Patent Publication Number: US-2020298343-A1

Title: Method for producing device support base and laser cleaning apparatus

Description:
TECHNICAL FIELD 
     The present disclosure relates to a method for producing a device support base and a laser cleaning apparatus. 
     BACKGROUND ART 
     A microscopic protrusion that is present on a top surface of a support base (hereinafter, such a protrusion will be referred to as a “protruding portion”) and a foreign object such as a particle or the like attached to the top surface of the support base (hereinafter, such a foreign object will be referred to as “contamination element”) may undesirably deteriorate the characteristics of a thin film or an element formed on the support base. For example, in the case where thin film transistors, interconnect lines and insulating layers are to be formed on a support base, such microscopic protruding portions or contamination elements on the top surface of the support base may cause defects to the thin film transistors, disconnect or shortcircuit the interconnect lines, or cause leakage in the insulating layers. 
     Patent Document No. 1 discloses a microscopic protrusion polishing device that puts a polishing tape into contact with a microscopic protrusion on a flat plate to polish the flat plate. 
     CITATION LIST 
     Patent Literature 
     Patent Document No. 1: Japanese Laid-Open Patent Publication No. 2008-213049 
     SUMMARY OF INVENTION 
     Technical Problem 
     As such a support base is increased in size, a top surface thereof has a larger area size and the number of microscopic protruding portions or contamination elements on the top surface of the support base is increased. In such a state, the method of moving the polishing tape to the positions of the protruding portions or contamination elements to polish the top surface causes the processing time to extend and significantly decreases the mass-productivity. 
     The present disclosure provides a method for producing a device support base and a laser cleaning apparatus that solve the above-described problems. 
     Solution to Problem 
     A method for producing a device support base according to the present disclosure includes step A of providing a support base having a first surface and a second surface parallel to the first surface; step B of forming a laser beam in a first direction parallel to the first surface of the support base; and step C of translating or rotating the laser beam in a second direction parallel to the first surface of the support base and crossing the first direction to remove at least a part of protruding portions or contamination elements on the first surface of the support base. 
     A laser cleaning apparatus according to the present disclosure includes a stage supporting a support base having a first surface and a second surface parallel to the first surface; a light source unit for forming a laser beam; a positioning device changing at least one of a position and an orientation of the light source unit with respect to the stage; and a control device electrically connected with the light source unit and the positioning device, the control device controlling the light source unit and the positioning device. The control device causes the light source unit to form the laser beam in a first direction parallel to the first surface of the support base; and causes the positioning device to translate or rotate the laser beam in a second direction, parallel to the first surface of the support base and crossing the first direction, to remove at least a part of a protruding portion or a contamination element on the first surface of the support base. 
     Advantageous Effects of Invention 
     According to the method for producing a device support base and a laser cleaning apparatus of the present invention, a protruding portion or a contamination element on a support base is removed or decreased in size with no polishing. Therefore, a thin film formed on the support base is suppressed from being declined in quality, or a device formed on the support base is suppressed from being deteriorated in characteristics. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a plan view showing an example of structure of a laser cleaning apparatus in a first embodiment according to the present disclosure. 
         FIG. 1B  is an isometric view showing the example of structure of the laser cleaning apparatus in the first embodiment according to the present disclosure. 
         FIG. 2  is a cross-sectional view schematically showing an example of relationship between a laser beam and a first surface of a support base. 
         FIG. 3  is a cross-sectional view schematically showing another example of relationship between the laser beam and the first surface of the support base. 
         FIG. 4  is a graph showing the relationship between the angle of incidence and the reflectance in the case where a light beam is incident on a support base having a refractive index N of 1.5 from the air. 
         FIG. 5  is a cross-sectional view showing an example of structure of the support base. 
         FIG. 6  shows a cross-section of the laser beam (plane parallel to a YZ plane). 
         FIG. 7  shows the radial position dependence of intensity I of the laser beam. 
         FIG. 8  schematically shows a beam radius R(x) in a propagation direction of the laser beam (X axis direction). 
         FIG. 9  is a cross-sectional view schematically showing still another example of relationship between the laser beam and the first surface of the support base. 
         FIG. 10  is a cross-sectional view schematically showing still another example of relationship between the laser beam and the first surface of the support base. 
         FIG. 11  is an isometric view schematically showing a state where a contamination element having a particle shape is irradiated with the laser beam. 
         FIG. 12  is an isometric view showing an example in which an image capturing device provided at a position facing the first surface of the support base captures an image of an irradiation target illuminated by being irradiated with the laser beam. 
         FIG. 13  is an isometric view showing another example of structure in an embodiment according to the present disclosure. 
         FIG. 14  is an isometric view showing still another example of structure in an embodiment according to the present disclosure. 
         FIG. 15  is an isometric view showing still another example of structure in an embodiment according to the present disclosure. 
         FIG. 16  is an isometric view showing still another example of structure in an embodiment according to the present disclosure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First, with reference to  FIG. 1A  and  FIG. 1B , an example of basic structure of a laser cleaning apparatus in an embodiment according to the present disclosure will be described.  FIG. 1A  and  FIG. 1B  are respectively a plan view and a cross-sectional view showing an example of structure in this embodiment. In the attached drawings, an X axis, a Y axis and a Z axis perpendicular to each other are shown for reference. 
     A laser cleaning apparatus in this embodiment (hereinafter, referred to as an “LC apparatus”)  100  includes a stage  20  for holding a support base  10 . The support base  10  has a first surface (top surface)  11  and a second surface (bottom surface)  12  parallel to the first surface  11 . Examples of the support base  10  may include a plastic support base, a glass support base, a semiconductor support base, and a glass support base including a functional layer such as a resin layer, an insulating layer, a semiconductor layer or the like formed at a surface thereof. In this application, the definition of the term “parallel” is not limited to a mathematically strict definition of “parallel”. 
     The stage  20  holds the support base  10  at the second surface  12  of the support base  10 . A top surface of the stage  20  is typically flat, but may have a recessed portion such as a groove, a hole or the like for vacuum suction. In the example shown in the figures, the support base  10  in the state of being supported by the stage  20  is parallel to an XY plane. The XY plane is typically horizontal, but may be oriented in any direction as long as the stage  20  firmly supports the support base  10 . 
     An unnecessary protruding portion  61  and/or contamination element  62  may be present on the first surface  11  of the support base  10 . The protruding portion  61  is a part of the support base  10 , whereas the contamination element  62  is a foreign object attached to the support base  10 . The contamination element  62  is typically a foreign object called a “particle”, and may be formed of any of various materials (organic material and/or inorganic material). The particle is often derived from a substance attached to a thin film deposition device, a transportation device or the like, or a substance floating in the air. The particle may be derived from a substance shaved out from the support base  10  during the transportation of the support base  10 . Some of such particles may be strongly attached to the support base and may not be removable from a surface of the support base  10  by a cleaning step. In addition, the contamination element such as a particle or the like may be attached to the surface of the support base  10  after the cleaning step. In this application, such a protruding portion  61  and contamination element  62  may be collectively referred to as an irradiation target (target)  60  of a laser beam. 
       FIG. 1A  and  FIG. 1B  show one protruding portion  61  and one contamination element  62  as an example. The number of the protruding portions  61  or the contamination elements  62  on the support base  10  is not limited to the above. For example, several to 100 particles may be attached to the first surface of the support base  10  per unit area size (1 m 2 ). The particles may each have a size (diameter or height) of, for example, 1 to 5 μm. The LC apparatus  100 , when detecting the protruding portions  61  and/or the contamination elements  62  present on the first surface  11  of the support base  10  with such a size and such a density, irradiates the protruding portions  61  and/or the contamination elements  62  with a laser beam to decrease the size of, or completely remove, each of the protruding portions  61  and/or the contamination elements from the support base  10 . In this embodiment, the protruding portions  61  and/or the contamination elements  62  are sensed by use of a laser beam as described below. Such sensing itself may be performed by a known method using an image sensor and an image processing technology. 
     In  FIG. 1A  and  FIG. 1B , a laser beam  3  usable to irradiate the protruding portion  61  and/or the contamination element  62  is shown schematically by two dashed lines. One feature of this embodiment is that the propagation direction of the laser beam  3  is “parallel” to the first surface  11  of the support base  10 . As described above, the definition of the term “parallel” in this application is not limited to the mathematically strict definition of “parallel”. The relationship between the laser beam  3  and the first surface  11  of the support base  10  will be described below. 
     The LC apparatus  100  includes a light source unit  30  for forming the laser beam  3 , a positioning device  40  changing at least one of a position and an orientation of the light source unit  30  with respect to the stage  20 , and a control device  50  controlling the light source unit  30  and the positioning device  40 . 
     The light source unit  30  may typically be a laser head including a semiconductor laser element, or an optical head of another type of solid-state laser or an gas laser. The positioning device  40  is typically a mechanical driving device drivable by an actuator such as an electric motor or the like. In the example shown in the figures, the positioning device  40  may move the light source unit  30  in a Y-axis direction along a guide rail and stop the light source unit  30  at any position. The position and the orientation of the light source unit  30  with respect to the stage  20  may be changed by adjusting a position and an orientation of the stage  20  in the state where the light source unit  30  is secured or is moving. 
     The control device  50  is electrically connected with the light source unit  30  and the positioning device  40  in a wired or wireless manner. The control device  50  typically includes a microcontroller, a memory and a communication interface mutually connected by a communication bus. The memory stores a software program that defines an operation of the microcontroller and the communication interface. The control device  50  may be a general-purpose computer in which a program for executing a laser cleaning processing operation is installed. 
     For performing a cleaning operation, the control device  50  causes the light source unit  30  to form the laser beam  3  in a first direction (X-axis direction) parallel to the first surface  11  of the support base  10 . The control device causes the positioning device  40  to translate the laser beam  3  in a second direction (Y-axis direction) parallel to the first surface  11  of the support base  10  and thus to remove at least a part of each of the irradiation targets  60  on the first surface  11  of the support base  10 . The “translation” of the laser beam  3  does not need to be always performed in the state where the laser beam  3  is produced. While the laser beam  3  is crossing a region where no irradiation target  60  is present, the intensity of the laser beam  3  may be zero. 
     In the example shown in  FIG. 1A  and  FIG. 1B , the second direction (Y-axis direction) is parallel to the first surface  11  of the support base  10  and is perpendicular to the first direction (X-axis direction). The second direction merely needs to be parallel to the first surface  11  of the support base  10  and cross the first direction. The second direction does not need to be perpendicular to the first direction. 
     In the example shown in the figures, the LC apparatus  100  includes a terminating device (beam damper)  70  receiving the laser beam  3  formed by the light source unit  30 . The terminating device  70  absorbs the laser beam  3  and thus prevents generation of stray light. The laser beam  3  incident on the terminating device  70  is absorbed by, for example, a diffuser or the like in the terminating device  70 . The terminating device  70  may be referred to as a beam absorber or a beam trap. 
     In this embodiment, the light source unit  30  and the terminating device  70  are respectively located at two opposing ends of the stage  20 . The positioning device  40  may change at least one of a position and an orientation of the terminating device  70  as the translation (parallel movement in the Y-axis direction) of the laser beam  3  proceeds. More specifically, the control device  50  may control the positioning device  40  to move the light source unit  30  and the terminating device  70  to move in a direction parallel to the first surface  11  of the support base  10  (in the Y-axis direction). 
     Now, with reference to  FIG. 2  through  FIG. 10 , the positional relationship between the laser beam  3  and the support base  10  will be described in detail. 
     In the example shown in  FIG. 2 , the laser beam  3  is formed by the light source unit  30  including a light source  32  such as a semiconductor laser element or the like, and lenses  34 ,  36  and  38 . The lenses  34 ,  36  and  38  form a collimation optical system. The laser beam  3 , when being collimated, is approximately a bundle of parallel light beams, but the degree of divergence thereof cannot be made zero. Therefore, the beam has a longer diameter as being farther from a portion having the shortest diameter (from the beam waist) along an optical axis thereof. 
     The structure of the light source unit  30  is not limited to the structure shown in the figures. The light source  32  may be switched in accordance with the wavelength of the laser beam  3  to be produced. The wavelength of the laser beam  3  may be appropriately selected in accordance with the spectral absorption coefficient of the irradiation target  60 . In the case where, for example, the irradiation target  60  contains quartz glass as a main component, laser light that is emitted from a carbon dioxide gas laser device or another gas dynamic laser device that oscillates at a wavelength of 10.6 μm is usable. Laser light emitted from such a laser device may be guided to the light source unit  30  via, for example, an optical fiber. In the case where the irradiation target  60  contains an organic material as a main component, laser light having a wavelength of 400 nm or shorter is preferably usable. The laser beam  3  may be of a pulse-like wave or a continuous wave (CW). 
     In the example shown in  FIG. 2 , the laser beam  3  is away from the first surface  11  of the support base  10 . The distance from the first surface  11  to the laser beam  3  is set to be shorter than the height of the irradiation target  60 . Therefore, at least a top portion of the irradiation target  60  is irradiated with the laser beam  3 . It is now assumed that the particle as the irradiation target  60  has a height exceeding, for example, fpm. In this case, when the particle is shortened to have a diameter of, for example, 0.5 μm or shorter as a result of being irradiated with the laser beam  3 , the particle may be considered to be made harmless (to be cleaned). The entirety of the irradiation target  60  does not need to be completely removed. The height of the irradiation target  60  that is permitted to remain on the first surface  11  of the support base  10  (upper-limit height) varies in accordance with the type of the thin film, or the structure of the device, to be formed on the support base  10 . It is preferred that the distance from the first surface  11  of the support base  10  to the laser beam  3  is shorter than the upper-limit height, and may be set to, for example, 1 μm or shorter. The distance does not need to be kept constant during the irradiation with the laser beam  3 . For example, an ultrasonic vibration may be applied to the support base  10  to fluctuate the distance. The distance may be different in accordance with the position on the first surface  11  of the support base  10 . 
     As shown in  FIG. 3 , as the distance between the laser beam  3  and the first surface  11  of the support base  10  is shortened, a part of the laser beam  3  may be incident on the first surface  11  of the support base  10 . In this case, the first surface  11  reflects the laser beam  3 . Hereinafter, this will be described. 
       FIG. 4  is a graph showing the relationship between the angle of incidence and the reflectance in the case where a light beam is incident on the first surface  11  of the support base  10  having a refractive index N of 1.5 from the air (refractive index: 1.0). The solid line shows a case where the light beam is s-polarized light (polarization axis is perpendicular to the plane of incidence), whereas the dashed line shows a case where the light beam is p-polarized light (polarization axis is parallel to the plane of incidence). The graph in  FIG. 4  is obtained from the Fresnel equations. Herein, the term “angle of incidence” is an angle between the normal to the first surface  11  of the support base  10  and the incident light beam. 
     In this embodiment of the present disclosure, the laser beam  3  is produced parallel to the first surface  11  of the support base  10 . Therefore, even if a part of the laser beam  3  is incident on the first surface  11  of the support base  10 , the angle of incidence is within a range of about 85 to 90 degrees. For this reason, even if a part of the laser beam  3  is incident on the first surface  11  of the support base  10 , most of the incident light is reflected without being absorbed by the support base  10 . From the point of view of making the reflectance close to 100%, it is preferred to use s-polarized light as the laser beam. 
     The support base  10  does not need to be formed of a single material such as one glass support base, but may have a stack structure. An example of the support base  10  having a stack structure is an assembly of a glass plate and a resin (plastic) layer or a semiconductor layer such as a silicon layer formed on a surface of the glass plate.  FIG. 5  is a cross-sectional view showing an example of structure of the support base  10 . The support base  10  shown here includes a base  10 A formed of a first material and a flexible film  103  supported by the base  10 A and formed of a second material. The base  10 A may be, for example, a glass plate. The flexible film  10 B may be a polyimide resin layer having a thickness of, for example, 5 to 20 μm. The cross-sectional structure of the support base  10  is not limited to this. The support base  10  in this example may adjust the refractive index of the flexible film  10 B to be higher or lower than the refractive index of the base  10 A. As the refractive index of the surface of the support base  10  is higher, the reflectance of the s-polarized light is higher. The flexible film  10 B itself may have a multilayer structure. 
     After various films or a device is formed on the flexible film  10 B, the flexible film  10 B is peeled off from the base  10 A. As a result, a flexible device is produced. After being separated from the base  10 A, the flexible film  10 B acts as a “flexible substrate” of the flexible device. In this application, the support base that supports the device will be referred to as a “device support base”. A typical example of the device supported by the device support base is an organic EL element, a thin film transistor element, or an array of such elements. 
       FIG. 6  schematically shows a cross-section (plane parallel to a YZ plane) of the laser beam  3 .  FIG. 7  is a graph showing the radial position dependence (light intensity distribution) of intensity I. Intensity I of the laser beam  3  varies in accordance with the distance or radial position from the center of the beam (optical axis). As shown in  FIG. 7 , the distribution of intensity I may be approximated by, for example, a Gaussian distribution. Where the intensity on the central axis is 1.0, the cross-section of the laser beam  3  is formed of a region having an intensity of, for example, e −2  or greater. Here, e is the base of natural logarithm. The cross-section of the laser beam  3  may be defined based another reference. In the case where the laser beam  3  is propagated in the X-axis direction, the beam radius of the laser beam  3  may be represented by R(x), which is a function of the x coordinate. 
       FIG. 8  schematically shows the beam radius R(x) in the propagation direction of the laser beam  3  (X axis direction). Two dashed lines represent the beam profile, and R0 is the minimum value of the beam radius R(x). The beam radius R(x) is minimized at the beam waist. In  FIG. 8 , the angle between the two dotted lines (straight lines) defines the divergence angle θ of the beam. In order to increase the parallelism of the laser beam  3 , it is preferred to decrease the divergence angle θ. 
     The quality of the laser beam  3  may be evaluated by the M 2  factor. Where the wavelength of the laser beam  3  is A, the M 2  factor is represented by (λ/π)·R0·θ. The minimum value R0 of the beam radius and the divergence angle θ are inverse-proportional to each other. Therefore, as the minimum value R0 of the beam radius is smaller, the divergence angle θ is larger. 
     The M 2  factor of the laser beam  3  may be set to a value in the range of, for example, 1.0 to about 3.0, typically, about 1.1 to about 1.7. In the case where the divergence angle θ is 0.1 milliradian, R0 is about 3λ. The beam radius R(x) is about 0.1 mm (100 μm) at a position having a distance of 1 m from the beam waist. 
     Such a laser beam  3 , while being outgoing from the light source unit  30  in a direction parallel to the first surface  11  of the support base  10 , is translated or rotated. As a result, the irradiation target  60  located on the first surface  11  of the support base  10  may be irradiated with the laser beam  3 . The irradiation target  60  irradiated with the laser beam  3  absorbs the energy of the laser beam  3  and thus is rapidly increased in temperature, and as a result, evaporated, volatilized or decomposed. As described above, the laser beam  3 , even if being partially incident on the first surface  11  of the support base  10 , is mostly reflected and is not absorbed by the support base  10  almost at all because the angle of incidence is about 90 degrees. However, on the irradiation target  60  located on an optical path of the laser beam  3 , namely, on the surface of the protruding portion  61  or the contamination element (typically, particle)  62 , the laser beam  3  has a small angle of incidence and a high transmittance. In the case where the irradiation target  60  is formed of a material not transparent for the laser beam  3  and absorbs light, the irradiation target  60  is selectively removed (cleaned) with no damage on the support base  10 . 
       FIG. 9  schematically shows a state where the laser beam  3  is incident on the first surface  11  of the support base  10  at an angle (angle of incidence) of 85 to 90 degrees, which is an angle between the optical axis thereof and normal N to the first surface  11 , and is reflected. In this example, while the irradiation target  60  is present in the vicinity of the point of incidence, the energy of the laser beam  3  may be provided to the irradiation target  60 . The light beam  3  may be focused on the point of incidence, so that the energy is provided to the irradiation target  60  at a high density. The orientation of the light source unit  30  may be adjusted as represented by the arrow in  FIG. 9  to move (scan) the point of incidence along the first surface  11  of the support base  10 . In the case where the position of the irradiation target  60  is specified, the light beam  3  may be focused on the position. 
     In the example shown in  FIG. 10 , a part of the laser beam  3  is propagated between the first surface  11  and the second surface  12  of the support base  10 . At least a bottom portion of the irradiation target  60  is irradiated with the laser beam  3 . The support base  10  may be formed of a material transparent for the laser beam  3 , so that the support base  10  does not absorb the laser beam  3  and is not increased in temperature. In this example, a part of the laser beam  3  is incident on an end surface of the support base  10 . This end surface may be covered with a reflection-preventive film. In the case where the support base  10  is formed of a material absorbing the laser beam  3 , the end surface may be covered with a reflective film. The laser beam  3  reflected by the reflective film is not absorbed by the support base  10 . It is preferred that an optical system is designed such that the reflective light is not returned to the light source  32  as stray light and that a structural body substantially the same as the terminating device  70  is provided inside, or in the vicinity of, the light source unit  30 . 
     As described above, in this embodiment of the present disclosure, the expression that the propagation direction of the laser light  3  and the first surface  11  of the support base  10  are “parallel” to each other is taken in a broad sense. Specifically, as long as the angle between the normal to the first surface  11  of the support base  10  and the central axis (optical axis) of the laser beam  3  is in the range of 90 degrees±5 degrees, the laser beam  3  is considered to be produced parallel to the first surface  11  of the support base  10 . 
       FIG. 11  is an isometric view schematically showing a state where the irradiation target  60  having a particle shape is irradiated with the laser beam  3 . A part of the laser beam  3  may be reflected or scattered by the irradiation target  60 . 
     The laser beam  3  may be used to detect the irradiation target  60 . While the laser beam  3  having a relatively low intensity is produced, the light source unit  30  and the terminating device  70  are moved in, for example, the X-axis direction in  FIG. 11 . The rate of the movement is, for example, 1 to 100 mm/sec. The distance by which the light source unit  30  and the terminating device  70  are moved varies in accordance with the size of the support base  10  in the moving direction of the light source unit  30  and the terminating device  70 . In the case where the size is, for example, 1 m or longer, it is desired that the rate of the movement is, for example, 5 mm/sec. or higher from the point of view of shortening the processing time (tact time). The terminating device  70  may include a photodetector (intensity sensor) such as a photodiode or the like, so that it is sensed that the irradiation target  60  is located on the optical path of the laser beam  3  based on a change in the output from the intensity sensor. When this is sensed, the intensity of the laser beam  3  is increased without changing the position thereof. As a result, the irradiation target  60  is increased in temperature and is removed. 
       FIG. 12  is an isometric view showing an example in which an image capturing device  80  provided at a position facing the first surface  11  of the support base  10  captures an image of the irradiation target  60  illuminated by being irradiated with the laser beam  3 . The image capturing device  80  typically includes an image sensor and an imaging lens. On an imaging surface of the image sensor, an image of the irradiation target  60  illuminated by being irradiated with the laser beam  3  is formed. Image data output from the image capturing device  80  may be processed by the control device  50 , so that position coordinates of the irradiation target  60  are detected. In the example shown in  FIG. 11 , the X coordinate of the irradiation target  60  is not detected. In the example shown in  FIG. 12 , the X coordinate and the Y coordinate of the irradiation target  60  are both detected. In the case where the light source unit  30  includes an optical system capable of changing the focal distance, the convergence point (beam waist) of the laser beam  3  may be matched to the position of the irradiation target  60  to increase the density of the energy with which the irradiation target  60  is irradiated (see  FIG. 9 ). In the case where the LC apparatus  100  includes a plurality of the light source units  30 , a plurality of the laser beams  3  may be formed by the plurality of light source units  30  located at different positions at the same time or sequentially to irradiate one, same irradiation target  60  with the plurality of laser beams  3 . 
       FIG. 13  is an isometric view showing an example in which the light source unit  30  includes a first light source  32 A for forming the laser beam  3  usable to remove the irradiation target  60  and a second light source  32 B for forming a laser beam  33  usable to detect the irradiation target  60  (hereinafter, this laser beam will be referred to as a “detection laser light  33 ”). While the detection laser light  33  having a relatively low intensity is produced, the light source unit  30  and the terminating device  70  are moved in the X-axis direction in  FIG. 13 . The terminating device  70  includes a photodetector (intensity sensor), such as a photodiode or the like, located at a position where the detection laser light  33  is incident. When it is sensed that the irradiation target  60  is present on an optical path of the detection laser light  33  based on a change in the output from the photodetector, the first light source  32 A produces the laser beam  3 . The light source unit  30  and the terminating device  70  are moved in the X-axis direction in  FIG. 13  in this state. In this manner, the irradiation target  60  is irradiated with the laser beam  3  to increase the temperature of at least a part of the irradiation target  60  and thus to remove the irradiation target  60 . In the case where an error range is assumed for the position of the irradiation target  60  detected by the detection laser light  33 , the light source unit  30  and the terminating device  70  may be moved in a reciprocating manner in the X-axis direction while the laser beam  3  is formed by the first light source  32 A. The amplitude of the reciprocating movement is determined in accordance with the value of the error range. 
       FIG. 14  shows a gas flow device  90 , which distances a component, volatilized or decomposed from the irradiation target  60  as a result of the irradiation target  60  being irradiated with the laser beam  3 , away from the first surface  11  of the support base  10  by a gas flow. The gas flow may be caused by a mechanism that at least either blows or absorbs atmospheric gas or inert gas. Such a gas flow prevents or suppresses foreign objects from being attached to the first surface  11  of the support base  10  as a result of the irradiation with the laser beam  3 . An example of mechanism that both blows and absorbs gas is a device that absorbs, through an absorption opening, gas blown to the support base  10  by a blowing nozzle. Such a device effectively collects the substance generated by the irradiation with the laser beam  3 . 
       FIG. 15  shows an example of structure in which the laser beam  3  is rotated instead of being translated. The light source unit  30  is pivotable about an axis perpendicular to the first surface  11  of the support base  10 .  FIG. 16  shows another example of structure in which the laser beam  3  is rotated instead of being translated. The light source  32  may be secured and a mirror  35  may be changed in at least orientation and position, so that the laser beam  3  is rotated. In the case where such a structure is adopted, the position of the terminating device  70  is moved as the rotation of the laser beam  3  proceeds. 
     As described above, according to the laser cleaning apparatus of the present disclosure, after step A of providing the support base  10  is performed, step B of forming the laser beam  3  in the first direction parallel to the first surface  11  of the support base  10 ; and step C of translating or rotating the laser beam  3  in a second direction, parallel to the first surface  11  of the support base  10  and crossing the first direction, to remove at least a part of protruding portions or contamination elements on the first surface  11  of the support base  10 ; are performed. Therefore, various device support bases that are not easily deteriorated in performance, or are not easily made defective, by microscopic protrusions are produced. 
     In an embodiment including step D of, before the step B, scanning a plane parallel to the first surface  11  of the support base  10  by detection laser light having a lower intensity than the intensity of the laser beam used in the step B to detect a position of each of the protruding portions or the contamination elements on the first surface  11  of the support base  10 , the laser beam is sequentially directed toward the positions of the protruding portions or the contamination elements in the step B. 
     INDUSTRIAL APPLICABILITY 
     An embodiment of the present invention is applicable to production of, for example, an organic EL device, especially a flexible organic EL device. 
     REFERENCE SIGNS LIST 
     
         
           3  laser beam 
           10  support base 
           11  first surface of the support base 
           12  second surface of the support base 
           20  stage 
           30  light source unit 
           33  detection laser light 
           40  positioning device 
           50  control device 
           60  irradiation target of laser beam (target) 
           61  protruding portion 
           62  contamination element 
           70  terminating device 
           100  laser cleaning apparatus (LC apparatus)