JP2890902B2 - Semiconductor device manufacturing method and manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing a semiconductor device, and more particularly to a dicing method and apparatus for dividing a semiconductor wafer into individual semiconductor chips.

[0002] As a method of dicing a semiconductor wafer, a method of cutting into a lattice by a rotating blade (dicing saw) is generally used. Initially, the wafer was cut with a blade so that part of the thickness of the wafer remained (this is called half-cutting), and then divided into chips by cracking. However, wafers tend to be broken during cracking. The method of cutting the entire thickness of a wafer (this is called a full cut) is mainly used.
In this method, adhesive tape is pasted on the backside of the wafer in advance, and the wafer is cut so that the entire thickness of the wafer and a part of the thickness of the adhesive tape are cut.However, since the blade gradually wears out during use, the cutting amount gradually increases It will decrease and eventually will not be fully cut. Therefore, it is important to manage the cut amount.

[0003]

2. Description of the Related Art A conventional dicing method and dicing apparatus will be described with reference to FIG. FIG. 2 is an explanatory view of a conventional example, and shows a main part of a dicing apparatus. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals. 1 is a blade, 2 is a table, 3 is a cover, and 4 is a cooling water supply means.

[0004] Dicing of a wafer is performed as follows. A wafer (not shown) having an adhesive tape adhered to the back surface is fixed on a table 2 and cut into a grid by a high-speed rotating blade 1. At this time, the cooling water is supplied from the cooling water supply means 4 to the vicinity of the cutting point to cool the blade 1. The cooling water is carbonated water (carbon dioxide gas is bubbled in pure water, and the specific resistance is extremely low ...
For example, about 0.3 MΩ-cm) is used. When the wafer is fully cut, the blade 1 is cut so that the entire thickness of the wafer and a part of the thickness of the adhesive tape are cut.

The cutting depth of the blade 1 is set by adjusting the height of the blade 1 from the table 2 (hereinafter referred to as the blade height). Specifically, when the wafer is not placed on the table 2 and the supply of the cooling water is stopped, the blade 1 is lowered toward the table 2 to electrically connect the blade 1 to the table 2. Is adjusted by raising the blade 1 by a desired height using this position as a reference point. This adjustment of the blade height is performed every time a fixed number of wafers are diced, in addition to when the blade is replaced.

[0006]

However, when dicing by such a conventional apparatus and method, cooling water remains on the upper surface of the table when adjusting the blade height.
Therefore, there is a problem that an error may occur in the blade height setting value. That is, if cooling water having a low specific resistance, such as the above-described carbonated water, remains on the upper surface of the table when adjusting the blade height, the blade is lowered and the blade and the table are cooled when the blade comes into contact with the cooling water. And the blade height is set with this position as the reference point.
The set value of the height becomes larger than the desired value. in this case,
Since the cutting depth of the blade becomes shallow from the beginning, the cutting of the blade becomes insufficient due to slight wear of the blade, which causes trouble in picking up chips in a later process (such as inability to pick up, chipping or cracking). . still,
The reason for using the cooling water having a low specific resistance is to prevent electrostatic breakdown of the semiconductor element.

An object of the present invention is to solve such a problem and to provide a dicing method and a dicing apparatus capable of accurately adjusting a blade height so as to always cut at an appropriate cutting amount. And

[0008]

According to the present invention, there is provided [1] pure water flowing over the upper surface of a table,
(2) Cleaning process and blur for cutting wafer
The contact between the outer periphery of the table 1 and the upper surface of the table 2
The upper surface of the table 2 of the blade 1
And a step of cutting the wafer placed on the upper surface of the table 2 by the blade 1 while supplying cooling water to the wafer surface, wherein the specific resistance of the pure water is [2] a table 2 on which a wafer is mounted, a blade 1 for cutting the wafer, and a cooling water supply for supplying cooling water. Means 4, a blade height adjusting mechanism for detecting the contact position between the blade 1 and the upper surface of the table 2 by electrical conduction, and adjusting the height of the blade 1 with respect to the upper surface of the table 2; Cleaning water supply means 5 for supplying high-resistance cleaning water;
This is achieved by providing a semiconductor device manufacturing apparatus having the following features.

[0009]

When the cutting of the wafer is temporarily suspended to adjust the blade height, cooling water having low specific resistance remains on the table. In some cases, cutting powder (silicon fine powder) is contained. If this is washed with running pure water having high specific resistance in advance, even if the pure water remains on the table, it will not be electrically conducted until the blade contacts the table.

If the cleaning water supply means for discharging the pure water onto the table is incorporated in the dicing apparatus so as to discharge the pure water at a desired timing, the blade height can always be stably adjusted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a dicing method and a dicing apparatus according to the present invention will be described with reference to FIG. FIG. 1 is an explanatory view of an embodiment of the present invention, showing a main part of a dicing apparatus.

This dicing apparatus comprises a blade 1, a table 2, a cover 3, a cooling water supply means 4, a cleaning water supply means 5, a compressed air supply means 6, a blade height adjusting means (not shown), and the like.

The blade 1 has a disk shape and rotates at a high speed to cut a wafer (not shown). The cutting edge (outer circumference)
Is obtained by bonding diamond abrasive grains with metal. The table 2 mounts and fixes (vacuum suction) a wafer to be cut under the blade 1. The cover 3 covers the outer periphery of the blade 1. The cooling water supply means 4 is composed of a pipe communicating with a cooling water source, nozzles on both sides of the blade 1 for discharging cooling water near a cutting portion, and the like, and is fixed to the cover 3. The washing water supply means 5 includes a pipe communicating with a pure water source,
It consists of a nozzle or the like that discharges pure water onto the upper surface of the table 2 and is fixed to the cover 3. The compressed air supply means 6 includes a pipe communicating with a supply source of clean and dry compressed air such as N ₂ or air, a nozzle for discharging the compressed air to the upper surface of the table 2, and is fixed to the cover 3. The blade height adjusting means is a mechanism for moving the blade 1 up and down. The blade height adjusting means detects the contact between the blade 1 and the upper surface of the table 2 by electrical continuity.
And a mechanism for raising the blade 1 from this stop position to a predetermined desired height (blade height).

The dicing of the wafer is performed as follows. A wafer (not shown) having an adhesive tape adhered to the back surface is fixed on a table 2 and cut by a high-speed rotating blade 1 set at a predetermined height from the upper surface of the table 2. At this time, neither supply of pure water from the cleaning water supply means 5 nor supply of compressed air from the compressed air supply means 6 is performed.
Cooling water is supplied from the cooling water supply means 4 to cool the blade 1. As the cooling water, carbonated water (specific resistance is, for example, 0.3
(Approximately MΩ-cm). When the wafer is fully cut, the blade 1 is cut so that the entire thickness of the wafer and a part of the thickness of the adhesive tape are cut.

The cutting depth of the blade 1 is set by adjusting the blade height in advance. Specifically, Table 2
In a state where the wafer is not placed on the upper side and the supply of the cooling water is stopped, first, the pure water (for example, 5
(MΩ-cm or more) onto the table 2
The cooling water remaining on the upper surface is washed, and then N ₂ or air pressure is blown from the compressed air supply means 6 to the upper surface of the table 2 to remove the washing water, and then the blade 1 is lowered toward the table 2 and both of them are lowered. The contact is detected by electrical conduction, and the position is adjusted by raising the blade 1 to a desired height with this position as a reference point. The adjustment of the blade height is performed when the blade is replaced and every time a predetermined number of wafers are diced.

By using the above apparatus and performing the blade height adjustment periodically by the above method, the wafer can always be diced with an appropriate cutting amount, and the chip pickup in the next step is stable. .

The present invention is not limited to the above embodiments, but can be implemented in various modifications. For example, both or one of the cleaning water supply unit 5 and the compressed air supply unit 6 may be fixed to the table 2 side. The present invention is also effective for an apparatus without the compressed air supply means 6 and a method for not performing blowing by compressed air.

[0018]

As described above, according to the present invention,
It is possible to provide a dicing method and a dicing apparatus capable of always accurately adjusting the blade height, thereby enabling a cutting to be always performed at an appropriate cutting amount, thereby contributing to an improvement in the yield of semiconductor device manufacturing. I do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blade 2 Table 3 Cover 4 Cooling water supply means 5 Cleaning water supply means 6 Compressed air supply means

Claims (4)

(57) [Claims] 1. A step of cleaning the table (2) by flowing pure water on the upper surface of the table (2), and a step of cleaning the outer periphery of a blade (1) for cutting a wafer and the table.
(2) Detects contact with the top surface by electrical conduction between both
Height of the blade (1) with respect to the upper surface of the table (2)
And cutting the wafer placed on the upper surface of the table (2) with the blade (1) while supplying cooling water to the surface of the wafer. A method for manufacturing a semiconductor device, wherein the method is higher than the specific resistance of water. Wherein said After a washing step with pure water, according to claim 1, half of, wherein the removing the pure water by gas
A method for manufacturing a conductor device. 3. A table (2) on which a wafer is placed, a blade (1) for cutting the wafer, cooling water supply means (4) for supplying cooling water, the blade (1) and the table (2). 2) The contact position with the upper surface is detected by electrical conduction, and the table of the blade (1) is
(2) A semiconductor device characterized by having a blade height adjusting mechanism for adjusting the height with respect to the upper surface, and cleaning water supply means (5) for supplying cleaning water having higher specific resistance than the cooling water. apparatus. 4. An apparatus for manufacturing a semiconductor device according to claim 3, further comprising a compressed air supply means (6) for supplying compressed air for removing said cleaning water to an upper surface of said table (2).