JPH07106287A - Method of automatically peeling slice base - Google Patents

Abstract

PURPOSE:To enable excellent slice base peeling, by detecting the load at the time of press peeling of a slice base, and controlling the temperature in a water tank according to the detected load. CONSTITUTION:After a sliced semiconductor wafer 100 to which a slice base 200 is bonded is dipped in a hot water tank 10, the slice base is peeled. In this method, the load at the time of press peeling is measured with a load sensor 1 installed on a peeling cutter 4. When the load exceeds the upper limit of a previously set load range, the water temperature in the hot water tank 10 is raised by increasing the temperature of a heater unit 12 which supplies hot water to the tank 10. When the load falls short of the lower limit of the set load range, the water temperature in the tank 10 is reduced by supplying pure water from a water feeding pipe 15 by opening a valve 13. Thereby the slice base peeling from a wafer is stably enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slice-based automatic peeling method for adhering a semiconductor wafer sliced from a semiconductor ingot.

[0002]

2. Description of the Related Art Semiconductor wafers (hereinafter simply referred to as "wafers") used for manufacturing semiconductor devices are, for example, compound semiconductor wafers of silicon, GaAs, GaSb, InP, InAs, etc., and these wafers are shown in FIG. As described above, the slice base 200 is sliced together with the slice base 200 by the slicer in a state where the carbon slice base 200 is adhered to the side wall of the rod-shaped semiconductor ingot 101 with the semiconductor (epoxy) adhesive.

Therefore, the sliced wafer 100 is
Have the slice bases 200 sliced together bonded together. The slice base is used to fix the ingot to the slicer when slicing the wafer from the ingot, and to prevent cracks (chipping etc.) of the ingot at the end of the slice.

The method for peeling off the slice base 200 is as follows.
The wafer 100 in which 00 is still adhered is dipped, the adhesive is softened, and the slice base 200 is peeled off.

There is a slice base automatic peeling device that automates the peeling work of the slice base 200. In the conventional slice base automatic peeling method using this device, as shown in FIG. 5, the slice base 200 remains bonded. Wafer 100 is immersed in a hot water tank 10 that maintains a water temperature of a constant temperature within a range of about 80 to 95 ° C. to soften the adhesive adhered to the slice base 200 and the wafer 100, and take out from the hot water tank 10. The wafer 100 is sandwiched between the lower support member 2 and the movable upper support member 3, and the slice base 200 is pressed by the peeling cutter 4 to peel the slice base 200 from the wafer 100.

[0006]

However, the method of adhering the wafer and the slice base differs depending on the amount of adhesive applied to the ingot, the temperature and humidity of the surrounding environment, and the like.

Therefore, in the conventional slice-based automatic peeling method, the water temperature during immersion in hot water is constant,
The adhesive softens differently depending on the ingot even at the same temperature, and depending on the ingot, such as when the slice base easily peels from the wafer or when it does not easily peel. In the case of easy peeling, the slice base is removed during warm water immersion and floats and moves in warm water, so there is a risk of scratching the wafer, while if it is difficult to peel off, when pressing with a peeling cutter. In addition, there is a problem that the slice base is not peeled off, and if it is bad, the wafer is broken.

Therefore, an object of the present invention is to adjust the water temperature in the hot water tank for softening the adhesive agent that attaches the wafer and the slice base to an appropriate value according to the adhesive force of the adhesive agent between the wafer and the slice base. By controlling the temperature,
An object of the present invention is to provide a slice-based automatic peeling method that enables good slice-based peeling.

[0009]

Means for Solving the Problems The present invention for solving the above-mentioned object is to provide a semiconductor wafer (100) sliced in a state where a slice base (200) is bonded by an adhesive,
Immerse in the hot water tank (10) to which hot water is supplied,
0) After immersion, the semiconductor wafer (100) taken out from the hot water tank (10) is attached to the slice base by a supporting member (2, 3).
In the slice base automatic peeling method, the (200) portion is fixed in a state of protruding from the supporting member (2, 3), and the slice base (200) is peeled by pressing with a pressing tool (4). (4) Load detecting means for detecting the load when the pressing tool (4) presses the slice base (200)
(1) is provided, when the load when pressing the slice base (200) obtained by the load detection means (1) exceeds the upper limit of the preset load range, the hot water tank (10 ), The water temperature in the hot water tank (10) is lowered when the water temperature is lower than the lower limit of the load range.

[0010]

According to the present invention configured as described above, the load at the time of pressing and peeling the slice base is detected by the load detecting means provided in the pressing portion, and the detected load is the upper limit of the preset load range. If it exceeds, increase the water temperature in the hot water tank, and if it is less than the set load range,
By lowering the water temperature, the optimum temperature for softening the adhesive that bonds the wafer and the slice base is obtained.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, an automatic peeling apparatus for carrying out the slice-based automatic peeling method of the present invention will be described.

FIG. 1 is a perspective view for explaining the structure of a slice-based automatic peeling apparatus.

The main components of this slice base automatic peeling apparatus are a hot water tank 10 for immersing the wafer with the slice base still adhered thereto, and an elevation mechanism for taking in and out the cassette 50 in which the wafer is loaded. 20 and a pusher 60 that pushes the wafer out of the cassette 50 loaded with the wafer pulled up from the hot water tank and sets it in a fixed position on the lower support member 2 described later,
A lower support member 2 for sandwiching and fixing a wafer, a movable upper support member 3, and a peeling cutter 4 which is a pressing tool. A load sensor 1 which is a load detecting means is attached to the peeling cutter 4. The load value at the time of pressure peeling is measured, and the measured load value is sent to the water temperature controller described later through the signal line 20.

As shown in FIG. 2, the hot water tank 10 is provided with hot water from a heater unit 12 and water from a water supply pipe 15 which will be described later, by a hot water supply tank 16 provided in the lower portion, and drained water by an upper drain pipe 17. It is an overflow type water tank that has a temperature sensor 1 for monitoring the temperature of hot water inside.
1 is provided. The heater unit 12 for supplying hot water is supplied with pure water from the water supply pipe 14, and heats the water to 80 to 95 ° C. to supply the hot water to the hot water tank 10.
Supplied by. Further, the hot water supply tank 16 includes the hot water tank 10
A water supply pipe 15 for lowering the water temperature inside is provided, and pure water is appropriately supplied by a valve 13 to lower the temperature of the hot water. In the temperature sensor 11, the measured temperature is connected to a water temperature controller described later by a signal line 18 and is constantly monitored, and the valve 13 is connected to a valve controller described later by a signal line 19 from the water temperature controller as appropriate. The flow rate is adjusted by opening and closing by the signal of.

The elevation mechanism 20 for loading / unloading the cassette 50 loaded with wafers into / from the hot water tank 10 is
The cassette base 22 supported by the arm portion 21
By moving up and down by the movement of the arm supporting portion 23 that supports the arm portion 21, it is moved in and out of the hot water tank 10. The operation of the arm support 23 is transmitted by the power of the motor 24 to the ball screw 26 by the belt 25, and the arm support 23 moves up and down by the rotation of the ball screw 26.

The pusher 60 pushes the wafers loaded in the cassette 50 pulled up from the hot water tank 10 by the cylinder 61 from the rear (left in the figure),
The portion of the slice base 200 adhered to the wafer 100 is set at a position where it projects from the lower support member 2.

The wafer 100 set at a fixed position on the lower support member 2 has the upper support member 3 as shown in FIG.
Therefore, the slice base 200 is sandwiched and pressed by the peeling cutter 4 to be peeled off. The upper support member 3
And the peeling cutter 4 is moved by the cylinders 35 and 45, and the maximum load when the peeling cutter 4 presses the slice base 200 is about 8.0 kg weight, but it is applied to the slice base 200 when pressing this. Since the load changes depending on the ease with which the slice base 200 is peeled off, the load sensor 1 provided on the peeling cutter 4 detects the load that actually pressed the slice base 200 during pressing.

The peeled slice base 200 falls into a basket 62 provided under the lower support member 2 and is collected, and the slice base 200 is peeled off from the wafer 1.
00 is carried by the pusher 60 on the conveyor belt 70 of the carry-out mechanism and sent to the subsequent step (not shown).

However, if a large load is applied when the slice base 200 is pressed and peeled by the peeling cutter 4, the wafer 100 may be broken. This is the wafer 10
0 and the slice base 200 are not sufficiently softened even by immersion in hot water, and the load at the time of pressing exceeds about 6.0 kg weight depending on the thickness of the wafer. It is empirically known to occur.

The reason why the adhesive does not soften sufficiently when immersed in hot water is that the temperature of the hot water is lower than that of the hardened adhesive. However, if the temperature of the hot water is kept high, The slice base 200 comes off during the hot water immersion, and the slice base floats in the hot water tank 10 to scratch the wafer, or even if it does not completely come off in the hot water tank 10, it seems to have hung from the wafer 100. In some cases, it may not be possible to set the stereotactic position.

Therefore, according to the automatic peeling method of the present invention, the load sensor 1 provided on the peeling cutter 4 measures the load at the time of pressure peeling, and when the preset upper limit of the load range is exceeded, If the temperature of the heater unit 12 that is supplying the hot water that is being supplied to the hot water tank 10 is increased to increase the water temperature in the hot water tank 10, while the temperature is lower than the lower limit of the set load range, the valve is 13 is opened and pure water is supplied from the water supply pipe 15 to lower the water temperature in the warm water tank 10.

As a set value of the load range, for example, the lower limit is set to about 2.0 kg weight, and the upper limit is set to 5.0 kg weight with a margin from the 6 kg weight that causes the wafer crack. When the upper limit of 5.0 kg weight is exceeded, when the load value exceeds the upper limit, the water temperature in the warm water tank is increased at a rate of 4 ° C. for a 10% increase in load, and when the lower limit is less than 2.0 kg weight. In order to reduce the water temperature by 10%, the water temperature is reduced by 4 ° C.

In the present embodiment, the temperature value to be raised and the temperature amount to be lowered were defined by the load value exceeding the upper limit or the lower limit as described above. However, these are empirical in the case of a silicon wafer. Was sought after by
It varies depending on the thickness and type of wafer and the type of adhesive, and needs to be adjusted appropriately.

Here, the water temperature and the softening of the adhesive will be explained. It is empirically known that the softening of the adhesive depends only on the temperature of the hot water and is not influenced by the immersion time. The time taken for the immersed wafer to reach its temperature is 600-80 wafer thickness.
From 0 μm, it is a very short time (several seconds), and even if it is immersed in warm water for a long time thereafter, the softening of the adhesive does not proceed unless it is at an appropriate temperature. In this embodiment, the time for loading and unloading the cassette in which the wafers are set is about 30 seconds for putting in the hot water tank, the immersion time is 1 minute, and the time for pulling is 1 minute.
It is set to 0 seconds.

Next, the flow of processing for adjusting the temperature will be described with reference to the flow chart shown in FIG.

Wafer 1 pulled up from hot water tank 10
00 is set in a fixed position, the slice base 200 is pressed and peeled by the peeling cutter 4, and the load value at that time is measured (S1). It is judged whether the load value exceeds the upper limit (S2), and if it exceeds the upper limit, the ratio of the load value exceeding the upper limit is calculated as (load value-upper limit value) / upper limit value x 100. (S10), the temperature rise temperature per calculated ratio of 10% is calculated, and the water temperature is raised (S1).
1).

If the load value does not exceed the upper limit, it is determined whether the load value is less than the lower limit (S
3) Obtain a ratio lower than the lower limit of the load value as (lower limit value−load value) / lower limit value × 100 (S20), calculate the temperature reduction temperature per 10% of the obtained ratio, and lower the water temperature. (S11).

As described above, the optimum water temperature adjustment for softening the adhesive that bonds the wafer and the slice base is performed. As a result, appropriate slice-based peeling is performed on the wafer that is subsequently subjected to the water temperature immersion. Note that 25 wafers are set in one cassette, and the number of wafers to which the wafer and the slice base are bonded under the same conditions as this wafer is the number of sliced pieces per ingot 200 to 3
Since the number of sheets is about 00, the 200 to 300 sheets are immersed in warm water at an appropriate temperature. Further, when the measured load value is too large, the slice base peeling may be performed after the cassette in which the wafer is set is immersed again in the warm water tank whose temperature has been raised.

The water temperature controller is the water temperature sensor 1
In order to control the water temperature from the water temperature measurement value from 1 and the load value from the load sensor 1, when the water temperature is raised, a heating signal is sent to the heater unit, and when the water temperature is lowered,
Any device can be used as long as it can perform control such as issuing a signal to open the valve 13, and it is not particularly limited, and a general personal computer or the like may be used. In the present embodiment, a computer having a configuration as shown in FIG. 4 was used, and a program for performing each control as described above was executed and used as a water temperature controller.

The water temperature controller 80 has a memory 83.
The program stored in is the central processing unit (CPU)
81, and via the I / O driver 82
The load detection from the load sensor 1 is detected, the temperature value from the temperature sensor 11 is detected, and the processing necessary for the control is performed by the CPU 81, so that the valve controller 21 or the device controller 84 is operated. A signal is sent to each heater unit 12, and the hot water tank 10
It controls the internal temperature.

In this embodiment, the water temperature is raised by increasing the heating amount of the heater, but it seems that hot water of high temperature and water are supplied to obtain hot water of an appropriate temperature. In this case, it is possible to raise the temperature by increasing the amount of hot water supplied relative to water. On the other hand, in the present embodiment, the temperature of the hot water is lowered by supplying pure water. However, even if this is done, the heating of the heater unit is stopped, and the hot water tank is used for cooling. It is also possible to install piping.

[0033]

As described above, according to the slice base automatic peeling method of the present invention, the load during the pressure peeling of the slice base is detected, and the temperature in the water tank is controlled based on the detected load. Therefore, it is possible to optimally soften the adhesive between the wafer and the slice base.
Therefore, it is possible to stably perform the slice base separation from the wafer, prevent the wafer from cracking and the transfer trouble, and improve the throughput and the yield.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining the configuration of a slice-based automatic peeling device used in an embodiment of the present invention.

FIG. 2 is a view for explaining a hot water tank portion of the slice-based automatic peeling device used in the embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation according to an exemplary embodiment of the present invention.

FIG. 4 is a block diagram for explaining a water temperature controller used in an embodiment of the present invention.

FIG. 5 is a view for explaining a slice base peeling operation.

FIG. 6 is a view for explaining slicing of a wafer from a semiconductor ingot.

[Explanation of Codes] 1 ... Wiper, 2 ... Lower support member, 3 ... Upper support member, 4
... Peeling cutter (pressing tool), 10 ... Hot water tank,
11 ... Temperature sensor, 12 ... Heater unit, 13 ... Valve, 14, 15 ...
Water pipe, 60 ... Pusher, 10
0 ... Wafer, 200 ... Slice base.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshimasa Miyazaki 3434 Shimada, Hikari City, Yamaguchi Prefecture Nittetsu Electric Co., Ltd.

Claims (1)

[Claims] 1. A semiconductor wafer (100) sliced with a slice base (200) bonded with an adhesive.
Is immersed in a hot water tank (10) to which hot water is supplied, and after dipping in the hot water tank (10), the semiconductor wafer (100) taken out from the hot water tank (10) is supported by a supporting member (2, 3). In the slice base automatic peeling method, the slice base (200) is fixed in a state of protruding from the supporting members (2, 3), and is peeled by pressing the slice base (200) with a pressing tool (4). The pressing tool (4) is attached to the slice base.
Load detection means to detect the load when pressing (200) (1)
When the load when pressing the slice base (200) obtained by the load detecting means (1) exceeds the upper limit of the preset load range, the hot water tank (10) A slice-based automatic peeling method comprising increasing the water temperature and lowering the water temperature in the hot water tank (10) when the water temperature is less than the lower limit of the load range.