Abstract:
An adjustable detection apparatus. The apparatus includes a first holding member and a second holding member and a detection device. The first holding member has a first sliding area, in which the second holding member is moveable. The second holding member has a second sliding area. The detection device comprises a detachable detector, wherein the detection device is moveable in the second sliding area.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a detection apparatus, and more particularly to a detection apparatus set up in a cleaning tank, and is adjustable according to the size thereof. 
     2. Description of the Related Art 
     A complete semiconductor process includes many steps such as film deposition, lithography, and etching. Large quantities of materials and solutions are used for manufacturing or washing, while mostly water is used in a wet bench. 
     Acidic or chemical solvents such as H 2 SO 4 , HF and H 3 PO 4  are the principal solutions used in etching or dissolving in semiconductor processes. Residue of acidic or chemical solvents easily remains on the wafer, which must then be thoroughly cleaned with large quantities of deionized water (DI water). 
     The chemical wet bench includes a cleaning tank, a cassette, and a megasonic device. 
     In  FIG. 1 , wafers  101  are vertically disposed in the cassette  102 . The two wafers  101  are separated by a divider  102   a . The wafers  101  are supported in an upright position by the divider  102   a.    
     In  FIG. 2 , the cassette  102  and the wafers  101  are placed in a cleaning tank  105 . The cleaning tank  105  has a bottom portion  104  provided with air holes  104   a.    
     A megasonic device  106  comprises a megasonic tank  106   a . Cleaning solution  107  is placed in the megasonic tank  106   a . The megasonic device  106  is coupled beneath the cleaning tank  105 . 
     The cleaning solution  107 , at megasonic energy levels, is injected into the cleaning tank  105  through the air holes  104   a  of the bottom portion  104 . 
       FIG. 3  shows a cleaning tank  105 , in which the cassette  102  is placed and a megasonic device  106 , which includes megasonic tank  106   a  containing DI water  107 , coupled beneath the cleaning tank  105 . 
     The DI water  107 , at megasonic energy levels, is injected from megasonic tank  106   a  into the cleaning tank  105  via the air holes of the bottom portion  104  when the megasonic device  106  is turned on. 
     The cleaning tank  105  contains DI water  107  and the wafers  101 . The cleaning tank  105  further comprises a discharging portion (not shown). Surplus DI water  107  is discharged by the discharging portion. Residue on the wafers  101  cannot be thoroughly removed if the megasonic device  106  provides insufficient megasonic energy due to damage. 
     There are several commercially available detectors to measure the megasonic energy levels of the DI water  107  in the cleaning tank  105 . The detector is placed in the activated cleaning tank  105  in a predetermined position, and the megasonic energy levels of the DI water  107  in the cleaning tank  105  are directly measured by the detector. The detector can be, for example, a sound level meter. 
     Because commercially available detectors require manual operation and estimation of distance by the operator, error can result. 
     SUMMARY OF THE INVENTION 
     Accordingly, the object of the present invention is to provide a detection apparatus for a cleaning tank. The detection apparatus can be adjusted according to the dimensions of the cleaning tank. In addition, the detection apparatus can detect the megasonic energy levels in the cleaning tank in a predetermined position when the coordinate values of the position are set. 
     The present invention provides an adjustable detection apparatus comprising a first holding member, a second holding member, and a detection device. The first holding member has a first sliding area, and the second holding member is moveable in the first sliding area. The second holding member has a second sliding area, and the detection device is moveable in the second sliding area. 
     The present invention also provides an adjustable detection apparatus, for detecting the megasonic energy levels of the clean liquid in a cleaning tank, comprises a first holding member, a second holding member, and a detection device with a detachable detector. The first holding member has a first sliding area, and the second holding member is moveable in the first sliding area. The second holding member has a second sliding area, and the detection device is moveable in the second sliding area. The detachable detector can measure the megasonic energy levels of the clean liquid in the cleaning tank. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a cross section of a cassette of a conventional chemical wet bench; 
         FIG. 2  is a top view of a conventional chemical cleaning machine in which a cassette is displaced; 
         FIG. 3  is a cross section taken along lines A—A of  FIG. 2 ; 
         FIG. 4   a  shows an adjustable detection apparatus of the present invention; and 
         FIG. 4   b  is a perspective view of the adjustable detection apparatus of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A detailed description of the adjustable detection apparatus of the present invention is given hereafter with reference to  FIGS. 4   a  and  4   b .  FIG. 4   a  shows the adjustable detection apparatus of the present invention.  FIG. 4   b  is a perspective view of the adjustable detection apparatus of the present invention. 
     The adjustable detection apparatus comprises first holding members  401 , second holding members  402 , and a detection device  403 . The first holding members  401  are coupled to the second holding members  402 . Running gears  401   c  and  402   c  are sequentially coupled to the first holding members  401  and the second holding members  402  and the detection device  403  to drive the detection device  403 . The running gear  401   c  and  402   c  can, for example, be a stepping motor. 
     The adjustable detection apparatus can be used on a wafer cleaning tank. The first holding members  401  are adjustable according to the length of the cleaning tank, suitable for any size of cleaning tank. 
     The first holding members  401 , parallel to each other, each have a sliding area  401   a . The second holding members  402  sequentially have a sliding area  402   a  and a sliding member  402   b . The second holding members  402  are parallel to each other, and the second holding member  402  and the first holding member  401  are perpendicular to one another. The detection device  403  has a sliding member  403   a.    
     The second holding members  402  are adjustable according to the width of the cleaning tank. The sliding member  402   a  is positioned within the sliding area  401   a , such that the holding members  402  are coupled to the holding members  401 . 
     The sliding member  403   a  is positioned within the sliding area  402   a , so that the detection device  403  is coupled to the second holding members  402 . 
     The running gear coupled to the first holding members  401  is turned on to drive the second holding members  402 , followed by the sliding member  402   b  moving in the sliding area  401   a.    
     The running gear coupled to the second holding members  402  is turned on to drive the detection device  403 , followed by the sliding member  403   a  moving in the sliding area  402   a.    
     The detector  404  is fixed in the detection device  403  via a hole  403   b  thereof. The hole  403   b  is adjustable according to the diameter of the detector  404 . After the detector  404  is fixed in the detection device  403  via the hole  403   b , the running gear  403   c , coupled to the detection device  403 , is turned on to drive the detector  404  up or down. The detector  404  can be a commercially available sound level meter. 
     The detecting method applied to the megasonic cleaning tank of the present invention is herein described. 
     First, a value that indicates a coordinate is input. For example, the coordinate value can be ( 25 ,  17 , and  4 ) or ( 25 ,  33 ,  4 ). 
     Next, the running gears  402   c  and  401   c  are turned on to sequentially drive the first holding members  401  and the second holding members  402  to the position indicated by the coordinate in the X-Y. For example, after the running  402   c  and  401   c  are turned on, the detection device  403  is driven to the position indicated by the coordinates ( 25 ,  17 ). 
     After that, the running gear coupled to the detection device  403  is turned on to drive the detector  404  on the Z-axis to arrive at the predetermined coordinates. For example, after the running gear  403   c  is turned on to drive the detector  404 , the detector  404  is driven in the Z-direction to the position indicated by the coordinate ( 25 ,  17 , and  4 ). 
     By this means, the detector  404  is moved into detecting position. The apparatus of the present invention can bring the detector to any predetermined position to perform detection. The results can then be compared to each other. 
     After detection is complete and the results of the detection are recorded, the running gears  402   c  and  401   c  are turned on again to drive the first holding members  401  and the second holding members  402  and the detection device  403  to the, next desired coordinates. 
     For example, if the next coordinate values are ( 25 ,  33 ,  4 ), the X-value of next position is the same number, but the Y-values of ( 25 ,  33 ,  4 ) and ( 25 ,  17 ,  4 ) are different. Thus the running gear  401   c  on the first holding member  401  that controls the movement of the detection apparatus in the Y-axis is turned on the second holding member  402  to Y=33 from Y=17. The Z-value of the next position is the same number as well, so the running gear  403   c  coupled to the detection device  403  is not turned on to drive the detector  404 . Then, the megasonic energy levels of the position at coordinates ( 25 ,  33 , and  4 ) are detected by the detector  404 . 
     The adjustable detection apparatus detects the megasonic energy levels of the clean liquid, such as DI water or chemical solution, when wafers are being cleaned, so real-time detecting results of the clean liquid are recorded. 
     The adjustable detection apparatus can detect the megasonic energy levels of the clean liquid at any position in the cleaning tank. The position of the cleaning tank can be selected by any controlling apparatus or user. 
     The adjustable detection apparatus of the present invention is not limited to detection of the megasonic energy levels of the clean liquid of the cleaning tank, and can be used in any suitable device. Furthermore, other types of detection can be performed in the cleaning tank. 
     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.