KR101739975B1

KR101739975B1 - Wafer supporting plate and method for using wafer supporting plate

Info

Publication number: KR101739975B1
Application number: KR1020110109778A
Authority: KR
Inventors: 가즈마 세키야
Original assignee: 가부시기가이샤 디스코
Priority date: 2010-10-29
Filing date: 2011-10-26
Publication date: 2017-05-25
Also published as: CN102468207A; CN102468207B; KR20120046034A; TW201250922A; TWI534953B; JP5686570B2; JP2012094793A

Abstract

[PROBLEMS] To provide a wafer holding plate capable of half cutting a wafer without using a dicing tape.
A wafer supporting plate for supporting and carrying a wafer, comprising: a wafer supporting portion formed as a circular concave portion for receiving and supporting a wafer; a plurality of through holes formed in the bottom of the circular concave portion; And a frame portion to which the conveying means of the apparatus is operated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a wafer supporting plate,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer support plate for supporting and transporting a wafer and a method of using the same.

For example, in a semiconductor device manufacturing process, devices such as ICs and LSIs are formed in respective regions partitioned by streets (lines to be divided) formed in a lattice shape on the surface of a semiconductor wafer which is substantially in a disk shape, Each device is manufactured by dividing each formed region along a line to be divided.

BACKGROUND OF THE INVENTION As a dividing device for dividing a semiconductor wafer into individual devices, a cutting device, generally called a dicing device, is used. The cutting device has a cutting blade having a very thin cutting edge, And the wafer is divided into individual devices. Devices thus divided are packaged and widely used in electric devices such as cellular phones and PCs.

BACKGROUND ART [0002] In recent years, electric devices such as cellular phones and PCs are required to be lighter and more compact, and thinner devices are required. As a technique for dividing a wafer into thinner devices, a dividing technique called a so-called prior dicing method has been developed and put into practical use (see, for example, Japanese Patent Application Laid-Open No. 11-40520).

In this deding method, dividing grooves having a predetermined depth (depth corresponding to the finish thickness of the device) are formed along the line to be divided from the surface of the semiconductor wafer, and thereafter, the back surface of the semiconductor wafer, And dividing the wafer into individual devices by exposing the dividing grooves on the back surface. It is possible to process the thickness of the device to 50 m or less.

In the dedinging method, since the wafer is not cut completely but half cut, it is not necessary to use a dicing tape used for full cutting, and a dedicated cutting apparatus for performing half cut to save the dicing tape is applied to the present applicant (See Japanese Patent Application Laid-Open No. 2004-235622).

Patent Document 1: JP-A-11-40520 Patent Document 2: Japanese Patent Application Laid-Open No. 2004-235622 Patent Document 3: Japanese Patent Application Laid-Open No. 2005-166969

However, the half-cut exclusive cutting apparatus disclosed in Patent Document 2 has no general versatility, and when half cut is not performed, there is a problem that the operation is interrupted and the productivity is poor. On the other hand, if the wafer is supported by the annular frame via the dicing tape, it is possible to perform half cut using a general dicing tape, but the use of a dicing tape is required, which is a problem in that it is uneconomical.

SUMMARY OF THE INVENTION The present invention has been made in view of this point, and an object thereof is to provide a wafer supporting plate which does not need to use a dicing tape when half-cutting a wafer, and a method of using the same.

According to a first aspect of the present invention, there is provided a wafer support plate for supporting and transporting a wafer, comprising: a wafer support portion formed as a circular concave portion for receiving and supporting a wafer; a plurality of through holes formed in the bottom of the circular recess; And a frame portion surrounding the support portion and on which the conveying means of the processing apparatus is operated.

Preferably, a slip-resistant sheet is formed on the bottom of the circular concave portion.

According to a third aspect of the present invention, there is provided a chuck table comprising a chuck table including a holding surface on which a suction force for holding a wafer acts, processing means for performing predetermined processing on the wafer held on the chuck table, 1. A method of using a wafer support plate according to claim 1 or 2 in a processing apparatus including a transfer means and a second transfer means for transferring a wafer from the chuck table, A wafer transfer step of transferring the wafer to the holding surface of the chuck table by the action of the first transfer means; and a transferring step of transferring the wafer to the holding surface of the chuck table through the plurality of through holes formed in the bottom of the circular concave portion, A holding step of sucking and holding the wafer, And a second transfer means for transferring the wafer from the chuck table to the frame portion of the wafer support plate and releasing the suction force acting on the holding surface of the chuck table to transfer the wafer from the chuck table And a wafer transfer step of transferring the wafer to and from the wafer transfer apparatus.

Preferably, the depth of the circular concave portion of the wafer support plate is set to be shallower than the distance from the bottom of the cut groove formed in the wafer to the back surface of the wafer.

By supporting the wafer with the wafer support plate of the present invention, the wafer can be half-cut using a general dicing apparatus without using a dicing tape, even if a dedicated cutting apparatus for half cut is not used, which is economical. Further, the wafer support plate of the present invention can be used repeatedly and is economical.

The present invention also relates to a laser processing apparatus for irradiating a wafer with a laser beam of a wavelength having an absorption property to a wafer and performing ablation processing to form a dividing groove, It is possible to use the wafer supporting plate of the present invention and it is economical to avoid the use of the dicing tape in the laser processing apparatus for forming the modified layer inside the wafer by being condensed and irradiated inside.

1 is an external perspective view of a cutting apparatus.
2 is an exploded perspective view showing a state in which a wafer is supported by a wafer support plate according to an embodiment of the present invention.
3 is a perspective view of the wafer supported by the wafer support plate.
4 is a longitudinal sectional view of the wafer supporting plate.
5 is a perspective view showing a state in which a wafer supported by a wafer support plate is cut.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown an external perspective view of a cutting apparatus 2 capable of half-cutting a wafer using the wafer support plate of the present invention.

On the front surface side of the cutting apparatus 2, an operation means 4 for inputting an instruction to a device such as a machining condition is provided by the operator. On the upper part of the apparatus, there is provided a display means 6 such as a CRT for displaying an image picked up by a guidance screen for the operator or an image pickup means described later.

As shown in Figs. 2 and 3, a first street (line to be divided S1) and a second street (line to be divided S2) are formed orthogonally on the surface of the device wafer W to be diced, A plurality of devices D are formed on the wafer W by the first streets S1 and the second streets S2. 11 is a notch as a mark indicating the crystal orientation of the silicon wafer W.

2, an exploded perspective view showing a state in which the wafer W is supported by the wafer support plate 30 of the embodiment of the present invention is shown. The wafer support plate 30 has a circular concave portion 32 having a diameter slightly larger than the diameter of the wafer W and a plurality of through holes 34 are formed in the bottom of the circular concave portion 32 . A protrusion 31 fitted to the notch 11 of the wafer W facing the circular concave portion 32 is formed.

The wafer support plate 30 has a frame portion 33 surrounding the circular recess 32. The transfer means of the cutting device 2 acts on the frame portion 33 to move the wafer support plate 30 Return. The wafer support plate 30 is preferably formed of a resin, but may be formed of a metal such as aluminum.

The depth of the circular concave portion 32 is equal to the distance from the bottom of the cut groove formed in the wafer W to the back surface of the wafer W because the wafer support plate 30 is used for half cutting the wafer W. [ Is set to a slightly shallower depth. For example, when the thickness of the wafer W is 700 占 퐉 and the depth of the cut groove is 100 占 퐉, the depth of the circular concave portion 32 is set to be shallower than 600 占 퐉, for example, 500 占 퐉.

The circular concave portion 32 is a wafer supporting portion for supporting the wafer W. The protrusion 31 of the wafer supporting plate 30 is fitted to the notch 11 of the wafer W, Is inserted into the circular concave portion 32 is shown in Fig. Preferably, a slip-resistant sheet 36 is formed on the bottom of the circular concave portion 32 for supporting the wafer, as shown in the longitudinal sectional view of Fig.

A plurality of through holes 37 communicating with the through holes 34 are formed in the non-slip sheet 36 as well. The slip prevention sheet 36 is formed on the bottom of the circular concave portion 32 serving as the wafer supporting portion so that the wafer W is supported by the wafer supporting plate 30 so that the wafer W is transferred to the circular concave portion 32 Is prevented.

Referring again to FIG. 1, a plurality of wafers W supported by the wafer support plate 30 are accommodated in the wafer cassette 8. The wafer cassette 8 is disposed on the cassette elevator 9 which is movable up and down.

A loading and unloading means 10 is provided at the rear of the wafer cassette 8 for taking out the wafer W before cutting from the wafer cassette 8 and for feeding the wafer after the cutting into the wafer cassette 8.

A provisional placement region 12 is formed between the wafer cassette 8 and the carry-in and carry-out means 10 as a region in which the wafer W to be carried in and out is temporarily placed. In the provisional placement region 12, W are positioned at a predetermined position.

A transfer means 16 having a swing arm for sucking and transporting the frame portion 33 of the wafer support plate 30 supporting the wafer W is provided in the vicinity of the temporary placement region 12, The wafer W taken out to the region 12 is sucked by the transfer means 16 and transferred onto the chuck table 18 and sucked on the holding surface of the chuck table 18, ) On the chuck table 18 by fixing the frame portion 33 of the wafer supporting plate 30. [

The chuck table 18 is rotatably and reciprocally movable in the X-axis direction. On the upper side of the movement path of the chuck table 18 in the X-axis direction, a street to be cut of the wafer W is detected And an alignment means 20 is provided.

The alignment means 20 includes an image pickup means 22 for picking up an image of the surface of the wafer W. The alignment means 20 can detect a street to be cut by processing such as pattern matching on the basis of an image obtained by image pickup have. The image acquired by the imaging means 22 is displayed on the display means 6. [

On the left side of the alignment means 20, a cutting means 24 for cutting the wafer W held by the chuck table 18 is provided. The cutting means 24 is integrally formed with the alignment means 20 so that they move in the Y-axis direction and the Z-axis direction in cooperation with each other.

The cutting means 24 is constituted by mounting a cutting blade 28 at the tip of a rotatable spindle 26 and is movable in the Y-axis direction and the Z-axis direction. The cutting blade 28 is located on the extension line of the imaging means 22 in the X-axis direction.

The cut wafer W is taken out of the chuck table 18 by the conveying means 25 and conveyed to the spinner cleaning apparatus 27 and spin-cleaned and spin-dried in the spinner cleaning apparatus 27.

Next, a method of using the wafer support plate 30 of the embodiment of the present invention constructed as described above will be described. The wafer support plate is used in such a manner that the transfer means 16 for transferring the wafer W to the frame portion 33 of the wafer support plate 30 on which the wafer W is received and supported acts, A wafer carrying step of carrying a wafer W to the holding surface of the wafer holding plate 30 by applying a suction force to the holding surface of the chuck table 18 to form a plurality of through holes 32 formed in the bottom of the circular concave portion 32 of the wafer holding plate 30 And a holding step of sucking and holding the wafer W through the holding member 34.

After the wafer W is sucked and held by the chuck table 18 via the wafer support plate 30 as described above, a cutting step of cutting the wafer W by the cutting means (processing means) 24 is performed . This cutting process will be described with reference to Fig.

Referring to FIG. 5, there is shown a perspective view of the wafer W supported on the wafer support plate 30 by the cutting means 24 being cut along the street. Reference numeral 25 denotes a spindle housing of the cutting means 24 and a spindle 26 rotatably driven by a servomotor (not shown) is rotatably received in the spindle housing 25. The cutting blade 28 is an electroforming blade, and has a cutting edge 28a formed at its outer periphery with a diamond abrasive grain dispersed in the nickel base material.

40 is a blade cover covering the cutting blade 28. A cutting water nozzle and a cutting water not shown extend along the side surface of the cutting blade 28 and the cutting edge 28a of the cutting blade 28 and the cutter blade 28 A cutting water spray nozzle 46 for spraying water onto the contact area of the nozzle plate 46 is attached.

Cutting water from the cutting water supply unit 44 is supplied to a cutoff nozzle not shown through the pipe 42 and supplied to the cutoff water injection nozzle 46 through the pipe 48. The cutting water is pressurized at the cutting water supply part 44, for example, at about 0.3 MPa, and is blown at a flow rate of 1.6 to 20 liters per minute from the cutting water injection nozzle 46.

A detachable cover 50 is detachably attached to the blade cover 40 by a screw 52. The detachable cover 50 has a cutting water nozzle 54 extending along the side of the cutting blade 28 and the cutting water is supplied to the cutting water nozzle 54 through the pipe 56.

Reference numeral 60 denotes a blade detection block incorporating a blade sensor for detecting the rim or abrasion of the cutting edge 28a of the cutting blade 28. The blade detection block 60 is detachably attached to the blade cover 40 by a screw 62. [ The blade detection block 60 has an adjusting screw 64 for adjusting the position of the blade sensor.

Before cutting the wafer W supported on the wafer support plate 30 along the streets S1 and S2, the streets S1 and S2 to be cut and the cutting blades 28 ).

After the alignment, the first street S1 and the cutting blade 28 are aligned to move the chuck table 18 in the X-axis direction indicated by the arrow X in Fig. 5, and the cutting blade 28 is moved in the direction of arrow A The cutting means 24 is lowered while rotating at a high speed (for example, 30000 rpm) in the direction of the first street S1 to form a dividing groove of a predetermined depth (depth corresponding to the finishing thickness of the device) .

The depth of the dividing groove is set to a depth not exceeding the upper surface of the frame portion 33 of the wafer support plate 30, for example, 100 占 퐉. As described above, the wafer W is half-cut by the cutting blade 28, so that the dividing groove of a predetermined depth can be formed without damaging the wafer supporting plate 30. [

The first streets S1 are all cut by half while the indexing of the cutting means 24 is performed in the Y axis direction by the street pitch stored in the memory, thereby forming the same dividing grooves. When the chuck table 18 is rotated by 90 degrees and then the same cutting is performed as described above, the second streets S2 are all half-cut to form the same dividing grooves.

After the suction process of the chuck table 18 is released after the processing of half cutting all the streets S1 and S2 as described above, the suction portion of the transfer means 25 is moved to the frame portion 33 of the wafer support plate 30, The wafer support plate 30 is suction held and transported to the spinner cleaning apparatus 27 and the wafer W is spin-cleaned and spin-dried by the spinner cleaning apparatus 27. [

Then, after the protective tape is adhered to the surface of the wafer W, the back surface of the wafer having the dividing grooves formed thereon is ground by the back grinding process using the grinding apparatus to expose the dividing grooves on the back surface, Can be divided into individual devices (D).

According to the embodiment of the present invention described above, the wafer W is supported by the wafer support plate 30, so that even if a dedicated cutting apparatus for performing half cut is not used, a general dicing apparatus is used and a dicing tape It is possible to half cut the wafer W without using the wafer W, which is very economical. Further, the wafer support plate 30 can be used repeatedly, which is economical.

Although the wafer support plate 30 of the present invention is applied to the cutting apparatus 2 in the above embodiment, the wafer support plate 30 of the present invention is not limited to this use method, And a laser beam of a wavelength having a transmittance to the wafer W is irradiated onto the wafer W by a laser processing apparatus for irradiating the surface of the wafer W with a laser beam having a water absorbing property to the wafer W, ), And forming a modified layer in the inside of the wafer.

2: Cutting device 18: Chuck table
24: cutting means 28: cutting blade
30: Wafer support plate 32: Circular concave (wafer support)
33: frame part 34: through hole

Claims

A chuck table including a holding surface on which a suction force for holding a wafer is applied; processing means for performing predetermined processing on the wafer held on the chuck table; first transfer means for transferring the wafer to the chuck table; A method of using a wafer support plate for supporting and carrying a wafer, which is used in a processing apparatus including a second transfer means for transferring a wafer from a table,
Wherein the wafer support plate comprises a wafer support portion formed as a circular recess and adapted to receive and support a wafer, a plurality of through holes formed in the bottom of the circular recess, and a plurality of through holes formed in the bottom of the circular recess, And a frame portion on which two conveying means are operated,
Wherein the processing means comprises a cutting means including a cutting blade for performing a cutting process on the wafer,
A wafer carrying step of bringing the wafer into the holding surface of the chuck table by the first carrying means acting on the frame portion of the wafer holding plate in which the wafer is housed,
A holding step of applying a suction force to the holding surface of the chuck table to suck and hold the wafer through the plurality of through holes formed in the bottom of the circular concave portion,
A processing step of forming a cutting groove in the wafer supported by the wafer supporting plate by the processing means,
A wafer carrying-out step of taking out the wafer from the chuck table by releasing the suction force acting on the holding surface of the chuck table, by operating the second carrying means for carrying the wafer from the chuck table to the frame part of the wafer holding plate,
&Lt; / RTI >

The method of claim 1, wherein a slip-resistant sheet is disposed on the bottom of the circular recess.

The method of claim 1 or 2, wherein the depth of the circular recess of the wafer support plate is shallower than the distance from the bottom of the cut groove formed in the wafer to the backside of the wafer.

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