Cleaning apparatus, processing apparatus including the cleaning apparatus, and cleaning method

Abstract

To provide a new technique for drying a workpiece after cleaning in a method for cleaning the workpiece.SOLUTION: The cleaning apparatus includes a rotatable spinner table for holding a workpiece, a housing for forming an internal space for housing the spinner table, a nozzle for supplying a cleaning liquid to the workpiece held on the spinner table, and at least one heater for heating the atmosphere of the internal space. Further, the heater is a second heater disposed above the object to be processed. Preferably, the workpiece is a plate-shaped wafer, the wafer is attached to a tape that shrinks by heat, and the second heater is provided at a position facing an exposed portion of the tape around the wafer.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a cleaning apparatus that cleans a workpiece such as a wafer by supplying a cleaning liquid to the workpiece while rotating the workpiece, a processing apparatus equipped with the cleaning apparatus, and a cleaning method. [Background technology]

[0002] In the semiconductor device manufacturing process, a large number of regions are partitioned on the surface of a roughly circular semiconductor wafer by dividing lines arranged in a grid pattern, and semiconductor devices such as ICs and LSIs are formed in each of the divided regions. The semiconductor wafer is then diced along the dividing lines to divide each region, producing individual device chips.

[0003] Contamination such as cutting chips generated during dicing can adhere to the surface of a semiconductor wafer. For this reason, after dicing, the semiconductor wafer is cleaned in a spinner cleaning device. For example, as shown in Patent Document 1, a spinner cleaning device supplies cleaning water to a rotating semiconductor wafer to clean the surface of the semiconductor wafer and remove contamination from the semiconductor wafer. The water used to clean the semiconductor wafer is guided to the surface of a housing by centrifugal force caused by the rotation and is sucked out by an exhaust duct opening on the side of the housing.

[0004] Furthermore, as shown in Patent Document 2, for example, it is known that after cleaning, air is blown from an air nozzle onto the rotating semiconductor wafer to dry the semiconductor wafer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-23138 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-115234 Summary of the Invention [Problem to be solved by the invention]

[0006] If the blown air contains even a small amount of particles (foreign matter), the particles will adhere to the semiconductor wafers after cleaning, contaminating them. Furthermore, negative pressure is created around the air flow, attracting particles in the atmosphere and carrying them with the air, causing them to adhere to the semiconductor wafers and contaminate them. Thus, blowing air can recontaminate semiconductor wafers that have already been cleaned.

[0007] For this reason, for some semiconductor wafers, which are sensitive to recontamination, the air blowing may be omitted and the wafers may be dried by simply rotating the spinner table.

[0008] However, the rotation of the spinner table itself generates particles in the atmosphere, and while it is desirable to shorten the time required for drying, omitting the air blow results in a long drying time.

[0009] On the other hand, in the dicing process, the semiconductor wafer is generally held on a holding table in a state where it is attached to an annular frame via adhesive tape, and is diced by a cutting blade.

[0010] At this time, in order to avoid interference between the cutting blade and the annular frame, the annular frame is pulled down below the holding surface of the holding table by a clamping mechanism and held there. However, this pulling down causes the outer periphery of the adhesive tape that holds the semiconductor wafer after dicing to stretch, and the adhesive tape may become loose after the hold is released.

[0011] If the adhesive tape is loose, adjacent device chips may come into contact with each other after dicing due to vibrations of the annular frame during transport, which could cause chips to form. For this reason, it is desirable to remove any looseness in the adhesive tape.

[0012] In view of the above problems, the present invention relates to a method for cleaning a workpiece, and proposes a new technique for drying the workpiece after cleaning. [Means for solving the problem]

[0013] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0014] According to one aspect of the present invention, a cleaning device is provided that includes a spinner table that can hold and rotate a workpiece, a housing that forms an internal space to accommodate the spinner table, a nozzle that supplies cleaning liquid to the workpiece held on the spinner table, and at least one heater that heats the atmosphere in the internal space.

[0015] According to one aspect of the present invention, the heater is a second heater disposed above the workpiece.

[0016] According to one aspect of the present invention, the workpiece is a plate-shaped wafer, the wafer is attached to a tape that shrinks when heated, and the second heater is provided in a position opposite the exposed portion of the tape around the wafer.

[0017] According to one aspect of the present invention, the heater is a first heater provided on an inner surface of a peripheral wall that constitutes the housing.

[0018] According to one aspect of the present invention, the device further comprises a first heater provided on the inner surface of the peripheral wall that constitutes the housing.

[0019] According to another aspect of the present invention, air can be blown from the nozzle toward the workpiece.

[0020] According to one aspect of the present invention, a processing apparatus is provided that includes a cleaning device and a processing unit that processes the workpiece, and the workpiece processed by the processing unit is cleaned by the cleaning device.

[0021] According to one aspect of the present invention, there is provided a cleaning method comprising: a cleaning step in which a workpiece is held on a spinner table and a cleaning liquid is supplied to the workpiece from a nozzle while the spinner table is rotated to clean the workpiece; and a drying step in which, after the workpiece has been cleaned, the atmosphere in the internal space of a housing that houses the spinner table is heated with at least one heater to dry the workpiece.

[0022] According to one aspect of the present invention, the workpiece is a plate-shaped wafer, the wafer is attached to a tape that shrinks when heated, and the heater is a second heater provided in a position opposite the exposed portion of the tape around the wafer. [Effects of the Invention]

[0023] The present invention provides the following effects. In other words, according to one aspect of the present invention, in applications where the rotation speed of the spinner table is slowed or drying is performed without rotation, the generation of particles caused by the rotation of the spinner table can be suppressed, thereby suppressing re-contamination of the workpiece by particles and shortening the drying time.

[0024] According to one aspect of the present invention, the exposed portions of the tape around the workpiece are heated, causing the exposed portions that were once stretched and loose to contract and eliminate the looseness, thereby preventing the occurrence of defects that could occur during subsequent transport, such as device chips coming into contact with each other due to loose tape. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view showing an example of a processing apparatus to which the present invention is applied; [Figure 2] FIG. 10 is a diagram showing an example of a frame unit. [Figure 3] 10A to 10C are diagrams showing an example of cutting processing. [Figure 4] FIG. 1 is a perspective view showing an example of the configuration of a cleaning device. [Figure 5] FIG. 2 is a partial cross-sectional side view showing an example of the configuration of a cleaning device. [Figure 6] FIG. [Figure 7] FIG. 10 is a diagram showing drying by air blowing. [Figure 8] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of a processing device 2 to which the present invention is applied.

[0027] 1, a holding table 20 is disposed on a base 4 of the processing device 2. A water cover 14 is disposed around the holding table 20, and a bellows 16 that covers an opening in the base 4 is connected to the water cover 14. Below the water cover 14 and the bellows 16, there are provided a movement mechanism (not shown) that moves the holding table 20 in the X-axis direction and a rotation mechanism (not shown) that rotates the holding table 20 around the Z-axis.

[0028] The holding table 20 has a holding surface 21 connected to a suction source (not shown), and holds the workpiece, i.e., the wafer W, by suction by generating a negative pressure on the holding surface 21. A plurality of clamping mechanisms 22 for clamping the annular frame F of the frame unit U are arranged around the holding table 20.

[0029] A cassette mounting table 8 for mounting a cassette 7 is provided at a front corner of the base 4. The cassette 7 accommodates a frame unit U to which a wafer W is fixed.

[0030] A gate-shaped column 9 is erected on the base 4, and a pair of guide rails 31 extending in the Y-axis direction are fixed to the column 9. A Y-axis moving block 33 is provided on the guide rails 31 so as to be movable in the Y-axis direction, and the Y-axis moving block 33 is guided by the guide rails 31 and moves in the Y-axis direction by a Y-axis moving mechanism 30 consisting of a ball screw 32 and a pulse motor 34.

[0031] A pair of guide rails 36 extending in the Z-axis direction are fixed to the Y-axis moving block 33. A Z-axis moving block 38 is provided so as to be movable in the Z-axis direction relative to the guide rails 36, and the Z-axis moving block 38 is guided by the guide rails 36 and moves in the Z-axis direction by a Z-axis moving mechanism 40 consisting of a ball screw 42 and a pulse motor 44.

[0032] The cutting unit 5 and the imaging unit 6 are attached to the Z-axis moving block 38. The cutting unit 5 is configured to have a spindle that is rotationally driven by a motor (not shown), and a cutting blade that is detachably attached to the tip of the spindle.

[0033] A cleaning device 60 having a spinner table 50 is provided on the base 4, and the wafer W after cutting is held by suction on the spinner table 50, where it is spin-cleaned and can be spin-dried.

[0034] The operation of each operating part of the processing device 2 is controlled by a control unit 100, and the device is configured to automatically perform continuous cutting processing and cleaning after processing.

[0035] FIG. 2 shows an example of the configuration of the frame unit U. The wafer W, which is the workpiece, is made of, for example, Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor materials. Alternatively, it is made of a composite oxide such as LT (lithium tantalate) or LN (lithium niobate). Alternatively, the wafer W is a substrate made of a material such as sapphire, glass, or quartz. Examples of glass include alkali glass, non-alkali glass, soda-lime glass, lead glass, borosilicate glass, and quartz glass.

[0036] 2 is configured as a disk-shaped semiconductor wafer, with devices D regularly formed on the surface Wa, with streets S (planned dividing lines) perpendicular to each other being set between each device D, and cutting grooves being formed along the streets S, as will be described in detail later. Note that the wafer W may not necessarily have any devices D formed thereon.

[0037] The back surface Wb of the wafer W is adhered to the adhesive surface of the tape T and fixed to the annular frame F via the tape T. The front surface Wa of the wafer W may be adhered to the tape T. The tape T is also called an expanding tape or a dicing tape, and is made of a base material that is stretchable at room temperature and shrinks (heat shrinks) when heated to a predetermined temperature (e.g., 70°C) or higher. An adhesive layer is formed on one side of the base material. Examples of the base material include synthetic resin sheets such as polyvinyl chloride, polypropylene, polyethylene, and polyolefin. The adhesive material forming the adhesive layer is an ultraviolet-curable resin that hardens when exposed to ultraviolet light. In this case, the tape T is configured as an ultraviolet-curable adhesive tape. The tape T may also be one that does not have an adhesive surface (glue layer).

[0038] Figure 3 shows an example of cutting processing (dicing) by the cutting unit 5, in which a frame unit U is placed on the holding table 20, an annular frame F is clamped by a clamping mechanism 22, and a wafer W is suction-held on the holding surface 21 via a tape T.

[0039] The cutting blade 5a of the cutting unit 5, whose position has been adjusted by alignment, is positioned at a predetermined height and rotated at high speed by a motor (not shown). Then, the holding table 20 is fed horizontally for processing, thereby performing cutting along the streets S (FIG. 2). By performing cutting on all of the mutually orthogonal streets S (FIG. 2), individual device chips are formed.

[0040] 3, during dicing, in order to avoid interference between the cutting blade 5a and the annular frame F, the annular frame F is pulled down and held below the holding surface 21 of the holding table 20 by the clamping mechanism 22. At this time, the exposed portion Ta of the tape T exposed around the periphery of the wafer W is stretched.

[0041] In this embodiment, the processing unit for processing the workpiece is configured to use a cutting unit 5 that performs cutting processing using a cutting blade 5a, but a laser processing unit that dices by irradiating a laser beam may also be used.

[0042] Fig. 4 is a perspective view showing an example of the configuration of the cleaning device 60, and Fig. 5 is a partial cross-sectional side view of the same. The cleaning device 60 may be incorporated into a processing device such as a cutting device as shown in Fig. 1, or may be configured as a standalone device.

[0043] 4, the wafer W (device chips) after dicing is cleaned in the cleaning device 60. Here, as described above, the tape T has been stretched once, and when it is transported to the cleaning device 60, the exposed portion Ta of the tape T is in a loose state.

[0044] 4 and 5, spinner table 50 of cleaning device 60 is housed within peripheral wall 61a of cylindrical housing 61, which is open at the top. Spinner table 50 is connected to the upper end of rotating shaft 63 (FIG. 5) provided within cover cylinder 62, and rotates at high speed (for example, 1000 rpm to 3000 rpm) by rotating rotating shaft 63 with a motor (not shown).

[0045] A cleaning arm 64 rotated by a motor 64m (FIG. 5) is disposed on the side of the spinner table 50 within the peripheral wall 61a of the housing 61. The cleaning arm 64 includes a rotating portion 64k extending vertically and a swinging portion 64y extending horizontally at the tip of the rotating portion 64k. A nozzle 64a for supplying a cleaning liquid (e.g., pure water) or air is provided at the tip of the swinging portion 64y.

[0046] A supply unit 65 capable of selectively supplying cleaning liquid or air is connected to the cleaning arm 64, and either one can be supplied under the control of the control unit 100. Note that two cleaning arms 64 may be provided, and cleaning liquid and air may be supplied from nozzles provided at the tip of each cleaning arm.

[0047] The spinner table 50 is configured to include a porous plate 51 and a frame 52 that surrounds the periphery of the porous plate 51 .

[0048] The porous plate 51 is made of a porous material such as alumina ceramics or resin, and its upper surface constitutes a holding surface 51a. The porous plate 51 is connected to a suction source (not shown) and is configured to hold the wafer W by suction via the tape T by generating a negative pressure on the holding surface 51a.

[0049] Furthermore, the porous plate 51 is connected to an air supply source (not shown), and when the wafer W is released after cleaning, a positive pressure is generated on the holding surface 51a, thereby peeling the tape T from the holding surface 51a.

[0050] A plurality of clamps 67, 67 are arranged at a plurality of positions on the frame body 52, and the frame F of the wafer unit U is clamped and held by each of the clamps 67, 67.

[0051] An exhaust duct 61d that is connected to a suction source (not shown) is formed in the peripheral wall 61a, and mist of cleaning liquid floating in the inner space of the peripheral wall 61a and foreign matter such as washed-away cutting chips are sucked into the exhaust duct 61d and removed.

[0052] In the above configuration, when cleaning is performed, as shown in Fig. 6, the spinner table 50 is rotated (for example, at 1000 rpm) and cleaning water 81 is supplied from the nozzle 64a to the front surface Wa of the wafer W. Foreign matter on the front surface Wa of the wafer W is washed away by the cleaning water 81.

[0053] 7, the spinner table 50 is rotated at high speed (for example, 2000 rpm to 3000 rpm) and air 82 is blown from the nozzle 64a toward the front surface Wa of the wafer W, thereby drying the front surface Wa of the wafer W. Note that either or both of the high speed rotation of the spinner table 50 and the blowing of the air 82 may be performed.

[0054] In addition to drying the wafer W by rotating the spinner table 50 and blowing air as described above, this embodiment also makes it possible to dry the wafer W by heating using a heater.

[0055] 8, the cleaning device 60 has at least one heater 71, 72 for heating the atmosphere in the internal space 61k of the housing 61. The heaters 71, 72 are not particularly limited, but may be configured, for example, as a unit including a heating wire that dissipates heat when energized. Furthermore, it is considered that the temperature of the atmosphere in the internal space 61k is set to, for example, 200°C to 700°C by heating.

[0056] First heater 71 is provided, for example, on the inner surface of peripheral wall 61a of housing 61, at a position to the side of holding surface 51a of spinner table 50, and is configured to radiate heat 83 toward internal space 61k. Note that there may be multiple first heaters 71, and they may be configured to be provided at multiple locations on the inner surface of peripheral wall 61a.

[0057] After cleaning, heating by the first heater 71 is started, whereby the cleaning liquid remaining on the surface of the wafer W and moisture in the atmosphere are heated and evaporated, thereby drying the surface of the wafer W. In particular, in applications where the rotation speed of the spinner table 50 is slowed or drying is performed without rotation, using the heater 71 for drying can suppress the generation of particles caused by the rotation of the spinner table 50, thereby suppressing recontamination of the wafer W by particles and shortening the drying time.

[0058] The second heater 72 is disposed above the wafer W, for example, at a position facing the exposed portion Ta of the tape T around the wafer W, and is configured to radiate heat 84 toward the exposed portion Ta.

[0059] In this embodiment, the second heater 72 is provided on a swinging portion 64y that extends horizontally on the cleaning arm 64. Note that the second heater 72 may be provided on the cleaning arm 64, or may be installed on a bracket fixed to the peripheral wall 61a, for example.

[0060] After cleaning, heating by the second heater 72 is started, whereby the exposed portions Ta of the tape T around the wafer W are heated, and as described above, the exposed portions Ta that were once stretched and loosened contract and the looseness is eliminated. This makes it possible to prevent the occurrence of defects during subsequent transportation, such as device chips coming into contact with each other due to looseness in the tape T.

[0061] Furthermore, when heating by the second heater 72, by rotating the spinner table 50 at a low speed (for example, 100 rpm or less), it is possible to heat the exposed portion Ta of the tape T over the entire circumference, and to evenly and reliably eliminate slack in the tape T. The second heater 72 also heats the atmosphere in the internal space 61k, and the cleaning liquid remaining on the surface of the wafer W and moisture in the atmosphere are heated and evaporated, thereby drying the surface of the wafer W.

[0062] The first heater 71 and the second heater 72 may both be operated simultaneously, or either one of them may be operated. By operating them simultaneously, the wafer W can be dried in a shorter time.

[0063] As described above, the cleaning method according to the present invention can be carried out. That is, as shown in FIG. 6, a cleaning method can be implemented that includes a cleaning step in which a wafer W, which is a workpiece, is held on spinner table 50 and cleaning wafer W by rotating spinner table 50 while supplying cleaning liquid 81 to wafer W from nozzle 64a, and a drying step in which, after cleaning wafer W, the atmosphere in internal space 61k of housing 61 that accommodates spinner table 50 is heated by at least one heater 71, 72 to dry wafer W, as shown in FIG. 8.

[0064] Also, as shown in Figure 8, the workpiece is a plate-shaped wafer W, which is attached to a tape T that shrinks (heat shrinks) when heated, and the heater is a second heater 72 provided in a position opposite the exposed portion Ta of the tape around the wafer W.

[0065] According to the above cleaning method, in applications where drying is performed by slowing down the rotation speed of spinner table 50 or without rotation, it is possible to suppress the generation of particles caused by the rotation of spinner table 50, thereby suppressing recontamination of wafer W by particles and shortening the drying time. [Explanation of symbols]

[0066] 2 Processing equipment 5 Cutting unit 20 Holding table 21 Holding surface 22 Clamping mechanism 50 Spinner Table 51 Porous Plate 51a Holding surface 52 Frame 60 Cleaning Equipment 61 Case 61a Peripheral wall 61d Exhaust duct 62 Cover tube 63 Rotation axis 64 Cleaning Arm 64a nozzle 64m motor 65 supply units 67 Clamp 71 First Heater 72 Second Heater D Device Front annular frame T-tape U Frame Unit W wafer Wa surface Wb back side

Claims

1. a spinner table that can hold and rotate a workpiece; a housing that forms an internal space for accommodating the spinner table; a nozzle for supplying a cleaning liquid to the workpiece held on the spinner table; at least one heater for heating the atmosphere in the interior space; A cleaning device comprising:

2. The heater is a second heater disposed above the workpiece.

2. The cleaning device according to claim 1.

3. The workpiece is a plate-shaped wafer, The wafer is attached to a heat-shrinkable tape; the second heater is provided at a position facing the exposed portion of the tape around the periphery of the wafer; 3. The cleaning device according to claim 2.

4. The heater is a first heater provided on the inner surface of a peripheral wall that constitutes the housing.

2. The cleaning device according to claim 1.

5. The heater further includes a first heater provided on an inner surface of a peripheral wall that constitutes the housing.

4. The cleaning device according to claim 2 or 3.

6. Air can be blown from the nozzle toward the workpiece.

5. The cleaning device according to claim 4.

7. Air can be blown from the nozzle toward the workpiece.

6. The cleaning device according to claim 5.

8. The cleaning device according to claim 6 ; A processing device comprising: a processing unit that processes the workpiece, The processing device cleans the workpiece processed by the processing unit with the cleaning device.

9. The cleaning device according to claim 7; A processing device comprising: a processing unit that processes the workpiece, The processing device cleans the workpiece processed by the processing unit with the cleaning device.

10. a cleaning step in which the workpiece is held on a spinner table and the workpiece is cleaned by rotating the spinner table while supplying a cleaning liquid to the workpiece from a nozzle; a drying step of drying the workpiece by heating the atmosphere in the internal space of the housing that houses the spinner table with at least one heater after cleaning the workpiece; A cleaning method comprising:

11. The workpiece is a plate-shaped wafer, The wafer is attached to a heat-shrinkable tape; the heater is a second heater provided at a position facing the exposed portion of the tape around the periphery of the wafer; The cleaning method according to claim 10 .

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