JP4704916B2 - Substrate outer periphery processing apparatus and method - Google Patents

Description

  The present invention relates to an apparatus and a method for removing unnecessary materials such as an organic film provided on the outer periphery of a substrate such as a semiconductor wafer or a liquid crystal panel.

The structure and functions of semiconductor devices are becoming finer, higher integrated, and faster year by year. They are realized by the change of semiconductor materials and the accompanying progress of manufacturing equipment. In general, the wiring material is changed from Al to Cu, and the insulating film is changed from SiO ₂ (relative dielectric constant of about 4) to a so-called low-k material having a lower dielectric constant.

Conventionally, when a trench for a wiring pattern is chemically etched in an insulating film formed on a semiconductor wafer, a protective material component made of, for example, fluorocarbon is mixed in the etching gas in order to suppress isotropic etching. As a result, a protective film of fluorocarbon is coated on the inner wall of the groove formed gradually so that etching proceeds anisotropically only in the direction of the bottom surface of the groove. On the other hand, the fluorocarbon may wrap around from the outer end surface of the wafer to the back side, and may be deposited on the outer peripheral portion of the back surface of the wafer.
When the insulating layer is SiO ₂ , when the photoresist on the insulating layer is dry-ashed with oxygen plasma, the fluorocarbon film on the outer periphery of the back surface is removed by passing the oxygen plasma from the front surface to the back surface of the wafer. It was possible enough.
However, when the insulating layer is a low-k film, if the dry ashing is made too strong, the low-k film is damaged. Therefore, an attempt has been made to perform an ashing process at a low output, but in this case, the fluorocarbon film on the back surface of the wafer cannot be completely removed. If this is left as it is, particles may be generated when the substrate is transported, and the yield may be reduced.

As a prior art document for removing unnecessary objects on the outer periphery of a semiconductor wafer, for example, the one described in Patent Document 1 sprays reactive gas on the outer periphery of a substrate to remove unnecessary objects on the outer periphery. At the same time, a cooling gas is blown onto the center of the wafer so as to flow radially over the surface of the wafer. This prevents reactive gas from flowing into the center of the wafer.
In the device described in Patent Document 2, a laser is irradiated to the outer peripheral portion of the wafer, and unnecessary materials on the outer peripheral portion are laser-etched.
JP-A-8-279494 (FIG. 10) JP 2003-197570 A

When organic substances such as fluorocarbon are removed, a sufficient etching rate cannot be obtained only by spraying a reactive gas as in Patent Document 1 described above. In addition, when locally irradiating a laser as in Patent Document 2, if the amount of irradiation heat is increased too much in order to increase the etching rate, there is a risk of damaging a required layer such as an insulating film coated on the front side of the semiconductor wafer.
An object of the present invention is to efficiently and reliably remove unnecessary materials on the back surface, the outer end surface, and the like without damaging a required layer of a base material such as a semiconductor wafer.

In order to solve the above-described problems, the present invention provides the above-mentioned unnecessary object in a base material having a first surface and a second surface that are front and back, and an unnecessary object is provided on an outer peripheral portion or an outer end surface of the second surface. A device for heating and removing
A support for supporting the substrate;
A cooling gas nozzle that blows a cooling gas locally to a first spot where the outer peripheral portion of the first surface of the base material supported by the support portion should be located;
A heat ray source; and an irradiation unit optically connected to the heat ray source, transmitting the heat ray from the heat ray source to the irradiation unit, and further supported by the support unit from the irradiation unit. a radiant heater which irradiates locally the heat rays to the second surface outer peripheral portion or the second spot outer end face to be positioned in the timber,
The first spot and the second spot are arranged at substantially the same position in the circumferential direction of the support portion and thus the base material supported by the support portion, and the tip of the cooling gas nozzle is disposed on the support portion. It arrange | positions in the side in which the said 1st surface of the direction orthogonal to the said base material has faced rather than the supported base material, and the said irradiation unit is orthogonal to the said base material rather than the base material supported by the said support part. It is arrange | positioned at the side which the said 2nd surface of direction faces .
The first surface is, for example, the front side surface of the substrate, and the second surface is, for example, the back surface of the substrate. On the first surface, for example, a required layer as a product such as an insulating layer or a conductive pattern is formed.
As a result, the second spot can be locally heated to remove unnecessary materials, but even if the heat of the second spot is transmitted to the first spot, it can be efficiently cooled by local spraying of the cooling gas. it can. This can prevent damage to the required layer on the first surface. In addition, since a large amount of heat can be supplied to the second spot, it is possible to increase the efficiency of removing unnecessary materials.

It is preferable that the flow direction of the cooling gas from the cooling gas nozzle is biased from the first spot to the outer end side of the base material supported by the support portion. Can be prevented from entering the first surface side of the base material by being caught in the cooling gas, and particles can be reduced.

It is preferable that the front end surface of the cooling gas nozzle is a slope inclined toward the outer end side of the base material with respect to the first surface of the base material supported by the support portion.
Accordingly, the cooling gas from the cooling gas nozzle can flow from the first spot toward the outer end of the substrate. For this reason, it is possible to prevent the by-product resulting from the removal of the unnecessary material from being entangled in the cooling gas or the like and wrapping around the first surface side of the substrate. As a result, particles can be reduced.

It is preferable to provide a throttle at the tip of the cooling gas nozzle.
Accordingly, the cooling gas can be adiabatically expanded while being blown out from the cooling gas nozzle to develop an endothermic effect, and the cooling efficiency can be increased without increasing the cooling gas flow rate. Since there is no need to increase the cooling gas flow rate, scattering of particles can be suppressed.

  The cooling gas nozzle is preferably made of a translucent material. As a result, the cooling gas nozzle can be prevented from absorbing heat from the heat beam, and the temperature of the cooling gas nozzle can be prevented from increasing. As the translucent material, glass, acrylic, transparent resin, or the like can be used. As the glass, quartz, borosilicate glass, alkali soda glass, or the like can be used. As the transparent resin, transparent polytetrafluoroethylene (PTFE), transparent tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), transparent polycarbonate, transparent vinyl chloride, or the like can be used.

It is preferable that a suction nozzle for locally sucking gases in the vicinity of the second spot is further provided on the side opposite to the cooling gas nozzle side from the first surface of the base material supported by the support portion.
The gases may include the cooling gas or a post-reaction reactive gas that has been processed. Further, by-products generated during the removal of unnecessary substances can be mixed into the gas. Accordingly, the cooling gas can be sucked and exhausted from the suction nozzle while being guided from the outer end surface of the base material to the second surface side. By-products generated by removing unnecessary substances are entrained in the flow of the cooling gas and can be sucked and discharged. As a result, particles can be reduced.

  It is desirable to further include a reactive gas nozzle that blows a reactive gas that reacts with the unnecessary material onto the second spot. When the unnecessary material is an organic material such as fluorocarbon, an oxygen-based gas such as ozone may be used as the reactive gas.

Further, the present invention is a method for heating and removing unnecessary materials provided on the outer peripheral portion or the outer end surface of the second surface in the base material having the first surface and the second surface forming the front and back,
While irradiating the unwanted matter locally with heat rays from the side facing the second surface in the direction orthogonal to the base material rather than the base material,
From the side where the first surface in the direction orthogonal to the base material is directed to the base material, the local surface position is substantially the same as the local irradiation position of the heat ray at the outer peripheral portion of the first surface of the base material. In addition, a cooling gas is sprayed on the substrate , and the irradiation of the heat beam and the spraying of the cooling gas are performed simultaneously .
As a result, the unwanted matter can be efficiently removed by sufficiently locally heating, but even if this heat is transmitted to the first surface side, it can be efficiently cooled by locally blowing the cooling gas. . This can prevent damage to the required layer on the first surface.

Furthermore, the present invention is a method for removing unnecessary materials provided on the outer peripheral portion or the outer end surface of the second surface in the base material having the first surface and the second surface forming the front and back,
A reactive gas that locally irradiates the unnecessary object with a heat beam from the side where the second surface in a direction orthogonal to the substrate is directed rather than the base material, and reacts with the unnecessary object at this local irradiation position And spraying from the side facing the second surface of the direction orthogonal to the base material than the base material,
For locally cooling from the side facing the first surface in the direction perpendicular to the base material to the base material to a position substantially in the same circumferential direction as the local irradiation position in the outer peripheral portion of the first surface of the base material It is characterized in that a gas is blown and the irradiation of the heat beam, the reactive gas and the cooling gas are carried out simultaneously .
As a result, unnecessary substances can be sufficiently locally heated and efficiently removed by the local spraying of the reactive gas. On the other hand, even if the heat is transmitted to the first surface side, the efficiency can be increased by the local spraying of the cooling gas. Can be cooled. This can prevent damage to the required layer on the first surface.

  The cooling gas is not particularly limited as long as it does not affect the substrate and the required layer on the substrate, and it is preferable to use an inert gas or air. Nitrogen is preferably used as the inert gas.

  According to the present invention, unnecessary materials can be sufficiently heated locally and efficiently removed, but even if this heat is transmitted to the first surface side, it is efficiently cooled by locally blowing cooling gas. It is possible to prevent the first surface from being damaged.

Hereinafter, a first embodiment of the present invention will be described. As shown in FIG. 4, the substrate to be processed in this embodiment is a semiconductor wafer 90 made of, for example, silicon. The silicon wafer 90 has a circular thin plate shape. On the front side surface (first surface) of the wafer 90, an insulating layer 91 made of a low-k material is formed as a required layer that constitutes the semiconductor device. The low-k material is an insulating material having a dielectric constant smaller than that of SiO ₂ . The relative dielectric constant of the low-k material is preferably about 15 to 30, for example. Examples of the material constituting the low-k material include Si 2 O ₃ CH ₃ . The insulating layer 91 may be made of SiO ₂ instead of the low-k material. A wiring pattern groove 91 a is formed in the insulating layer 91. A wiring pattern 94 made of Cu is provided in the wiring pattern groove 91a. The wiring pattern 94 may be made of another conductive material such as Al instead of Cu.

  A fluorocarbon film 93 a is coated on the outer peripheral portion of the back surface (second surface) of the silicon wafer 90. The fluorocarbon film 93a extends over the entire circumference of the wafer 90 and has a width along the radial direction (direction perpendicular to the circumferential direction). When the wiring pattern groove 91a is formed by etching, the fluorocarbon film 93a is deposited by the fluorocarbon mixed in the etching gas as a protective material for securing the etching anisotropy around the backside of the wafer. In other words, the photoresist for etching is left unremoved even in the ashing step.

  The substrate outer periphery processing apparatus 1 according to the present embodiment removes the fluorocarbon film 93a on the outer periphery of the back surface of the wafer 90 as an unnecessary material. As shown in FIG. 1, the substrate outer periphery processing apparatus 1 includes a stage 11 and a frame 50.

  The stage 11 has a horizontal disk shape and is rotated around a vertical central axis. The rotational speed of the stage 11 can be adjusted as appropriate.

  The stage 11 constitutes a support part for supporting the wafer 90. The diameter of the upper surface of the stage 11 is slightly smaller than the diameter of the wafer 90. A wafer 90 is set horizontally on the upper surface of the stage 11 with its center aligned. The outer peripheral portion of the set wafer 90 protrudes slightly from the outer edge of the stage 11. As a result, the entire width of the fluorocarbon film 93a is exposed, and the outer edge of the stage 11 is positioned in the immediate vicinity of the radially inner edge of the fluorocarbon film 93a.

  A shallow recess 11 a is formed at the center of the upper surface of the stage 11. Only the upper surface 11 b (base material support surface) of the stage 11 on the outer peripheral side from the recess 11 a comes into contact with the portion immediately inside the outer peripheral protrusion of the wafer 90. A suction groove 11c is formed on the outer peripheral upper surface 11b of the stage 11, and this suction groove 11c is connected to a vacuum suction means. The wafer 90 is vacuum-sucked to the stage 11 by a suction chuck mechanism including the suction groove 11c and vacuum suction means. Since the contact area between the stage 11 and the wafer 90 is small, the number of particles generated can be reduced. As the suction chuck mechanism, an electrostatic type may be used instead of the vacuum suction type.

A cooling chamber 11 d is formed inside the stage 11. A cooling medium such as water or air is fed into the cooling chamber 11d. As a result, the stage 11 can be cooled, and as a result, heat can be absorbed from the wafer 90 through the contact surface between the stage outer peripheral upper surface 11 b and the portion immediately inside the outer peripheral protrusion of the wafer 90.
The stage 11 may be provided with a cooling passage for circulating a cooling medium such as water or air as a heat absorption means instead of the cooling chamber 11d, or may be provided with a Peltier element.
As the material of the upper plate of the stage 11, a material having good thermal conductivity (for example, aluminum) is used.
The stage 11 is not necessarily provided with heat absorption means such as the cooling chamber 11d. Thereby, the configuration of the stage can be simplified.

  As shown in FIG. 1, a frame 50 is disposed on one side of the stage 11. The frame 50 can be moved back and forth, for example, in the radial direction of the stage 11 between the illustrated set position and the retracted position away from the stage 11. In the following description, it is assumed that the frame 50 is located at the set position unless otherwise specified.

  As shown in FIG. 3, the frame 50 is provided with a reactive gas nozzle 21 and a suction nozzle 22 that constitute the reactive gas supply / discharge means 20, and an irradiation unit 32 that constitutes the radiant heater 30.

As shown in FIG. 1, the reactive gas nozzle 21 is connected to a reactive gas source 24 via a gas supply path 23. The reactive gas source 24, the supply path 23, and the reactive gas nozzle 21 constitute a reactive gas supply means. As the reactive gas source 24, an ozonizer that generates ozone (O ₃ ) is used. Ozone is a reactive gas suitable for removing organic films such as the fluorocarbon film 93a.
An atmospheric pressure plasma discharge device is used instead of the ozonizer 24 as a reactive gas source, and oxygen is introduced into the plasma discharge space between the electrodes of the atmospheric pressure plasma discharge device to obtain an oxygen-based reactive gas such as oxygen radicals. It may be.
Oxygen (O ₂ ) as a reactive gas may be supplied as it is to the reactive gas nozzle 21 and blown out.
As the reactive gas, a fluorine-based gas such as CF ₄ may be used instead of the oxygen-based gas.

The reactive gas nozzle 21 has a tubular shape. The reactive gas nozzle 21 is disposed on the lower side of the wafer 90, and the front end portion thereof is directed to a processing position P <b> 2 (second spot) at one place on the outer peripheral portion of the wafer 90. As shown in FIG. 3, the blowing direction of the reactive gas nozzle 21 is substantially along the circumferential direction (tangential direction) of the wafer 90 in plan view. Specifically, the reactive gas nozzle 21 is slightly inclined with respect to the tangent line of the wafer 90 so as to face the outer edge portion of the wafer 90 from the inner side of the wafer 90 in a plan view, but the outer edge of the wafer 90 from the outer side of the wafer 90. It may be slightly inclined with respect to the tangent of the wafer 90 so as to face the portion, or may be directed to the outer edge portion of the wafer 90 just along the tangent. In addition, as shown in FIG. 2, the reactive gas nozzle 21 is inclined, for example, about 45 degrees with respect to the wafer 90 in a side view.
The diameter of the reactive gas nozzle 21 is a size corresponding to the width of the fluorocarbon film 93a.

  The reactive gas nozzle 21 is made of a translucent material. As the translucent material, glass, acrylic, transparent resin, or the like can be used. As the glass, quartz, borosilicate glass, alkali soda glass, or the like can be used. As the transparent resin, transparent polytetrafluoroethylene (PTFE), transparent tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), transparent polycarbonate, transparent vinyl chloride, or the like can be used.

As shown in FIG. 1, an exhaust passage 25 extends from the suction nozzle 22 and is connected to an exhaust means 26 such as an exhaust pump. As shown in FIG. 3, the suction nozzle 22 has a tubular shape and is disposed so as to face the reactive gas nozzle 21 along the circumferential direction (tangential direction) of the wafer 90 in plan view. Therefore, the suction direction of the suction nozzle 22 is substantially along the circumferential direction (tangential direction) of the wafer 90 in a plan view and substantially coincides with the blowing direction from the blowing nozzle 21. As shown in FIG. 2, it is inclined, for example, about 45 degrees from the lower side of the wafer 90 toward the processing position P2 in a side view.
Instead of the suction nozzle 22 extending along the tangential direction of the wafer 90, the suction nozzle 22 is directed from the outside of the wafer 90 toward the processing position P <b> 2 along the radial direction of the wafer 90, or disposed upward from the wafer 90. May be.

  The suction nozzle 22 is made of a light-transmitting material similar to the reactive gas nozzle 21.

  The diameter of the suction nozzle 22 is larger than the diameter of the reactive gas nozzle 21, for example, about 2 to 5 times. For example, the diameter of the reactive gas nozzle 21 is about 1 to 3 mm, whereas the diameter of the suction nozzle 22 is about 2 to 15 mm.

Along the flow direction of the reactive gas (ozone), the tip of the reactive gas nozzle 21 is arranged in the vicinity of the upstream side of the processing position P2, and the tip of the suction nozzle 22 is arranged in the vicinity of the downstream side of the processing position P2. Has been.
The reactive gas nozzle 21 is disposed on the upstream side in the rotational direction and the suction nozzle 22 is disposed on the downstream side in the rotational direction along the rotational direction (for example, clockwise in plan view) of the stage 11 and the wafer 90.
The direction of the nozzles 21 and 22 and the mutual arrangement relationship can be set as appropriate.

  As shown in FIG. 1, the substrate outer periphery processing apparatus 1 is provided with a laser heater 30 as radiation heating means. The laser heater 30 includes a laser light source 31 as a heat beam source and an irradiation unit 32.

  The laser light source 31 emits, for example, an LD (semiconductor) laser beam having an emission wavelength of 808 nm to 940 nm. The laser light source 31 is not limited to the LD, and various types such as YAG and excimer may be used.

An optical fiber 34 extends from the emission part of the laser light source 31 to the irradiation unit 32 of the frame 50. As shown in FIG. 3, the irradiation unit 32 is disposed between the reactive gas nozzle 21 and the suction nozzle 22 along the circumferential direction of the stage 11 and then the wafer 90 in a plan view. As shown in FIG. 1, the irradiation unit 32 is disposed on the lower side and the radially outer side of the wafer 90, and is directed obliquely upward so as to face the outer peripheral portion of the wafer 90.
The irradiation unit 32 may be disposed directly below the outer peripheral portion of the wafer 90.

  The irradiation unit 32 houses a condensing optical system (not shown) including optical elements such as a convex lens and a cylindrical lens. The tip of the optical fiber 34 is optically connected to the condensing optical system. The condensing optical system converges and irradiates the laser L transmitted through the optical fiber 34 obliquely upward toward the outer peripheral portion of the wafer 90. The condensing spot on the wafer outer periphery of the laser L becomes the processing position P2 (second spot).

  As indicated by the white arrow A1 in FIG. 4, the irradiation unit 32 is provided with a focus adjustment mechanism of a system that shifts the condensing optical system along the laser optical axis, for example. As a result, the focal position of the laser beam L, and thus the focused spot diameter on the outer periphery of the wafer can be adjusted. Further, as indicated by a white arrow A2 in FIG. 4, the irradiation unit 32 is connected to a radial movement mechanism for moving the irradiation unit 32 along the radial direction of the stage 11 and then the wafer 90. Alternatively, instead of the radial direction moving mechanism, as shown by the white arrow A3 in the figure, the angle adjustment is performed so that the angle of the irradiation unit 32 is adjusted around an axis parallel to the tangent in the vicinity of the focused spot P2 of the laser light L. The mechanism is connected. Thereby, the position of the condensing spot P2 can be adjusted in the width direction of the fluorocarbon film 93a (the radial direction of the wafer 90).

  As shown in FIG. 1, an upper frame portion 51 is provided on the frame 50 of the substrate outer periphery processing apparatus 1. In the set state of the frame 50, the upper frame portion 51 covers the upper periphery of the stage 11. A gas nozzle 61 for cooling of the local cooling means 60 is attached to the upper frame portion 51. A cooling gas path 63 extends from the cooling gas source 62, and the leading end of the cooling gas path 63 is connected to the cooling gas nozzle 61. In the cooling gas source 62, for example, nitrogen is stored as a cooling gas.

  As shown in FIG. 1, the cooling gas nozzle 61 has a tubular shape. The cooling gas nozzle 61 is vertically arranged above the outer peripheral portion of the wafer 90 on the stage 11 with the blowout port at the front end facing downward. The outlet of the cooling gas nozzle 61 is disposed close to the outer peripheral portion of the upper surface (front side surface) of the wafer 90. Cooling nitrogen gas is locally blown from one outlet (first spot P1) of the front side surface of the wafer 90 from the outlet of the cooling gas nozzle 61. As shown in FIG. 3, the condensing spot of the irradiation unit 32, that is, the second spot P2 is arranged just behind the first spot P1. Therefore, the first spot P 1 and the second spot P 2 are arranged at substantially the same position in the circumferential direction of the wafer 90.

  As shown in FIG. 1, the lower end surface that forms the outlet of the cooling gas nozzle 61 is cut obliquely so that the portion closer to the inner side in the radial direction of the wafer 90 approaches the upper surface of the wafer 90. The slope is inclined to the outer end side. Therefore, as shown by the thick arrow lines in FIG. 4, the flow direction of the cooling gas from the cooling gas nozzle 61 is biased toward the outer end side of the wafer 90 from the first spot P1.

  The cooling gas nozzle 61 is made of a translucent material. As the translucent material, glass (for example, quartz, borosilicate glass, alkali soda glass), acrylic, transparent resin (for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-par) is used in the same manner as the reactive gas nozzle 21. A fluoroalkyl vinyl ether copolymer (PFA), polycarbonate, vinyl chloride) or the like can be used.

The base-material outer periphery processing apparatus 1 of the said structure is used as follows.
The wafer 90 is aligned and placed on the stage 11, and the outer peripheral portion including the fluorocarbon film 93 a of the wafer 90 is projected outward in the radial direction of the stage 11. Then, while rotating the stage 11 around the central axis, the laser light L from the laser light source 31 is emitted from the irradiation unit 32 through the optical fiber 34, and the second spot of the fluorocarbon film 93 a on the outer periphery of the back surface of the wafer 90. Focus on P2. As a result, the fluorocarbon film 93a of the second spot P2 is heated at a high temperature locally and instantaneously. At the same time, ozone from the ozonizer 24 is blown from the reactive gas nozzle 21 substantially along the tangential direction of the wafer 90 and applied to the locally heated second spot P2. Thereby, the fluorocarbon film 93a of the second spot P2 is removed by reacting with ozone. Further, by driving the exhaust means 26, the processed ozone and reaction by-products are sucked and discharged almost in the tangential direction by the suction nozzle 22. Also, as shown by the white arrow A1 in FIG. 4, the focal point of the irradiation unit 32 is adjusted to change the focused spot diameter, or as shown by the white arrow A2 or A3 in the same figure, the stage of the irradiation unit 32 The entire fluorocarbon film 93a can be removed by adjusting the position and angle along the radial direction to shift the focused spot position in the width direction of the fluorocarbon film 93a.

In parallel with the laser irradiation and the ozone spraying, the cooling nitrogen gas from the cooling gas source 62 is sprayed from the cooling gas nozzle 61 to the first spot P1 on the outer periphery of the upper surface of the wafer 90. Thus, even if the radiant heat supplied to the second spot P2 on the outer peripheral portion of the lower surface of the wafer 90 is transmitted to the first spot P1 on the upper surface via the inside of the outer peripheral portion of the wafer 90, the radiant heat is blown onto the first spot P1. Heat can be removed by the nitrogen gas flow, and the temperature rise of the first spot P1 can be suppressed. Therefore, it is possible to prevent damage to required layers such as the first spot P1 or the surrounding insulating layer 91 and the wiring pattern 94. As a result, the quality of the semiconductor device can be ensured. Since the cooling nitrogen gas is blown locally only to the first spot P1, it can be efficiently cooled with a small flow rate.
On the other hand, the amount of laser heat applied to the second spot P2 can be increased to the extent that the required layers 91 and 94 are damaged without the cooling of the nitrogen gas. As a result, the etching rate of the fluorocarbon film 93a can be sufficiently increased, and the processing speed can be increased.

  Since the tip of the cooling gas nozzle 61 is cut obliquely outwardly from the wafer 90, nitrogen gas is directed toward the outer edge of the wafer in the vicinity of the first spot P1, as indicated by the thick arrow line in FIG. It will flow like Then, it goes around from the outer end surface of the wafer 90 to the lower side of the wafer 90 and is sucked into the suction nozzle 22. Therefore, the nitrogen gas is not diffused radially from the first spot P1 in all directions on the upper surface of the wafer 90. As a result, it is possible to prevent the by-product resulting from the removal of the fluorocarbon film 93a from flowing into the upper surface side of the wafer 90 and being deposited by being involved in the nitrogen gas flow. As a result, particles can be reduced and the yield of products can be improved.

Since the cooling gas nozzle 61 is translucent, heat absorption from the laser L can be suppressed and high temperature can be prevented.
Furthermore, since the reactive gas nozzle 21 and the suction nozzle 22 are also translucent, the nozzles 21 and 22 can be brought as close as possible to the focused spot P2, and the removal efficiency of the fluorocarbon film 93a is reliably increased. Can do.

Next, another embodiment of the present invention will be described.
As shown in FIG. 5, a throttle 64 is provided on the inner wall of the tip of the cooling gas nozzle 61 according to the second embodiment. As a result, the flow cross-sectional area at the tip of the cooling gas nozzle 61 is reduced.

  According to the second embodiment, as shown by the thick arrow line in FIG. 5, the cooling nitrogen gas is depressurized by the throttle 64 in the distal end portion of the cooling gas nozzle 61. And after passing through this diaphragm 64, it blows off toward the 1st spot P1, adiabatic expansion. By this adiabatic expansion, the temperature of the nitrogen gas is lowered, and an endothermic effect can be expressed in the nitrogen gas flow. As a result, the cooling efficiency of the first spot P1 can be sufficiently increased without increasing the flow rate of nitrogen gas. Moreover, since it is not necessary to increase the nitrogen gas flow rate, the scattering of particles can be suppressed.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, the unnecessary object 93a may be provided not on the outer peripheral portion of the back surface of the wafer 90 but on the outer end surface of the wafer 90, or not only on the outer peripheral portion of the wafer 90 but also on the outer peripheral surface of the wafer 90 from the outer end surface of the wafer 90. It may be provided across.
Air may be used instead of nitrogen as the cooling gas blown to the first spot P1. An inert gas other than nitrogen may be used. If there is almost no reactivity with the required layer of the wafer 90, substances other than oxygen, other inert gases, and air may be used.
The front end portion of the cooling gas nozzle 61 may be disposed so as to be directed from the inside of the wafer 90 toward the first spot P <b> 1 in plan view (viewed from a direction orthogonal to the wafer 90).
The tip of the cooling gas nozzle 61 may be disposed toward the first spot P1 so as to be inclined obliquely downward and outward from above the inside of the wafer 90 in a side view (as viewed from a direction parallel to the wafer 90). Good.
The surface temperature of the first spot P1 or the second spot P2 may be measured by a radiation thermometer or the like, and the supply amount of the cooling gas may be adjusted according to the measured temperature.
The reactive gas nozzle 21 may be omitted, and unnecessary substances may be removed by spot irradiation with heat rays in a reactive gas atmosphere.
As the reactive gas, oxygen gas (O ₂ ) can be used in addition to ozone.
The unnecessary object to be removed is not limited to fluorocarbon, and may be an inorganic substance in addition to other organic substances.
The state of the unnecessary material is not limited to the film, and may be a powder or the like.
The substrate is not limited to a wafer, and may be a substrate for a flat panel display such as a liquid crystal television or a plasma television.

  The present invention can be applied, for example, to remove unnecessary materials on the outer periphery of a substrate in the manufacture of a semiconductor substrate or a liquid crystal substrate.

It is front sectional drawing which shows schematic structure of the base-material outer periphery processing apparatus which concerns on 1st Embodiment of this invention. It is a side view of the said apparatus which follows the II-II line | wire of FIG. It is a top view of the said apparatus which follows the III-III line of FIG. It is a front expanded sectional view which exaggerates the thickness of a silicon wafer and a film, and shows a mode that the fluorocarbon film | membrane of the outer peripheral part of a silicon wafer is removed by the said base material outer periphery processing apparatus. The state of removing the fluorocarbon film on the outer peripheral portion of the silicon wafer by the substrate outer peripheral processing apparatus provided with the cooling gas nozzle with constriction according to the second embodiment of the present invention is shown by exaggerating the thickness of the silicon wafer and the coating. It is a front expanded sectional view shown.

Explanation of symbols

11 stage (support)
11a Recess 11b Upper surface on the outer peripheral side of the stage (base material support surface)
11c Adsorption groove 11d Cooling chamber 20 Reactive gas supply / discharge means 21 Reactive gas nozzle 22 Suction nozzle 23 Gas supply path 24 Ozonizer (reactive gas source)
25 Exhaust path 26 Exhaust means 30 Laser heater (radiant heater)
31 Laser light source (thermal light source)
32 Irradiation unit 34 Optical fiber 50 Frame 51 Upper frame 60 Local cooling means 61 Cooling gas nozzle 62 Cooling gas source 63 Cooling gas path 64 Diaphragm 90 Silicon wafer (base material)
91 low-k insulating layer 91a wiring pattern groove 93a fluorocarbon film (unnecessary)
94 Wiring pattern P1 First spot P2 Second spot, local irradiation position (condensing spot, position to be processed)
L Laser (heat ray)
L33 Optical axis

Claims (9)

A device that has a first surface and a second surface that form front and back surfaces, and that heats and removes the unnecessary material in a base material provided with an unnecessary material on an outer peripheral portion or an outer end surface of the second surface,
A support for supporting the substrate;
A cooling gas nozzle that blows a cooling gas locally to a first spot where the outer peripheral portion of the first surface of the base material supported by the support portion should be located;
A heat ray source; and an irradiation unit optically connected to the heat ray source, transmitting the heat ray from the heat ray source to the irradiation unit, and further supported by the support unit from the irradiation unit. a radiant heater which irradiates locally the heat rays to the second surface outer peripheral portion or the second spot outer end face to be positioned in the timber,
The first spot and the second spot are arranged at substantially the same position in the circumferential direction of the support portion and thus the base material supported by the support portion, and the tip of the cooling gas nozzle is disposed on the support portion. It arrange | positions in the side in which the said 1st surface of the direction orthogonal to the said base material has faced rather than the supported base material, and the said irradiation unit is orthogonal to the said base material rather than the base material supported by the said support part. The substrate outer peripheral processing apparatus is disposed on the side on which the second surface of the direction faces .   The base material according to claim 1, wherein a flow direction of the cooling gas from the cooling gas nozzle is biased toward an outer end side of the base material supported by the support portion from the first spot. Perimeter processing device.   2. The base according to claim 1, wherein a front end surface of the cooling gas nozzle is a slope inclined toward an outer end side of the base material with respect to a first surface of the base material supported by the support portion. Material peripheral processing equipment.   The base-material outer periphery processing apparatus in any one of Claims 1-3 provided with the aperture_diaphragm | restriction in the front-end | tip part of the said gas nozzle for cooling.   5. The substrate outer periphery processing apparatus according to claim 1, wherein the cooling gas nozzle is made of a translucent material.   A suction nozzle for locally sucking gases in the vicinity of the second spot on a side opposite to the cooling gas nozzle side from the first surface of the base material supported by the support portion; The base-material outer periphery processing apparatus in any one of Claims 1-5 to do.   The substrate outer periphery processing apparatus according to claim 1, further comprising a reactive gas nozzle that blows a reactive gas that reacts with the unnecessary substance onto the second spot. It is a method of heating and removing unnecessary materials provided on the outer peripheral portion or outer end surface of the second surface in the base material having the first surface and the second surface forming the front and back,
While irradiating the unwanted matter locally with heat rays from the side facing the second surface in the direction orthogonal to the base material rather than the base material,
From the side where the first surface in the direction orthogonal to the base material is directed to the base material, the local surface position is substantially the same as the local irradiation position of the heat ray at the outer peripheral portion of the first surface of the base material. And a cooling gas is sprayed on the substrate , and the irradiation with the heat beam and the cooling gas are simultaneously performed . It is a method of removing unnecessary materials provided on the outer peripheral portion or outer end surface of the second surface in the base material having the first surface and the second surface forming the front and back,
A reactive gas that locally irradiates the unnecessary object with a heat beam from the side where the second surface in a direction orthogonal to the substrate is directed rather than the base material, and reacts with the unnecessary object at this local irradiation position And spraying from the side facing the second surface of the direction orthogonal to the base material than the base material,
For locally cooling from the side facing the first surface in the direction perpendicular to the base material to the base material to a position substantially in the same circumferential direction as the local irradiation position in the outer peripheral portion of the first surface of the base material A base material outer periphery treatment method characterized by performing gas spraying and simultaneously performing irradiation with the heat beam, spraying of the reactive gas, and spraying of the cooling gas .

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