JPH0536638A - Rear etching treatment equipment - Google Patents

Abstract

PURPOSE:To simplify etching process, and reduce flaw on the surface of a substrate and adhesion of fine particles, by magnetically levitating a conveying tool on which a substrate is mounted, carrying the substrate without contact of the substrate surface, and etching the rear. CONSTITUTION:A substrate 2 is carried into a treatment chamber, and mounted on a conveying tool 4. Since a current does not flow in this case, the conveying tool 4, which mounts the substrate 2 in the state that the surface faces upward, is situated on the lower electrode 1. When a current flows through a coil 5, the conveying tool 4 mounting the substrate 2 is levitated by the magnetic repulsive force between the magnetic field generated by the coil 5 and the magnetic field generated by the conveying tool 4, and brought into contact with an upper electrode 3. In this state, reaction gas containing halogen elements is introduced into the treatment chamber from a gas introducing inlet 8. The rear of the substrate 2 is etched by applying high frequency electric voltage to the lower electrode 1. Thereby etching process is simplified. Flaw on the substrate surface and adhesion of fine particles thereon are reduced, and yield also is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a semiconductor device, and more particularly to an apparatus for removing a thin film formed on the back surface of a semiconductor substrate.

[0002]

2. Description of the Related Art A semiconductor device is manufactured mainly by repeating steps such as film deposition on a semiconductor substrate (hereinafter referred to as a substrate), pattern formation, heat treatment, and impurity introduction.

Here, in order to form a thin film, a batch type chemical vapor deposition for simultaneously processing a plurality of substrates is used.
When using (CVD method) or the like, a thin film is also formed on the back surface of the substrate. Usually, in a semiconductor device, it is necessary to remove the thin film formed on the back surface in order to form the conductive portion on the back surface. Conventionally, as a method of removing the thin film formed on the back surface of the substrate, the first method is to apply a resist on the front surface of the substrate, and then perform plasma treatment on the substrate to form a resist on the back surface. There is a method of removing the thin film. As a second method, there is a method of inverting the substrate so that the back surface is the top surface, and then plasma processing is performed by an apparatus in which only the top surface is exposed to plasma for etching to remove the thin film formed on the back surface.

FIG. 3 is a diagram showing a conventional etching method, and shows an apparatus of the second method in which the substrate is inverted and only the back surface is etched. In this device, the substrate 2 which has been inverted and conveyed is placed on the upper part of the lower electrode 1 with the surface thereof facing downward. In this state, a reaction gas containing a halogen element such as chlorine or fluorine is introduced into the processing chamber through the gas inlet 8 and a high frequency voltage is applied to the lower electrode 1 to etch the back surface of the substrate 2. The reaction gas that does not contribute to the reaction, the gas after the reaction is generated, and the like are exhausted from the exhaust port 9. In this method, the central portion of the lower electrode 1 is concave and the peripheral portion of the substrate 2 is in order to prevent scratches and adhesion of fine particles due to contact of the substrate 2 with the lower electrode 1. It is supposed to be supported by only. Further, a projecting portion is also provided on a transfer arm or the like to reduce the contact portion with the substrate 2 and to support only the peripheral portion.

[0005]

By the way, in the conventional back surface etching apparatus, the substrate 2 is inverted and processed, so that the substrate 2 is manually inverted or the substrate 2 is inverted.
A transport device for reversing is required. for that reason,
In case of manual reversal, it is necessary to perform the work carefully,
Not only is it complicated, but it may be scratched if handled incorrectly. In addition, when a carrier device is used, the mechanism becomes complicated and dust is generated. Further, since the plasma treatment is performed in a state where the surface of the substrate 2 is in contact with the lower electrode 1, adhesion of fine particles and generation of scratches on the surface of the substrate 2 easily occur.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an etching apparatus and an etching method capable of levitating a substrate and performing back surface etching with high cleanliness.

[0007]

A plasma processing apparatus according to the present invention comprises a substrate transfer tool made of a magnetic material, and a magnetic material for floating the transfer tool.

Further, in the manufacturing method of the present invention, the substrate is placed on a carrier tool made of a magnetic material, and the carrier tool is magnetically floated to etch the back surface of the substrate.

[0009]

The backside etching apparatus according to the present invention magnetically levitates the carrying tool on which the substrate is placed, and the substrate can be carried and the backside can be etched without contacting the surface of the substrate. Therefore, the process can be simplified and adhesion of fine particles to the surface of the substrate can be prevented.

[0010]

EXAMPLES Example 1. An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an etching method by an etching apparatus according to an embodiment of the present invention. 4 is a substrate provided in the processing chamber of the etching apparatus, and the substrate 2 is mounted thereon and lifted.
The transfer tool 5 that moves down is a coil that is provided outside the processing chamber and that floats the transfer tool 4. Transport tool 4
Is a ring-shaped permanent magnet whose upper and lower parts have opposite magnetism, and as shown in FIG. 2, the outer peripheral portion 7 of the supporting surface 6 of the substrate 2 is formed higher than the supporting surface by a height h. There is. The height h is larger than the thickness of the substrate 2. The coil 5 is formed in a ring shape corresponding to the carrying tool 4, and is provided on the lower side of the carrying tool 4.

Next, the operation will be described. First, Fig. 1
As shown in (a), the substrate 2 is transferred from the carry-in port (not shown) into the processing chamber and placed on the transfer tool 4. At this time, since no current is flowing in the coil 5 yet, the transfer tool 4 on which the substrate 2 with the surface thereof facing upward is placed on the lower electrode.

Next, as shown in FIG. 1 (b), an electric current is passed through the coil 5, and the magnetic field generated by the coil 5 and the magnetic field generated by the transfer tool 4 cause the magnetic repulsion to transfer the substrate 2 on the transfer. The tool 4 floats and contacts the upper electrode 5. In this state, for example, a reaction gas containing a halogen element such as chlorine or fluorine is introduced into the processing chamber through the gas introduction port 8 and then a high frequency voltage is applied to the lower electrode 1 to etch the back surface of the substrate 2. Be done.

In FIG. 2, the substrate 2 is placed on the flat surface 6 of the transfer tool 4 with the surface upward, and the height h of the outer peripheral portion 7 of the transfer tool 4 is larger than the thickness of the substrate 2, so that the magnetic force is high. As a result, when the outer peripheral portion 7 of the transfer tool 4 comes into close contact with the upper electrode 3, the reaction gas is prevented from entering the inside and the surface of the substrate 2 is not etched.

Example 2. In the above embodiment, the carrying tool 4 is a permanent magnet and the coil 5 is used to create a magnetic field for levitating the carrying tool 4, but both may be electromagnets, and the carrying tool 4 may be an electromagnet. Then, a permanent magnet may be attached below the lower electrode 1. Further, the electromagnet 5 has the same effect whether it is mounted on the upper electrode 3 or embedded in the upper electrode 1 or the lower electrode 3.

By the way, in the above embodiment, the case where the film formed on the back surface is removed has been described, but the present invention is not limited to this. First, the surface of the substrate 2 in the state of FIG. In the state of (b), it is possible to carry out etching continuously with the back surface.

[0016]

As described above, according to the present invention, by magnetically levitating the substrate transfer tool made of a magnetic material, the back surface can be etched without inverting the substrate manually or by a complicated device. Therefore, the process can be simplified. In addition, scratches and adhesion of fine particles to the surface of the substrate can be reduced, so that the yield is improved.

Furthermore, it is possible to etch both the front surface and the back surface of the substrate in the same processing chamber, and the effect of increasing the efficiency can be expected by continuously etching the front surface and the back surface.

[Brief description of drawings]

FIG. 1 is a sectional view showing a back surface etching apparatus according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a substrate transfer tool according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional back surface etching apparatus.

[Explanation of symbols]

 2 Semiconductor substrate 4 Transfer tool 5 Coil

Claims (1)

Claim: What is claimed is: 1. A transfer means, which is provided in the processing chamber, is configured to mount a semiconductor substrate, and which is formed so as to expose an inner central portion of the semiconductor substrate to the processing chamber, and a transfer means. A backside etching processing apparatus which is provided correspondingly and has a magnetic raising / lowering means capable of floating the conveying member. The semiconductor substrate is placed on the magnetic material conveying means, the conveying means is levitated by the magnetism ascending / descending means and brought into close contact with the upper electrode side, and then a reaction gas is introduced into the processing chamber to generate plasma, A backside etching processing apparatus that exposes the backside of the semiconductor substrate exposed from the opening of the transfer means to this plasma and performs etching.