JP2003133396A - Fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing tool suitable for a semiconductor wafer with reduced thickness. SOLUTION: A frame 1 is adapted to include a stopper portion 13 on the inside surface of a frame-shaped body section 11 and further to include a plurality of stop surface pedestals 14 provided on the upper surface of the stopper section 13. A heat sink 2 is adapted to include a plurality of protrusions 21. The numbers of the stop surface pedestals 14 and the protrusions 21 are set equal and are provided at positions respectively, such that when the heat sink 2 is mounted on the opening section of a window of the frame 1, the top surface pedestal 14 and the protrusions 22 are brought into abutment. A fixing tool is obtained by a combination of the frame 1 and the heat sink 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixture for mounting a semiconductor substrate on a vacuum vapor deposition apparatus or the like, and more particularly to a structure of the fixture improved to be suitable for manufacturing thin semiconductor wafers.

[0002]

2. Description of the Related Art When manufacturing a semiconductor device, various processes are performed on a semiconductor wafer, and when forming a metal film for an electrode on the surface of the semiconductor wafer, a vacuum deposition process is mainly performed. Most of the vacuum vapor deposition apparatuses currently used employ a method in which a semiconductor wafer is attached to a planetary dome installed in a processing chamber to perform vapor deposition processing. Here, the fixture for attaching the semiconductor wafer to the planetary dome has a structure as shown in FIG. 5 as an example. The fixture shown in FIG. 5 is made up of two parts, a frame 4 and a heat sink 5, which will be described below.

The main body 41 of the frame 4 is a ring-shaped frame. A locking portion 43 is continuously provided on the inner surface of the frame body 41, and
A flange 42 is continuously formed on the outer surface of 1. Here, one opening of the window of the frame 4 (hereinafter, referred to as a storage-side opening) is shaped so that the semiconductor wafer 3 can be fitted in and fitted therein. The other opening of the window (hereinafter referred to as the vapor deposition side opening) is narrower than the storage side opening due to the presence of the locking portion 43, and is approximately equal to the semiconductor wafer 3
The outer periphery of the is trimmed by a few millimeters. On the other hand, the main body 51 of the heat sink 5 is a flat plate having a plane shape substantially the same as the semiconductor wafer 3. Here, in the vicinity of the edge of one surface of the heat sink main body 51, an edge step 52 that slightly protrudes from the surface.
Are formed.

In the fixture made of such a combination of the frame 4 and the heat sink 5, the semiconductor wafer 3 is housed in the window of the frame 4 through the housing side opening, and then the housing side opening of the frame 4 window is covered. Heat sink 5
Put on. At this time, the outer edge portion of the semiconductor wafer 3 is sandwiched between the locking portion 43 and the edge step 52, so that the semiconductor wafer 3 is held in the window of the frame 4. The semiconductor wafer 3, the frame 4 and the heat sink 5 are attached to the planetary dome of the vacuum vapor deposition apparatus in a state where the semiconductor wafer 3 is accommodated in the window of the frame 4 and the accommodation side opening of the window is covered with the heat sink 5. To be

[0005]

In recent years, there has been a demand for thinner semiconductor wafers in order to reduce the manufacturing cost of semiconductor devices, or to reduce the size and height of semiconductor devices. However, even if the thickness of the semiconductor wafer is reduced, a number of new problems must be solved in order to actually manufacture a semiconductor device by using the thin wafer. When a thin semiconductor wafer is attached to a vacuum vapor deposition apparatus using a fixture having a structure as shown in FIG. 5 and vapor deposition processing is performed on the semiconductor wafer, specifically, the following problems occur. It was

During the vapor deposition process, the surface of the semiconductor wafer 3 is exposed to the evaporated metal and its temperature rises. In the fixture shown in FIG. 5, almost the entire outer edge of the semiconductor wafer 3 is sandwiched between the locking portion 43 and the edge step 52, and substantially the entire outer edge of the semiconductor wafer 3 contacts the edge step 52. To do. For this reason,
The heat generated in the semiconductor wafer 3 due to the temperature rise is conducted from the outer edge portion thereof to the heat sink 5 via the edge step 52. Here, the thinner the thickness of the semiconductor wafer 3, the less likely diffusion and conduction of heat on the wafer occurs. For this reason, in the thin semiconductor wafer 3, the temperature difference between the central portion and the outer edge portion becomes large, resulting in unevenness that cannot be overlooked in the vapor deposition amounts of the metal at the central portion and the outer edge portion.

During the vapor deposition process, the evaporated metal diffuses and attaches to various places. When the amount of evaporated metal is increased, the evaporated metal also enters the gap between the semiconductor wafer 3 and the locking portion 43 of the frame 4 and acts as an adhesive to act as an adhesive. The phenomenon of pasting often occurs. When the thickness of the semiconductor wafer 3 is thin, its mechanical strength is low. Therefore, even if a small amount of metal acts like an adhesive, the semiconductor wafer 3 will be damaged when the semiconductor wafer 3 is taken out from the frame 4. .

After the vapor deposition process, it is necessary to remove the heat sink 5 from the frame 4 and take out the semiconductor wafer 3. At this time, in the fixture having the structure shown in FIG. 5, when the heat sink 5 is lifted to remove it from the frame 4,
Due to the shapes of the frame 4 and the heat sink 5, a suction force due to a pressure difference is generated between the heat sink 5 and the semiconductor wafer 3. The suction force also lifts the semiconductor wafer 3 together with the heat sink 5. However, when the heat sink 5 is completely removed from the frame 4, air leaks into the space between the heat sink 5 and the semiconductor wafer 3, the suction force disappears, and the semiconductor wafer 3 falls. Then, the semiconductor wafer 3 having a small thickness and low mechanical strength is damaged by the impact when dropped.

Further, in the fixture shown in FIG. 5, the inner surface side of the frame main body 41 and the outer peripheral surface of the heat sink main body 51 are cut out substantially vertically. In such a structure,
If the heat sink 5 is not taken in and out perpendicularly to the opening on the storage side, the heat sink 5 may be caught in the middle and the heat sink 5 may not move. If a force is applied to push the heat sink 5 in here, the heat sink 5 suddenly starts moving at the moment the catch is removed, and the edge step 5
2 collides with the outer edge of the semiconductor wafer 3. Then, the outer edge of the thin semiconductor wafer 3 may be hit and broken by the impact at this time. Therefore, an object of the present invention is to solve the above problems and provide a fixture suitable for use in a thin semiconductor wafer.

[0010]

A fixture of the present invention for solving the above-mentioned problems is a frame-like body whose main body has a window inside, and which holds a semiconductor substrate on the inner surface of the main body. The semiconductor substrate is pressed between the pedestal and a frame in which a locking portion is formed and a plurality of pedestals are formed on the upper surface of the locking portion to separate the semiconductor substrate from the upper surface of the locking portion. And a heat sink attached to one opening of the window of the frame.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The fixture of the present invention is roughly composed of two parts, a frame and a heat sink.
The frame has a structure in which a locking portion is provided on the inner surface of a frame-shaped frame body and a plurality of pedestals are provided on the upper surface of the locking portion. On the other hand, the heat sink has a structure in which a plurality of protrusions are provided in the vicinity of the outer edge of the flat plate-shaped heat sink body. Here, it is assumed that the number of pedestals and the number of protrusions are the same, and that the semiconductor substrate is sandwiched between the pedestals and the protrusions when the heat sink is attached to the storage-side opening of the window of the frame, respectively. Then, the inner surface of the frame and the outer peripheral surface of the heat sink are tapered so as to be compatible with each other.

[0012]

EXAMPLE A fixture according to the invention is shown in FIGS. 1 is a partial cross section of the fixture, FIG. 2 is an outline view of a frame that constitutes the fixture, and FIG. 3 is an outline view of a heat sink that constitutes the fixture. In the frame 1 shown in FIGS. 1 and 2, a locking surface pedestal 14 is formed on the upper surface of the locking portion 13. Here, the plurality of locking surface pedestals 14 are provided so that the upper surface thereof slightly projects from the upper surface of the locking portion 13. Specifically, the locking surface pedestal 14 is the locking portion 1
It is formed by shaving the upper surface of 3. In addition,
The main body 11 is made of a ring-shaped frame, the locking portion 13 is continuously provided on the inner surface of the frame main body 11, and the flange 12 is continuously provided on the outer surface of the frame main body 11. The points provided are the same as the conventional ones.

In the frame 1 shown in FIGS. 1 and 2, a notch portion 15 having a depth at least a part of which reaches the upper surface of the engaging portion 13 is formed in a part of the frame body 11. The notch 15 is provided for inserting the tip of tools such as tweezers when the semiconductor wafer 3 is stored in the window of the frame 1 before the vapor deposition process or when the semiconductor wafer 3 is taken out from the frame 1 after the vapor deposition process. used. Also, when viewed in cross section, the inner surface of the frame body 11 is slightly inclined, so that the window of the frame 1 is tapered so that the opening on the storage side is wide and the opening on the deposition side is narrow. ing.

On the other hand, the heat sink 2 shown in FIGS.
Has a projection 22 at a position where it abuts on the locking surface pedestal 14 of the frame 1 when it is attached to the storage side opening of the frame 1. Here, the projections 22 are formed in the same number as the locking surface pedestals 14 so that their heads slightly project from the surface of the heat sink body 21. Specifically, the protrusion 22 is formed by embedding the pin 23 in the heat sink body 21. Also, when viewed in cross section, the outer peripheral surface of the heat sink body 21 is slightly inclined,
As a result, the heat sink 2 is tapered so as to match the inner surface of the frame body 11. The main body 21 is the same as the conventional one in that it is made of a flat plate having substantially the same plane shape as the semiconductor wafer 3.

In the fixture of the present invention in which the frame 1 and the heat sink 2 are combined, the outer edge portion of the semiconductor wafer 3 is sandwiched between the locking surface pedestal 14 and the protrusion 22, so that the window of the frame 1 is closed. The semiconductor wafer 3 is held therein. At this time, the semiconductor wafer 3 and the protrusions 22 are in point contact with each other, and the amount of heat conducted from the semiconductor wafer 3 to the heat sink 2 during the vapor deposition process is small. As a result, the temperature difference between the central portion and the outer edge portion of the semiconductor wafer 3 becomes small, and the metal deposition amounts of the central portion and the outer edge portion can be made substantially uniform.

Further, in the fixture of the present invention, the projections 22 are formed in places.
With the structure provided with, air can easily leak and enter the space between the heat sink 2 and the semiconductor wafer 3. For this reason,
When the heat sink 2 is lifted to be removed from the frame 1 after the vapor deposition process, the semiconductor wafer 3 is prevented from being lifted together with the heat sink 2. Further, in the fixture of the present invention, the window (inner surface) of the frame 1 and the taper provided on the outer periphery of the heat sink 2 are unlikely to be caught when the heat sink 2 is taken in and out. This is also advantageous in preventing damage to the semiconductor wafer 3 and improving workability when the heat sink 2 is taken in and out.

By the way, in the fixture according to the present invention, the metal evaporated from the three directions may enter into the gap between the contact surface pedestal 14 and the contact surface of the semiconductor wafer 3. For this reason,
It seems that the fixture of the present invention is more likely than the conventional fixture to stick the semiconductor wafer 3 to the frame 1 due to the vapor-deposited metal. However, when an experiment is performed by actually increasing the amount of evaporated metal, the phenomenon of the semiconductor wafer 3 sticking to the frame 1 and being unable to be removed is less likely to occur in the fixture of the present invention than in the conventional fixture. Although the process is not clear, from the results of various experiments, the contact area between the heat sink 2 and the semiconductor wafer 3 is small,
It is almost certain that it is related that the locking surface pedestal 14 and the protrusions 22 are arranged in a dispersed manner.

Since the fixture of the present invention shown in FIGS. 1 to 3 described above assumes a semiconductor wafer to be processed, the frame has a ring shape and the heat sink has a disk shape. However, the fixture of the present invention can also be applied to a fixture used when performing vacuum deposition processing on a semiconductor substrate for a display panel, for example. In this case, since the display panel is usually rectangular, the fixture is composed of the frame 6 having a rectangular frame shape and the heat sink 7 having a rectangular plate shape. Although detailed description of the structure is omitted, specifically, the outer shapes of the frame and the heat sink in such a case are as shown in FIG.

In the description of the embodiment of the fixture according to the present invention shown in FIGS. 1 to 3, the number of the projections provided on the locking surface pedestal provided on the frame and the number of projections provided on the heat sink are nine, respectively. It is convenient to increase the number of locking surface pedestals and protrusions in terms of dispersing the stress applied to the semiconductor wafer when fixing the semiconductor wafer. Considering the strength of the wafer, the number of locking surface pedestals and protrusions is preferably at least five, and practically six or more. (However, if too many locking surface pedestals and protrusions are used, the temperature difference between the central portion and the outer edge portion of the semiconductor wafer will increase, which may cause uneven metal deposition amount. There is a need.)

[0020]

As described above, the fixture according to the present invention is used in combination with the frame having a plurality of pedestals formed on the upper surface of the engaging portion and the heat sink having the protrusion formed at a predetermined position. Here, the number of pedestals and the number of protrusions are the same, and each of them is provided at a position where the pedestal and the protrusions come into contact with each other when the heat sink is attached to the storage side opening of the frame. With such a structural characteristic portion, it is possible to reduce the temperature difference between the central portion and the outer edge portion during the vapor deposition process, and it is possible to make the vapor deposition amounts of the metal in the central portion and the outer edge portion substantially uniform.

Further, it is possible to prevent the semiconductor wafer from being lifted up together with the heat sink due to the shape of the heat sink. Further, it is possible to reduce the possibility of the semiconductor wafer sticking to the frame due to the adhesive action of the evaporated metal. Then, by adding a configuration in which the frame and the heat sink are tapered, it is possible to prevent the heat sink 2 from being caught when the heat sink 2 is taken in and out. That is, it is possible to reduce the chance that the semiconductor wafer will be damaged. Therefore, according to the present invention, it is possible to provide a fixture suitable for use on a thin semiconductor wafer.

[Brief description of drawings]

1 is a partial cross-sectional view of a fixture according to the present invention.

FIG. 2 is an external view of a frame that constitutes a fixture according to the present invention.

FIG. 3 is an external view of a heat sink that constitutes a fixture according to the present invention.

FIG. 4 is an outline view of a fixture according to another embodiment of the present invention.

FIG. 5 shows a conventional fixture.

[Explanation of symbols]

1: Frame 2: Heat Sink 3: Semiconductor Wafer 11: Frame Main Body 12: Flange 13: Locking Part 14: Locking Surface Pedestal (Pedestal)
15: Notch 21: Heat sink body
22: Protrusion 23: Pin

Continued front page    F-term (reference) 4K029 AA06 BD01 CA01 EA08 JA01                       JA05                 4M104 DD34 HH20                 5F031 CA02 DA01 HA03 HA08 HA09                       HA24 MA29 PA08 PA11 PA20

Claims (3)

[Claims] 1. A fixture for attaching a semiconductor substrate to a processing apparatus such as vacuum deposition, the main body of which has a frame shape having a window inside, and which holds the semiconductor substrate on an inner surface of the main body. A locking part for
A frame in which a plurality of pedestals are formed on the upper surface of the locking portion to separate the semiconductor substrate from the upper surface of the locking portion, and a plurality of frames for pressing the semiconductor substrate between the pedestal and the frame. And a heat sink attached to one opening of the window of the frame. 2. The main body of the heat sink is formed of a flat plate having substantially the same shape as the semiconductor substrate, and the protrusion is formed by a pin embedded near the outer edge of the main body of the heat sink so that its tip projects. The fixing device according to claim 1, wherein the fixing device is provided. 3. The fixture according to claim 1, wherein the inner surface of the frame and the outer peripheral surface of the heat sink are tapered so as to be compatible with each other.