JP6074154B2 - Processing equipment - Google Patents

Description

  The present invention relates to a processing apparatus that performs grinding and polishing on the back surface of a wafer such as a semiconductor wafer or an optical device wafer.

  In the semiconductor device manufacturing process, a large number of rectangular areas are defined by planned cutting lines called streets arranged in a lattice pattern on the surface of a semiconductor wafer having a substantially disk shape, and ICs, LSIs, etc. are divided into the rectangular areas. Form the device. Individual devices are formed by separating the semiconductor wafer having such a large number of devices along the streets. In addition, an optical device wafer in which a plurality of regions are defined by streets formed in a lattice pattern on the surface of a sapphire substrate or the like, and an optical device in which a gallium nitride compound semiconductor or the like is stacked in the partitioned region is It is divided into optical devices such as individual light-emitting diodes and laser diodes along the planned dividing line, and is widely used in electrical equipment.

  In order to reduce the size and weight of the individually divided devices as described above, the wafer back surface is usually ground and cut in advance before the wafer is cut along the street and divided into individual devices. The thickness is formed. Grinding of the back surface of the wafer is usually performed by pressing a grinding wheel formed by fixing diamond abrasive grains with an appropriate bond such as a resin bond against the back surface of the wafer while rotating at high speed. When the back surface of the wafer is ground by such a grinding method, processing strain such as microcracks is generated on the back surface of the wafer, thereby considerably reducing the bending strength of the individually divided devices. As a countermeasure to remove the processing strain generated on the back surface of the ground wafer, a wet etching method or etching in which the back surface of the ground wafer is chemically etched using an etching gas solution containing nitric acid and hydrofluoric acid. A dry etching method using a gas is used. A polishing method for polishing the back surface of the ground wafer using loose abrasive grains has also been put into practical use. However, there is a problem that the wafer is damaged when the wafer is transported from the grinding device to the etching device or the polishing device in order to etch or polish the wafer ground by the grinding device.

  In order to solve the problems described above, a turntable that is rotatably arranged, a plurality of chuck tables that are provided on the turntable and have a holding surface that holds a wafer, and the plurality of chuck tables are positioned. 2. Description of the Related Art A wafer processing apparatus has been proposed that includes a grinding unit that performs grinding processing on a wafer that is disposed in each of a plurality of processing regions and is held by the plurality of chuck tables, and a polishing unit that performs polishing processing. (For example, refer to Patent Document 1.)

JP 2005-153090 A

  A production system in which an inline system is constructed by placing a tape tensioner that attaches protective tape to the surface of the wafer before and after the above-mentioned processing equipment, and a splitting device that splits the wafer along the street, so that the processing equipment is fully operated. Has been put to practical use. However, when a processing defect occurs in the wafer that has been ground and polished by the processing apparatus, there is a problem that the defective wafer is transported to the next process and defective products continue.

  The present invention has been made in view of the above facts, and a main technical problem thereof is a processing apparatus capable of stopping the operation of the apparatus when a processing defect occurs in a ground and polished wafer. Is to provide.

In order to solve the above technical problem, according to the present invention, a processing apparatus for forming a back surface of a wafer having a protective tape adhered to a surface thereof to a predetermined thickness,
Wafer holding means for holding a wafer, grinding means for grinding the wafer held by the wafer holding means, polishing means for polishing the wafer held by the wafer holding means, grinding processing and polishing processing Cleaning means for cleaning the wafer subjected to the processing, a cassette for storing the processed wafer, and a processing state for detecting the processing state of the wafer after grinding, polishing and cleaning before storing in the cassette Detection means, and a control means for controlling each means based on a detection signal from the machining state detection means,
The control means determines the quality of the wafer processing state based on the detection signal from the processing state detection means, and outputs a processing failure message to the alarm means when it is determined that the processing is defective. the been made to stop,
The processing state detection means images the first processing state detection means that images the protective tape attached to the front surface of the wafer and outputs an image signal, and images the back surface of the wafer that has been subjected to grinding and polishing. Second machining state detection means for outputting a signal,
A wafer processing apparatus is provided.

A processing apparatus according to the present invention includes a processing state detection unit that detects a processing state of a wafer that has been ground, polished, and cleaned before being accommodated in the cassette, and a detection signal from the processing state detection unit. Control means for controlling each means, and the control means determines whether the processing state of the wafer is good based on a detection signal from the processing state detection means, and if it is determined that the processing is defective, an alarm means A processing failure message is output and the operation of each means is stopped , and the processing state detection means is a first processing state in which a protective tape attached to the surface of the wafer is imaged and an image signal is output. a detecting means, since the grinding and polishing are and a second machining state detecting means for outputting a captured image signal back surface of the wafer which has been subjected, subsequently, processing defects wafers of manufacture Rukoto is not.

The perspective view of the processing apparatus comprised according to this invention. The perspective view of the grinding | polishing means with which the processing apparatus shown in FIG. 1 is equipped. The block block diagram of the control means with which the processing apparatus shown in FIG. 1 is equipped. The perspective view of the semiconductor wafer as a to-be-processed object. Explanatory drawing of the protective tape sticking process which sticks a protective tape on the surface of the semiconductor wafer shown in FIG. Explanatory drawing which shows the state which the process water entered between the surface of the semiconductor wafer, and the protective tape, and the part which expands locally on the protective tape produced. Explanatory drawing which shows the state in which a grinding saw remains on the semiconductor wafer back surface. Explanatory drawing which shows the state in which the scratch is formed in the semiconductor wafer back surface. Explanatory drawing which shows the state which the crack has generate | occur | produced in the semiconductor wafer.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a processing apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a perspective view of a processing apparatus constructed in accordance with the present invention.
The processing apparatus shown in FIG. 1 is provided with an apparatus housing generally indicated by numeral 2. This device housing 2 has a rectangular parallelepiped main portion 21 that extends elongated and an upright wall 22 that is provided at the rear end portion (upper right portion in FIG. 1) of the main portion 21 and extends substantially in the vertical direction. ing. The apparatus housing 2 formed in this way includes a carry-in / carry-out area 2a for carrying in / out a wafer, which will be described later, a rough grinding area 2b, a finish grinding area 2c, and a polishing area 2d.

  A turntable 3 is rotatably disposed in the main portion 21 of the apparatus housing 2, and the turntable 3 is loaded and unloaded area 2a, rough grinding area 2b, and finish grinding area by a table rotating means (not shown). It is rotated in the direction indicated by arrow A along 2c and polishing region 2d. The turntable 3 is provided with four chuck tables 4a, 4b, 4c, and 4d as wafer holding means. The four chuck tables 4a, 4b, 4c, and 4d are arranged at an equal angle of 90 degrees in the illustrated embodiment. Each of the chuck tables 4a, 4b, 4c, and 4d includes a disk-shaped base and a suction holding chuck made of a porous ceramic material disposed on the top surface of the base. The workpiece placed on the surface is sucked and held by operating a suction means (not shown). The chuck tables 4a, 4b, 4c, and 4d configured as described above are rotated by a rotation driving mechanism (not shown).

  On the upper surface of the turntable 3, partition plates 36, 36, 36, 36 for partitioning an area where the four chuck tables 4a, 4b, 4c, 4d are disposed are disposed. The partition plates 36, 36, 36, 36 are arranged to extend in the radial direction from the rotational axis of the turntable 3, and the height thereof is higher than the height of the chuck tables 4 a, 4 b, 4 c, 4 d. ing.

  A rough grinding unit 5 as a rough grinding means is disposed in the rough grinding region 2b. The rough grinding unit 5 includes a unit housing 51, a rough grinding wheel 52 rotatably attached to the lower end of the unit housing 51, and a rough grinding wheel 52 attached to the upper end of the unit housing 51 to rotate in a predetermined direction. A servo motor 53 and a moving base 54 on which the unit housing 51 is mounted are provided. Guided rails 55, 55 are provided on the moving base 54, and the guided rails 55, 55 are movably fitted to the guide rails 22 a, 22 a provided on the upright wall 22, so that rough movement is achieved. The grinding unit 5 is supported so as to be movable in the vertical direction, that is, in a direction perpendicular to the holding surfaces of the chuck tables 4a, 4b, 4c, and 4d. The rough grinding unit 5 in the illustrated form includes grinding feed means 56 that moves the moving base 54 along the guide rails 22a and 22a. The grinding feed means 56 includes a male screw rod 57 disposed in the vertical direction in parallel with the guide rails 22a, 22a provided on the upright wall 22 and rotatably supported, and a pulse for rotationally driving the male screw rod 57. A rough grinding unit includes a motor 58 and a female screw block (not shown) that is mounted on the moving base 54 and is screwed with the male screw rod 57. The pulse motor 58 drives the male screw rod 57 to rotate forward and backward. Move 5 up and down.

  A finish grinding unit 50 as finish grinding means is disposed in the finish grinding region 2c. The finish grinding unit 50 has substantially the same configuration as that of the rough grinding unit 5 except that the finish grinding wheel 520 is different from the rough grinding wheel 52 of the rough grinding unit 5. The same members are denoted by the same reference numerals, and the description thereof is omitted.

  A polishing means 7 is disposed in the polishing region 2d (part of the outline is shown by a two-dot chain line in FIG. 1). The polishing means 7 will be described with reference to FIG. The polishing means 7 shown in FIG. 2 comprises chemical mechanical polishing (CMP) means, a mounter 72 for detachably mounting the polishing tool 71, a spindle unit 73 for rotating the mounter 72, and the spindle unit 73 as described above. The chuck table 4a, 4b, 4c, 4d is supported so as to be movable in the direction perpendicular to the holding surface of the chuck table 4a, 4c, 4d (Z-axis direction) and in the direction parallel to the holding surface of the chuck table (Y-axis direction). Spindle unit supporting means 74 for rotating, first polishing feed means 75 for moving the spindle unit 73 in a direction perpendicular to the holding surface of the chuck table (Z-axis direction), and the spindle unit 73 for the holding surface of the chuck table. Second polishing feed means 76 for moving in a direction parallel to the direction (Y-axis direction); It is provided. The spindle unit 73 includes a servo motor 731 for rotating the mounter 72.

  In the illustrated embodiment, the spindle unit support means 74 includes a support base 741, a first moving base 742, and a second moving base 743. On one side surface of the support base 741, first guide rails 741a and 741a extending in a direction indicated by an arrow Y parallel to the holding surfaces of the chuck tables 4a, 4b, 4c, and 4d are provided. On one side surface of the first moving base 742, there are provided first guided rails 742b and 742b that fit with the first guide rails 741a and 741a provided on the support base 741. Second guide rails 742a and 742a extending in a direction indicated by an arrow Z perpendicular to the holding surfaces of the chuck tables 4a, 4b, 4c, and 4d are provided on the other side surface of one moving base 742. The first moving base 742 configured in this manner is supported by fitting the first guided rails 742b and 742b with the first guide rails 741a and 741a provided on the support base 741. The base 741 is supported so as to be movable along the guide rails 741a and 741a.

  On one side surface of the second moving base 743, second guided rails 743b and 743b which are fitted to the second guide rails 742a and 742a provided on the first moving base 742 are provided. By fitting the second guided rails 743b and 743b with the second guide rails 742a and 742a provided on the first moving base 742, the second moving base 743 The movable base 742 is supported so as to be movable along the second guide rails 742a and 742a. The spindle unit 73 is mounted on the other side surface of the second moving base 743 configured as described above.

  The first polishing feed means 75 has the same configuration as the grinding feed means 56. That is, the first polishing feed means 75 is a male motor which is disposed between the pulse motor 751 and the second guide rails 742a and 742a in parallel with the second guide rails 742a and 742a and is driven to rotate by the pulse motor 751. A screw rod (not shown) and a female screw block (not shown) mounted on the second moving base 743 and screwed with the male screw rod are provided, and a male screw rod (not shown) is driven forward and reverse by a pulse motor 751. Thus, the second moving base 743, that is, the spindle unit 73 is moved in the direction indicated by the arrow Z perpendicular to the holding surfaces of the chuck tables 4a, 4b, 4c, and 4d. The second polishing feed means 76 is disposed between the pulse motor 761 and the first guide rails 741a and 741a in parallel with the first guide rails 741a and 741a, and is driven to rotate by the pulse motor 761. A male screw rod (not shown) and a female screw block (not shown) mounted on the first moving base 742 and screwed with the male screw rod are provided, and the male screw rod (not shown) is driven to rotate forward and backward by a pulse motor 761. As a result, the first moving base 742, that is, the second moving base 743 and the spindle unit 73 are moved in the direction indicated by the arrow Y parallel to the holding surfaces of the chuck tables 4a, 4b, 4c and 4d. .

  Returning to FIG. 1 and continuing the description, a first cassette mounting portion 11a and a second cassette mounting portion 11b are provided at the front end portion (the lower left end portion in FIG. 1) of the main portion 21 of the apparatus housing 2. It has been. A first cassette 111 in which a wafer before processing is accommodated is placed on the first cassette placing portion 11a, and a second cassette for housing the processed wafer is placed on the second cassette placing portion 11b. A cassette 112 is placed. Here, the wafer accommodated in the first cassette 111 will be described with reference to FIGS. 4 and 5. FIG. 4 shows a semiconductor wafer 10 as a wafer. The semiconductor wafer 10 shown in FIG. 4 is made of, for example, a silicon wafer having a thickness of 700 μm, and a plurality of streets 101 are arranged in a lattice pattern on the surface 10a. A device 102 such as an LSI is formed. In order to protect the device 102 formed on the surface 10a of the semiconductor wafer 10 when the back surface 10b of the semiconductor wafer 10 before processing thus formed is ground to a predetermined thickness (for example, 100 μm), As shown in FIGS. 5A and 5B, a protective tape T made of vinyl chloride or the like is attached to the surface 10a of the semiconductor wafer 10 (protective tape attaching step). The semiconductor wafer 10 having the protective tape T adhered to the front surface 10a in this manner is accommodated in the first cassette 111 with the back surface 10b, which is the processing surface, facing upward. Then, the first cassette 111 in which the semiconductor wafer 10 before processing is accommodated is placed on the first cassette placing portion 11a, and an empty second cassette 112 for accommodating the wafer after processing is placed in the second cassette 112. 2 is placed on the cassette mounting portion 11b.

  In addition, a temporary placement area 12 is provided in the front portion (lower left portion in FIG. 1) of the main portion 21 of the apparatus housing 2, and the pre-working area unloaded from the first cassette 111 in the temporary placement area 12 is provided. Centering means 120 for aligning the center of the semiconductor wafer 10 is provided. A cleaning region 13 is provided behind the temporary storage region 12 (upper right in FIG. 1), and a spinner cleaning means 130 for cleaning the processed wafer is disposed in the cleaning region 13. The spinner cleaning means 130 cleans the semiconductor wafer 10 after being ground by the rough grinding unit 5 as the rough grinding means and the finish grinding unit 50 as the finish grinding means and polished by the polishing means 7. Cleaning water is scattered from the cleaning surface of the semiconductor wafer 10 by centrifugal force, and spinner drying is performed.

  Wafer transfer means 14 is disposed behind the first cassette mounting portion 11a and the second cassette mounting portion 11b. The wafer transport means 14 includes a conventionally known multi-axis joint robot 142 to which a hand 141 is attached, and a moving means 143 that moves the multi-axis joint robot 142 in the width direction of the apparatus housing 2. The hand 141 is configured to be inverted 180 degrees (upside down). The moving means 143 is mounted on a guide rod 143b attached to support pillars 143a and 143a erected on the main portion 21 of the apparatus housing 2 at intervals in the width direction, and is movably mounted on the guide rod 143b. A moving block 143c, a screw rod 143d that is arranged in parallel with the guide rod 143b and is screwed into a screw hole formed in the moving block 143c, and a pulse motor 143e that can be rotated forward and reversely and that rotates the screw rod 143d. The multi-axis joint robot 142 is attached to the moving block 143c. The moving means 143 configured as described above moves the moving block 143c, that is, the multi-axis joint robot 142 along the guide rod 143b by driving the pulse motor 143e in the normal direction or the reverse direction to rotate the screw rod 143d. The wafer transport means 14 configured as described above carries out the unprocessed semiconductor wafer 10 accommodated in a predetermined position of the first cassette 111 by operating the moving means 143 and the multi-axis joint robot 142. Then, the ground semiconductor wafer 10 that has been cleaned and dried by the spinner cleaning means 130 is transported to the centering means 120, and is further transported to the centering means 120 to be described later. The semiconductor wafer 10 whose processing state has been detected by the above is accommodated in a predetermined position of the second cassette 112.

  The grinding apparatus in the illustrated embodiment includes a chuck table 4 (a, b, c, d) in which the unprocessed semiconductor wafer 10 conveyed to the centering means 120 and centered is positioned in the loading / unloading region 2a. The wafer carrying means 15 for carrying the wafer and the processed semiconductor wafer 10 held on the chuck table 4 (a, b, c, d) positioned in the carry-in / out area 2a are carried out, and a protective tape cleaning described later is carried out. And a wafer unloading means 16 for transporting to the spinner cleaning means 130. The wafer carry-in means 15 and the wafer carry-out means 16 are fixed to support pillars 17 and 17 attached to the apparatus housing 2 and are mounted so as to be movable along guide rails 18 extending in the front-rear direction (longitudinal direction) of the apparatus housing 2. ing. The wafer carrying means 15 includes a suction pad 151, a support rod 112 that supports the suction pad 151 at the lower end, and a moving block 153 that is connected to the upper end of the support rod 152 and is attached to the guide rail 18. . In the wafer carry-in means 15 configured as described above, the moving block 153 is appropriately moved along the guide rail 18 in the direction indicated by the arrow B by the moving means (not shown), and the support rod 152 is moved by the moving means (not shown) to the arrow C. Is moved appropriately in the vertical direction indicated by, and is turned in the direction indicated by arrow H.

  The wafer carry-out means 16 includes a suction pad 161, a guide rail 162 that supports the suction pad 161 so as to be movable in the direction indicated by arrow D, a support rod 163 that supports the guide rail 162 at the lower end, and the support The moving block 164 is connected to the upper end of the rod 163 and mounted on the guide rail 18 and moves in the direction indicated by the arrow E. The diameter of the suction pad 161 of the wafer carry-out means 16 is formed larger than the diameter of the suction pad 151 of the wafer carry-in means 15. The reason why the suction pad 161 of the wafer unloading means 16 is formed to have a large diameter is to increase the suction holding area because the wafer that has been ground and thinned is easily broken. In the wafer unloading means 16 configured as described above, the moving block 164 is appropriately moved along the guide rail 18 by a moving means (not shown), and the suction pad 161 is indicated by an arrow D by the moving means (not shown). The support rod 163 is appropriately moved in the vertical direction as indicated by an arrow F by a moving means (not shown).

  The processing apparatus in the illustrated embodiment includes a protective tape cleaning means 19 for cleaning the protective tape T affixed to the surface 10a of the semiconductor wafer 10 after processing carried out by the wafer carry-out means 16. . The protective tape cleaning means 19 includes a rotatable cleaning sponge 191 and a cleaning pool 192 for storing the cleaning sponge 191 in a submerged state, and the suction pad 161 between the carry-in / out area 2a and the spinner cleaning means 130. It is arrange | positioned in the movement path | route.

  The processing apparatus in the illustrated embodiment includes first processing state detection means 8 disposed in the movement path of the suction pad 161 between the protective tape cleaning means 19 and the spinner cleaning means 130. In the illustrated embodiment, the first processing state detection means 8 is constituted by a CCD imaging means, images the protective tape T attached to the surface 10a of the processed semiconductor wafer 10, and uses it as a detection signal. The image signal is sent to the control means described later.

  Further, the machining apparatus in the illustrated embodiment includes second machining state detection means 9 disposed on the upper side of the centering means 120. In the illustrated embodiment, the second processing state detection means 9 is constituted by a CCD imaging means, and is a processing surface of the semiconductor wafer 10 that has been cleaned by the spinner cleaning means 130 and transferred to the centering means 120. The back surface 10b is imaged and an image signal as a detection signal is sent to a control means described later.

  The processing apparatus in the illustrated embodiment includes a control means 6 shown in FIG. The control means 6 is constituted by a microcomputer, and a central processing unit (CPU) 61 that performs arithmetic processing according to a control program, a read-only memory (ROM) 62 that stores control programs and the like, and a read / write that stores arithmetic results and the like. A random access memory (RAM) 63, an input interface 64, and an output interface 65. Detection signals from the first machining state detection unit 8, the second machining state detection unit 9, and the like are input to the input interface 64 of the control unit 6 configured as described above. From the output interface 65, the turntable 3, the four chuck tables 4a, 4b, 4c, 4d, the rough grinding unit 5, the finish grinding unit 50, the polishing means 7, the centering means 120, the spinner cleaning means 130, Control signals are output to the wafer transfer means 14, the wafer carry-in means 15, the wafer carry-out means 16, the protective tape cleaning means 19, the alarm means 60, the first machining state detection means 8, the second machining state detection means 9, and the like. The alarm unit 60 may be a screen display unit, a voice display unit, or both a screen display unit and a voice display unit.

The wafer processing apparatus in the illustrated embodiment is configured as described above, and the operation thereof will be described mainly with reference to FIG.
In order to process the wafer by the above-described processing apparatus, the first cassette 111 in which the semiconductor wafer 10 before processing is accommodated is placed on the first cassette mounting portion 11a and the wafer after processing is accommodated. The empty second cassette 112 is placed on the second cassette placing portion 11b. When a processing start switch (not shown) is turned on, the control means 6 operates the wafer transport means 14 to a predetermined position of the first cassette 111 placed on the first cassette placement portion 11a. The stored unprocessed semiconductor wafer 10 is unloaded and transferred to the centering means 120. The centering means 120 performs centering of the transported semiconductor wafer 10 before processing. Next, the wafer carry-in means 15 is operated, and the unprocessed semiconductor wafer 10 centered by the centering means 120 is carried to the chuck table 4a positioned in the carry-in / out area 2a, and the protective tape T side is moved. Place on the chuck table 4a. At the start of machining, the turntable 3 is positioned at the origin position shown in FIG. 1, the chuck table 4a disposed on the turntable 3 is in the carry-in / out area 2a, and the chuck table 4b is in the rough grinding area. 2b, the chuck table 4c is positioned in the finish grinding area 2c, and the chuck table 4d is positioned in the polishing area 2d. As described above, the unprocessed semiconductor wafer 10 on which the protective tape T side is placed on the chuck table 4a positioned in the loading / unloading area 2a by the wafer loading means 15 is activated by operating the suction means (not shown). It is sucked and held on the chuck table 4a via T. Accordingly, the semiconductor wafer 10 sucked and held on the chuck table 4a has the back surface 10b, which is the surface to be processed, on the upper side.

  If the unprocessed semiconductor wafer 10 is sucked and held on the chuck table 4a positioned in the carry-in / carry-out area 2a, a table rotating means (not shown) is operated to move the turntable 3 in a predetermined direction indicated by an arrow A in FIG. In the illustrated embodiment, it is rotated by an angle of 90 degrees. As a result, the chuck table 4a that sucks and holds the unprocessed semiconductor wafer 10 is positioned in the rough grinding region 2b, the chuck table 4b is in the finish grinding region 2c, the chuck table 4c is in the polishing region 2d, and the chuck table 4d is It is positioned in the carry-out area 2a. If the chuck tables 4a, 4b, 4c and 4d are positioned in the respective areas in this way, the rough grinding unit 5 is applied to the semiconductor wafer 10 held on the chuck table 4a positioned in the rough grinding area 2b. With this, rough grinding is performed. During this time, the unprocessed semiconductor wafer 10 is transferred to the chuck table 4d positioned in the loading / unloading area 2a, and the unprocessed semiconductor wafer 10 is sucked and held on the chuck table 4d.

  Next, a table rotating means (not shown) is operated to rotate the turntable 3 further 90 degrees in a predetermined direction indicated by an arrow A in FIG. 1 (therefore, the turntable 3 is 180 degrees from the origin position shown in FIG. 1). Rotate). As a result, the chuck table 4a holding the semiconductor wafer 10 that has been roughly ground in the rough grinding region 2b is positioned in the finish grinding region 2c, and the chuck table that holds the semiconductor wafer 10 before processing in the carry-in / out region 2a by suction. 4d is positioned in the rough grinding region 2b. The chuck table 4b is positioned in the polishing area 2d, and the chuck table 4c is positioned in the loading / unloading area 2a. In this state, the finish grinding unit 50 performs finish grinding on the roughly ground semiconductor wafer 10 held by the chuck table 4a located in the finish grinding region 2c, and is positioned in the rough grinding region 2b. The semiconductor wafer 10 held on the chuck table 4d is subjected to rough grinding by the rough grinding unit 5. During this time, the unprocessed semiconductor wafer 10 is conveyed to the chuck table 4c positioned in the loading / unloading area 2a, and the unprocessed semiconductor wafer 10 is sucked and held on the chuck table 4c.

  Next, a table rotating means (not shown) is operated to further rotate the turntable 3 by 90 degrees in a predetermined direction indicated by an arrow A in FIG. 1 (therefore, the turntable 3 is 270 degrees from the origin position shown in FIG. 1). Rotate). As a result, the chuck table 4a that holds the semiconductor wafer 10 that has undergone finish grinding in the finish grinding region 2c is positioned in the polishing region 2d, and the chuck table 4d that holds the semiconductor wafer 10 that has undergone rough grinding in the rough grinding region 2b. The chuck table 4c that is positioned in the finish grinding region 2c and sucks and holds the semiconductor wafer 10 before processing in the carry-in / out region 2a is positioned in the rough grinding region 2b. Then, the chuck table 4b is positioned in the loading / unloading area 2a. As described above, the finish grinding unit 50 performs finish grinding on the semiconductor wafer 10 that has been roughly ground and is held by the chuck table 4d positioned in the finish grinding region 2c. At the same time, the rough grinding unit 5 performs rough grinding on the semiconductor wafer 10 held on the chuck table 4c positioned in the rough grinding region 2b.

  Further, the polishing process is performed by the polishing means 7 on the semiconductor wafer 10 that has been subjected to finish grinding and is held by the chuck table 4a positioned in the polishing region 2d. On the other hand, the unprocessed semiconductor wafer 10 is conveyed to the chuck table 4b positioned in the loading / unloading area 2a during this time, and the unprocessed semiconductor wafer 10 is sucked and held on the chuck table 4b.

  Next, the turntable 3 (not shown) is operated to turn the turntable 3 further 90 degrees in the direction indicated by the arrow A in FIG. 1 (therefore, the turntable 3 is rotated 360 degrees from the origin position shown in FIG. 1). Move). As a result, the chuck table 4a holding the semiconductor wafer 10 which has been polished in the polishing region 2d, removed the grinding distortion and formed to a predetermined thickness is positioned in the carry-in / out region 2a, and finish grinding in the finish grinding region 2c. The chuck table 4d holding the processed semiconductor wafer 10 is positioned in the polishing region 2d, and the chuck table 4c holding the semiconductor wafer 10 subjected to rough grinding in the rough grinding region 2b is positioned in the finish grinding region 2c and is carried in. In the unloading area 2a, the chuck table 4b that sucks and holds the semiconductor wafer 10 before processing is positioned in the rough grinding area 2b.

  The chuck table 4a positioned in the carry-in / carry-out area 2a releases the suction holding of the semiconductor wafer 10. Next, the control means 6 operates the wafer unloading means 16 to hold the semiconductor wafer 10 on the chuck table 4 a on the suction pad 161, unloads it from the chuck table 4 a, and conveys it to the protective tape cleaning means 19. Then, the control unit 6 rotates the cleaning sponge 191 of the protective tape cleaning unit 19 to clean the protective tape T attached to the surface (lower surface) of the semiconductor wafer 10. When the protective tape T adhered to the surface (lower surface) of the semiconductor wafer 10 is cleaned in this way, the control means 6 operates the wafer carry-out means 16 to attach the cleaned protective tape T. The semiconductor wafer 10 is transported toward the spinner cleaning means 130. In the middle of the conveyance, the control means 6 operates the first processing state detection means 8 to image the protective tape T attached to the surface (lower surface) of the semiconductor wafer 10. Then, the first processing state detection unit 8 sends the captured image signal to the control unit 6. The quality of the processing state based on the image signal sent from the first processing state detection means 8 will be described in detail later.

  As described above, when the first processing state detection means 8 images the protective tape T attached to the surface (lower surface) of the semiconductor wafer 10, the wafer carry-out means 16 transfers the semiconductor wafer 10 to the spinner cleaning means 130. Transport. The processed semiconductor wafer 10 conveyed to the spinner cleaning means 130 is cleaned and spinner dried here. When the semiconductor wafer 10 is cleaned and spinner dried in the spinner cleaning means 130 in this way, the control means 6 operates the wafer transport means 14 to focus on the semiconductor wafer 10 cleaned and spinner dried in the spinner cleaning means 130. It is conveyed to the aligning means 120. Next, the control unit 6 operates the second processing state detection unit 9 to image the back surface 10 b that is the processing surface of the semiconductor wafer 10. Then, the second processing state detection unit 9 sends the captured image signal to the control unit 6. The quality of the processing state based on the image signal sent from the second processing state detection means 9 will be described in detail later.

  As described above, when the second processing state detection unit 9 images the back surface 10b, which is the processing surface of the semiconductor wafer 10, the control unit 6 operates the wafer transport unit 14 to move the semiconductor wafer 10 to the second processing state. The cassette 112 is accommodated in a predetermined position.

Next, a method for determining the quality of the machining state based on the image signals picked up by the first machining state detection unit 8 and the second machining state detection unit 9 will be described.
The first processing state detecting means 8 images the protective tape T attached to the front surface (lower surface) of the semiconductor wafer 10 to process the back surface 10b, which is the processing surface of the semiconductor wafer 10 described above, during processing. It is possible to detect that processing water has entered between the surface 10a of the semiconductor wafer 10 and the protective tape T. When the processing water enters between the surface 10a of the semiconductor wafer 10 and the protective tape T, a portion T-1 in which the protective tape T swells locally is generated as shown in FIG. In this way, when the portion T-1 that locally swells on the protective tape T is generated, the image signal is locally diffusely reflected at the portion T-1 where the image signal swells. Therefore, based on the image signal input from the first processing state detection unit 8, the control unit 6 has an image signal having a light intensity that is locally higher than the light intensity of the image signal obtained by imaging the plane. It is determined that the processing is defective.

  The second processing state detecting means 9 is in an unpolished state in which the grinding saw 105 remains on the back surface 10b, which is the processing surface of the semiconductor wafer 10, as shown in FIG. 7, or in the semiconductor wafer as shown in FIG. It is possible to detect whether or not the scratch 106 is formed on the back surface 10b, which is the surface to be processed 10, and whether or not the crack 107 is generated in the semiconductor wafer 10 as shown in FIG. When the grinding saw 105, scratch 106, and crack 107 are generated in this way, the image signal corresponding to the grinding saw 105, scratch 106, and crack 107 is locally diffusely reflected, so that the light intensity is higher than the image signal obtained by imaging the plane. high. Therefore, the control means 6 is based on the image signal input from the second processing state detection means 9, and when there is an image signal having a light intensity that is locally higher than the light intensity of the image signal obtained by imaging the plane, It is determined that the processing is defective.

  As described above, when the control unit 6 checks the quality of the processing state of the semiconductor wafer 10 based on the image signals from the first processing state detection unit 8 and the second processing state detection unit 9, and determines that the processing is defective. Outputs a processing failure message by screen display or voice display or both screen display and voice display to the alarm means 60 and the turntable 3, chuck tables 4a, 4b, 4c, 4d, rough grinding unit 5, and finish grinding unit. 50, a polishing means 7, a centering means 120, a spinner cleaning means 130, a wafer transport means 14, a wafer carry-in means 15, a wafer carry-out means 16, and a control signal for stopping the operation are output. As described above, when it is determined that the processing state of the semiconductor wafer 10 is processing failure, a processing failure message is output to the alarm means 60 by screen display or voice display, or both screen display and voice display, and the processing apparatus is operated. Since the process is stopped, a wafer having a defective processing is not manufactured thereafter. If the processing state of the semiconductor wafer 10 is not determined to be processing failure, the control means 6 continues to perform the processing of the semiconductor wafer 10.

2: Device housing 2a: Loading / unloading area 2b: Rough grinding area 2c: Finish grinding area 2d: Polishing area 3: Turntables 4a, 4b, 4c, 4d: Chuck table 5: Rough grinding unit 50: Finish grinding unit 51: Unit housing 52: Grinding wheel 520: Grinding wheel for finishing 53: Servo motor 56: Grinding feed means 6: Control means 60: Alarm means 7: Polishing means 71: Polishing tool 72: Mounter 73: Spindle unit 75: First Polishing feed means 76: Second polishing feed means 8: First processing state detection means 9: Second processing state detection means 10: Semiconductor wafer 111: First cassette 112: Second cassette 120: Centering means 130: Spinner cleaning means 14: Wafer conveying means 15: Wafer carrying means 1 6: Wafer unloading means 19: Protection tape cleaning means

Claims (1)

A processing apparatus for forming a back surface of a wafer having a protective tape attached to a surface thereof to a predetermined thickness,
Wafer holding means for holding a wafer, grinding means for grinding the wafer held by the wafer holding means, polishing means for polishing the wafer held by the wafer holding means, grinding processing and polishing processing Cleaning means for cleaning the wafer subjected to the processing, a cassette for storing the processed wafer, and a processing state for detecting the processing state of the wafer after grinding, polishing and cleaning before storing in the cassette Detection means, and a control means for controlling each means based on a detection signal from the machining state detection means,
The control means determines the quality of the wafer processing state based on the detection signal from the processing state detection means, and outputs a processing failure message to the alarm means when it is determined that the processing is defective. the been made to stop,
The processing state detection means images the first processing state detection means that images the protective tape attached to the front surface of the wafer and outputs an image signal, and images the back surface of the wafer that has been subjected to grinding and polishing. Second machining state detection means for outputting a signal,
A wafer processing apparatus characterized by that.

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