as a channel through which the coolant circulates. The coolant cools the substrate W by absorbing the heat of the substrate W through the support unit 200. The support unit 200 and the substrate W may be cooled, and the substrate W may be maintained at a desired temperature by the circulation of the coolant.

[0064] The gas supply unit 400 supplies process gases to the internal space 501. The gas supply unit 400 includes a first gas supply pipeline 411 connected to the first gas supply source 410, a second gas supply pipeline 421 connected to the second gas supply source 420, and a third gas supply pipeline 431 connected to the third gas supply source 430. The first gas and the second gas may be reaction gases for processing the substrate, and the third gas may be a purge gas for purification. A first valve 412 for opening the channel of the first gas supply pipeline 411 or adjusting the flow rate of the fluid flowing through the channel may be installed in the first gas supply pipeline 411. A second valve 422 for opening the channel of the second gas supply pipeline 421 or adjusting the flow rate of the fluid flowing through the channel may be installed in the second gas supply pipeline 421. A third valve 432 for opening the channel of the third gas supply pipeline 431 or adjusting the flow rate of the fluid flowing through the channel may be installed in the third gas supply pipeline 431.

[0065] The plasma source 300 generates plasma from the process gases remaining in the discharge space. The discharge space may be the region above the support unit 200 in the process chamber 510. The plasma source 300 may have capacitively coupled plasma. The plasma source 300 may include an upper electrode 315, the lower electrode 210 of the support unit 200, a first high-frequency power supply 320, and a second high-frequency power supply 340. The upper electrode 315 and the lower electrode 210 may be arranged opposite to each other in the vertical direction.

[0066] The upper electrode 315 is stacked on the window 311. The upper electrode 315 is coated on the window 311. The upper electrode 315 is configured such that a laser beam applied from the laser emitting unit 100 can be transmitted to the substrate W without loss (or with minimized loss). The upper electrode 315 is a transparent electrode. The upper electrode 315 can be indium tin oxide (ITO). In addition, the upper electrode 315 can be any one of AZO, FTO, ATO, SnO2, ZnO, IrO2, RuO2, graphene, metal nanowires, and CNTs, or a mixture thereof, or can be formed by multi-layer stacking. The upper electrode 315 has a thickness equal to or less than a first thickness. The first thickness is the thickness that allows light or microwaves to pass through the determined material. The first thickness depends on the material determined for the upper electrode 315. "Allowing transmission" in this specification means that it does not significantly affect permeability. For example, when the upper electrode 315 is ITO, the first thickness can be 1 μm. The upper electrode 315 and the lower electrode 210 are combined to generate an electric field by applying an RF voltage to any one or more of them. According to an embodiment, the upper electrode 315 can be grounded, and high-frequency power can be applied to the lower electrode 210 through the first high-frequency power supply 320. Optionally, the power of the second high-frequency power supply 340 can be applied to the upper electrode 315, and the lower electrode 210 can be grounded. In addition, optionally, high-frequency power can be applied to both the upper electrode 315 and the lower electrode 210.

[0067] The window 311 is provided in a disk shape. The window 311 is made of a material capable of transmitting a laser beam for heating the substrate W. In addition, the window 311 is made of a material having corrosion resistance. Quartz can be provided as an example of the window 311.

[0068] The laser emitting unit 100 can emit a laser beam toward the substrate W.

[0069] The laser beam emitted by the laser emitting unit 100 heats the substrate W on the support unit 200.

[0070] The temperature of the area of the substrate W where the laser beam emitted by the laser emitting unit 100 is incident can increase. Accordingly, the area irradiated with the laser beam can be etched relatively more, while the area not irradiated with the laser beam can be etched relatively less.

[0071] According to an embodiment of the present invention, a laser beam is emitted to the entire area of the surface of the substrate W, so that the entire area of the surface of the substrate W is heated simultaneously. In addition, the emission amount of the laser beam is adjusted for each area of the substrate W, whereby each area of the substrate W can be heated to a different temperature. The laser beam may be a large-area laser beam suitable for the size of the substrate. That is, the laser beam can be emitted to the entire area of the substrate W. The laser emission unit 100 can heat the entire substrate W at once by emitting the laser beam to the entire area to be heated in the area of the substrate W at once.

[0072] The laser emission unit 100 will be described in more detail below.

[0073] The laser emission unit 100 includes a laser source 110, a laser transmission member 120, and a laser emission module 600.

[0074] The laser source 110 can generate light. The laser source 110 can generate light with straightness. The light generated by the laser source 110 can be emitted to the substrate W and can heat the substrate W. The light can be a laser beam, a fiber laser, a laser diode, etc. Hereinafter, it is exemplarily described that the light is a laser beam L. The laser source 110 may have a power within 20 W per unit area (cm 2 ) When the laser source 110 has a power within 20 W per unit area (cm 2 ), the light modulation device 642 described below can be appropriately driven without being damaged.

[0075] The laser beam is a beam having a wavelength band that is not absorbed by the upper electrode 315. In one embodiment, the laser beam may have a wavelength of 500 nm to 550 nm.

[0076] The laser transmission member 120 transmits the laser beam generated by the laser source 110 to the laser emission module 600 without loss. The laser source 110 and the laser emission module 600 are optically connected through the laser transmission member 120. According to an embodiment, the laser transmission member 120 may be an optical fiber.

[0077] Figure 2 is a view schematically showing Figure 1 the configuration of the laser emission module.

[0078] The laser emission module 600 includes a housing 602, a mirror 610, a beam shaper 620, a prism optical device 630, a light modulation unit 640, and an imaging unit 650.

[0079] The housing 602 protects the mirror 610, the beam shaper 620, the prism optical device 630, the light modulation unit 640, and the imaging unit 650 by accommodating them in the internal space. The housing 602 can be fixedly mounted above the process chamber 510. That is, the laser emission module 600 can be fixedly mounted above the process chamber 510.

[0080] The mirror 610 reflects and transmits the laser beam entering the laser emission module 600 to the beam shaper 620 through the laser transmission member 120. The mirror 610 can include a plurality of mirrors to appropriately reflect the laser beam. For example, the mirror 610 can include a first mirror 612 and a second mirror 614.

[0081] The beam shaper 620 can change the type of light output from the laser source 110.

[0082] Figure 3 is a graph showing the distribution of the light output from the laser source, and Figure 4 is a graph showing the distribution of the light that has passed through the beam shaper.

[0083] Refer to Figures 2 to 4 , as Figure 4 shown, the laser beam output from the laser source 110 can have a Gaussian type, in which the intensity distribution has a Gaussian distribution. More specifically, the intensity of the laser beam output from the laser source 110 can be high at the center of the laser beam, and the intensity (intensity or strength) of the laser beam can gradually decrease as it moves away from the center of the laser beam (see Figure 3 ). Therefore, when the laser beam output from the laser source 110 is emitted onto the substrate W, the area near the center of the laser beam can be heated more, while the area near the edge of the laser beam can be heated less. Therefore, in the laser emission module 600 according to an embodiment of the present invention, the beam shaper 620 can be disposed on the traveling path of the laser beam output from the laser source 110. The beam shaper 620 can change the Gaussian-type laser beam output from the laser source 110 into a flat-top laser beam. The laser beam output from the laser source 110 can be converted by the beam shaper 620 into a flat-top type having a flat-top distribution, in which the intensity (brightness) distribution is relatively uniform (see Figure 4 ).

[0084] Refer to Figure 2 again, the laser beam that has passed through the beam shaper 620 can be transmitted to the prism optical device 630.

[0085] The prism optical device 630 can reflect the laser beam that has passed through the beam shaper 620 back to the light modulation unit 640. The laser beam transmitted to the light modulation unit 640 can be modulated at the light modulation unit 640 and then output. The laser beam modulated and output from the light modulation unit 640 can be transmitted to the imaging unit 650 through the prism optical device 630.

[0086] The light modulation unit 640 can modulate the transmitted laser beam. The light modulation unit 640 can include a light modulation device 642, an optical dump 644, and a cooling device 646.

[0087] The light modulation device 642 can modulate the distribution of the laser beam generated by the laser source 110. In this case, changing the distribution of the laser beam can mean forming a laser beam distribution corresponding to the emission distribution of the laser beam to be emitted to the substrate W.

[0088] The light modulation device 642 can be a digital micromirror device (DMD).

[0089] That is, the light modulation unit 640 can be a DMD unit including a digital micromirror device (DMD).

[0090] Figure 5 is a view schematically showing the appearance of the light modulation device. The light modulation device 642 can include a plate substrate SB and a plurality of micromirrors MI. A plurality of electrodes corresponding to the plurality of micromirrors MI can be mounted on the plate substrate SB. The control unit can transmit a digital signal "0" or "1" to the electrodes mounted on the plate substrate SB. The micromirror MI can be configured to be rotatable. The micromirror MI can be configured to be rotatable about a direction parallel to the plane passing through the first direction X, the second direction Y, or the first direction X and the second direction Y. The micromirror MI corresponding to the electrode receiving the digital signal "0" can be in the off state, while the micromirror MI corresponding to the electrode receiving the digital signal "1" can be in the on state. The micromirror MI in the on state can emit a laser beam to the substrate W, while the laser beam reflected by the micromirror MI in the off state cannot be emitted to the substrate W.

[0091] Figure 6 is a view showing the output of light from the light modulation device. In Figure 6 For ease of description, the traveling path of the light reflected by any one of the plurality of micromirrors MI is shown. Referring to Figure 2 、 Figure 5 and Figure 6 , the micromirror MI in the on state can transmit light to the substrate W through the imaging unit 650 described below.

[0092] Figure 7 is a view showing that the light output from the light modulation device is removed at the optical dump. InFigure 7 In the figure, for ease of description, the traveling path of the laser beam reflected by any one of the plurality of micromirrors MI is shown. Refer to Figure 2 , Figure 5 and Figure 7 , the micromirror MI in the off state cannot transmit the laser beam to the substrate W by reflecting the laser beam. Specifically, as described above, the micromirror MI is configured to be rotatable. The micromirror MI in the off state can change the traveling path of the laser beam received from the laser source 110 by rotation, so that the light is not transmitted to the substrate W. The laser beam emitted from the micromirror MI in the off state can disappear by being emitted to the inner surface of the optical dump 644 without passing through the second hole 644b of the optical dump 644, which will be described below.

[0093] Figure 8 is a view for explaining the principle of removing light at the optical dump. Refer to Figure 2 and Figure 8 , the optical dump 644 may have a box shape with an internal space. The optical dump 644 may be made of a material capable of removing the laser beam by absorbing the laser beam, for example, made of a synthetic resin. The prism optical device 630 may be disposed in the internal space of the optical dump 644. The light modulation device 642 may be disposed in the internal space of the optical dump 644, or may be mounted outside the optical dump 644.

[0094] The first hole 644a and the second hole 644b may be formed in the optical dump 644. The first hole 644a may be formed on the side surface of the optical dump 644. The first hole 644a may be a hole through which the laser beam generated by the laser source 110 and converted by the beam shaper 620 passes. The second hole 644b may be a hole through which the laser beam modulated by the light modulation device 641 passes. The second hole 644b may be formed in the lower part of the optical dump 644.

[0095] The groove G may be formed on the inner surface 644c of the optical dump 644. The groove G formed on the inner surface 644c of the optical dump 644 may be configured to be able to absorb the light reflected by the micromirror MI in the off state. Specifically, when the laser beam is transmitted to the groove G, the laser beam may be removed by being reflected several times at the groove G. The laser beam may be removed while being reflected several times at the groove G and losing energy to the optical dump 644. In Figure 2 and Figure 8 , it is exemplarily shown that the groove G is only formed in the lower part of the optical dump 644, but the present invention is not limited thereto, and the groove G may be formed on the entire inner surface 644c of the optical dump 644.

[0096] Refer again to Figure 2, since the optical dump 644 removes the laser beam, the temperature of the optical dump 644 may increase. Accordingly, the optical modulation unit 640 according to an embodiment of the present invention may include a cooling device 646 that cools the optical dump 644. The cooling device 646 may be a fan that generates an air flow for cooling the optical dump 644.

[0097] The imaging unit 650 may emit the laser beam that is modulated and output from the optical modulation unit 640 and passes through the prism optical device 630 to the substrate W by adjusting the laser beam to correspond to the area to which the laser beam is emitted. The imaging unit 650 includes a plurality of lenses that can adjust the size of the laser beam and can adjust the profile of the laser beam emitted to the substrate W by increasing or decreasing the diameter of the laser beam. The imaging unit 650 may adjust the laser beam to a large-area laser beam having a size corresponding to the substrate W.

[0098] The imaging unit 650 may include a component that removes a noise pattern from the refraction pattern output from the optical modulation unit 640. For example, the imaging unit 650 may include a spatial filter.

[0099] The imaging unit 650 includes an emission lens 652. The laser beam that is modulated and output from the optical modulation unit 640 and passes through the prism optical device 630 is adjusted by the imaging unit 650 and emitted to the substrate W through the emission lens 652.

[0100] Figure 9 is a view for explaining the emission pattern of the light output from the optical modulation unit. Refer to Figure 2 , Figure 5 and Figure 9 , as described above, the micromirror MI may change between an on state and an off state. The state change of each micromirror MI between the on state and the off state may be completed in a very short time. Through the on / off state change of each micromirror MI, the optical modulation unit 640 may form a very diverse emission pattern HP. For example, in Figure 9 , the heat transferred to the substrate W by the laser beam reflected by each micromirror MI within a unit time (e.g., 1 second) is shown. The emission pattern HP may be composed of a plurality of patterns P corresponding to the plurality of micromirrors MI, respectively. In order to increase the heat transferred from each micromirror MI to the substrate W per unit time, the on state of the micromirror MI per unit time may be maintained for a long time, and the off state per unit time may be maintained for a short time. In order to reduce the heat transferred from each micromirror MI to the substrate W per unit time, the on state of the micromirror MI per unit time may be maintained for a short time, and the off state per unit time may be maintained for a long time.

[0101] The laser beam modulated by the optical modulation unit 640 and adjusted by the imaging unit 650 is emitted to the substrate W.

[0102] The components of the apparatus 1000 for processing a substrate can be controlled by a control unit (not shown). The control unit (not shown) can control the overall operation of the apparatus 1000 for processing a substrate. The control unit (not shown) can include a Central Processing Unit (CPU), a Read Only Memory (ROM), and a Random Access Memory (RAM). The CPU performs desired processing, such as etching processing, according to various recipes stored in their storage areas.

[0103] Control information of the apparatus for process conditions is input into the recipe. At the same time, the recipe showing the program or processing conditions can be stored in a non-transitory computer-readable medium. The non-transitory computer-readable medium is not a medium that stores data for a short time (such as a cache and a memory), but a medium that can store data semi-permanently and can be read by a computer. Specifically, the above various applications or programs can be stored and provided in a non-transitory computer-readable medium (e.g., CD, DVD, hard disk, Blu-ray disc, USB, memory card, and ROM).

[0104] Figure 10 It is a flowchart showing a method of processing a substrate as an embodiment of an apparatus for processing a substrate using the present invention.

[0105] Reference Figure 10 , a method of processing a substrate according to an embodiment of the present invention includes a substrate loading step S100, a modification step S200, a first purification step S300, a removal step S400, a second purification step S500, and a substrate unloading step S600. In addition, the removal step S400 includes a laser modulation step S420 and a laser emission step S440.

[0106] The following will refer to Figures 11 to 15 to describe a method of processing a substrate using an apparatus for processing a substrate according to an embodiment of the present invention.

[0107] Execute Figure 10 the substrate loading step S100. The substrate W is loaded into the internal space 501 of the process chamber 510. The substrate W undergoes a step of checking the thickness of the substrate W before being loaded into the internal space 501, whereby a distribution map of the film thickness of the substrate W can be created. The distribution map of the film thickness of the substrate W includes thickness data for each of a plurality of positions on the substrate, that is, thickness data for each of a plurality of regions on the substrate. The following describes the step of processing the substrate W using the distribution map of the film thickness of the substrate W.

[0108] Figure 11is a view showing the state of the apparatus when performing Figure 10 the modification step.

[0109] Referring to Figure 11 , in the modification step S200, a first gas is supplied to the internal space 501, and the first gas is excited by plasma. The plasma excited from the first gas is adsorbed to the surface of the substrate W, and the surface of the substrate W is modified. The modification step S200 is performed when the substrate W is at a first temperature. The first temperature is the temperature at which the plasma excited from the first gas is adsorbed to the surface of the substrate W to the maximum extent. For example, the first temperature may be about 20°C. Since the substrate W is processed at the temperature at which the adsorption on the surface of the substrate W is maximized, the time of the adsorption reaction can be reduced. For example, the adsorption reaction can be performed within 1 second.

[0110] Figure 12 is a view showing the state of the apparatus when performing Figure 10 the first purification step.

[0111] Referring to Figure 12 , when the modification step S200 is completed, the first purification step S300 is performed. In the first purification step S300, a third gas is supplied to the internal space 501. The third gas may be nitrogen. In addition, the atmosphere in the internal space 501 is discharged. The process gas and process by-products remaining in the internal space 501 during the purification process are discharged through the discharge hole 503. The first purification step S300 may be performed for about 5 seconds, but is not limited thereto, as long as the remaining process gas and process by-products are properly discharged.

[0112] Figure 13 is a view showing the state of the apparatus when performing Figure 10 the removal step.

[0113] Referring to Figure 13 , the removal step S400 is performed after the first purification step S300. In the removal step S400, a second gas is supplied to the internal space 501, and the second gas is excited by plasma. The plasma excited from the second gas removes the surface of the modified substrate W.

[0114] The removal step S400 includes a laser modulation step S420 and a laser emission step S440.

[0115] In the removal step S400, the surface of the substrate W is heated by a laser beam emitted by the laser emission unit 100. The laser beam applies thermal energy to the substrate W. The laser beam is modulated and then emitted by the optical modulation device 642. That is, the laser beam emitted to the substrate W is modulated by the laser modulation step S420 and then emitted to the substrate W in the laser emission step S440.

[0116] Figure 14 shows an embodiment of the emission pattern of the laser beam modulated in the Figure 10 laser modulation step.

[0117] In the laser modulation step S420, the optical modulation unit 640 can change the shape of the emission pattern of the laser by adjusting the on / off state of the above-mentioned micromirror MI. The emission pattern of the laser modulated by the optical modulation unit 640 can reflect the distribution map created in the thickness inspection of the substrate W performed before the substrate W is loaded into the internal space 501 of the process chamber 510.

[0118] Referring to Figure 14 , it shows the heat transferred to the substrate W per unit time by the laser beam reflected by the micromirror MI for the emission pattern (per unit time (e.g., 1 second)). The laser beam having the Figure 14 shown emission pattern is emitted onto the substrate W corresponding to the distribution map of the film thickness at each position on the substrate W, and the heating amount corresponding to the film thickness can be adjusted according to the position on the substrate W, that is, the film thickness of the substrate W in each local area on the substrate W.

[0119] In the laser emission step S440, the laser beam modulated in the laser modulation step S420 is emitted onto the substrate W.

[0120] In this case, the imaging unit 650 of the laser emission unit 100 can adjust the laser beam to a large-area laser beam having a size corresponding to the substrate W. The laser beam passing through the imaging unit 650 of the laser emission unit 100 can be emitted to the entire area of the substrate W. That is, the laser emission unit 100 can emit the laser beam to the entire area of the substrate W.

[0121] When a laser beam is emitted onto the substrate W, products generated on the surface of the substrate W can be physically removed from the surface of the substrate W. The entire substrate W is etched, and the substrate W can be further etched by selectively heating a predetermined area of the substrate W according to the emission pattern of the laser beam. The degree of etching depends on the amount of heat transmitted by the laser beam per unit time, and the light modulation unit 640 of the present invention can form emission patterns of various shapes, so that the etching of the substrate W can be controlled in various ways. Therefore, for each local area of the substrate W, the heating amount corresponding to the film thickness of the substrate W can be adjusted. For example, the micromirror MI corresponding to the emission pattern in the area of the substrate W having a relatively large film thickness maintains the on state per unit time for a long time and the off state per unit time for a short time, whereby the amount of heat transmitted to the substrate W can be increased, and thus etching can be performed well. In addition, the micromirror MI corresponding to the emission pattern in the area of the substrate W having a relatively small film thickness maintains the on state per unit time for a short time and the off state per unit time for a long time, whereby the amount of heat transmitted to the substrate W can be reduced, so that less etching is performed.

[0122] When the removal step S400 is completed, the second purification step S500 is executed.

[0123] Figure 15 is a view showing the state of the apparatus when the Figure 10 second purification step is executed.

[0124] See Figure 15 . When the removal step S400 is completed, a third gas is supplied to the internal space 501. The third gas can be nitrogen. In addition, the atmosphere of the internal space 501 is discharged. Process gases and process by-products remaining during the purification process in the internal space 501 are discharged through the discharge hole 503. The purification step can be performed for about 5 seconds, but is not limited thereto, as long as the remaining process gases and process by-products are properly discharged.

[0125] The modification step S200 - the first purification step S300 - the removal step S400 - the second purification step S500 can be repeated multiple times until the desired etching conditions are achieved.

[0126] When the etching of the substrate W is completed, the substrate unloading step S600 is executed. The substrate W is unloaded from the internal space 501 of the process chamber 510 out of the process chamber 510.

[0127] According to the above embodiments of the present invention, the laser emission unit 100 forms different emission patterns of the laser emitted to each local area in the local area of the substrate W, so that the heat of each area in the area where the substrate W is heated can be selectively adjusted. The etching amount can be partially adjusted by adjusting the heat of each area in the area where the substrate is heated, and the heating amount and etching amount of each local area in the local area of the substrate W can be adjusted by reflecting the distribution map of the film thickness of the substrate W.

[0128] Therefore, even if the film thickness of the substrate W forms an asymmetric distribution, etching can be performed by selectively heating the substrate W, so that a uniform film can be formed on the substrate W.

[0129] In the above embodiments, it is shown and described that the laser emission unit 100 is used to heat the substrate W in the removal step S400, but the present invention is not limited thereto. For example, also in the modification step S200, the substrate W can be selectively heated by modulating the laser using the laser emission unit 100 and emitting the laser to the substrate W.

[0130] In the above embodiments, it is exemplarily described that the device for processing a substrate of the present invention uses the laser emission unit 100 to perform a so-called atomic layer etching (ALE) process, but the device for processing a substrate of the present invention can also be applied to annealing the substrate W. In addition, the device can be applied to another high-temperature heating process not described.

[0131] The laser emission unit 100 of the present invention can adjust the laser beam to a large-area laser beam corresponding to the size of the substrate W through the imaging unit 650. In addition, since the light modulation unit 640 forms different emission patterns of the laser beam for each local area in the local area of the substrate W, the heat of each area for heating the substrate W can be selectively adjusted, and the etching amount can be partially adjusted by adjusting the heat of each area for heating the substrate W. Therefore, the laser emission unit 100 of the present invention and the method for processing a substrate according to the laser emission unit 100, that is, the process including the laser modulation step S420 and the laser emission step S440, are not limited to etching the substrate W by the ALE process, and can be modified and applied to the process of heating the substrate W in various ways, such as a dry etching process or dry cleaning using plasma, ashing, etc.

[0132] It should be understood that exemplary embodiments are disclosed herein and other variations are possible. Individual elements or features of a particular exemplary embodiment are generally not limited to that particular exemplary embodiment but are interchangeable and can be used in the selected exemplary embodiment, where applicable, even if not specifically shown or described. Such modifications should not be regarded as departing from the spirit and scope of the invention, and all such modifications that are obvious to those of ordinary skill in the art are intended to be included within the scope of the appended claims.

Claims

1. A device for processing a substrate, the device comprising: a chamber providing a processing space; a substrate supporting unit, the substrate supporting unit being disposed in the processing space; a gas supply unit that introduces gas into the processing space; a plasma source, the plasma source providing energy, the plasma source utilizing plasma to excite the gas introduced into the processing space; an exhaust unit, the exhaust unit exhausting the atmosphere in the processing space out of the processing space; as well as a laser emitting unit disposed above the supporting unit and emitting a laser beam toward a substrate placed on the supporting unit, Wherein, the laser emitting unit comprises: a laser source that generates the laser beam; and a digital micromirror device (DMD) unit which is a light modulation unit that modulates the laser beam generated from the laser source, Wherein, the digital micromirror device DMD unit comprises: a micromirror configured to be rotatable; and A plate substrate on which the micromirrors are mounted.

2. The device according to claim 1, wherein: The laser emitting unit further includes an imaging unit which adjusts the laser beam modulated by the digital micromirror device (DMD) unit and emits the laser beam to the substrate to correspond to a region to which the laser beam is emitted.

3. The device according to claim 2, wherein: The laser emitting unit further includes a beam shaper that converts the type of the laser beam generated by the laser source, and The beam shaper converts the type of the laser beam and then transmits the laser beam to the digital micromirror device (DMD) unit.

4. The device according to claim 2, further comprising: a window disposed on a top portion of the chamber; an upper electrode, the upper electrode being stacked on the window; a lower electrode disposed lower than the substrate; and a high frequency power source connected to any one or more of the upper electrode and the lower electrode, Wherein, the upper electrode is a transparent electrode, and The laser emitting unit is arranged above the window.

5. The device according to claim 4, wherein: The window is made of quartz material.

6. The device according to claim 4, further comprising a control unit, in, The control unit controls each of the micromirrors of the digital micromirror device (DMD) unit to selectively switch between an on state and an off state, so that the heat energy required for each area of ​​the substrate can be transmitted by emitting the laser beam to the substrate. In the on state, each of the micromirrors reflects the laser beam to the substrate, and in the off state, each of the micromirrors dumps the laser beam.

7. The device according to claim 6, wherein: The control unit performs control to perform a removal step in which the gas supply unit introduces a process gas into the processing space, the plasma source excites the introduced process gas with plasma, and then the laser emitting unit heats the substrate by emitting the laser beam to the substrate.

8. The device according to claim 7, wherein: In the removing step, the laser emitting unit emits the laser beam to the entire area of ​​the substrate, and the digital micromirror device DMD unit forms a different emission pattern of the laser beam emitted to each local area among the local areas of the substrate, thereby selectively adjusting the amount of heat for heating each of the areas of the substrate.

9. The device according to claim 8, wherein: In the removing step, the emission pattern of the laser beam is formed by reflecting thickness data of each of the regions of the substrate.

10. A method for processing a substrate, wherein the substrate is arranged to be supported on a substrate supporting unit, the substrate supporting unit including a lower electrode located in a chamber providing a processing space, the method performing a removal step, in which a process gas is introduced into the processing space, the process gas is excited with plasma by applying high frequency power, and a laser emitting unit heats the substrate by emitting a laser beam to the substrate, in, The removing step comprises: a laser modulation step of forming an emission pattern by modulating the laser beam by means of a light modulation unit included in the laser emission unit; and Laser emitting step: emitting the laser beam modulated by the light modulation unit toward the substrate.

11. The method according to claim 10, wherein: The light modulation unit is a digital micromirror device (DMD) unit, and The digital micromirror device (DMD) unit forms a different emission pattern of a laser beam emitted to each of the local regions of the substrate, thereby selectively adjusting the amount of heat for heating each of the regions of the substrate.

12. The method according to claim 11, wherein: The digital micromirror device (DMD) unit includes a micromirror, the micromirror is configured to be rotatable, and In the laser modulation step, an emission pattern is formed by adjusting the directions in which the micromirrors each reflect the laser beam, selectively switching an on state and an off state, in which each of the micromirrors reflects the laser beam to the substrate, and in which each of the micromirrors dumps the laser beam.

13. The method according to claim 11, wherein: The laser beam modulated by the digital micromirror device (DMD) unit is adjusted to correspond to the size of the substrate and then emitted to the substrate by the laser emitting unit, and In the removing step, the emission pattern is formed by reflecting thickness data of each of the regions of the substrate.

14. The method according to claim 10, wherein: The method performs: a modification step of: processing the substrate by introducing a process gas into the process space and exciting the process gas with plasma; and a first purge step of introducing a purge gas into the processing space and exhausting the processing space before the removal step, and The method performs a second purge step: after the removing step, introducing a purge gas into the processing space and exhausting the processing space; and The modifying step, the first purifying step, the removing step, and the second purifying step are sequentially performed.

15. The method according to claim 10, wherein: The laser beam is transmitted to the substrate through an upper electrode disposed on the top of the chamber; The upper electrode includes a window made of quartz and a transparent electrode stacked on the window; and The high frequency power is applied to any one or more of the transparent electrode and the lower electrode.

16. A device for processing a substrate, the device comprising: a chamber providing a processing space; a substrate supporting unit, the substrate supporting unit being disposed in the processing space; a gas supply unit that introduces gas into the processing space; a plasma source, the plasma source providing energy, the plasma source utilizing plasma to excite the gas introduced into the processing space; an exhaust unit, the exhaust unit exhausting the atmosphere in the processing space out of the processing space; a window disposed on a top portion of the chamber; an upper electrode, the upper electrode being stacked on the window; A lower electrode, the lower electrode being arranged lower than the substrate; A high-frequency power source connected to any one or more of the upper electrode and the lower electrode; as well as a laser emitting unit disposed above the window and emitting a laser beam toward a substrate placed on the supporting unit, Wherein, the laser emitting unit comprises: a laser source, the laser source generating the laser beam; a digital micromirror device (DMD) unit, the digital micromirror device (DMD) unit being a light modulation unit that modulates the laser beam generated from the laser source; an imaging unit that adjusts the laser beam modulated by the digital micromirror device (DMD) unit and emits the laser beam to the substrate to correspond to a region to which the laser beam is emitted; and a beam shaper that converts the type of the laser beam generated by the laser source, Wherein, the digital micromirror device DMD unit comprises: a micromirror configured to be rotatable; and a plate substrate on which the micromirrors are mounted, and The upper electrode is a transparent electrode.

17. The device according to claim 16, further comprising a control unit, in, The control unit controls each of the micromirrors of the digital micromirror device (DMD) unit to selectively switch between an on state and an off state, so that the heat energy required for each area of ​​the substrate can be transmitted by emitting the laser beam to the substrate. In the on state, each of the micromirrors reflects the laser beam to the substrate, and in the off state, each of the micromirrors dumps the laser beam.

18. The device according to claim 17, wherein: The control unit performs control to perform: a modification step in which the gas supply unit introduces a first process gas into the processing space and excites the introduced first process gas with plasma by controlling the plasma source, thereby processing the substrate; a first purging step, in which the gas supply unit introduces a third process gas into the processing space and discharges the processing space by controlling the discharge unit; a removing step, in which the gas supply unit introduces a second process gas into the processing space, excites the introduced second process gas with plasma by controlling the plasma source, and then the laser emitting unit heats the substrate by emitting the laser beam toward the substrate; as well as a second purging step, in which the gas supply unit introduces the third process gas into the processing space and discharges the processing space by controlling the discharge unit, and The modifying step, the first purifying step, the removing step, and the second purifying step are sequentially performed.

19. The device according to claim 18, wherein: In the removing step, the laser emitting unit emits the laser beam to the entire area of ​​the substrate, and the digital micromirror device (DMD) unit forms a different emission pattern of the laser beam emitted to each local area of ​​the substrate, thereby selectively adjusting the amount of heat for heating each of the areas of the substrate.

20. The device according to claim 19, wherein In the removing step, the emission pattern of the laser beam is formed by reflecting thickness data of each of the regions of the substrate.

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