Patent Publication Number: US-6671041-B2

Title: Apparatus for inspecting a substrate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation-in-Part application of U.S. patent application Ser. No. 09/158,362, filed Sep. 22, 1998, now U.S. Pat. No. 6,362,884, the entire contents of which are incorporated herein by reference. 
    
    
     This application is based upon and claims the benefit of priority from the prior Japanese Patent applications No. 9-258552, filed Sep. 24, 1997; and No. 10-264342, filed Sep. 18, 1998, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus for inspecting defects in a substrate such as a glass substrate for a liquid crystal display (LCD). 
     Of conventionally-known apparatuses for inspecting defects of LCD glass substrates, some apparatuses are known in which defects (e.g., scratch) formed in the surface of the glass substrate can be checked by using a macro observation and a micro observation interchangeably. In the macro observation, light is applied onto the surface of the glass substrate and then optical change of the reflected light is observed, thereby detecting the defects. In the micro observation, the defects found by the macro observation are magnified and observed. 
     For example, Jpn. Pat. Appln. KOKAI No. 5-322783 employs the macro observation system and the micro observation system which are set so as to correspond to an X-Y stage designed movable horizontally in X and Y directions. In the apparatus, the macro observation or the micro observation is performed by mounting a substrate on the X-Y stage and bringing a portion of the substrate to be inspected (defect) into an observation filed of the macro observation system or the micro observation system by moving the X-Y stage two-dimensionally in the X and Y directions. 
     Recently, the size of the glass substrate tends to be increased with an enlargement of LCD. In the case where such a large glass substrate is inspected by using the inspecting apparatus having the X-Y stage which is movable horizontally and two-dimensionally (X, Y directions), four times as large as the area of the glass substrate is required as a space for moving the X-Y stage. Therefore, the substrate inspecting apparatus is inevitably large with the increase of the glass substrate. 
     Furthermore, in the conventional inspection apparatus thus constructed, it is difficult to inspect a small scratch since the surface of the substrate is far away from an eye position of the inspector. Moreover, it is difficult to obtain positional data of the defect found in the surface of the substrate. Accordingly, it has been impossible to inspect the substrate highly accurately. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an substrate inspecting apparatus capable of detecting a defect of the substrate efficiently with high accuracy as well as to provide the apparatus in a reduced size. 
     The substrate inspecting apparatus of the present invention comprises substrate holding member for holding a substrate to be inspected, a driving mechanism for raising the substrate holding member to a predetermined angle or less, a position coordinate detecting section provided at side edge of the substrate in at least two directions, for detecting coordinates of a defect present in the substrate, an observation system supporting section provided for supporting a micro observation system and moving on the surface of the substrate, and a controlling section for controlling of the movement of the micro observation system of the observation system supporting section to correspond to a defect formed present in the substrate, on the basis of the position coordinates of the defect detected by the position coordinate detecting section. 
     Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
     FIG. 1 is a perspective view showing a structure of a substrate inspecting apparatus according to an embodiment of the present invention; 
     FIG. 2 is a side view showing a structure of the substrate inspecting apparatus according to the embodiment of the present invention; 
     FIG. 3 is a top plan view showing a structure of the substrate inspecting apparatus according to the embodiment of the present invention; 
     FIG. 4 is a view showing a structure of a transmission linear light according to an embodiment of the present invention; 
     FIG. 5 is a view showing a structure of a position detector according to an embodiment of the present invention; 
     FIG. 6 is a view showing how to inspect a substrate, according to an embodiment of the present invention; 
     FIG. 7 is a view showing a holder according to an embodiment of the present invention; 
     FIG. 8 is a view showing a structure of the position detector according to an embodiment of the present invention; 
     FIG. 9 is a view showing a structure of the position detector according to another embodiment of the present invention; 
     FIG. 10 is a view showing a structure of the position detector according to a further embodiment of the present invention; 
     FIG. 11 is a perspective view of the substrate inspecting apparatus according to an embodiment of the present invention; 
     FIG. 12 is a side view of the substrate inspecting apparatus according to the embodiment of the present invention; 
     FIG. 13 is a side view of the substrate inspecting apparatus according to another embodiment of the present invention; 
     FIG. 14 is a perspective view showing the position detector employed in the substrate inspecting apparatus according to the embodiment of the present invention; 
     FIG. 15A is a top view of the guide movement member and showing the retracting mechanism employed in the substrate inspecting apparatus of the present invention; 
     FIG. 15B is a side view of the guide movement member and showing the retracting mechanism employed in the substrate inspecting apparatus of the present invention; 
     FIG. 15C is a top view of the guide movement member and showing the retracting mechanism employed in the substrate inspecting apparatus of the present invention; and 
     FIG. 15D is a side view of the guide movement member and showing the retracting mechanism employed in the substrate inspecting apparatus of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 to  3  are views showing a structure of the substrate inspecting apparatus according to Embodiment 1 of the present invention. FIGS. 1,  2  and  3  show its perspective view, side view, and top plan view, respectively. In FIGS. 1 to  3 , a holder  2  for holding a substrate  3  is provided on the main apparatus  1 . As shown in FIG. 2, the holder  2  whose basal portion is supported by a supporting shaft  15  rotatably to the main apparatus  1 . A pulley  16  is set in the periphery of the supporting shaft  15 . The main apparatus  1  has a motor  18 . A ring-form belt  17  is stretched between a rotation shaft  181  of the motor  18  and the pulley  16 . When rotational driving force generated by the motor is transmitted from the rotation shaft  181  to the pulley  16  by way of the belt  17 , the holder  2  can be raised from a horizontal posture up to a position indicated by two-dot and dashed line, in a rotating manner around the supporting shaft  15 . In other words, the holder  2  is raised up to a predetermined angle θ and allowed to stand in an inclined posture. 
     The holder  2  takes a frame form and mounts the large substrate  3  (e.g., a glass substrate for an LCD) thereon and holds it by the peripheral portion. The holder  2  has a square-form hollow portion surrounded by the peripheral portion and its area is slightly smaller than the substrate  3 . The holder  2  has a plurality of substrate urging members  201  (formed of cylindrical pins) along the peripheral portions in the X-axis and Y-axis directions. The urging members  201  are arranged so as to protrude slightly from the surface of the holder  2 . The substrate  3  is positioned at a right place on the holder  2  by bringing two sides of the substrate  3  into contact with a side portion of each of the substrate urging members  201 . The peripheral portion of the substrate  3  is adsorbed onto the surface of the holder  2  by use of an aspirator (not shown) through a plurality of holes (adsorptive pads) (not shown), which are formed along the entire peripheral portion of the holder  2 . By virtue of this mechanism, the substrate  3  is held on the holder  2  without falling out. 
     Furthermore, guide scales  19 ,  20  are arranged on the holder  2  along sides of the substrate  3  in the X-axis and Y-axis directions. The guide scales  19 ,  20  are responsible for detecting coordinates of the defect present in the substrate  3 . The guide scale  19  has a reflector (mirror)  215  of the Y-axis direction. The guide scale  20  has a reflector (mirror)  216  of the X-axis direction. The reflectors  215 ,  216  are provided movably along the guide scales  19 ,  20 , respectively. A beam splitter  214  is fixed on the holder  2  at a point of intersection of extension lines of the guide scales  19 ,  20 . A light source section  21  (described later) is disposed on a position slightly separate from the guide scale  20  (extension line of the guide scale  20 ) with respect to the beam splitter  214 . 
     As shown in FIGS. 1 to  3 , a pair of guide rails  4 ,  4  are arranged in parallel to the Y-axis direction along both sides of the holder  2  on the main apparatus  1 . An observation unit supporting section  5  is arranged above the holder  2  so as to cross over the holder  2 . The observation unit supporting section  5  is formed movably along the guide rails  4 ,  4  in the Y-axis direction above the substrate  3 , or above the holder  2 . 
     The observation unit supporting section  5  has an observation unit  6  which is supported movably along a guide rail (not shown) in the X-axis direction perpendicular to the moving direction (Y-axis) of the observation unit supporting section  5 . Furthermore, the observation unit supporting section  5  is equipped with a linear transmission light source  7  so as to face a moving line of the observation unit  6 . The linear transmission light source  7  is arranged along the X-axis direction on a rear board  51  of the supporting section  5 , which moves under the holder  2 . Accordingly, the substrate  3  is illuminated by transmission light linearly from the bottom. The linear transmission light source  7  is designed movable in the Y axis direction together with the observation unit supporting section  5 . 
     The observation unit  6  has a micro observation unit  9  equipped with a reference light  8  for use in the micro observation and a partial illumination macro light  10  for use in macro observation. The reference light source  8 , which plays a role in identifying defect positions on the substrate  3 , projects an optically-converged spot-light upon the surface of the substrate  3 . The reflected spot light from the surface of the substrate  3  is brighter than the light emitted from the partial illumination macro light  10  and reflected at the surface of the substrate  3 . It is therefore possible to visually perform an observation even if the macro observation process is performed using the partial illumination macro light  10 . 
     The micro observation unit  9  has a microscopic function including an objective lens  91 , an ocular lens  92  and an incident light source (not shown). Therefore, an image of the surface of the substrate  3  can be observed through the ocular lens  92  via the objective lens. The micro observation unit  9  is equipped with a TV camera  93  through a tri-lens barrel. When the visual micro observation is not required, a TV camera  93  alone may be set on a liner cylinder. The image of the substrate surface obtained through the objective lens  91  is photographed by the TV camera  93  and sent to a controller  11 . The controller  11  instructed to display the photographed image on the TV monitor  12 . To the controller  11 , an input section  111  is connected so as to enable an inspector to input data and to instruct operations. 
     The partial illumination macro light  10  is used for the macro observation. The surface of the substrate  3  on the holder  2  is partially illuminated with the macro light  101 . The incident angle of the partial illumination macro light source  10  with the substrate surface can be controlled at the most suitable angle for the macro observation. 
     FIG. 4 is a view showing a structure of the linear transmission light  7 . As shown in FIG. 4, the linear transmission light  7  has a light source section  71  and a solid glass rod  72 . The light emitted from the light source section  71  is diffusely reflected by the reflecting board  712  and injected into an end of the glass rod  72 . The incident light is transmitted through the glass rod  72  while totally reflected and simultaneously dispersed by white stripes  73  (which have been coated and processed into stripes) on a rear portion (lower portion) of the glass rod  72 . As a result, linear light is emitted upwardly by virtue of a lens-like function of the glass rod  72 . The structure of the linear transmission light is not limited to the aforementioned one. For example, a fluorescent lamp may be employed as the linear illumination. 
     FIG. 5 is a view showing a structure of a position detector of the substrate inspecting apparatus of the present invention. In FIG. 5, like reference numerals are used to designate like structural elements corresponding to those in FIG.  3 . The position detector has a light source section  21 , a beam splitter  214  and reflectors (mirrors)  215 ,  216 . The light source section  21  is formed of a laser light source  211  and cylindrical lenses  212 ,  213 . The beams splitter  214  splits the laser light emitted from the laser light source  211  into light beams in the X-axis and Y-axis directions. The reflectors  215 ,  216  are respectively formed on the guide scales  19 ,  20 . The beam splitter  214  and the reflectors  215 ,  216  are vertically set at a right angle or an acute angle with the substrate surface  3 . 
     The laser light emitted from the laser light source  211  is transmitted through the cylindrical lenses  212 ,  213  and finally emitted in the X-axis direction in the form of a planar light virtually perpendicular to the surface of the substrate  3 . The planar laser light is split into two beams in the X-axis and Y-axis directions. The laser light beam in the X-axis direction is reflected by the reflector  216  and proceeds in the perpendicular direction, namely, the Y-axis direction, in the form of a planar laser light  217  virtually perpendicular to the surface of the substrate  3 . On the other hand, the laser light beam in the Y-axis direction is reflected by the reflector  215  and proceeds in the perpendicular direction, namely, the X-axis direction, in the form of a planer laser light  218  virtually perpendicular to the surface of the substrate  3 . 
     The inspector moves the reflector  215  along the guide scale  19  to permit the laser light  218  to correspond with the defect present in the substrate surface. In the same manner, the inspector moves the reflector  216  along the guide scale  20 , thereby permitting the laser light  217  to correspond with the defect. Thereafter, when the inspector turns on a switch (not shown), values of the guide scales  19 ,  20 , that is, moving amounts of the reflectors  215 ,  216  in the X-axis direction and Y-axis direction from their origins can be detected by respective detectors (not shown) of the guide scales  19 ,  20 , as coordinates (X, Y) of the defect. The detected results are output from the detector to the controller  11 . Note that the origin of the coordinate of the reflector  215  is present at the forefront side of the guide scale  19 . The origin of the coordinate of the reflector  216  is present at the rightmost end of the guide scale  20  (see FIG.  3 ). 
     FIG. 6 shows how to inspect a substrate by use of the inspecting apparatus of the present invention. As shown in FIG. 6, an entire-area illuminating macro light source  30  is set above the main apparatus  1 . The macro light source  30  irradiates the entire area of the surface of the substrate  3  on the holder  2 . The macro light source  30  is constituted of a metal halide lamp  31  serving as a point light source, a reflecting mirror  32  arranged so as to face the metal halide lamp  31 , and a fresnel lens  33  arranged below the reflecting mirror  32 . The reflecting mirror  32  is tilted at an angle of 45° with the main apparatus  1  and plays a role in reflecting light incident from the metal halide lamp  31  and injected into the fresnel lens  33 . The fresnel lens  33  converges the light reflected by the reflecting mirror  32 , as shown in the figure, and injects the converged light over the entire surface of the substrate  3  on the holder  2 . Note that, as shown in FIG. 1, the main apparatus  1  has a Y-scale  13  for detecting the position coordinate of the observation unit supporting section  5  in the Y-axis direction. An X-scale  14  is provided on the observation unit supporting section  5  for detecting the position coordinate of the observation unit  6  in the X-axis direction. 
     The controller  11  shown in FIG. 1 is responsible for not only position coordinates (X, Y) of the defect detected by the guide scales  19 ,  20  and position coordinates of the observation unit supporting section  5  and the observation unit  6  detected by the Y-scale  13  and the X-scale  14 , but also movement control of the observation unit supporting section  5  and the observation unit  6  by a driving mechanism (not shown). Furthermore, the controller  11  has a memory (not shown) for storing data of the interval X0 between an optical axis of the reference light source  8  and an optical axis of the objective lens  91 . The control  11  controls movements of the observation unit supporting section  5  and the observation unit  6  so as to permit the optical observation axis of the objective lens  91  of the micro observation unit  9  to correspond with the position coordinates (X, Y) of the defect in the substrate  3  given by the guide scales  19 ,  20 . 
     While a spot of the reference light  8  is being focused on the defect present in the substrate  3 , the controller  11  controls the movements of the observation unit supporting section  5  and the observation unit  6  upon receiving a predetermined instruction given by the inspector from the input section  111 . To explain more specifically, first, the position coordinates of the defect are obtained from the position coordinate data of the X-scale  13  and Y-scale  13 , detected by detectors (not shown) of the Y scale  13  and the X-scale  14 . Then, on the basis of the coordinate data thus obtained and the data of the interval X0 between the optical axis of the reference light  8  and the optical axis of the objective lens  91 , the observation unit supporting section  5  and the observation unit  6  are moved in such a way that the observation axis of the objective lens  91  corresponds to the defect present in the substrate  3 . 
     Now, how to operate the substrate inspecting apparatus thus constructed will be explained. In the case of the macro observation of the surface of the substrate  3 , the operation is performed as follows. First, the inspector gives a predetermined instruction from the input section  111  to the controller  11 . Then, the controller  11  instructs the observation unit supporting section  5  to move backward to the initial position shown in FIG.  1 . Thereafter, the inspector places the substrate  3  onto the holder  2  placed horizontally. Upon setting of the substrate  3  at a right position on the holder  2  by a plurality of substrate urging members  201 , the substrate  3  is adsorbed onto the holder  2  by the aspirator so as not to drop from the holder  2 . In this way, the macro inspecting observation of the defect is initiated. 
     Next, we will explain how to perform the macro observation of the entire surface of the substrate  3  using the macro light, at one time. First, the motor  18  shown in FIG. 2 is driven by the inspector, thereby rotating the supporting shaft  15  through the pulley  16  via the rotation shaft  181  and the belt  17 . The holder  2  is then tilted at a predetermined angle θ, preferably 30-45° around the supporting shaft  15 . Thereafter, the motor is stopped to terminate the movement of the holder  2 . Subsequently, a metal halide lamp  31  shown in FIG. 6 is lighted on by the inspector. The light from the metal halide lamp  31  is converged by the reflection mirror  32  and the fresnel lens  33 , and then applied onto the entire surface of the substrate  3  on the holder  2 . While maintaining this state, the substrate  3  on the holder  2  is visually inspected by the naked eye of the inspector for scratches. Note that the defect is inspected while not only staying the holder  2  at a predetermined angle but also swinging the holder  2  at a predetermined angular range around the supporting shaft  15  by changing a rotation direction of the motor  18  periodically under control of the controller  11 . In the later case, it is possible to change the angle of the light supplied from the metal halide lamp  31  incident onto the substrate  3 , so that the substrate  3  can be inspected under the illumination light incident from various angles. 
     FIG. 7 is a view showing the holder  2  having the substrate  3  with a defect. When the inspector recognizes a defect a in the substrate  3  during the macro observation, as shown in FIG. 7, the inspector moves the reflector  215  along the guide scale  19  so as to permit the laser light  218  to correspond with the defect a. Subsequently, the inspector moves the position reflector  216  along the guide scale  20  to permit the laser light  217  to correspond with the defect a. At this point, the position coordinates (X, Y) of the defect a are determined by reading the scale values of the guide scales  19 ,  20  at which the reflectors  215 ,  216  are located by the detectors of the guide scales  19 ,  20 . The detected results are output from the detector into the controller  11 . In this way, the data showing the position coordinates (X, Y) of the defect a is stored in the memory of the controller  11 . Thereafter, the same operation is repeated whenever the inspector recognizes a defect in the substrate  3  and the data indicating the position coordinates (X, Y) of each defect is stored in the controller  11 . After the macro observation over the entire surface of the substrate  3  is completed, the motor  18  is driven again by the inspector to rotate the supporting shaft  15  in the opposite direction as mentioned above, through the pulley  16  via the rotation shaft  181  and the belt  17 . In this way, the holder  2  is returned to a horizontal posture initially taken. 
     Next, we will explain how to perform the micro observation of each defect which has been found by the macro observation by use of the micro observation unit  9 . First, the position coordinates (X, Y) of the defect stored in the memory are read out by the controller  11 . Then, the observation unit supporting section  5  and the observation unit  6  are moved along the guide rails  4 ,  4 , and a guide rail (not shown) in such a manner that the observation axis of the objective lens  91  in the micro observation unit  9  corresponds to the coordinates under the control of the controller  11 . 
     With this operation, the defect present in the substrate  3 , i.e., an image of the defect obtained through the objective lens  91  can be microscopically observed by looking into the ocular lens  92  of the micro observation unit  9 . In the case where the image of the defect found in the surface of the substrate  3  is photographed by the TV camera  93  and displayed on the TV monitor  12 , the micro observation of the defect is performed by watching the image on the TV display. 
     Next, we will explain the case in which a defect is inspected by the macro observation using a partial illumination macro light source  10  and then subjected to the micro observation performed by the micro observation unit  9 . In this case, the inspector places the substrate  3  at the right position on the holder  2  and adsorbed in the same manner as above. Then, the partial illumination macro light source  10  of the observation unit  6  is lighted on by the inspector to partially irradiate the surface of the substrate  3  mounted on the holder  2 . 
     Subsequently, as shown in FIG. 3, the inspector operates an operation section (joystick, not shown) to move the observation unit  6  linearly along the guide rail of the observation unit supporting section  5  in the X-axis direction, and to move the observation unit supporting section  5  linearly along the guide rails  4 ,  4  in the Y-axis direction. While raster-scanning over the substrate  3  by the macro light  101 , the inspector visually inspects scratches and spots over the entire surface of the substrate  3 . In this case, the irradiation angle of the macro light  101  with the substrate  3  is adjusted so as to perform partial macro observation suitably. 
     In the partial macro observation using the partial illumination macro light source  10 , when the inspector recognizes the defect in the substrate  3  under the illumination of the macro light  101 , the observation unit  6  is moved along the X-axis and Y-axis by operating the operation section by the inspector so as to focus the spotlight of the reference light source  8  on the defect present in the substrate  3 . 
     The position coordinates of the defect on the surface of the substrate  3  are determined by the controller  11  on the basis of the position coordinate data detected by the Y-scale  13  and X-scale  14 . Subsequently, using the position coordination data and the previously stored data indicating the interval X0 between the optical axis of the reference light source  8  and the optical axis of the objective lens  91 , the movements of the observation unit supporting section  5  and the observation unit  6  are controlled so as to permit the optical axis of the objective lens  91  to correspond with a specified defect present in the substrate  3 . 
     Since the specified defect is brought into the center of the visual field of the objective lens  91  by the aforementioned operation, the micro observation of the defect can be made through the objective lens  91 . At the same time, the defect obtained by the objective lens  91  is photographed by the TV camera  93 . Therefore, the micro observation may be made on the TV monitor  12  by the inspector. In this case, the incident light can be used interchangeably with the transmission light depending upon types of the defects and substrates. 
     When the inspector instructs the macro observation again to the controller  11  through the input section  111 , the defect is brought back within the illumination range of the macro light  101 , so that an inspector can check the defect under the macro observation. If another defect is continuously observed, the same operation as mentioned above may be repeated. After the defect inspection is completed, the inspector gives a predetermined instruction to the controller  11  through the input section  111  to return the observation unit supporting section  5  to the initial position. The inspector removes the inspected substrate  3  from the holder  2 , a new substrate  3  is mounted on and held by the holder  2 . 
     In the case explained above, the macro observation is performed while the surface of the substrate  3  mounted on the holder  2  is partially illuminated with the partial illumination macro light source  10  and then the micro observation is performed when the defect is recognized in the substrate  3 . In the case where only the macro observation is performed under illumination of the partial illumination macro light source  10 , the operation is performed as follows. First, the inspector moves back the observation unit supporting section  5  to the initial position and mounts the substrate  3  on the holder  2 . Then, the partial illumination macro light source  10  is lighted on to partially irradiating the surface of the substrate  3  on the holder  2  with the macro light  101  by the inspector. While the observation unit  6  is moved linearly in the X-axis direction along the guide rail of the observation unit supporting section  5  by operating the operation section and the observation unit supporting section  5  is further linearly moved in the Y-axis direction along the guide rails  4 ,  4 , the substrate  3  is raster-scanned by use of the macro light  101 . In this manner, the defect can be visually inspected over the entire surface of the substrate  3  by the inspector. 
     In this case, if the spotlight of the reference light source  8  is focused on each defect under the illumination of the macro light  101 , the position coordinates of the defect are detected by detectors (not shown) respectively set at the X-scale and Y-scale. The detected position coordinates can be stored in the memory of the controller  11 . 
     When the defect whose coordinate data is stored in the memory of the controller  11  is subjected to the micro observation by the micro observation unit  9 , the operation is as follows. First, the inspector moves back the observation unit supporting section  5  to the initial position. Then, the inspector mounts the substrate  3  on the holder  2 . The transmission linear light source  7  is lighted on, thereby irradiating the substrate linearly from the bottom of the holder  2  in the X-axis direction. Subsequently, the micro observation unit  9  is moved linearly under control of the controller  11  along the guide rail of the observation unit supporting section  5  in the X-axis direction. Consequently, the objective lens  91  is moved linearly in the X-direction along the transmission linear light source  7 . Furthermore, the observation unit supporting section  5  is moved linearly in the Y-axis direction along the guide rails  4 ,  4 . In this manner, a predetermined range of the substrate  3  can be observed microscopically via the objective lens  91 . At the same time, the surface of the substrate  3  is photographed by the TV camera  93  and the image thereof is displayed on the TV monitor  12 . Also in this case, the transmission light can be interchangeably used with the incident light depending upon the type of the substrate  3  and the defect. 
     According to the substrate inspecting apparatus of the present invention, the substrate  3  is raised at a predetermined angle by rotating the holder  2  having the substrate  3  held thereon, about the supporting shaft  15 . By virtue of the operation, the substrate  3  is placed at a position close to an inspector&#39;s eye, so that the inspector can perform the macro inspection of the substrate  3  in an easy posture. In addition, the laser light source section  21 , the beam splitter  214 , the reflectors  215 ,  216 , and the guide scales  19 ,  20  for use in detecting the position of the defect present in the substrate  3 , are integrally provided on the rotatable (up and down) holder  2 . It is therefore possible to detect the coordinates of the defect on the substrate  3  always in the same plane whenever the holder  2  is tilted at any angle. As a result, the coordinates of the defect can be detected highly accurately, and therefore a complicated process for amending the coordinate data depending upon the tilt angle is no longer required. The position coordinates (X, Y) of the defect can be determined only by detecting the positions of the reflectors  215  and  216  corresponding to the detect while manually moving them along the guide scales  19 ,  20  (which are provided along the side edges of the substrate  3 ). Therefore, the positional data of the defect can be easily obtained. 
     The observation unit  6  can be moved to any position on the substrate  3  by moving the observation unit supporting section  5  along one direction on the substrate  3  and moving the observation unit  6  in the direction perpendicular to the moving direction of the observation unit supporting section  5 . As a result, the area of the holder  2  can be set at almost the same value as the substrate  3 . As a result, miniaturization of the substrate inspecting apparatus can be realized. In addition, the area in which the substrate detection apparatus is placed, can be drastically reduced. 
     FIG. 8 is a view showing the structure of the position detector of the substrate inspecting apparatus according to Embodiment 2 of the present invention. In FIG. 8, like reference numerals are used to designate like structural elements corresponding to those in FIG.  7 . The position detector is applied to the substrate inspecting apparatus shown in Embodiment 1. The position detector is constituted of two light source sections  21 ,  22  and reflectors (mirrors)  215 ,  216 . Each of the light source sections  21 ,  22  has the laser light source  211  and the cylindrical lenses  212 ,  213  shown in FIG.  5 . 
     The holder  2  has the guide scales  19 ,  20  formed in the Y-axis direction and the X-axis direction along a side of the substrate  3 , as shown in FIG.  8 . The guide scales  19 ,  20  play a role in detecting position coordinates of a defect present in the substrate  3 . The guide scale  19  is equipped with the reflector (mirror)  215  in the Y-axis direction. The guide scale  20  is equipped with the reflector (mirror)  216  in the X-axis direction. The reflectors  215 ,  216  are movably provided along the guide scales  19 ,  20 , respectively. The reflectors  215 ,  216  are set vertically at a right angle or an acute angle with the surface of the substrate  3 . The holder  2  has the light source  21  at a position slightly apart from the right side of the guide scale  20  (the extension line of the guide scale  20 ). The light source section  22  is set at a position slightly ahead the guide scale  19  (the extension line of the guide scale  19 ). 
     The laser light emitted from the laser light source  211  of the light source section  21  transmits through the cylindrical lenses  212 ,  213  and finally emitted in the X-axis direction in the form of a planar laser virtually perpendicular to the surface of the substrate  3 . The laser light is reflected by the reflector  216  in the perpendicular direction, namely, in the Y-axis direction, to become planar-form laser light  217  virtually perpendicular to the surface of the substrate  3 . The laser light emitted from the laser light source  211  of the light source section  22  transmits through the cylindrical lenses  212 ,  213 , and finally emitted in the Y-axis direction in the form of a planar laser light virtually perpendicular to the surface of the substrate  3 . The laser light is reflected by the reflector  215  in the perpendicular direction, namely, in the X-axis direction, to become planer-form laser light  218  virtually perpendicular to the surface of the substrate  3 . 
     In the same manner as in Embodiment 1, the inspector moves the reflector  215  along the guide scale  19  to permit the laser light  218  to correspond with the defect a formed in the surface of the substrate  3 . Similarly, the inspector moves the reflector  216  along the guide scale  20  to permit the laser light  217  to correspond with the defect a. Thereafter, the inspector turns on the foot switch. The values of the guide scales  19 ,  20 , that is, the moving amounts of the reflectors  215 ,  216  from the origins (the foremost position of the guide scale  19 , the rightmost position of the guide scale  20  in FIG. 3) in the Y-axis and X-axis directions are determined by the detectors (not shown) of the guide scales  19 ,  20 , as coordinates (X, Y) of the defect a. The detection results are output from the detectors to the controller  11 . 
     According to the substrate inspecting apparatus according to Embodiment 2, the positional data of the defect can be easily obtained by moving the reflectors  215 ,  216  manually by the inspector. 
     FIG. 9 is a view showing the structure of the position detector of the substrate inspecting apparatus according to Embodiment 3 of the present invention. In FIG. 9, like reference numerals are used to designate like structural elements corresponding to those in FIG.  7 . The position detector can be applied to the substrate inspecting apparatus shown in Embodiment 1. 
     In FIG. 9, holding members  301 ,  302  are respectively provided on one of side surfaces of the holder  2  in the Y-axis direction and on one of side surfaces of the holder  2  in the X-axis direction, respectively. The surfaces of the holding members  301 ,  302  are lower than the surface of the holder  2 , so that a step is formed between them. The holding members  301  and  302  are respectively equipped with guide rails  303 ,  304  along the Y-axis direction and the X-axis direction of the side edge of the holder  2 . Furthermore, guide moving sections  305  and  306  are movably provided along the guide rails  303 ,  304  so as to cross over the guide rails  303 ,  304 . 
     The holding members  301  and  302  have a pair of pulleys  307 ,  308 , and a pair of pulleys  309 ,  310  supported by shafts and positioned respectively at both ends. A belt  311  and a belt  312  are respectively stretched between the pulley  307  and the pulley  308 , and between the pulley  309  and pulley  310 , in the form of a ring. The guide moving section  305  is fixed at a part of the belt  311 . The guide moving section  306  is fixed at a part of the belt  312 . To the pulleys  307 ,  310 , respective rotation axis  315 ,  316  of the motors  313 ,  314  are inserted, respectively. A pair of optical sensors  317 ,  318  and a pair of optical sensors  319 ,  320  are respectively provided at one of side surfaces in the Y-axis direction and one of side surfaces in the X-axis direction of the holder  2 , for detecting the presence of the guide moving sections  305 ,  306 . 
     The guide moving section  305  is equipped with the reflector (mirror)  215  in the Y-axis direction. The guide moving section  306  is equipped with the reflector (mirror)  216  in the X-axis direction. These reflectors are vertically provided at a right angle or an acute angle with the surface of the substrate  3 . A holding member  321  is provided at a point of intersection between the holding members  301  and  302 . The holding member  321  is virtually as high as the holder  2 . The beam splitter  214  is vertically provided on the holding member  321  at a point of intersection of the extension lines of the guide rails  303 ,  304 , at a right angle or an acute angle with the surface of the substrate  3 . The light source section  21  is set on the extension line of the guide rail  304  at a position slightly apart from the right side of the beam splitter  214 . The light source section  21  is formed of the laser light source  211  and the cylindrical lenses  212 ,  213  as shown in FIG.  5 . 
     The laser light emitted from the laser light source  211  of the light source section  21  transmits through the cylindrical lenses  212 ,  213 , and finally emitted in the X-direction in the form of a planar laser light virtually perpendicular to the surface of the substrate  3 . The laser light is split by the beam splitter  214  into two light beams in the X-direction and Y-direction. The laser light split in the X-axis direction is reflected by the reflector  216  and proceeds in the perpendicular direction, namely the Y-axis direction, in the form of a planar laser light  217  virtually perpendicular to the surface of the substrate  3 . On the other hand, the laser light split in the Y-axis direction is reflected by the reflector  215  and proceeds in the perpendicular direction, namely, the X-axis, in the form of a planer laser light  218  virtually perpendicular to the surface of the substrate  3 . 
     When the inspector operates the operation section (joystick) to drive the motor  313 , the rotation shaft  315  moves in one direction, with the result that the belt  311  moves in said one direction along the Y-axis via the pulleys  307 ,  308 . Alternatively, when the rotation shaft  315  is moved in the other (opposite) direction by moving the motor  313  by operating the operation section, the belt  311  moves in the other direction along the Y-axis via the pulleys  307 ,  308 . Consequently, the reflector  215  on the guide moving section  305  is moved along the guide rail  303  to permit the laser light  218  to correspond with the defect a present in the substrate  3 . 
     Furthermore, when the motor  314  is driven by operating the operation section by the inspector, the rotation shaft  316  is moved in one direction, with the result that the belt  312  moves in said one direction along the X-axis via the pulleys  310 ,  309 . Alternatively, when the rotation shaft  316  is moved in the other direction (opposite direction) by driving the motor  314  under the control of the operation section, the belt  312  is moved in the other direction along the X-axis via the pulleys  310 ,  309 . With this operation, the reflector  216  on the guide moving section  306  is moved along the guide rail  304  to permit the laser light  217  to correspond with the defect a present in the substrate  3 . 
     Thereafter, the inspector turns on the foot switch. At this time, the values of guide scales (not shown) provided on the guide rails  303 ,  304 , that is, moving amounts of the reflectors  215 ,  216  from the origins (positions of the sensors  318 ,  319 ) in the Y-axis direction and the X-axis direction, are detected by the detectors (not shown) of the guide scales as the coordinates (X, Y) of the defect a. The detection results are output from the detector to the controller  11 . 
     Note that when the presence of the guide moving section  305  is detected by the sensor  317  or  318 , the driving of the motor  313  is automatically stopped by the controller  11 . This means that the guide moving section  305  can be moved back and forth on the guide rail  303  only between the position corresponding to the sensor  317  and the position corresponding to the sensor  318 . Similarly, when the presence of the guide moving section  306  is detected by the sensor  319  or  320 , the driving of the motor  314  is automatically stopped by the controller  11 . This means that the guide moving section  306  is moved back and forth on the guide rail  304  only between the position corresponding to the sensor  319  and the position corresponding to the sensor  320 . 
     According to the substrate inspecting apparatus of Embodiment 3 of the present invention, a single laser light source  21  is used and the guide moving sections  305 ,  306  equipped with the reflectors  215 ,  216  are electrically driven. It is therefore possible for an inspector to control the movements of the reflectors  215 ,  216  by operating the operation section manually. By virtue of this, in a specific case where a large substrate is inspected, the positional data of the defect present far away from the inspector can be readily determined. To move the guide moving sections  305 ,  306 , a ball screw with a guide and a linear motor may be used. 
     The substrate inspecting apparatus of Embodiment 3 may be formed by setting two light source sections on the holder  2  instead of the beam splitter in the same manner as in Embodiment 2. The light from the light sources irradiates the reflectors  215 ,  216 , respectively. 
     FIG. 10 is a view showing a structure of the position detector of the substrate inspecting apparatus according to Embodiment 4 of the present invention. In FIG. 10, like reference numerals are used to designate like structural elements corresponding to those in FIG.  7 . The position detector can be applied to the substrate inspecting apparatus shown in Embodiment 1. The position detector is constituted of two light source sections  401 ,  402 . Each of the light source sections  401 ,  402  is constituted of the laser light source  211  and cylindrical lenses  212 ,  213  shown in FIG.  5 . 
     As shown in FIG. 10, the holder  2  has the guide scales  19 ,  20  along the side edges of the substrate  3  in the Y-axis direction and X-axis direction, for detecting the position coordinates of the defect present in the substrate  3 . The light source sections  401 ,  402  are movably provided on the guide scales  19 ,  20 , respectively. 
     The laser light emitted from the laser light source  211  of the light source section  401  transmits through the cylindrical lenses  212 ,  213  and finally emitted in the X-axis direction in the form of a planar laser light  403  virtually perpendicular to the surface of the substrate  3 . Similarly, the laser light emitted from the laser light source  211  of the light source section  402  transmits through the cylindrical lenses  212 ,  213  and finally emitted in the Y-axis direction in the form of a planar laser light  404  virtually perpendicular to the surface of the substrate  3 . 
     In the same manner as in Embodiment 1, the inspector moves the light source section  401  along the guide scale  19  to permit the laser light  403  to correspond to the defect a in the surface of the substrate  3 . Similarly the inspector moves the light source section  402  along the guide scale  20  to permit the laser light  404  to correspond with the defect a. Thereafter, the inspector turns on the foot switch. The values of the guide scales  19 ,  20 , that is, moving amounts of the light source sections  401 ,  402  from the origins (the foremost position of the guide scale  19 , the rightmost position of the guide scale  20  in FIG. 10) in the Y-axis and X-axis directions are determined by the detectors (not shown) of the guide scales  19 ,  20 , as coordinates (X, Y) of the defect a. The detection results are output from the detector to the controller  11 . 
     According to the substrate inspecting apparatus of Embodiment 4 of the present invention, two laser light source sections  401 ,  402  are provided on the guide scales  19 ,  20 . Different from the constitutions of Embodiments 1 and 2, the beam splitter and reflectors are not used. The inspector can easily determine the positional data of the defect only by moving the light sources  401 ,  402 , manually. Note that the substrate inspecting apparatus of Embodiment 4 may be formed in the same manner as in Embodiment 3. That is, the laser light sources  401 ,  402  are provided on the guide moving sections  305 ,  306  and the laser light sources  401 ,  402  may be electrically moved along the guide scales  19 ,  20 . 
     FIGS. 11 and 12 show the structure of a substrate inspecting apparatus according to Embodiment 5 of the present invention. FIG. 11 is a perspective view thereof and FIG. 12 is a side view thereof. In FIGS. 11 and 12, like reference numerals are used to designate like structural elements corresponding to those in FIGS. 1 and 2, and any further explanation is omitted for brevity&#39;s sake. In the substrate inspecting apparatus shown in FIGS. 1 and 2, the rotation driving force of the motor  18  is transmitted from the rotation shaft  181  to the pulley  16  by way of the belt  17 , whereby the holder  2  is lifted from the horizontal posture up to a predetermined angle around the supporting axis. In the substrate inspecting apparatus according to Embodiment 5, the holder  2  is lifted up in a swinging manner by a link mechanism to a predetermined angle and allow to stand in an inclined posture. 
     As shown in FIG. 11, on the main apparatus body  1 , a long and narrow hole  501  is formed along the side of the holder  2  arranged horizontally. Through the hole  501 , a connecting member  502  is inserted. On the side surface of the holder  2 , a hook  503  is formed so as to cross at a right angle with the surface of the holder  2  on which the substrate  3  is mounted. An end of the connecting member  502  is rotatably connected to the hook  503  via a rotation shaft  504 . The other end of the connecting member  502  is rotatably connected to a moving piece  506  via the rotation shaft  505  below the main apparatus body  1 , as shown in FIG.  12 . 
     Furthermore, as shown in FIG. 12, pulleys  509 ,  510  are provided respectively at ends of holding members  507 ,  508  while being supported by a shaft. The belt  511  is stretched between the pulleys  509  and  510  in a ring form. The moving piece  506  is fixed onto a part of the belt  511 . The rotation shaft  512  of a motor (not shown) is inserted in the pulley  509 . 
     The inspector operates a holder operation section (not shown) to drive the motor. At this point, when the rotation shaft  512  is rotated counterclockwise, the belt  511  is moved in the “−Y” direction via the pulleys  509 ,  510 . Alternatively, when the rotation shaft  512  is rotated clockwise by driving the motor, the belt  511  is moved in the “+Y” direction via the pulleys  509 ,  510 . With this movement, the moving piece  506  fixed on the belt  511  is moved in the −Y direction and +Y direction (forward and backward to the holder  2 ). 
     As shown in FIG. 12, when the moving piece  506  moves in the −Y direction while maintaining the holder  2  horizontally, the end of the connecting member  502  connected to the moving piece  506  rotates clockwise by the rotation shaft  505 . As a result, the connecting member  502  is gradually lifted up from the inclined posture. In accordance with this movement, the end of the connecting member  502  pushes up the holder  2  via the hook  503  while rotating around the rotation shaft  504 , with the result that the holder  2  is rotated at an angle of about 30° around the supporting shaft  15  and lifted up to a position indicated by a two dot-and-dash line from the horizontal posture, allowing the holder  2  to stand up in an inclined posture. Thereafter, the inspector terminates the movement of the motor to stop the holder  2 . Subsequently, the macro observation is performed. 
     After completion of the macro observation of the entire substrate  3 , the inspector operates the holder operation section again to drive the motor. When the rotation axis  512  is rotated clockwise, the moving piece  506  is moved in the +Y direction via the pulleys  509 ,  510  and the belt  511 . Upon the movement of the moving piece  506  in the +Y direction, the end of the connection member  502  connected to the moving piece  506  is rotated counterclockwise by the rotation axis  505 . As a result, the connecting member  502  is gradually inclined from the stand-up posture. With this movement, the end of the connecting member  502  brings down the holder  2  via the hook  503  while rotating the end of the connecting member  502  around the rotation shaft  504 . Consequently, the holder  2  returns in a horizontal posture initially taken. In this state, the micro observation is performed by the inspector. The moving piece  506  may be moved back and forth by a well known ball-screw or a linear motor in place of the belt. 
     As described in the above, it is possible to lift up the holder  2  up to an angle of about 30° by using the link mechanism because of the swing movement of the holder  2 . In addition, since the holder  2  is supported by the connecting member  502  when lifted up, the macro observation can be performed while setting the holder  2  in a more stable posture. 
     FIG. 13 is a side view of the structure of a substrate inspecting apparatus according to Embodiment 6 of the present invention. In FIG. 13, like reference numerals are used to designate like structural elements corresponding to those in FIG. 12, and any further explanation is omitted for brevity&#39;s sake. In Embodiment 5, the link mechanism is constituted by using a single connecting member, whereas the link mechanism is constituted by using two connecting members in Embodiment 6. 
     As shown in FIG. 13, the proximal end of a first connecting member  601  is rotatably connected by a rotation shaft  602  to the main apparatus body  1  while being supported by the shaft. To the free end of the first connecting member  601 , a roller  600  moving on the rear surface of the holder  2  is rotatably connected while being supported by the shaft. To the position near the free end of the first connecting member  601 , an end of a second connecting member  604  is rotatably connected via a rotation axis  603 . The other end of the second connecting member  604  is rotatably connected to the moving piece  506  via a rotation axis  605  below the main apparatus body  1 . 
     As shown in FIG. 13, when the moving piece  506  moves in the −Y direction while maintaining the holder  2  in the horizontal posture, the other end of the second connecting member  604  connected to the moving piece  506  rotates clockwise by the rotation axis  605 . As a result, the second connecting member  604  is gradually lifted up from the inclined posture. With this movement, the end of the second connecting member  604  lifts up the first connecting member  601  while rotating around the rotation axis  603 . Further, with this movement, the roller  600  of the first connecting member  601  rotatably moves on the rear surface of the holder  2  and pushes up the holder  2 . As a result, the holder  2  is lifted up at an angle of about 60° around the supporting shaft  15  to a position indicated by a two dot-and-dash line from the horizontal posture, allowing the holder  2  to stand in an inclined posture. After the holder  2  is allowed to stand in the inclined posture, the inspector terminates the movement of the motor to stop the holder  2 . Thereafter, the macro observation is performed. 
     When the moving piece  506  moves in the +Y direction, from this state, the other end of the second connection member  604  connected to the moving piece  506  is rotated counterclockwise by the rotation axis  605 . As a result, the second connecting member  604  is gradually inclined from the stand-up posture. Accordingly, the end of the second connecting member  604  brings down the first connecting member  601  while rotating around the rotation shaft  603 . With this movement, the holder  2  is brought down following the movement of the roller  600  of the first connecting member  601 . Consequently, the holder  2  returns in a horizontal posture initially taken. In this state, the micro observation is performed by the inspector. 
     As described above, the link mechanism is constituted by using two connecting members in order to swing the holder  2 . With the structure, the holder  2  can be lift up to about an angle of 60° and allowed to stand in an inclined posture. If the holder  2  is lifted up to about 60° by means of one connecting member in Embodiment 5, very long connecting member is required. As a result, a broad space is required to set the apparatus. However, in Embodiment 6, since double link mechanism is constituted by using two connecting members, the holder  2  can be swung to be lifted up to about 60°. In addition, since the link mechanism is formed by employing two short connecting members, the space occupied by the apparatus can be saved. 
     The link mechanisms shown in Embodiments 5 and 6 may be applied to the substrate inspecting apparatuses shown in Embodiments 1 to 4. 
     FIG. 14 is a perspective view showing the position detector employed in the substrate inspecting apparatus of Embodiment 7. In FIG. 14, the same reference numerals as used in FIG. 1 denote structural elements similar or corresponding to those of the foregoing embodiments. The position detector is applied to the substrate inspecting apparatus described in relation to Embodiment 1. 
     Referring to FIG. 14, holding members  7011  and  7012  are attached to the Y-axis direction side surfaces of a holder  2 . A holding member  702  is attached to an X-axis direction side surface of the holder  2 . The upper surfaces of the holding members  7011 ,  7012  and  702  are located lower than the upper surface of the holder  2 , so that there is a step between the holder  2  and the holding members. Guide rails  7031  and  7032  are provided for the holding members  7011  and  7012  in such a manner that they extend along the Y-axis direction sides of the holder  2 . Guide movement members  7051  and  7052  are mounted on the guide rails  7031  and  7032  so that they are slidable along the guide rails  7031  and  7032 . Likewise, guide rail  704  is provided for the holding member  702  in such a manner that it extends along an X-axis direction side of the holder  2 . A guide movement member  706  is mounted on the guide rail  704  so that it is slidable along the guide rail  704 . 
     Pulleys  709  and  710  are rotatably supported at the respective ends of the holding member  702 . A belt  712  is wound around the pulleys  709  and  710  to form a loop. The guide movement member  706  is in engagement with part of the belt  712 . The pulley  710  is coupled to the rotating shaft  716  of a motor  714 . On one of the X-axis direction side surfaces of the holder  2 , optical sensors  719  and  720  are provided. The sensors  719  and  720  detect the guide movement member  706  when this member come into their detection regions. 
     A Y-axis direction reflecting member (e.g., a mirror)  707  is provided on the guide movement member  706 . The reflecting member  707  stands upright on the member  706  or at an acute angle with reference thereto. A holding member  721  having substantially the same height as the holder  2  is provided at the position where holding members  7011  and  702  intersect with each other. A laser light source  21  is arranged on the holding member  721  in such a manner that it is located on an extension of the guide rail  704 . The laser light source  21  is made up of a laser light source section  211  and cylindrical lenses  212  and  213 , which are shown in FIG.  5 . 
     Pulleys  7071  and  7081  are rotatably supported at the respective ends of the perpendicular surface  7013  of holding member  7011 , and pulleys  7072  and  7082  are rotatably supported at the respective ends of the perpendicular surface  7014  of holding member  7012 . A belt  7111  is wound around pulleys  7071  and  7081  to form a loop, and a belt  7112  is wound around pulleys  7072  and  7082  to form a loop. Guide movement member  7051  is in engagement with part of belt  7111 ; likewise, guide movement member  7052  is in engagement with part of belt  7112 . The pulley  7071  is coupled to the rotating shaft  7131  of a motor  713 . On one of the Y-axis direction side surfaces of the holder  2 , optical sensors  717  and  718  are provided. The sensors  717  and  718  detect the guide movement member  7051  when this member come into their detection regions. A coupling shaft  730  is arranged under the holder  2 , and the ends of this coupling shaft  730  are rotatably inserted into the hollow sections of the pulleys  7081  and  7082 , respectively. 
     Support columns  741  and  742  are rotatably coupled to those side walls of the guide movement members  7051  and  7052  which are closer to the holder  2 . The ends of an elongated projection plate  743  are attached to the tops of the respective support columns  741  and  742 . The projection plate  743  has a black surface, for example, and is slanted at an angle of about 45° with reference to the surface of the substrate  3  under inspection. The side edge of the projection plate  743  is directed toward the reflector  707 . In this state, the support columns  741  and  742  stand upright with reference to the surface of the substrate  3 . 
     The projection plate  743  moves in accordance with the synchronous movement between the guide movement members  7051  and  7052 . That is, the plate  743  moves in the Y-axis direction in parallel to the surface of the substrate  3 , i.e., with a certain distance maintained. As will be described later, a guide member  744  for rotating the support column  741  is fixed to the guide rail  7031  at a position that is in the neighborhood of the holding member  721  and close to the holder  2 . 
     A laser beam emitted from the laser light source section  211  of the light source  21  and transmitted through the cylindrical lenses  212  and  213  is in the form of a plane that is substantially orthogonal to the surface of the substrate  3 . The laser beam in this form first travels in the X-axis direction, and is then reflected 90° by the reflector  707  so that the reflected laser beam travels in the Y-axis direction. The reflected laser beam  750  is in the form of a plane substantially orthogonal to the surface of the substrate  3 , and in this state falls on the inclined surface of the projection plate  743 . 
     As shown in FIG. 2, the holding member  702  attached to the proximal end of the holder  2  is supported by the supporting shaft  15  in such a manner as to be rotatable with reference to the main apparatus  1 . Owing to this structure, the holder  2  can be raised at a predetermined angle, or swung, as indicated by the two-dot-dash line in FIG.  2 . 
     With the holder  2  raised at the predetermined angle, the inspector illuminates the surface of the substrate  3  by macro illumination, as shown in FIG.  6 . If a defect a is found on the substrate  3  during this macro observation, the inspector operates the operation section (e.g., a joy stick) to drive the motor  714 . With the rotating shaft  716  moved in one direction or another, the belt  712  is moved in one direction or another along the X axis through the pulleys  710  and  709 . The reflector  707  on the guide movement member  706  is moved along the guide rail  704  with reference to the defect a on the substrate  3 , until the laser beam  750  falls on the defect a. 
     Further, the inspector operates the operation section to drive the motor  713 . With the rotating shaft  7131  moved in one direction or another, the belt  7111  is moved in one direction or another along the Y axis through the pulleys  7071  and  7081 . In accordance with this movement, the support column  741  and the projection plate  743  are moved as well as the guide movement member  7051 , such that they move along the guide rail  7031  with reference to the defect a on the substrate  3 . The support column  741  and the projection plate  743  are moved until the lower side  7431  of the projection plate  743  comes to the position above the defect a. In accordance with the rotation of pulley  7081 , pulley  7082  is rotated in the same direction as pulley  7081  by the coupling shaft  730 . Belt  7112  is driven by the pulleys  7072  and  7082  in the same direction as belt  7111 . Since, therefore, the guide movement members  7051  and  7052  synchronously move in the same direction along the Y axis, the projection plate  743  moves in the Y-axis direction in parallel to the X axis at all times. 
     Subsequently, the inspector turns on a foot switch. The values of guide scales (not shown) extending along the guide rails  7031  and  704  are detected as position coordinates (X, Y) of the defect a by detectors (not shown) of the guide scales. That is, the Y-axis direction moving amount of the projection plate  743 , as measured from a predetermined origin, and the X-axis direction moving amount of the reflector  707 , as measured from a predetermined origin, are detected. Results of this detection are output from the detectors to the controller  11 . 
     If the guide movement member  7051  is sensed by sensor  717  or  718 , the controller  11  automatically stops the driving of the motor  713 . This means that the guide movement member  7051  is allowed to reciprocate along the guide rail  7031  between the two positions corresponding to the sensors  717  and  718 . Similarly, if the guide movement member  706  is sensed by sensor  719  or  720 , the controller  11  automatically stops the driving of the motor  714 . This means that the guide movement member  706  is allowed to reciprocate along the guide rail  704  between the two positions corresponding to the sensors  719  and  720 . 
     FIGS. 15A to  15 D show a mechanism for retracting the projection plate  743 . FIG. 15A is a plan view showing the guide movement member  7051  along with its neighboring portions. FIG. 15B is a side view of the guide movement member  7051 . FIG. 15C is a plan view showing the guide movement member  744  along with its neighboring portions. FIG. 15D is a side view of the guide movement member  744 . When the projection plate  743  is being moved to the position above the defect a, the support columns  741  and  742  are upright, and the projection plate  743  is located above the substrate  3  such that it is inclined at an angle of 45°, as shown in FIGS. 15A and 15B. The support columns  741  and  742  are rotatably supported by the guide movement members  7051  and  7052  by means of rotating shafts  7411  and  7421  (not shown). 
     As indicated by the solid line in FIG. 1, when micro observation is performed by the micro observation unit  9 , with the holder  2  kept in the horizontal state, the projection plate  743  must be retracted from above the substrate  3  so as to avoid collision between the projection plate  743  and the objective lens  91 . To retract the projection plate  743 , the operator operates the operation section to drive the motor  713 . As a result, the guide movement members  7051  and  7052  are moved toward the holding member  702 . When the support column  741  comes into contact with the guide member  744  shown in FIG. 15C, the projection at the lower end of the support column  741  is gradually moved up along the inclined surface  7441  of the guide member  744 . In accordance with this movement, the support columns  741  and  742  rotate on the rotating shafts  7411  and  7421 , respectively, until they become parallel to the substrate  3 . At the time, the support columns  741  and  742  are fitted in a space extended from the space defined between the holder  2  and the guide rail  704 . In this retracted state, the support columns  741  and  742  are lower in level than the holder  2 . Owing to this structure, the collision between the objective lens  91  and the projection plate  743  can be avoided during micro observation. 
     According to the substrate inspecting apparatus of the seventh embodiment, the position coordinate detecting section can be raised together with the holder  2  even if this holder  2  is raised at any angle. Owing to this structure, a defect position can be reliably detected at all times even if the substrate  3  under inspection is tilted at any angle. Moreover, since the guide movement members  7051  and  706 , which constitute the position coordinate detecting section, are electrically driven, the reflector  707  and projection plate  743  can be easily controlled by the operator who operates the operation section. In particular, where a large-sized substrate is inspected, a laser beam and the projection plate  743  are controlled to correspond in position to a defect. The position information on this defect can be easily obtained even if the defect is far away from the inspector. 
     The guide movement members  7051  and  7052  and the projection plate  743  can be driven by use of a guide-provided ball screw and a linear motor. In addition, the light source may be a type which, like an LED, flashes and emits a collimated beam. Such a light source may be provided for the guide movement member  706 , replacing the reflector  707 . Moreover, the projection plate  743  need not be limited to an elongated plate; it may be a linear member or a triangle pole as long as a slit beam or a spot beam, such as that of a laser beam, can be projected thereon. 
     According to the present invention, the following functions are obtained. 
     According to the substrate inspecting apparatus of the present invention, the substrate holding member can be raised at a predetermined angle while holding the substrate. It is therefore possible to perform the macro observation of the surface of the substrate from a position close to the eye of an inspector. Hence, the defect can be inspected highly accurately. In addition, since the position coordinates of the defect present in the substrate are determined by the position detector, the micro observation system is controlled on the basis of the coordinates so as to correspond to the defect present in the substrate. As a result, the micro observation can be made smoothly and continuously following the macro observation, increasing the efficiency of the defect inspection by the macro observation and the micro observation. 
     According to the substrate inspecting apparatus of the present invention, it is possible to determine the position coordinates of the defect easily only by detecting the position of the position detector corresponding to the defect while moving the position detector along the guide scale provided along the side edge of the substrate. 
     According to the substrate inspecting apparatus of the present invention, the observation unit can be moved in any position on the substrate only by moving the observation unit supporting section on the substrate in one direction and moving the observation unit in the direction perpendicular to the moving direction of the observation unit supporting section. It is therefore possible to form the substrate holding member in virtually the same size as the substrate. Hence, miniaturization of the apparatus is attained and the setting area of the apparatus can be drastically reduced. 
     Furthermore, in the present substrate inspecting apparatus, the electrical wiring for providing the light source section on the guide scale can be made simply by moving the reflector. In addition, the space required for the wiring can be reduced. Hence the miniaturization of the apparatus is attained. Since the apparatus can be constituted by using only one light source, the apparatus can be formed inexpensively. 
     According to the substrate inspecting apparatus of the present invention, the movement of the reflector can be controlled by a predetermined manual operation the inspector performed at a proximal side of the apparatus. Therefore, in a specific case where a large substrate is inspected, the positional data of the defect can be easily obtained even if the defect is present far away from the inspector. 
     According to the substrate inspecting apparatus of the present invention, a connecting function is used to swing the substrate holding member. It is therefore possible to lift up the substrate holding member up to an angle of about 30°. Since the substrate holding member is supported by the connecting function when lifted up, the macro observation is performed while the substrate holding member is placed in a stable state. 
     According to the substrate inspecting apparatus of the present invention, the connecting function is constituted of a plurality of connecting members. It is therefore possible to lift up the substrate holding member in a swinging manner to an angle of about 60°. Furthermore, the link mechanism is constituted by using a plurality of short connecting members. It is therefore possible to save the space for setting the apparatus. 
     To be more specifically, the present invention makes it possible not only to reduce the size of the substrate inspecting apparatus but also to increase the accuracy and efficiency in inspection of the substrate inspecting apparatus. 
     Note that the present invention is not limited to the aforementioned Embodiments and may be modified within the scope of the present invention. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.