Vertical wafer sawing apparatus

Details Vertical wafer sawing apparatus Vertical wafer sawing apparatus

2001-10-09

2003-12-16

Nguyen, George (Department: 3723)

Stone working

Sawing

C125S013010, C438S462000

Reexamination Certificate

active

06662799

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for manufacturing semiconductor devices and, more particularly, to a wafer sawing apparatus for separating a wafer into individual semiconductor chips.
2. Description of the Related Arts
After a well-known wafer fabrication process is performed a semiconductor wafer is cut and separated into individual semiconductor chips by a wafer sawing apparatus. The wafer sawing apparatus mostly uses a scribing blade as a cutter. Alternatively, a laser cutter may be used. The scribing blade rotates at high speed, and scribes the wafer along scribe lines. Therefore, the wafer is divided into a plurality of separate individual dices.
FIG. 1
is a plan view showing a conventional wafer sawing apparatus.
FIG. 2
is a front view showing the conventional wafer sawing apparatus.
Referring to FIG.
1
and
FIG. 2
, a conventional wafer sawing apparatus
300
has a chuck table, on which a wafer
10
is fixedly mounted, and a scribing blade
321
which cuts the wafer
10
along scribe lines
13
in order to divide the wafer
10
into chips
11
. The wafer sawing apparatus
200
further has a loader
330
in which a wafer cassette
20
containing the wafers
10
is placed, and transporters
340
and
350
, which transfer the wafer
10
between the chuck table
311
and the wafer cassette
20
.
As discussed, the wafer sawing apparatus
300
includes the first transporter
340
which puts the wafer
10
into the wafer cassette
20
or takes the wafer
10
out of the wafer cassette
20
, and the second transporter
350
which rotates the wafer
10
at a predetermined angle and transfers the wafer
10
to the chuck table
311
.
During the wafer sawing processing, the wafer
10
is being supported to a wafer ring
17
by an adhesive tape
15
, which is attached to the backside of both the wafer
10
and the ring
17
.
In the conventional wafer sawing apparatus
300
, the first transporter
340
takes out the wafer
10
from the wafer cassette
20
placed on the loader
330
, then the second transporter
350
transfers the wafer
10
to the chuck table
311
. At this time, the second transporter
350
horizontally rotates the wafer
10
.
Additionally, the first and second transporters
340
,
350
have vacuum suction holes to affix the wafer
10
by vacuum suction force. The wafer
10
is stuck to the chuck table
311
by vacuum suction force. After affixing the wafer
10
to the chuck table
311
, the scribing blade
321
cuts the wafer
10
along scribe lines so that the wafer
10
is separated into individual semiconductor chips
11
.
The scribing blade
321
is rotated by a driving motor
323
and moved either in a direction of the y-axis by a y-axis driver
317
or in a direction of the z-axis by a z-axis driver
319
. On the other hand, the chuck table
311
is moved in a direction of the x-axis by an x-axis driver
315
. Herein, while the x-axis and the y-axis run are parallel to the ground, the z-axis runs perpendicular to the ground. In addition, the x-axis is perpendicular to the y-axis.
During scribing, silicon particles are produced as the scribing blade
321
abrades a surface of the wafer
10
. These silicon particles may remain on the wafer
10
and cause defects in subsequent manufacturing processes. Therefore, the wafer sawing apparatus
300
has a spray nozzle
325
positioned on a side of the scribing blade
321
to spray a washing solution onto the scribing blade
321
and a top surface of the wafer
10
. However, a cleaning operation by the washing solution still has limitations in effectively cleaning the wafer.
One of the approaches designed to overcome the limitations of using washing solution alone is disclosed in Japanese laid-open patent application No. 4-348546. The wafer sawing apparatus presented there is illustrated in FIG.
3
. As shown in
FIG. 3
, the wafer sawing apparatus
400
has a revolving chuck table
411
on which a wafer
10
is mounted and to which a cylinder
417
is connected by a revolving unit
415
. To effectively remove silicon particles, the cylinder
417
takes up the revolving chuck table
411
and thus the wafer
10
is positioned vertically. The scribing blade
421
is maneuverable along the x, y, and z axes, thereby controlling the sawing depth of the wafer
10
. While the x-axis and the y-axis are parallel to the ground, the z-axis is perpendicular to the ground. In addition, the x-axis is perpendicular to the y-axis.
The conventional wafer sawing apparatus, including the wafer sawing apparatus shown in
FIG. 3
, has a drawback in that the chuck table occupies a relatively greater space since the chuck table lies horizontally. Therefore, the entire size of the wafer sawing apparatus becomes larger. Such a drawback becomes more serious if the wafer increases in size. For example, in the case of using 200-mm-diameter wafers (namely, 8-inch wafers), the wafer sawing apparatus covers an area of about 1.58 square meters (1.35 m′ 1.17 m). In case of 300-mm-diameter wafers (namely, 12-inch wafers), the area of the wafer sawing apparatus increases about 2.55 square meters (1.82 m ′ 1.4 m).
Consequently, there is a need for a wafer sawing apparatus that occupies a smaller space and removes contaminants such as silicon scraps and dust more efficiently.
SUMMARY OF THE INVENTION
A wafer sawing apparatus that has a smaller “footprint” than those of the prior art is provided. Also, a wafer sawing apparatus that can effectively remove silicon scraps and dust produced during the sawing process is provided.
In accordance with the preferred embodiment of the present invention, the wafer sawing apparatus comprises a vertical chuck table, which has a first surface to hold a wafer and a second surface connected to a driving member. The first and second surfaces of the chuck table are disposed substantially vertically to a support surface for the chuck table. The wafer sawing apparatus further includes a scribing member that moves perpendicular to the front surface of the wafer or the chuck table and separates the wafer into individual semiconductor chips. The apparatus further provides transporting members that transfer the wafer, and the wafer is then fixedly supported relative to the chuck table by the transporting members in an upright position.
The vertical chuck table or the scribing member is movable along the x, y or z-axis. Here, the direction of x-axis runs perpendicular to the wafer stage and parallel to the ground or the support surface for the chuck table, direction of y-axis runs parallel to the wafer stage and parallel to the ground, and direction of z-axis runs parallel to the wafer stage and perpendicular to the ground. Additionally, the scribing member may comprise one or more laser cutters or one or more scribing blades rotated by a driving motor, so that the scribing blade runs parallel to the ground or vertical to the ground.
As a result, the set-up dimensions of the apparatus can be decreased even as wafer size increases. Further, contaminants such as silicon scraps and dust on the wafer can be efficiently removed during the wafer sawing process.


REFERENCES:
patent: 04348546 (1992-12-01), None

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