KR101151001B1 - Apparatus and method for processing notch of wafer - Google Patents

Abstract

The present invention relates to the etching of wafers used as substrates of semiconductor devices.

The present invention comprises the steps of grinding the notch of the wafer; Etching the notch of the wafer with an etchant; And it provides a notch processing method of the wafer comprising the step of grinding the notch of the wafer.

Therefore, according to the present invention, it is possible to sufficiently remove particles such as fine dust and water by improving the roughness of the wafer surface, particularly the notch portion, through grinding, etching and polishing processes.

Wafer, notch, etch

Description

Apparatus and method for processing notch of wafer}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wafers used as substrates for semiconductor devices, and more particularly to notch etching of wafers.

Silicon (Si) wafers are widely used as materials for semiconductor device manufacturing. A silicon wafer is a wafer in which homogeneous silicon is grown on a silicon surface. The silicon wafer is widely used because of its excellent purity and crystallinity in a region for directing a semiconductor and for improving yield and device characteristics of a semiconductor device.

Typically, after slicing a silicon single crystal ingot formed by a method such as Czozhralski, it is formed into a wafer through molding processes such as lapping and etching. In order to fabricate the wafer into a high quality wafer, each wafer is subjected to various processes, and it is necessary to precisely position the wafer within a specific process or conveying apparatus. In addition, in order for the above process to proceed effectively, a plurality of wafers must be arranged or positioned in a fixed direction in advance.

Therefore, there are a flat wafer in which a flat zone has been formed in the wafer as a reference point for the crystal lattice direction and wafer alignment of the wafer, or a notched wafer in which a notch is formed in a part of the outer circumference of the wafer. . Here, since the notched wafer has a smaller area cut for the mark than the flat wafer, there is an advantage in that the semiconductor devices can be formed in a larger area.

Here, in the production stage of the integrated circuit manufactured by the process of developing and etching the circuit pattern on the wafer surface, particles such as fine dust or moisture should be actively removed because they damage the formation of the circuit pattern. However, in order to reduce the roughness of the surface of the wafer in the grinding process of the notch of the silicon wafer, there is a problem in that the grinding time is increased. There is a costly and costly problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to reduce the surface roughness of the surface of the wafer, particularly the notched portion, in the wafer manufacturing process to sufficiently remove particles such as fine dust and water. And to provide an apparatus.

It is another object of the present invention to provide a method and apparatus for notching a wafer which sufficiently reduces the roughness of the wafer notch while reducing the cost and time required for grinding and polishing the silicon wafer notch.

In order to solve the above problems, the present invention comprises the steps of grinding the notch of the wafer; Etching the notch of the wafer with an etchant; And it provides a notch processing method of the wafer comprising the step of grinding the notch of the wafer.

According to another embodiment of the present invention, an etchant supply pipe; And a plurality of holes spaced apart from each other by a predetermined interval on the side surface of the etching solution supply pipe and ejecting the etching solution in a direction perpendicular to the etching solution supply pipe.

The effects of the notch etching apparatus and method of the wafer according to the present invention described above are as follows.

First, it is possible to sufficiently remove particles such as fine dust or water by improving the surface roughness of the surface of the wafer, particularly the notched portion through grinding, etching and polishing processes.

Second, an etching process may be added to the notched portion of the wafer before the polishing process, thereby sufficiently reducing the roughness of the notch while reducing the cost and time required for the grinding process and the polishing process.

Third, since the etchant is temporarily stored after being injected and then ejected into the holes on the surface, a large amount of etchant is ejected suddenly to prevent the etching of portions other than the notch of the wafer, and the etchant is supplied from the plurality of holes to supply the notch portion. The whole can be etched sufficiently.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described. The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

1 is a view showing an embodiment of a process of grinding the notch of the wafer, Figure 2a is a view showing an embodiment of a process of etching the notch of the wafer with the etching solution, Figure 2b is a etching solution supply apparatus of FIG. 3 is a view showing in detail an embodiment of a process for polishing the notch of the wafer.

Hereinafter, an embodiment of a notch processing method and apparatus for a wafer according to the present invention will be described with reference to FIGS. 1 to 3.

First, as illustrated in FIG. 1, the wafer 100 is ground, and the notch of the wafer 100 is ground with a wheel 110. In addition, the grinding process may be performed by aligning a plurality of wafers in one unit for efficient wafer grinding.

In addition, grooves are notched by being grooved inward from the edge of the wafer to align the wafer, and at least one of the wheel 110 and the wafer 100 rotates and the wafer 100 is rotated by frictional force. ) The notched part is ground.

Here, the wheel 110 may be made of a material such as diamond in order not to wear easily, the notched portion of the wafer 100 after the grinding process is left with a rough trace in the minute portion.

Subsequently, the notch of the wafer is etched with the etchant as shown in FIG. 2A. At this time, the etching process may be performed by aligning a plurality of wafers in one unit for efficient wafer grinding. Here, storing the wafer in a unit such as a plurality of cassettes is effective in terms of productivity and cost.

Specifically, the etching solution is supplied by etching while the notches of the wafer 100 are aligned. Here, the notch etching apparatus 130 of the wafer includes an etching solution supply pipe 132, an etching solution storage pipe 134, and a hole 136.

The notch etching apparatus 130 of the wafer has a long pipe shape as shown in the drawing, and an etching solution supply pipe 132 is formed therein, and the etching solution is supplied and flows therethrough.

An etchant storage tube 134 is provided outside the etchant supply tube 132. The etchant storage tube 134 serves as a passage before the etchant that is supplied from the outside and flows along the etchant supply tube 132 is ejected into the hole 136 on the surface thereof. As shown in FIG. 2B, the etchant that has traveled through the etchant supply pipe 132 flows to the outer etchant storage pipe 134 and is then ejected into a hole 136.

Here, the etchant supply pipe 132 is to be provided in the shape of a long pipe, the etchant storage pipe 134 is provided in a concentric shape around the etchant supply pipe 132. The hole 136 is provided on the surface of the notch etching apparatus 130 of the wafer.

Here, since the etchant is temporarily stored in the etchant storage tube 134 and then ejected into the hole 136, a sudden amount of etchant is ejected to etch to a portion outside the notch of the wafer.

In addition, at least two holes 136 may correspond to the notches of one wafer to eject the etchant to sufficiently etch each portion of the notch. In the embodiment shown in FIG. 2A, one hole 136 corresponding to the center portion of the notch and two holes 136 on both sides are formed.

That is, at least two holes 136 corresponding to the one wafer should be provided in parallel with the wafer. In addition, it is a matter of course that the holes 136 are also formed to be spaced apart from each other by a plurality of wafers aligned in one unit.

In addition, since potassium hydroxide or sodium hydroxide may be used as the etching solution, the notch etching apparatus 130 should be made of a material that does not corrode the etching solution. In addition, the etching solution may be used by mixing hydrofluoric acid, nitric acid, acetic acid, etc. in addition to potassium hydroxide and sodium hydroxide.

Therefore, the notch etching apparatus 130 can use plastic materials, such as vinyl chloride resin and a fluororesin, rubber material, ceramics material, and other chemical-resistant materials, so that an etching liquid may not be damaged.

In addition, the notch etching process using the apparatus 130 in the notch etching process of the wafer should be performed for 1 to 10 minutes. If the etching is less than 1 minute, the notch is not sufficiently etched and rough surfaces remain in the notch of the wafer. When etching for more than 10 minutes, the notch of the wafer is etched too deeply.

Then, the notches of the wafer are polished as shown in FIG.

The polishing process supplies slurry to the notch portion of the wafer 100 as shown, and polishes the notch using the pad 120. In the polishing process, the slurry and the pad may be mirror-polished on the notch portion of the wafer, and in particular, the time and cost of the polishing process may be reduced through the above-described etching process.

Figure 4 is a photograph showing the notch of the wafer processed by the conventional method and the present invention, respectively, Figure 5 is a view showing the roughness of the notch of the wafer processed by the conventional method and the present invention, respectively.

On the left side of FIG. 4, the notch of the wafer processed by the conventional method photographed by the optical microscope shows that the surface has a lot of curvature and roughness. However, on the right side of FIG. 4 it can be seen that the surface of the notch of the wafer ground, etched and polished in the manner according to the invention is very smooth.

In addition, as shown in FIG. 5, the notch of the wafer in which the roughness of the notch is processed in a conventional manner exhibits about 14 angstroms, but the notch of the wafer processed by the present invention is 2 angstroms. It is showing degree.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

The above notch processing apparatus and method of the wafer can be used to improve the surface roughness of the notched portion of the wafer.

1 is a view showing an embodiment of a process for grinding the notch of the wafer,

2A is a view showing an embodiment of a process of etching the notch of the wafer with an etchant,

2B is a view showing in detail the etching solution supply apparatus of FIG.

3 is a view illustrating an embodiment of a process of polishing a notch of a wafer;

4 shows the notch of the processed wafer,

5 shows the roughness of the notch of the processed wafer.

<Explanation of symbols for the main parts of the drawings>

100: wafer 110: grinding wheel

120: polishing pad 130: notch etching apparatus of the wafer

132: etching solution supply pipe 134: etching solution storage pipe

136: hall

Claims (5)

Etching solution supply pipe; And And a plurality of holes provided on the side surfaces of the etching solution supply pipe and spaced apart from each other by a predetermined interval, and for ejecting the etching solution in a direction perpendicular to the etching solution supply pipe. The method of claim 1, And at least two holes correspond to each wafer in the cassette. The method of claim 2, And at least two holes corresponding to one wafer are provided in a direction parallel to the wafer and eject the etching solution at different positions within the notch of the wafer. The method of claim 2, At least two holes corresponding to one wafer are provided in a direction parallel to the wafer to eject etching liquid in different directions in the notch of the wafer. The method of claim 1, And an etchant storage tube provided at an outer side of the etchant supply tube, wherein the etchant ejected from the etchant supply tube is ejected into the hole through the etchant storage tube.

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