Pre-cleaning device for semiconductor substrate and pre-cleaning method using same

Abstract

The present invention discloses a pre-cleaning apparatus for a semiconductor substrate and a pre-cleaning method using the same, the pre-cleaning apparatus for a semiconductor substrate comprising: a process chamber having a hollow interior and including a process gas supply hole formed in an upper portion of a side portion and a lower discharge hole formed in a lower surface; a susceptor which is located at the lower part inside the process chamber and is used for placing a semiconductor substrate; a flushing head which is formed of a transparent material, is coupled to the process chamber in the horizontal direction between the upper surface of the base and the process gas supply hole, and has a head gas hole penetrating from the upper surface to the lower surface; a laser beam transmission plate formed of a transparent material and coupled to the process chamber in a horizontal direction at an upper portion of the process gas supply hole; a substrate heating unit located at the upper part of the laser beam transmission plate and configured to irradiate the laser beam to the semiconductor substrate; and a gas supply unit that supplies to the process gas supply hole a process gas that reacts with the silicon oxide film and converts the silicon oxide film into a sublimable film.

Description

Technical Field

[0001] The present invention relates to a pre-cleaning apparatus for removing oxides or nitrides present on the surface of a semiconductor substrate and a pre-cleaning method using the same. Background Art

[0002] A semiconductor substrate such as a silicon substrate may have a silicon oxide film on its surface, and the silicon oxide film may prevent a desired thin film layer from being formed on the surface of the semiconductor substrate. Therefore, before performing semiconductor processes on the semiconductor substrate, it is necessary to pre-clean the silicon oxide film through a pre-cleaning process.

[0003] Existing pre-cleaning methods for pre-cleaning a silicon oxide film may include a first step of converting the silicon oxide film into ammonium hexafluorosilicate and a second step of sublimating the converted ammonium hexafluorosilicate. The first step is performed by supplying a plasma state NF3 gas and a transfer gas to the surface of a semiconductor substrate placed on the upper surface of a pedestal together. The first step is performed by heating the semiconductor substrate at a first temperature using the pedestal. The second step is performed by heating the semiconductor substrate at a second temperature higher than the first temperature. Therefore, the pre-cleaning method can be performed by heating the semiconductor substrate at the first temperature and the second temperature in sequence.

[0004] An existing pre-cleaning apparatus for pre-cleaning a silicon oxide film is performed by heating a semiconductor substrate and a pedestal at the first temperature and the second temperature together. Therefore, since the pre-cleaning apparatus takes a certain time to raise the temperature from the first temperature to the second temperature, the overall process time may increase. Summary of the Invention

[0005] Technical Problem

[0006] An object of the present invention is to provide a pre-cleaning apparatus for a semiconductor substrate and a pre-cleaning method using the same, which can easily control the temperature of the semiconductor substrate during the process of removing oxides or nitrides formed on the surface of the semiconductor substrate.

[0007] Technical Solution

[0008] The pre-cleaning apparatus for a semiconductor substrate according to the present invention is characterized in that a process gas is supplied to a silicon oxide film formed on the upper surface of a semiconductor substrate to convert the silicon oxide film into a convertible film capable of sublimation, and a laser beam oscillated from a vertical cavity surface emitting laser (VCSEL) device is irradiated to the convertible film to sublimate and remove the convertible film.

[0009] Moreover, the pre-cleaning device for a semiconductor substrate according to the present invention pre-cleans a silicon oxide film formed on the upper surface of the semiconductor substrate, and is characterized by including: a process chamber, which is hollow inside, including a process gas supply hole formed in the upper part of the side and a lower discharge hole formed in the lower surface; a susceptor, located at the lower part inside the process chamber, for placing the semiconductor substrate; a rinse head, formed of a transparent material, horizontally coupled to the process chamber between the upper surface of the susceptor and the process gas supply hole, and having a head air hole penetrating from the upper surface to the lower surface; a laser beam transmission plate, formed of a transparent material, horizontally coupled to the process chamber above the process gas supply hole; a substrate heating unit, located above the laser beam transmission plate, for irradiating a laser beam onto the semiconductor substrate; and a gas supply unit, for supplying a process gas that reacts with the silicon oxide film to convert the silicon oxide film into a film that can sublime, to the process gas supply hole.

[0010] Moreover, the pre-cleaning device for a semiconductor substrate according to the present invention may further include an intermediate heat insulation plate, formed of a transparent material, horizontally coupled to the process chamber between the laser beam transmission plate and the substrate heating unit.

[0011] Moreover, the process chamber may include a chamber side wall and a lower plate. The chamber side wall is formed in a cylindrical shape with a hollow inside, the lower plate is coupled to the lower part of the chamber side wall, the outer peripheral surface of the susceptor is spaced from the inner peripheral surface of the chamber side wall, and the lower discharge hole penetrates the lower plate from the upper surface to the lower surface between the inner peripheral surface of the chamber side wall and the outer peripheral surface of the susceptor.

[0012] Moreover, the susceptor may further include an edge ring, which is annular and coupled to the upper part of the outer peripheral surface of the susceptor, and the edge ring is coupled to the susceptor in such a way that the outer peripheral surface is spaced from the inner peripheral surface of the chamber side wall by a distance corresponding to an exhaust gap.

[0013] Moreover, the substrate heating unit may include a vertical cavity surface emitting laser module. The vertical cavity surface emitting laser module includes a device arrangement plate coupled to the inner side of the upper part of the process chamber and vertical cavity surface emitting laser devices for oscillating the laser beam, and is arranged in a lattice shape on the lower surface of the device arrangement plate for irradiating the laser beam onto the upper surface of the semiconductor substrate.

[0014] Moreover, the pre-cleaning method of the semiconductor substrate of the present invention is characterized by including: a semiconductor substrate providing step of placing a semiconductor substrate having a silicon oxide film formed thereon on the upper surface of a susceptor located inside a process chamber; a silicon oxide film transformation step of supplying a process gas including NF3 and NH3 to the upper surface of the semiconductor substrate to transform the silicon oxide film into a transformed film; and a transformed film sublimation step of irradiating a laser beam onto the upper surface of the semiconductor substrate to sublime the transformed film.

[0015] Moreover, after the transformed film sublimation step, the pre-cleaning method of the semiconductor substrate may further include: a sublimation residue removal step of supplying a process gas including hydrogen to the upper surface of the semiconductor substrate to remove sublimation residues remaining on the upper surface of the semiconductor substrate.

[0016] Effects of the Invention

[0017] In the pre-cleaning apparatus for a semiconductor substrate and the pre-cleaning method using the same according to the present invention, during the process of removing oxides or nitrides formed on the surface of the semiconductor substrate, the semiconductor substrate is heated by a substrate heating unit formed by a vertical cavity surface emitting laser device, so that the temperature of the semiconductor substrate can be easily controlled.

[0018] Moreover, in the pre-cleaning apparatus for a semiconductor substrate and the pre-cleaning method using the same according to the present invention, the semiconductor substrate is heated by irradiating a laser beam oscillated from the substrate heating unit onto the upper surface of the semiconductor substrate. Therefore, the heating rate of the semiconductor substrate can be increased and the process time can be shortened.

[0019] Moreover, in the pre-cleaning apparatus for a semiconductor substrate and the pre-cleaning method using the same according to the present invention, when the irradiation of the laser beam irradiated onto the upper surface of the semiconductor substrate is interrupted, the cooling rate of the semiconductor substrate can be increased and the process time can be shortened.

[0020] Moreover, in the pre-cleaning apparatus for a semiconductor substrate and the pre-cleaning method using the same according to the present invention, the susceptor is used to perform the first heating of the semiconductor substrate, and the laser beam of the substrate heating unit is used to further heat the semiconductor substrate. Therefore, the semiconductor substrate can be effectively heated. Description of the Drawings

[0021] Figure 1 It is a vertical cross-sectional view of a pre-cleaning apparatus for a semiconductor substrate according to an embodiment of the present invention.

[0022] Figure 2 It is Figure 1 a horizontal cross-sectional view taken along A-A.

[0023] Figure 3 It is Figure 1 a partial enlarged view of "B".

[0024] Figure 4 Partial perspective view of the substrate heating unit according to an embodiment of the present invention.

[0025] Figure 5 Partial perspective view of the substrate heating unit according to another embodiment of the present invention.

[0026] Figure 6 Partial perspective view of the substrate heating unit according to another embodiment of the present invention.

[0027] Figure 7 Process flow chart of the pre - cleaning method for a semiconductor substrate according to an embodiment of the present invention.

[0028] Figure 8 To show Figure 1 The role of the pre - cleaning device in Figure 7 The silicon oxide film conversion step of the vertical sectional view.

[0029] Figure 9 To show Figure 1 The role of the pre - cleaning device in Figure 7 The conversion film sublimation step of the vertical sectional view. Detailed implementation manners

[0030] Hereinafter, through embodiments and drawings, the pre - cleaning device for a semiconductor substrate of the present invention and the pre - cleaning method using the same will be described in more detail.

[0031] First, the pre - cleaning device for a semiconductor substrate according to an embodiment of the present invention will be described.

[0032] Figure 1 Vertical sectional view of the pre - cleaning device for a semiconductor substrate according to an embodiment of the present invention. Figure 2 Horizontal sectional view along A - A of Figure 1 The horizontal sectional view. Figure 3 For Figure 1 Partial enlarged view of "B". Figure 4 Partial perspective view of the substrate heating unit according to an embodiment of the present invention. Figure 5 Partial perspective view of the substrate heating unit according to another embodiment of the present invention. Figure 6 Partial perspective view of the substrate heating unit according to another embodiment of the present invention.

[0033] Referring to Figures 1 to 4 , the pre - cleaning device 10 for a semiconductor substrate according to an embodiment of the present invention may include a process chamber 100, a susceptor 200, a rinse head 300, a laser beam transmission plate 400, a substrate heating unit 600, and a gas supply unit 700. And, the pre - cleaning device 10 may further include an intermediate heat insulation plate 500.

[0034] The pre-cleaning device 10 can remove silicon oxides formed on the surface of a semiconductor substrate a such as a silicon substrate. The pre-cleaning device 10 can remove the silicon oxide film formed on the upper surface of the semiconductor substrate a through a process of removing the existing silicon oxide film. That is, the pre-cleaning device 10 can supply a process gas including NF3 and NH3 to remove the silicon oxide film. And, the pre-cleaning device 10 can change the type of the process gas supplied by the gas supply unit 700 to remove the silicon nitride film or a film of other materials formed on the upper surface of the semiconductor substrate a. Therefore, the applicable films of the pre-cleaning device are not limited to silicon oxide films, and various films can be applied. And, the pre-cleaning device 10 can be applied not only to the pre-cleaning process of the semiconductor substrate a, but also to the etching of the semiconductor substrate a or the etching process of various material films formed on the upper part of the semiconductor substrate a.

[0035] The pre-cleaning device 10 can heat the semiconductor substrate a by irradiating a laser beam from the substrate heating unit 600 located above the semiconductor substrate a to the upper part of the semiconductor substrate a. Therefore, the pre-cleaning device 10 can directly heat the semiconductor substrate a by irradiating a laser beam thereto, and thus the temperature of the semiconductor substrate a can be easily controlled. That is, the pre-cleaning device 10 can raise the temperature of the semiconductor substrate a in a relatively short time. And, the pre-cleaning device 10 can cool the semiconductor substrate a in a relatively short time. Herein, "relatively" means in comparison with the existing device for heating the semiconductor substrate a through the susceptor 200. The pre-cleaning device 10 can heat the semiconductor substrate a to a temperature of 200 °C or higher. And, the pre-cleaning device 10 can heat the semiconductor substrate a to a temperature of 100 °C to 150 °C.

[0036] The pre-cleaning device 10 can heat the semiconductor substrate a by irradiating a laser beam in the infrared wavelength range through the substrate heating unit 600. And, the pre-cleaning device 10 can irradiate a laser beam of a single wavelength. For example, preferably, the pre-cleaning device 10 can be a device that irradiates a laser beam of a single wavelength of approximately 940 nm. And, the pre-cleaning device 10 can be a device that irradiates laser beams of multiple wavelengths.

[0037] The process chamber 100 may include a chamber side wall 110 and a lower plate 120. And, the process chamber 100 may further include an upper plate (not shown) coupled to the upper part. The process chamber 100 can be formed in a cylindrical shape with a hollow interior. The process chamber 100 can be generally formed in a cylindrical shape, a rectangular prism shape, a pentagonal prism shape, or a hexagonal prism shape. And, the upper part of the process chamber 100 may be in an open state.

[0038] The process chamber 100 can form a space inside for accommodating the rinse head 300, the laser beam transmission plate 400, and the substrate heating unit 600. Also, the process chamber 100 can form a process area for accommodating the semiconductor substrate a inside and performing a pre-cleaning process.

[0039] The process chamber 100 can be formed in a shape with a horizontal cross-sectional area larger than that of the semiconductor substrate a accommodated inside. The process chamber 100 can be formed of a metal material that is durable against breakage caused by pressure and temperature changes, so as to cope with positive and negative pressure conditions and rapid temperature change conditions occurring during the manufacturing process. Also, the process chamber 100 can be formed of a metal material that is corrosion-resistant to the process gases used in the manufacturing process. The process chamber 100 can be formed of metal materials such as stainless steel, invar alloy, and Hastelloy.

[0040] The chamber sidewall 110 can include a process gas supply hole 111 and a substrate inlet / outlet 112. Also, although not specifically shown, the chamber sidewall 110 can further include holes required for performing the pre-cleaning process.

[0041] The chamber sidewall 110 can be formed in a hollow cylindrical shape inside. The chamber sidewall 110 can be generally formed in a cylindrical shape, a square cylindrical shape, a pentagonal cylindrical shape, or a hexagonal cylindrical shape. Also, the chamber sidewall 110 can form a space inside for accommodating the susceptor 200, the rinse head 300, the laser beam transmission plate 400, and the substrate heating unit 600.

[0042] The process gas supply hole 111 can be formed to penetrate from the outside to the inside on one side of the chamber sidewall 110. The process gas supply hole 111 can be formed in the upper part of the side of the process chamber 100. The process gas supply hole can be formed at a position between the rinse head 300 and the laser beam transmission plate. The process gas supply hole 111 can provide a path for supplying the process gas to the upper part of the rinse head 300.

[0043] The substrate inlet / outlet 112 can be formed to penetrate from the outside to the inside on the other side of the chamber. The substrate inlet / outlet 112 can be formed at the same height as or higher than the height of the susceptor 200. The substrate inlet / outlet 112 can provide a path for the semiconductor substrate a placed on the susceptor 200 to enter and exit together with the transfer robot for performing the pre-cleaning process. Therefore, the width of the substrate inlet / outlet 112 can be greater than the diameter of the semiconductor substrate a. Also, the height of the substrate inlet / outlet 112 can be greater than the thickness of the semiconductor substrate a and the thickness of the transfer robot.

[0044] Also, although not specifically shown, a gate valve may be coupled to the substrate inlet / outlet 112 at the outer end. The gate valve may seal the substrate inlet / outlet 112 during the pre-cleaning process. Also, the gate valve may open the substrate inlet / outlet 112 when the semiconductor substrate a enters and exits.

[0045] The lower plate 120 may include a lower discharge hole 121 and a lower center hole 122. Also, although not specifically shown, the lower plate 120 may further include holes required for performing the pre-cleaning process.

[0046] The lower plate 120 may be formed in a plate shape corresponding to the planar shape of the chamber sidewall 110. For example, the lower plate 120 may be formed in a disk shape with a predetermined thickness. The lower plate 120 may be coupled to the lower part of the chamber sidewall 110.

[0047] The lower discharge hole 121 may be formed to penetrate from the upper surface to the lower surface of the lower plate 120 adjacent to the inner circumferential surface of the chamber sidewall 110. The lower discharge hole 121 may be formed in the lower surface of the process chamber 100. Also, the lower discharge hole 121 may be formed to penetrate from the upper surface to the lower surface in the region between the inner circumferential surface of the chamber sidewall 110 and the outer circumferential surface of the susceptor 200. Therefore, the diameter of the lower discharge hole 121 may be smaller than the distance between the inner circumferential surface of the chamber sidewall 110 and the outer circumferential surface of the susceptor 200. At least one lower discharge hole 121 may be formed, and a plurality of the lower discharge holes 121 may be formed at intervals along the circumferential direction of the lower plate 120.

[0048] The lower discharge hole 121 may provide a path for discharging the process gas supplied from the outside during the pre-cleaning process and the exhaust gas including the reaction by-product gas sublimated through the pre-cleaning.

[0049] The lower discharge hole 121 may be connected to a suction unit (not shown) such as a vacuum pump located outside the process chamber 100. Therefore, the lower discharge hole 121 may discharge the process gas and the reaction by-product to the outside by the suction force of the suction unit.

[0050] The lower center hole 122 may be formed to penetrate from the upper surface to the lower surface in the central region of the lower plate 120. The diameter of the lower center hole 122 may be smaller than the diameter of the susceptor 200. The lower center hole 122 may be formed such that a lifter (not shown) coupled to the susceptor 200, a cooling water pipe (not shown) of the cooling flow path connected to the susceptor 200, a power line (not shown) of the electrostatic electrode connected to the susceptor 200, etc. pass through.

[0051] The pedestal 200 can be formed by the pedestal used in a general semiconductor processing apparatus. For example, the pedestal 200 can be formed in a disk shape with a predetermined thickness. The diameter of the pedestal 200 can be larger than the diameter of the semiconductor substrate a. Also, the pedestal 200 can be provided with a substrate placement groove on the upper surface to stably place the semiconductor substrate a. The pedestal 200 can be provided with ejector pins (not shown) that penetrate from the bottom surface of the placement groove to the lower surface of the pedestal 200. Also, the pedestal 200 can include a cooling water flow path (not shown) and an electrostatic electrode (not shown) inside.

[0052] The process chamber 100 can have a process space 100a for performing a pre-cleaning process above the pedestal 200. The semiconductor substrate a can be placed on the upper surface of the pedestal 200, so that the upper surface can be exposed to the process space 100a.

[0053] The pedestal 200 can be disposed at the upper center of the lower plate 120. The pedestal 200 can be separated from and supported by the upper part of the lower 120 through a separate support plate 210. The outer diameter of the support plate 210 can correspond to the outer diameter of the pedestal 200. Also, the support plate 210 can have a groove with a diameter equal to the inner diameter of the lower center hole 122 and extending upward. Also, the support plate 210 can have a hole with an inner diameter equal to the inner diameter of the lower center hole or form a larger inner diameter. The support plate 210 can support the pedestal 200 and seal between the lower surface of the pedestal 200 and the upper surface of the lower plate 120. The support plate 210 can be formed of a heat insulating material. For example, the support plate 210 can be formed of a polyimide material. The support plate 210 can prevent the heat of the pedestal 200 from being transferred to the outside through the lower plate 120.

[0054] The diameter of the pedestal 200 can be such that the outer diameter is smaller than the inner diameter of the chamber sidewall 110. The outer peripheral surface of the pedestal 200 can be spaced apart from the inner peripheral surface of the chamber sidewall 110. An annular exhaust gas passage 100b can be formed between the outer peripheral surface of the pedestal 200 and the inner peripheral surface of the chamber sidewall 110. The exhaust gas passage 100b can provide a path for the process gas supplied from the outside and the reaction by-product gas sublimated from the upper surface of the semiconductor substrate a through pre-cleaning to flow from the process space 100a and flow to the lower discharge hole 121. The width of the discharge passage can be larger than the inner diameter of the lower discharge hole 121. Also, the discharge passage can be formed with a sufficient width for the exhaust gas to flow.

[0055] The base 200 may further include an edge ring 220 coupled to the upper portion of the outer circumferential surface. The inner diameter of the edge ring 220 may be such that the inner circumferential surface contacts the outer circumferential surface of the base 200. Also, the edge ring 220 may be formed with an outer diameter required to form an exhaust gap 100c between the outer circumferential surface and the inner circumferential surface of the chamber wall body. The width of the exhaust gas cover may be smaller than the width of the exhaust gas passage 100b. The width of the exhaust gap 100c may be 1 to 5 mm. The edge ring 220 may be integrally coupled to the base 200. For example, the edge ring 220 may be fixedly coupled through a separate fixing unit such that the inner circumferential surface contacts the outer circumferential surface of the base 200. Also, the edge ring 220 may be placed on a step formed in the upper outer side of the base 200 and coupled thereto in a separable manner.

[0056] Also, the thickness of the edge ring 220 may be smaller than the thickness of the base 200. The thickness of the edge ring 220 may be 3 to 6 mm. Also, the edge ring 220 may be formed of a material such as aluminum or silicon carbide. The edge ring 220 is preferably formed with a relatively thin thickness so that it can be heated together when the semiconductor substrate a is heated. Thus, the edge ring 220 can allow the multi-layer silicon oxide film formed on the upper surface of the semiconductor substrate a to sublimate smoothly. Also, the edge ring 220 can prevent the sublimated and transferred gas from being re-solidified and adhering.

[0057] The edge ring 220 may be located above the exhaust gas passage 100b to separate the lower exhaust gas passage 100b from the lower process execution space 100a. Also, the edge ring 220 may connect the exhaust gas passage 100b to the process execution space 100a through the exhaust gap 100c. During the process of discharging the exhaust gas, the edge ring 220 can maintain a relatively low negative pressure in the exhaust gas passage 100b and a relatively high positive pressure in the process execution space 100a. Thus, the exhaust gas can flow more effectively from the process execution space 100a into the exhaust gas passage 100b and be discharged to the outside.

[0058] The rinse head 300 may include head air holes 310. The rinse head 300 may be formed in a plate shape having the same planar shape as the process chamber 100. The rinse head 300 may be formed in a disc shape. The rinse head 300 may be formed of a transparent material that transmits a laser beam. Also, the rinse head 300 may be formed of a material having corrosion resistance to process gases. The rinse head 300 may be formed of quartz material.

[0059] The head air holes 310 may be formed to penetrate from the upper surface to the lower surface of the rinsing head 300. The head air holes 310 may be formed with an inner diameter required for process gas. For example, the inner diameter of the head air holes 310 may be 0.5 to 1.2 mm. A plurality of the head air holes 310 may be spaced apart and provided in the rinsing head 300.

[0060] The rinsing head 300 may be located above the base 200, that is, may be located below the process gas supply hole 111 above the process space 100a. The rinsing head 300 may be horizontally coupled to the process chamber 100 between the upper surface of the base 200 and the lower part of the process gas supply hole 111. The outer peripheral surface of the rinsing head 300 may be integrally coupled to the inner peripheral surface of the chamber sidewall 110. The rinsing head 300 may form a process gas space 100d above the laser beam transmission plate 400 and the process space 100a. The rinsing head 300 may inject process gas toward the upper part of the semiconductor substrate a.

[0061] The laser beam transmission plate 400 may be formed in a plate shape corresponding to the horizontal plane shape of the chamber sidewall 110. The laser beam transmission plate 400 may be formed in a disk shape. The outer diameter of the laser beam transmission plate 400 may be equal to or greater than the inner diameter of the chamber sidewall 110. The laser beam transmission plate 400 may be located above the process gas supply hole 111 of the chamber sidewall 110 above the rinsing head 300. The laser beam transmission plate 400 may be horizontally coupled to the inside of the chamber sidewall 110. The laser beam transmission plate 400 may be coupled in parallel with the rinsing head 300.

[0062] The laser beam transmission plate 400 may be formed of a transparent material capable of transmitting a laser beam. For example, the laser beam transmission plate 400 may be formed of quartz. The laser beam transmission plate 400 may transmit downward the laser beam irradiated from the upper substrate heating unit 600.

[0063] Moreover, the laser beam transmission plate 400 may seal the upper part of the process gas supply hole 111 in the chamber sidewall 110. The laser beam transmission plate 400 may prevent the process gas flowing in from the process gas supply hole 111 from flowing upward. That is, the laser beam transmission plate 400 may prevent the process gas from flowing into the substrate heating unit 600. The laser beam transmission plate 400 may prevent the heat of the process space 100a from flowing upward and being lost.

[0064] The intermediate heat insulation plate 500 may be formed as a plate corresponding to the planar shape of the chamber sidewall 110. For example, the intermediate heat insulation plate may be formed in a disc shape. The outer diameter of the intermediate heat insulation plate may be equal to or greater than the inner diameter of the chamber sidewall 110. The thickness of the intermediate heat insulation plate may be less than the thickness of the laser beam transmissive plate 400.

[0065] The intermediate heat insulation plate may be coupled to the chamber sidewall 110 above the laser beam transmissive plate 400. Thus, the intermediate heat insulation plate may form a heat insulation space 100e above the laser beam transmissive plate 400. The heat insulation space 100e may be filled with air or an inert gas. The intermediate heat insulation plate may prevent heat in the process performing space 100a from being lost by flowing through the laser beam transmissive plate 400 to the outside. Also, the intermediate heat insulation plate may prevent heat generated from the process performing space 100a from being transferred to the substrate heating unit 600 through the laser beam transmissive plate 400.

[0066] Two of the intermediate heat insulation plates may be spaced apart from each other and an air layer or a gas layer may be formed therebetween. Thus, the heat insulation performance of the intermediate heat insulation plate may be increased.

[0067] Also, the intermediate heat insulation plate may be formed of a transparent material that transmits the laser beam. For example, the intermediate heat insulation plate may be formed of the same quartz as the laser beam transmissive plate 400. Also, the intermediate heat insulation plate may be formed of a transparent material such as glass. The intermediate heat insulation plate may transmit the laser beam irradiated from the substrate heating unit 600 located above downward.

[0068] The substrate heating unit 600 may include a device arrangement plate 610 and a vertical cavity surface emitting laser module 620. As Figure 5 shown, in the substrate heating unit 600, a plurality of vertical cavity surface emitting laser modules 620 may be arranged on the upper surface of the device arrangement plate 610 along the x direction and the y direction.

[0069] The substrate heating unit 600 may be located above the process chamber 100. That is, the substrate heating unit 600 may be located above the laser beam transmissive plate 400. Also, when an intermediate heat insulation plate is formed, the substrate heating unit may be located above the intermediate heat insulation plate. The substrate heating unit 600 may be coupled to the inside of the chamber sidewall 110 in such a manner that the device arrangement plate is located above and the vertical cavity surface emitting laser module is located below. The substrate heating unit 600 may irradiate a laser beam onto the upper surface of the semiconductor substrate a through the laser beam transmissive plate 400.

[0070] The device arrangement plate 610 may be formed in a plate shape with a predetermined area and thickness. The diameter of the device arrangement plate 610 may be equal to or greater than the inner diameter of the chamber sidewall 110. The area of the device arrangement plate 610 may correspond to the horizontal plane of the chamber sidewall 110. The device arrangement plate 610 may be formed of a ceramic material or a metal material having heat conductivity. The device arrangement plate 610 may release the heat generated from the vertical cavity surface emitting laser module 620.

[0071] The vertical cavity surface emitting laser module 620 may include a device substrate 621, a vertical cavity surface emitting laser device 623, electrode terminals 625, and a cooling block 627. The vertical cavity surface emitting laser module 620 can be arranged in a lattice shape on the lower surface of a plurality of device arrangement plates 610. The vertical cavity surface emitting laser module 620 may irradiate a laser beam released from the vertical cavity surface emitting laser device 623 onto the upper surface of the semiconductor substrate a for heating.

[0072] On the upper surface of the device substrate 621 of the vertical cavity surface emitting laser module 620, a plurality of vertical cavity surface emitting laser devices 623 are arranged along the x-axis direction and the y-axis direction. When the vertical cavity surface emitting laser module 620 is arranged along the y-axis direction, terminal regions 621b may be arranged adjacent to each other along the x-axis direction, and the terminal regions 621b are located on the rear end side of the vertical cavity surface emitting laser module 620 adjacent to the terminal regions 621b on the other side of the front end. In the vertical cavity surface emitting laser module 620, the device region 621a and the terminal regions 621b may be arranged in a straight line along the x-axis direction respectively, and the device region 621a and the terminal regions 621b may be arranged alternately along the y-axis direction.

[0073] The device substrate 621 may be formed of a general substrate for mounting electronic devices. The device substrate 621 may be divided into a device region 621a for mounting a plurality of vertical cavity surface emitting laser devices 623 and a terminal region 621b for mounting terminals. A plurality of vertical cavity surface emitting laser devices 623 can be arranged and mounted in the device region 621a in a lattice shape. The terminal region 621b can be arranged and mounted in contact with the device region 621a with a plurality of terminals.

[0074] The vertical cavity surface emitting laser devices 623 are arranged along the x-axis direction and the y-axis direction on the upper surfaces of a plurality of device substrates 621. The vertical cavity surface emitting laser devices 623 may irradiate a laser beam with a single wavelength of 940 nm. The vertical cavity surface emitting laser devices 623 may oscillate a high-output laser beam, and thus can effectively heat the semiconductor substrate a.

[0075] The vertical cavity surface emitting laser device 623 may be formed by arranging a plurality of micro-emitters along the x-axis direction and the y-axis direction. Although not specifically shown, the vertical cavity surface emitting laser device 623 may include a light emitting frame (not shown) for fixing the micro-emitters and a power line (not shown) for supplying current to the micro-emitters. The vertical cavity surface emitting laser device 623 may apply the same current to the entire micro-emitters. Also, the vertical cavity surface emitting laser device 623 may apply different powers to each micro-emitter.

[0076] A plurality of the electrode terminals 625 may be formed in the terminal region 621b of the device substrate 621. The electrode terminals 625 may include a + terminal and a - terminal, and may be electrically connected to the vertical cavity surface emitting laser device 623. Although not specifically shown, the electrode terminals 625 may be electrically connected to the vertical cavity surface emitting laser device 623 in various ways. The electrode terminals 625 may supply the current required for driving the vertical cavity surface emitting laser device 623.

[0077] The cooling block 627 can be formed in a planar shape corresponding to the planar shape of the device substrate 621 and a predetermined height. The cooling block 627 may be formed of a ceramic material or a metal material having thermal conductivity. The cooling block 627 may be bonded to the lower surface of the device substrate 621 through a separate adhesive layer. The cooling block 627 may release the heat generated from the vertical cavity surface emitting laser device 623 mounted on the surface of the device substrate 621 downward. Thus, the cooling block 627 may cool the device substrate 621 and the vertical cavity surface emitting laser device 623. The reference numeral 626 not described may be an adhesive layer that bonds the device substrate 621 and the cooling block 627.

[0078] Also, the cooling block 627 may form a cooling flow path (not shown) inside for the cooling water to flow. The cooling flow path may form an inlet and an outlet on the lower surface, and various forms of flow paths may be formed inside the cooling block 627.

[0079] In another embodiment, in the substrate heating unit 600, the vertical cavity surface emitting laser module 620 may be formed in various shapes according to the shapes of the vertical cavity surface emitting laser device 623 and the electrode terminals 625 provided on the upper surface of the device substrate 621.

[0080] Refer to Figure 5, the vertical cavity surface emitting laser module 620 of another embodiment of the present invention may be generally square or rectangular in shape. In the vertical cavity surface emitting laser module 620, the device region 621a may be formed in a quadrilateral shape with an overall width and a specified length, and a terminal region 621b may be integrally formed at the front end or the rear end of the device region 621a. Moreover, the length of the terminal region 621b may be less than the length of the device region 621a.

[0081] In the substrate heating unit 600, when the vertical cavity surface emitting laser modules 620 are arranged along the y-axis direction on the device arrangement board 610, the terminal region 621b located at the front end and the device region 621a of the sub-irradiation module 620 located at the front side may be arranged in a contacting manner.

[0082] In this case, the substrate heating unit 600 may continuously arrange the device regions 621a and the terminal regions 621b of the vertical cavity surface emitting laser modules 620 along the x-axis direction, and alternately arrange the device regions 621a and the terminal regions 621b along the y-axis direction.

[0083] Moreover, referring to Figure 6 , the vertical cavity surface emitting laser module 620 of another embodiment of the present invention may be generally triangular in shape. And, in the vertical cavity surface emitting laser module 620, the terminal region 621b may be formed from a quadrilateral shape into a square shape having a specified length and a width with a cut corresponding to the overall width at the other side of the front end and the other side of the rear end. That is, the width of the terminal region 621b may correspond to the width cut of the sub-device module. The terminal regions 621b may be located in a diagonal direction with respect to each other on the square. In the vertical cavity surface emitting laser module 620, the region other than the terminal region 621b may be formed as the device region 621a.

[0084] Moreover, one side and the other side of the vertical cavity surface emitting laser module 620 may be formed in a straight line shape. The length of the terminal region 621b may be less than the length of the device region 621a. The terminal regions 621b may be formed with the same length at the front side and the rear side.

[0085] When the vertical cavity surface emitting laser module 620 is arranged along the y-axis direction on the device arrangement board 610, the terminal region 621b located at one end of the front side and the device region 621a located at the other side of the rear end of the vertical cavity surface emitting laser module 620 may be adjacently arranged. When the vertical cavity surface emitting laser module 620 is arranged along the y-axis direction, the terminal region 621b located at the other side of the rear end and the device region 621a existing at the other side of the front end of the vertical cavity surface emitting laser module 620 located at the front side may be adjacently arranged.

[0086] Further, in the vertical cavity surface emitting laser module 620, with the y-axis direction as a reference, the device regions 621a and the terminal regions 621b may be alternately arranged along the x-axis direction in the region where the terminal region 621b is formed, and the device regions 621a may be arranged in a straight line shape along the x-axis direction in the region where the terminal region 621b is not formed.

[0087] Therefore, the substrate heating unit 600 may include a region where the device regions 621a and the terminal regions 621b are alternately arranged along the x-axis direction and a region where only the device regions 621a are arranged, and the device regions 621a and the terminal regions 621b may be alternately arranged along the y-axis direction.

[0088] The gas supply unit 700 may include a main gas supply pipe 710, a remote plasma unit 720 (RPU; Remote Plasma Unit), a first gas supply source 730, a second gas supply source 740, and a third gas supply source 750. The gas supply unit 700 may supply process gases required for a pre-cleaning process of the semiconductor substrate a to the semiconductor substrate a. More specifically, the gas supply unit 700 may supply process gases to the process gas supply holes 111 on the sidewalls 110 of the chamber. The process gases may be gases that react with the silicon oxide film formed on the surface of the semiconductor substrate a to convert it into a film that can sublime. The gas supply unit 700 may supply process gases including NF3 and NH3. The process gases may include a first process gas having NF3 and a second process gas having NH3.

[0089] The main gas supply pipe 710 may be formed of a general gas pipe for supplying gases. One end of the main gas supply pipe 710 may be connected to the process gas supply holes 111. The main gas supply pipe 710 may supply the process gases supplied from the first gas supply source 730, the second gas supply source 740, and the third gas supply source 750 to the process gas supply holes 111.

[0090] The remote plasma unit 720 can plasmaize the inflowing gas. The remote plasma unit 720 can be a general device for plasmaizing gas. For example, the remote plasma unit 720 can be an inductively coupled plasma (ICP) device. Also, the remote plasma unit 720 can be an electron cyclotron resonance (ECR) device or a capacitively coupled plasma (CCP) device. The remote plasma unit 720 can be coupled to the other end of the main gas supply pipe 710. The remote plasma unit 720 can plasmaize the inflowing gas and supply it to the main gas supply pipe 710.

[0091] The first gas supply source 730 can be connected to the remote plasma unit 720. The first gas supply source 730 can supply a first process gas to the remote plasma unit 720. The first process gas can be a processing gas that constitutes the process gas. The first process gas can include NF3. Also, the first process gas can further include gases such as argon (Ar) gas, nitrogen (N2) gas, and oxygen (O2) gas. The first gas supply source 730 can be connected to the remote plasma unit 720 through a separate gas supply pipe 731.

[0092] The second gas supply source 740 can be directly connected to the main gas supply pipe 710. That is, the second gas supply source 740 can be connected to the main gas supply pipe 710 between the process gas supply hole 111 and the remote plasma unit 720. Thus, the second gas supply source 740 can supply a second process gas to the main gas supply pipe 710. The second process gas can include NH3 gas. The second gas supply source 740 can be connected to the main gas supply pipe 710 through a separate gas supply pipe 741. On the other hand, the second gas supply source 740 can also be connected to the remote plasma unit 720. Thus, the second gas supply source 740 can supply the second process gas to the remote plasma unit 720 to react with the first process gas.

[0093] The third gas supply source 750 can be directly connected to the main gas supply pipe 710. That is, the third gas supply source 750 can be connected to the main gas supply pipe 710 between the process gas supply hole 111 and the remote plasma unit 720. Therefore, the third gas supply source 750 can supply the third process gas to the main gas supply pipe 710. The third process gas may include an inert gas. The inert gas may be argon (Ar) gas or nitrogen (N2) gas. The third gas supply source 750 can be connected to the main gas supply pipe 710 through a separate gas supply pipe 751.

[0094] Next, a pre-cleaning method using the pre-cleaning apparatus according to an embodiment of the present invention will be described.

[0095] Figure 7 It is a process diagram of a pre-cleaning method for a semiconductor substrate according to an embodiment of the present invention. Figure 8 To show Figure 1 of the pre-cleaning apparatus in Figure 7 a vertical cross-sectional view showing the role in the silicon oxide film conversion step. Figure 9 To show Figure 1 of the pre-cleaning apparatus in Figure 7 a vertical cross-sectional view showing the role in the conversion film sublimation step.

[0096] Referring to Figure 7 , the pre-cleaning method using the pre-cleaning apparatus according to an embodiment of the present invention may include a semiconductor substrate providing step S10, a silicon oxide film conversion step S20, and a conversion film sublimation step S30. The pre-cleaning method may further include a sublimation residue removing step S40. Among them, the pre-cleaning method is described centering on the case where a silicon oxide film is formed on the surface of the semiconductor substrate. However, the pre-cleaning method can also be similarly applied to the case where other films such as a silicon nitride film are formed. In this case, the process gases used in the pre-cleaning method may be different.

[0097] The semiconductor substrate providing step S10 is a step of placing a semiconductor substrate on the upper surface of the susceptor 200 located inside the process chamber 100. The semiconductor substrate a is in a state where a silicon oxide film is formed on the surface.

[0098] The silicon oxide film conversion step S20 is a step of forming a conversion film by converting the silicon oxide film formed on the upper surface of the semiconductor substrate. The silicon oxide film conversion step S20 can heat the semiconductor substrate a to a conversion temperature. The conversion temperature can be set in the range of 20 to 60 °C. Preferably, the conversion temperature can be set in the range of 30 to 40 °C. In the silicon oxide film conversion step S20, the semiconductor substrate a can be heated by a heating unit built in the susceptor 200. Also, in the silicon oxide film conversion step S20, a laser beam can be irradiated from the substrate heating unit 600 to heat the semiconductor substrate a.

[0099] In the silicon oxide film conversion step S20, a process gas including NF3 and NH3 can be supplied. More specifically, in the silicon oxide film conversion step S20, a first process gas including NF3 and a second process gas including NH3 can be supplied to the upper part of the semiconductor substrate a. The second process gas may further include H2 or H2O. The first process gas can be supplied in a state of being passed through the remote plasma unit 720 and being plasmaized. The first process gas passes through the remote plasma unit 720 and flows into the process gas supply hole 111 through the main gas supply pipe 710. The second process gas flows into the process gas supply hole 111 through the process main gas supply pipe 710. The first process gas and the second process gas are mixed with each other in the process gas space 100d and are sprayed onto the upper surface of the semiconductor substrate a through the rinse head 300. The first process gas and the second process gas can react with the silicon oxide formed on the upper surface of the semiconductor substrate a through the following reaction formula and be converted into a conversion film such as ammonium hexafluorosilicate.

[0100] 2NH4F(g)+4HF(g)+SiO2=(NH4)2SiF6(s)+2H2O

[0101] The first process gas flows into the process gas space 100d in a plasmaized state. Therefore, it reacts with NF3 and NH3 during the mixing process with the second process gas and is preferentially converted into NH4F(g) gas. Also, the silicon oxide film conversion step S20 can be performed under the condition that a laser beam is irradiated from the substrate heating unit 600 to heat the semiconductor substrate a to the conversion temperature.

[0102] The transition film sublimation step S30 is a step of heating the transition film to a sublimation temperature to sublime it. In the transition film sublimation step S30, the upper surface of the semiconductor substrate a may be irradiated with a laser beam oscillated from a vertical cavity surface emitting laser module of the substrate heating unit 600 to heat the semiconductor substrate a. The transition temperature may be set within a range of 100 to 300°C. The transition temperature may be set within a range of 100 to 150°C. Furthermore, the transition temperature may be set within a range of 200 to 300°C.

[0103] Ammonium hexafluorosilicate as the transition film can be sublimated according to the following reaction formula.

[0104] (NH4)2SiF6(g)=SiF4(g)+2NH3(g)+2HF(g)

[0105] In the transition film sublimation step S30, exhaust gas including gas generated during the transition film sublimation process can be discharged from the semiconductor substrate a. The transition film sublimation step S30 can be performed in the process of supplying a third process gas including an inert gas. Therefore, the exhaust gas can be a gas mixed with the gas generated during the transition film sublimation process and the third process gas. The transition film sublimation step S30 can be performed in the process of operating the exhaust unit connected to the lower exhaust hole 121 and exhausting the exhaust gas. Therefore, the exhaust gas can be arranged side by side to the lower exhaust hole 121 through the exhaust gap 100c and the exhaust gas passage 100b formed on the outside of the base 200. The exhaust gap 100c can increase the pressure difference between the process space 100a and the exhaust gas passage 100b and increase the speed of exhausting the exhaust gas from the process space 100a.

[0106] The sublimation residue removal step S40 is a step of supplying a second process gas including hydrogen to the upper surface of the semiconductor substrate to remove the sublimation residue remaining on the upper surface of the semiconductor substrate. The sublimation residue may be a substance including fluorine (F) remaining on the upper surface of the semiconductor substrate a during the sublimation of the transition film. The sublimation residue removal step S40 may be performed in the process of heating the semiconductor substrate a at a removal temperature. The removal temperature may be set within a range of 150 to 300° C. The sublimation residue removal step S40 may be performed in the process of irradiating the upper surface of the semiconductor substrate a with a laser beam oscillating from the substrate heating unit 600.

[0107] The embodiments disclosed in this specification are only the most preferred embodiments selected from among multiple feasible examples to assist those of ordinary skill in the art to which the present invention pertains in understanding. The technical concept of the present invention is not limited to these embodiments, and various changes, additions, and modifications can be made without exceeding the scope of the present invention, and other equivalent embodiments can be implemented.

Claims

1. A pre-cleaning device for a semiconductor substrate, characterized in that, A process gas is supplied to a silicon oxide film formed on the upper surface of a semiconductor substrate to convert the silicon oxide film into a conversion film capable of sublimation. A laser beam oscillated from a vertical cavity surface emitting laser device is irradiated onto the conversion film to sublime the conversion film and remove it.

2. A pre-cleaning device for a semiconductor substrate, which pre-cleans a silicon oxide film formed on the upper surface of the semiconductor substrate, characterized in that, Comprising: A process chamber, which is hollow inside, includes a process gas supply hole formed in the upper part of the side and a lower discharge hole formed in the lower surface; A susceptor, located at the lower part inside the process chamber, for placing the semiconductor substrate; A rinse head, formed of a transparent material, is horizontally combined in the process chamber between the upper surface of the susceptor and the process gas supply hole, and has a head air hole penetrating from the upper surface to the lower surface; A laser beam transmission plate, formed of a transparent material, is horizontally combined in the process chamber above the process gas supply hole; A substrate heating unit, located above the laser beam transmission plate, for irradiating a laser beam onto the semiconductor substrate; And A gas supply unit, which supplies a process gas that reacts with the silicon oxide film to convert the silicon oxide film into a sublimable film to the process gas supply hole.

3. The pre-cleaning device for a semiconductor substrate according to claim 2, characterized in that, It further includes an intermediate heat insulation plate, formed of a transparent material, which is horizontally combined in the process chamber between the laser beam transmission plate and the substrate heating unit.

4. The pre-cleaning device for a semiconductor substrate according to claim 2, characterized in that, The process chamber includes a chamber side wall and a lower plate. The chamber side wall is formed in a cylindrical shape with a hollow inside, and the lower plate is combined with the lower part of the chamber side wall. The outer peripheral surface of the susceptor is spaced from the inner peripheral surface of the chamber side wall. The lower discharge hole penetrates the lower plate from the upper surface to the lower surface between the inner peripheral surface of the chamber side wall and the outer peripheral surface of the susceptor.

5. The pre-cleaning device for a semiconductor substrate according to claim 4, characterized in that, The susceptor further includes an edge ring that is annular and combined with the upper part of the outer peripheral surface of the susceptor. The edge ring is combined with the susceptor in such a way that the outer peripheral surface is spaced from the inner peripheral surface of the chamber side wall by a distance corresponding to an exhaust gap.

6. The pre-cleaning device for a semiconductor substrate according to claim 2, characterized in that, The substrate heating unit includes a vertical cavity surface emitting laser module. The vertical cavity surface emitting laser module includes a device arrangement plate combined with the inner upper part of the process chamber and a vertical cavity surface emitting laser device that oscillates the laser beam, and is arranged in a lattice shape on the lower surface of the device arrangement plate for irradiating the laser beam onto the upper surface of the semiconductor substrate.

7. A pre-cleaning method for a semiconductor substrate, characterized in that, Comprising: A semiconductor substrate providing step of placing a semiconductor substrate formed with a silicon oxide film on the upper surface of a susceptor located inside a process chamber; A silicon oxide film conversion step of supplying a process gas including NF3 and NH3 to the upper surface of the semiconductor substrate to convert the silicon oxide film into a conversion film; And A conversion film sublimation step of irradiating a laser beam onto the upper surface of the semiconductor substrate to sublime the conversion film.

8. The pre-cleaning method for a semiconductor substrate according to claim 7, characterized in that, After the conversion film sublimation step, it further includes: A sublimation residue removing step of supplying a process gas including hydrogen to the upper surface of the semiconductor substrate to remove the sublimation residues remaining on the upper surface of the semiconductor substrate.

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