JPH08323579A - Method of eliminating foreign matter on workpiece support surface - Google Patents

Abstract

PURPOSE: To prevent any foreign matter from being restuck to a workpiece support surface supporting a workpiece such as semiconductor wafer. CONSTITUTION: First of all, an etching solution 22 including a potassium hydroxide aqueous solution, a sodium hydroxide aqueous solution or the like is applied onto a support table 10 before the suction of a water, dissolving foreign matter 20, and thus the foreign matter 20 is prevented from being restuck onto the support table 10. Next, a neutralizer solution such as acetic acid is applied onto the support table 10 where the foreign matter 20 is dissolved, neutralizing the etching solution 22. Therefore, even when a semiconductor wafer 12 is placed on the support table 10, since the etching solution is neutralized by the neutralizer, so that this wafer 12 receives no adverese effect of the etching solution 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing foreign matter on a work support surface, and more particularly to a method for removing foreign matter deposited on a support table of a surface grinding machine such as a semiconductor wafer or a hard disk.

[0002]

2. Description of the Related Art For example, as shown in FIG. 5, a wafer 1 cut into thin pieces by a slicing machine is supported on a support table 2 of a grinder, and its surface 1A has a grindstone 3 thereon.
To be ground. At this time, the wafer 1 and the support table 2
If a foreign matter (such as grinding powder of the wafer) 4 is sandwiched between and, a portion of the wafer 1 near the foreign matter 4 is deformed and a bulge portion 5 is generated on the wafer surface 1A. Wafer surface 1A in this state
Is ground flat as shown in FIG.
Since the portion of the wafer 1 taken out from the wafer 1 which has been deformed by the foreign matter 4 returns to its original shape, there is a drawback that a depression 6 shown in FIG. 7 is formed at the position of the bulging portion 5 shown in FIG. is there.

Therefore, conventionally, in order to remove such foreign matter 4, oil mixed with ultrafine particles is used, and the foreign matter 4 is washed off from the support table 2 with this oil.

[0004]

However, in the conventional foreign matter removing method, when dirt is accumulated on the oil, the dirt adheres to the support table, and when the dirt is removed from the support table, the dirt is re-applied to the support table. There is a drawback in that they adhere to each other and, as a result, adversely affect the wafer after grinding.

The present invention has been made in view of the above circumstances, and provides a method for removing foreign matter from a workpiece support surface, which is capable of preventing foreign matter from reattaching to the workpiece support surface. With the goal.

[0006]

In order to achieve the above object, the present invention applies an etching solution to a work piece supporting surface on which a work piece is supported to dissolve foreign matters on the work piece supporting surface. After that, a neutralizing solution is applied to the workpiece support surface to neutralize the etching solution.

[0007]

According to the present invention, first, an etchant is applied to the workpiece support surface to dissolve the foreign matter on the workpiece support surface to prevent reattachment of the foreign matter, and then to support the workpiece. A neutralizing solution is applied to the surface to neutralize the etching solution so that the etching solution does not adversely affect the work piece.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the method for removing foreign matter from a work supporting surface according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a side view of essential parts showing an embodiment of a support table of a wafer surface grinder to which a method for removing foreign matter from a work support surface according to the present invention is applied.

The support table 10 shown in the figure has a vacuum suction portion formed on the upper surface 10A thereof, and the semiconductor wafer 12 (see FIG. 3) is ground by the vacuum suction portion 12A.
Is supported upward. A spindle 14 is provided below the support table 10.
A motor (not shown) is connected to 4. Therefore, the support table 10 can be rotated at a predetermined speed by transmitting the rotational force from the motor via the spindle 14.

A grindstone 16 (see FIG. 3) for grinding the semiconductor wafer 12 is formed in a cup shape and has a grindstone shaft 1 formed therein.
It is fixed to the lower part of 8. The grindstone 16 is rotationally driven by the rotational force of a motor (not shown) connected to the grindstone shaft 18, and is moved up and down by an up / down moving mechanism (not shown). Therefore, the grindstone 16 is rotated by the motor and is lowered by the lifting / lowering moving mechanism to move the grinding surface 1 of the semiconductor wafer 12
2A is pressed and the support table 10 is rotated, the ground surface 12A of the semiconductor wafer 12 is ground.

Next, a method of removing the foreign matter 20 adhering to the support table 10 will be described. First, as shown in FIG. 1, an etching liquid (a light etching liquid such as an aqueous solution of potassium hydroxide or an aqueous solution of sodium hydroxide) 22 is applied onto the support table 10 before wafer adsorption. As a result, the foreign matter 20 is dissolved by the etching solution 22,
The foreign matter 20 does not reattach to the support table 10.

Next, as shown in FIG. 2, a neutralizing solution (acetic acid or the like) 24 is applied on the support table 10 in which the foreign matter 20 is dissolved to neutralize the etching solution 22. Therefore, even when the semiconductor wafer 12 is placed on the support table 10, the etching liquid 22 is neutralized by the neutralizing liquid 24, and therefore the semiconductor wafer 12 is not adversely affected by the etching liquid 22. This completes the foreign matter removal operation of the present embodiment.

Then, as shown in FIG.
The semiconductor wafer 12 is placed on the support table 10 in which 2 is neutralized.
The surface of the semiconductor wafer 12 is ground by the grindstone 16 described above. As a result, since the semiconductor wafer 12 after the grinding is not affected by the foreign matter 20, the processed surface 12B is ground flat without the depression due to the foreign matter 20 as shown in FIG. Therefore, a high quality semiconductor wafer 12 can be obtained by performing the foreign matter removing method of this embodiment.

In this embodiment, the surface grinding machine for semiconductor wafers has been described, but the invention can also be applied to the surface grinding machine for hard disks. Further, in the present embodiment, the etching solution is neutralized with the neutralizing solution, but when the etching solution is a weak alkali, it may be washed away with water. When the etching solution is acidic, it is neutralized with a weak alkaline neutralizing solution.

[0015]

As described above, according to the method for removing foreign matter on the workpiece support surface according to the present invention, the etching solution is applied to the workpiece support surface to dissolve the foreign matter on the workpiece support surface. As a result, it is possible to prevent the reattachment of foreign matter, and since the neutralizing solution is applied to the workpiece supporting surface after the foreign matter is dissolved to neutralize the etching solution, It is possible to prevent the adverse effect of the etching liquid applied.

[Brief description of drawings]

FIG. 1 is an explanatory view of applying an etching liquid on a support table.

FIG. 2 is an explanatory diagram of applying a neutralizing solution onto a support table in which foreign matter is dissolved.

FIG. 3 is an explanatory view showing surface grinding of a semiconductor wafer.

FIG. 4 is a side view of a semiconductor wafer whose surface is ground.

FIG. 5 is an explanatory view of a semiconductor wafer supported with foreign matter attached on a support table.

FIG. 6 is an explanatory view of a semiconductor wafer whose surface is ground with foreign matter adhering to the support table.

FIG. 7 is an explanatory diagram of the single semiconductor wafer shown in FIG.

[Explanation of symbols]

 10 ... Supporting table 12 ... Semiconductor wafer 16 ... Grinding stone 20 ... Foreign matter 22 ... Etching liquid 24 ... Neutralizing liquid

Claims (1)

[Claims] 1. A workpiece supporting surface on which a workpiece is supported is coated with an etching solution to dissolve foreign matters on the workpiece supporting surface, and then a neutralizing solution is coated on the workpiece supporting surface. The method for removing foreign matter from a work piece supporting surface, comprising: