JPS61147523A - Method and device for removing projection of vapor phase grown substrate - Google Patents

Abstract

PURPOSE:To readily and effectively remove the abnormally grown projection on the surface of a wafer by pressing the surface of a vapor phase grown substrate through a film having flexibility. CONSTITUTION:An upper pressing plate 3 is moved down toward a lower pressing plate 2 by a pressing mechanism to press the surface F of a wafer W interposed through a film 12 by the pressing surface 6. The projection formed on the surface F of the wafer 1 is pressed and collapsed on the surface 6 of the plate 3. The chips of the collapsed projection are buried in the film 12 having plasticity and contained. When the plate 3 is raised, the chips of the projection buried in the film 12 are integrally raised together with the film 12 and removed from the surface F of the wafer W.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for removing unnecessary protrusions from a vapor-phase growth substrate in the manufacturing process of semiconductor devices and the like. Regarding equipment.

(Prior art and its problems) In general, in epitaxial growth and CvD growth of oxide films, polycrystalline silicon, etc., R44 foreign matter etc. are deposited on the surface of the vapor phase growth substrate (hereinafter referred to as wafer) before growth. If there is dirt or scratches, the foreign matter or scratches will become a nucleus during vapor phase growth, and the foreign matter will grow as a hill-like protrusion several micrometers in height.Also, it may cause the deposits to fall in the vapor phase growth reactor. Similar protrusions also occur when oxides from reactant gas piping, etc., or dust in the atmosphere adhere to the surface of the wafer.

However, such abnormally grown protrusions damage the mask during the device process, shorten the life of the mask, and cause a decrease in precision in the masking process, so it is necessary to remove them in advance.

Conventionally, methods for removing this type of protrusion can be broadly classified into scientific methods and mechanical methods. Among these, chemical methods include coating the wafer surface with an oxide film or chemical-resistant film, removing the tops of the protrusions, and dissolving only the exposed protrusions with acid or alkaline solution. There is, but
The disadvantage is that the operation is complicated.

Further, as a mechanical method for removing the protrusions, a method of pressing the wafer between a pair of press tools disposed facing each other to crush the protrusions is often used due to its advantages such as ease of operation.

However, in the method using the conventional press tool, there is a problem that fragments of the crushed protrusions are scattered on the wafer surface around the protrusions and are pressed by the press tool, causing scratches on the wafer surface. there were. Furthermore, in the above method, even in areas where the protrusions are not present, if any foreign matter adheres to the surface, there is a risk of damage during pressing with the press tool.

Therefore, in order to particularly suppress the occurrence of scratches caused by the press tool, a highly viscous anti-friction agent is applied to the surface of the wafer as shown in Japanese Patent Application Laid-Open No. 57-69746, and the crushed particles are removed by the anti-friction agent. There is also a method of embedding the lubricant inside the lubricant, but this method has the disadvantage that the operation is extremely complicated and therefore the manufacturing cost increases.

(Object of the Invention) The present invention has been made in view of the above circumstances, and it is possible to easily and reliably remove abnormally grown protrusions on the wafer surface, and there is no fear of causing scratches around the protrusions.
Therefore, it is an object of the present invention to provide a method and apparatus for removing protrusions from a vapor-phase growth substrate, which can greatly improve the yield of products.

[Structure of the invention]

The method for removing protrusions from a vapor-phase growth substrate according to the present invention involves pressing the surface of the vapor-phase growth substrate on which abnormally grown protrusions are formed through a plastic film to crush the protrusions and removing them. be.

Further, the vapor growth substrate protrusion removal apparatus of the present invention for carrying out the above method includes a pair of presses I which are disposed opposite to each other so as to be able to approach and separate, with a vapor growth substrate having abnormally grown protrusions on the surface sandwiched therebetween; tK, a plastic film inserted between the press tool and the surface of the vapor growth substrate having the abnormally grown protrusions, and the pair of press tools are brought relatively close together to form the vapor growth substrate. It is equipped with a suppression mechanism for pressing.

〔Example〕

The figure shows an example of a protrusion removing apparatus for carrying out the method for removing protrusions from a vapor-phase growth substrate according to this explanation, and the reference numeral 1 in the figure shows an example of a protrusion removing apparatus.
1 shows the base of this protrusion removing device.

A press tool 4 consisting of a lower press plate 2 and an upper press plate 3 is provided on the base 1.

The lower press 2 of the press tool 4 is a flat plate member made of stainless steel, and is fixed on the base 1 with the press 5 as the upper surface. The upper press plate 3 is a flat plate member made of synthetic sapphire, and is disposed opposite to the press plate 5 of the lower press plate 2 with its press plate 6 facing downward. The upper press plate 3 can be moved toward and away from the lower press plate 2 as indicated by arrows in the figure by a pressing mechanism such as a pneumatic cylinder (not shown).

In addition, the press surface 5 of the lower press plate 2 of this press tool 4
A transport mechanism 7 is provided above. This conveying mechanism 7 is formed by winding the film 9 between a pair of rotatably provided rolls 8 and 8. A drive device (not shown) moves the film 9 onto the surface having the abnormal growth protrusion. The structure is such that the wafers W placed with F facing upward are sequentially fed onto the press surface 5 of the lower press base 2.

On the other hand, above the transport mechanism 7 and below the lower press plate 3, a film transport mechanism 10 is provided. This film transport mechanism 10 is formed by winding a film 12 between a pair of rotatably provided rolls 11 and 11, and the lower surface of the film 12 is placed above the transport mechanism 7. It is set opposite to the top surface of 9.

The film transport mechanism 10 is configured to transport the film 12 in the direction of the arrow in the figure at the same speed as the film 9 of the transport mechanism 7 by a drive device (not shown).

Here, the transport mechanism 7 and the film transport mechanism 10 are
．． The C shims 9 and 12 are made of polyester, pvc, pv△, PS, and PE each having plasticity.

It is made of synthetic resin such as PP, and its thickness is 1~
It is said to be 10 μm.

Therefore, a method for removing protrusions using such a protrusion removing device will be specifically explained below. First, the wafer W is placed on the film 9 of the transport mechanism 7 with the surface F on which the protrusions are formed facing upward! do. Next, the transport mechanism 7 and the film transport mechanism 10 are controlled by a drive device (not shown).
- Rotate the wheels 8 and 11 to separate the films 9 and 12.
is sent at a constant speed in the direction of the arrow in the figure. And the above film 9
When the upper wafer W is positioned on the press surface 5 of the lower press plate 2, the rotation of the rolls 8 and 11 is respectively stopped. Next, the upper press plate 3 is lowered toward the upper press plate 2 by its pressing mechanism, and the front surface F of the wafer W is pressed with the press surface 6 with the film 12 interposed therebetween. Then, the protrusions formed on the surface F of the wafer W are pressed and crushed by the press surface 6 of the upper press plate 3. At this time, the crushed fragments of the protrusion are embedded in the plastic film 12. In this case, the film 1
As mentioned above, the thickness of No. 2 is desirably within the range of 1 to 10 μm. That is, the film 12
If the thickness is less than 1 μm, it is difficult to obtain a sufficient effect of enclosing the fragments of the protrusion, and conversely, if the thickness exceeds 10 μm, the effect of crushing the protrusion decreases and the protrusion This is because the removal will be incomplete.

In this way, after pressing the surface F of the wafer W with the upper press plate 3 and crushing the protrusions, the upper press plate 3
When the wafer W is raised, the crushed fragments of the projections embedded in the film 12 rise together with the film 12 and are removed from the surface F of the wafer W.

According to the removal method using such a protrusion removing device, when pressing the wafer W with the press tool 2 to crush the protrusions on the surface F, there is plasticity between the press tool 2 and the wafer W. Since the film 12 is interposed, the fragments of the crushed protrusion can be wrapped in the film 12 and removed integrally with the film 12.

Therefore, there is no fear that fragments of the projections will scatter onto the surface F of the wafer W and cause scratches on the surface F during pressing. Moreover, since the film 12 has the effect of protecting the surface F of the wafer W on which no protrusions are present during pressing, it is also possible to prevent scratches caused by foreign objects other than the protrusions. Therefore, it is possible to reliably prevent the production of defective products, and therefore it is possible to greatly improve the product yield in the protrusion removal work.

Further, in the removing device shown in the above embodiment, a transport mechanism 7 using a film 9 similar to the film 12 is provided, and the film 12 is transported in parallel with the film 9. The removal of protrusions from the wafers W can be performed continuously, which is efficient, and also protects the lower surface of the wafers W.

〔Example〕

The table below shows an experiment in which the protrusion removal device shown in the above example was used to remove protrusions from 100 4-inch 3i-processed pitaxial wafers each having at least one protrusion on the surface of various plastic films. The results are shown below.

Table [Effects of the Invention] As explained above, the method for removing protrusions from a vapor-phase growth substrate of the present invention involves pressing the surface of the vapor-phase growth substrate on which abnormally grown protrusions are formed through a film having plasticity; The above-mentioned protrusion is crushed and removed. Further, the device for removing protrusions from a vapor-phase growth substrate of the present invention for carrying out the above-mentioned method includes a pair of press tools that are arranged opposite to each other so as to be able to approach and separate, with a vapor-phase growth substrate having abnormally grown protrusions on the surface sandwiched therebetween. , a plastic film inserted between the press tool and the surface of the vapor growth substrate having abnormally grown protrusions, and the pair of press tools are brought relatively close together to press the vapor growth substrate. It is equipped with a suppression mechanism. Therefore, according to the protrusion removal method and removal device of the present invention, when the protrusions are crushed with a press tool, the surface of the film is protected, and fragments of the protrusions are embedded in the film so as to be integrated with the film. Since the protrusions can be removed, the protrusions can be removed easily and reliably, and there is no fear that fragments of the protrusions will scatter on the surface of the wafer and cause scratches. Therefore, the product yield in this type of protrusion removal work can be greatly improved.

[Brief explanation of the drawing]

The figure is a schematic configuration diagram showing an embodiment of the device for removing protrusions from a vapor-phase growth substrate according to this description. 2...Lower press plate, 3...Upper press plate, 4...Press tool, 5.6...
Press surface, 9, 12... Film, 10...
...Film transport mechanism, F...Surface, W...
...Wafer (vapor growth substrate).

Claims (2)

[Claims] (1) In a vapor growth substrate protrusion removal method in which the surface of the vapor growth substrate on which abnormally grown protrusions are formed is pressed to crush and remove the protrusions, the surface of the vapor growth substrate is made plastic. 1. A method for removing protrusions on a vapor-phase growth substrate, the method comprising pressing through a film comprising: (2) a pair of press tools that are arranged opposite to each other so as to be able to approach and separate with a vapor growth substrate having abnormally grown protrusions on the surface sandwiched therebetween;
A film having plasticity inserted between the press tool and the surface of the vapor growth substrate having abnormally grown protrusions, and a press to press the vapor growth substrate by bringing the pair of press tools relatively close to each other. A vapor phase growth substrate protrusion removal device equipped with a mechanism.