JPH08195382A - Semiconductor manufacturing device - Google Patents

Abstract

PURPOSE: To provide a technique for removing unnecessary substances adhering to the rear of a wafer after an etching operation is finished. CONSTITUTION: An ashing chamber 2 coupled to a plasma etching chamber 1 in one piece is provided with a pushing pin 30 which pushes up a wafer 17 subjected to plasma etching to a second position from a first position. By this setup, the wafer 17 is pushed up by the pushing pin 30 to a second position so as to be kept separate from an ashing electrode 27, whereby the rear of the wafer 17 is exposed to a plasma, so that unnecessary substances adhering to the rear of the wafer 17 is removed after a plasma etching operation is finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a technique effectively applied to a semiconductor manufacturing apparatus for removing unnecessary substances attached to the back surface of a semiconductor substrate.

[0002]

2. Description of the Related Art A dry etching process is widely used as a process processing means for manufacturing a semiconductor device represented by an LSI. In this dry etching process, plasma etching is used for various insulating films,
It is becoming indispensable for selectively removing the conductive film and the like.

In order to selectively remove the insulating film and the like by this plasma etching, after the insulating film is adhered to the entire surface of the semiconductor substrate (wafer) in advance, the wafer is masked with a photoresist while leaving unnecessary portions. Is placed in a plasma etching chamber and exposed to a plasma atmosphere to remove unnecessary portions of the unmasked insulating film. Next, this wafer is transferred into an ashing chamber and subjected to ashing, whereby the photoresist is ashed and removed.

Recently, a semiconductor manufacturing apparatus has been widely used in which such a plasma etching processing chamber is integrated with an ashing processing chamber, that is, a so-called in-line type is provided to improve processing efficiency. For example, "Latest LSI Process Technology", published by Industrial Research Institute, January 20, 1991, P481 to P482.
Describes the idea of such an in-line method in a process manufacturing apparatus.

[0005]

When the wafer is placed in the plasma etching chamber as described above and the plasma etching process is performed, an etching reaction product or a plasma etching process is formed on the back surface of the wafer after the plasma etching process is completed. There is a problem that foreign matter in the room adheres to form unnecessary substances, and the unnecessary substances cannot be removed.

That is, after the plasma etching process, the components of the photoresist as the mask and the components of the etched material are mixed and adhere to the front and back surfaces of the wafer as reaction products. Further, the foreign matter attached to the inner wall of the plasma etching processing chamber or the jig is also peeled off and attached to the front and back surfaces of the wafer together with the reaction products.

[0007] Among these unnecessary substances, those attached to the surface of the wafer are removed by plasma etching processing in the plasma etching processing chamber or by ashing processing in the ashing processing chamber. What was attached to the back is
Since the back surface of the wafer is supported by the etching electrode and the ashing electrode, it becomes impossible to remove it.

Particularly, in a semiconductor manufacturing apparatus in which the plasma etching processing chamber uses an electrostatic attraction plate to improve the contact between the back surface of the wafer and the etching electrode, the deposition of such unwanted substances becomes significant.

Thus, if the unwanted matter remains on the back surface of the wafer, the unwanted matter will be redeposited on the surface of the same wafer or on the surface of another wafer in a later process, so that pattern defects are caused. May occur.

An object of the present invention is to provide a technique capable of removing unnecessary substances attached to the back surface of a wafer after the etching process is completed.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0012]

Among the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

(1) The semiconductor manufacturing apparatus of the present invention is provided with a processing chamber for accommodating a semiconductor substrate on which desired processing has been completed and for removing unnecessary substances attached to the back surface of this semiconductor substrate.

(2) In the semiconductor manufacturing apparatus of the present invention, a plasma etching processing chamber for accommodating a semiconductor substrate and performing plasma etching processing, and a semiconductor which is integrally connected to the plasma etching processing chamber and has completed the plasma etching processing. And an ashing processing chamber that carries in the substrate and removes unnecessary substances attached to the back surface of the semiconductor substrate.

[0015]

According to the above-mentioned means (1), the semiconductor manufacturing apparatus of the present invention has a processing chamber for accommodating the semiconductor substrate on which the desired processing has been completed and for removing unnecessary substances adhering to the back surface of the semiconductor substrate. Since it is provided, it is possible to remove the unnecessary substances attached to the back surface of the wafer after the etching process is completed.

According to the above-mentioned means (2), the semiconductor manufacturing apparatus of the present invention has a plasma etching treatment chamber for accommodating a semiconductor substrate and performing a plasma etching treatment, and a plasma etching treatment chamber integrally connected to the plasma etching treatment chamber. Since an ashing processing chamber is provided for carrying in the semiconductor substrate after the plasma etching process and removing the unwanted matter attached to the back surface of the semiconductor substrate, the unwanted matter attached to the back surface of the wafer after the etching process is removed. Can be removed.

Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments.

In all the drawings for explaining the embodiments, parts having the same functions are designated by the same reference numerals, and the repeated description thereof will be omitted.

[0019]

【Example】

(Embodiment 1) FIG. 1 is a block diagram showing a semiconductor manufacturing apparatus according to Embodiment 1 of the present invention. The semiconductor manufacturing apparatus according to the present embodiment carries in a plasma etching processing chamber 1 that accommodates a wafer and performs plasma etching processing, and a wafer that is integrally coupled to the plasma etching processing chamber 1 and that has undergone the plasma etching processing, An ashing processing chamber 2 for removing unnecessary substances attached to the back surface of the wafer.

The plasma etching processing chamber 1 has a container 3, an anode electrode 4 is arranged above the container 3, and a reaction gas introducing pipe 5 is introduced from the upper plate 3A to carry out this reaction. A regulating valve 6 is provided in the gas introduction pipe 5. A discharge pipe 8 is provided in the bottom plate 7 common to the plasma etching processing chamber 1 and the ashing processing chamber 2, and a pressure adjusting valve 9 is provided in the discharge pipe 8.

A gate 10 for transferring a wafer is provided on the side plate 3B of the container 3, and the gate 10 can be opened and closed by a gate valve 11. An etching electrode 13 is provided on the bottom plate 7 via an insulating plate 12, and a high frequency power supply 15 is connected between the etching electrode 13 and ground through a blocking capacitor 14. A wafer 17 to be plasma-etched is arranged on the etching electrode 13 via an electrostatic attraction plate 16. A DC power supply 1 for electrostatic attraction on the electrostatic attraction plate 16.
8 are connected. Helium cooling pipe 19 from bottom plate 7
Is introduced, and a thermometer 20 is provided.

The ashing chamber 2 has a convex container 21.
And has an electrode 22 around the convex portion 21A of the container 21.
A high frequency power supply 23 is connected between the electrode 22 and the ground. 22A is a ground electrode.
An exhaust pipe 24 is provided on the bottom plate 7, and the exhaust pipe 24 is connected to a vacuum pump 25.
6 is provided. 5A is a reaction gas introducing pipe, and 6A is a regulating valve.

The wafer 17 can be transferred to and from the ashing processing chamber 2 through the gate 10, so that the wafer 17 after the plasma etching processing in the plasma etching processing chamber 1 can be carried in.

An ashing electrode 27 is provided on the bottom plate 7, and a heater 28 and a thermometer 29 are provided below the ashing electrode 27. On the ashing electrode 27, the wafer 17 loaded from the plasma etching processing chamber 1 is placed.

The wafer 17 is supported by push-up pins 30, and the push-up pins 30 can be moved up and down by a push-up mechanism 31. As a result, the wafer 17 can be switched between two height positions, the first stage being in contact with the ashing electrode 27 and the second stage being pushed up to the position indicated by the broken line by the push-up pin 30. ing. At the height position of the second stage, the wafer 17 can be subjected to the ashing process of the unwanted matter from the back surface.

Next, the operation of this embodiment will be described. As an example, a processing example of forming a contact hole in an insulating film attached on the wafer 17 will be described.

First, as shown in FIG. 2, a wafer 17 masked with a photoresist 33 leaving an unnecessary portion of an insulating film 32 such as an oxide film attached to the entire surface is transferred by a wafer transfer device to a gate. The valve 11 is opened, the gate 11 is carried into the plasma etching processing chamber 1 and the electrostatic chucking plate 16 on the etching electrode 13 is placed. Next, a reaction gas such as Freon gas is introduced from the reaction gas introduction pipe 5 to generate plasma between the anode electrode 4 and the etching electrode 13.

This plasma contains not only ions and radicals that contribute to etching, but also carbon, hydrogen, fluorine, etc., which are the components of the reaction product. These components adhere to the front and back surfaces of the wafer 17 as reaction products after the plasma etching process is completed. Further, the foreign matter attached to the inner wall of the plasma etching processing chamber 1 or the jig is also peeled off and attached to the front surface and the back surface of the wafer 17 together with the reaction product, and both of them form an unnecessary material. Further, since these unnecessary substances also remain on the electrostatic attraction plate 16, they affect the wafer to be processed next.

The plasma pressure is adjusted by the pressure adjusting valve 9, and the reaction gas is exhausted through the exhaust pipe 8.

As shown in FIG. 3, the wafer 17 which has been subjected to the plasma etching process in this manner has contact holes 34 formed by removing the unnecessary portions of the insulating film 3 which are not masked by the photoresist 33, and the surface of the wafer 17. Also, the unnecessary material 35 remains attached to the back surface.

Subsequently, the gate valve 11 is opened and the wafer 17 is loaded into the ashing processing chamber 2 through the gate 10 and placed on the ashing electrode 27. Next, plasma is generated from the high frequency power supply 23 through the electrode 22 to perform an ashing process. As a result, as shown in FIG. 6, the wafer 17 on the ashing electrode 27 is subjected to the ashing process at the position of the first stage, and the unnecessary material 35 on the surface is removed as shown in FIG. However, the unnecessary material 35 on the back surface remains attached.

At the position of the first stage, the wafer 17 is heated by the heater 28, so that the removal speed of the unnecessary material 35 is increased. The temperature of the heater 28 is measured by a thermometer 29.
Is measured by

Next, the push-up mechanism 31 is driven to push the wafer 17 up to the position indicated by the broken line by the push-up pin 30. As a result, as shown in FIG.
The wafer 17 on 0 is subjected to the ashing process at the position of the second stage, and the unnecessary material 35 on the back surface thereof is removed as shown in FIG. That is, at the second stage position, since the wafer 17 is supported in a state of being separated from the ashing electrode 27, the back surface of the wafer 17 is also exposed to the plasma, so that the unnecessary material 35 on the back surface is removed.

As a result, even when the plasma etching chamber 1 uses the electrostatic attraction plate 16 to improve the contact between the back surface of the wafer 17 and the etching electrode 13, it is attached to the back surface thereof. Since the unnecessary substances 35 can be almost removed, the features of the electrostatic attraction plate 16 can be utilized as they are.

The wafer 17 for which the ashing process has been completed is transferred to the outside of the ashing process chamber 2 through the gate 10. The ashing pressure is adjusted by the pressure adjusting valve 26, and the exhaust gas is exhausted through the exhaust pipe 24.

According to the first embodiment, the following effects can be obtained.

The ashing process chamber 2 integrally connected to the plasma etching process chamber 1 has push-up pins 30 for switching the wafer 17 after the plasma etching process to the first stage position and the second stage position. Since the wafer 17 is held by the push-up pin 30,
The back surface of the wafer 17 can be exposed to the plasma by pushing it up to the position of the above step and separating it from the ashing electrode 27.
It becomes possible to remove the unwanted matter 35 attached to the back surface of the.

(Embodiment 2) FIG. 8 is a block diagram showing a semiconductor manufacturing apparatus according to Embodiment 2 of the present invention. In the semiconductor manufacturing apparatus according to the present embodiment, the ashing processing chamber 2 for loading the wafer 17 after the plasma etching processing from the plasma etching processing chamber into the ashing processing chamber 2 after the front and back surfaces of the loaded wafer 17 are inverted in advance. Inversion chamber 37 for transfer
It has.

The inversion chamber 37 has a container 38, and the container 3
A wafer reversing stage 39 for reversing the wafer 17 carried in from the plasma etching processing chamber through the gate 10 is provided in the inside 8. This wafer reversal stage 39
In the state where the wafer 17 is held, the wafer 17 is rotated about the rotation axis 40 in the direction of the arrow so that the back surface of the wafer 17 is directed upward.

The wafer 17 whose front and back surfaces are thus inverted
Is transferred into the ashing processing chamber 2 through the gate 10. In the ashing processing chamber 2, the wafer 17 is placed on the ashing electrode 27 via the clamper 41. Figure 9
As shown in FIG. 5, the wafer 17 is subjected to the ashing process while the back surface of the wafer 17 is held upward by the clamper 41. The material of the clamper 41 is
A material that does not adversely affect the wafer 17 is selected, and materials such as aluminum and ceramics are desirable.

According to the second embodiment, the following effects can be obtained.

The ashing processing chamber 2 for loading the wafer 17 after the plasma etching processing into the plasma etching processing chamber reverses the front and back surfaces of the loaded wafer 17 in advance and then transfers it to the ashing processing chamber 2.
Since the ashing chamber 2 is equipped with
Can be carried in with the back surface thereof facing upward, and the back surface can be exposed to plasma, so that it is possible to remove the unwanted material 35 attached to the back surface of the wafer 17 after the plasma etching process is completed. Become.

As described above, the invention made by the present inventor is
Although the present invention has been specifically described based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the scope of the invention.

For example, in the first embodiment, the example in which the unwanted matter on the front surface of the wafer is removed at the position of the first step and then the unwanted matter on the back surface of the wafer is removed at the position of the second step has been described. In addition, after removing the unwanted matter on the back surface of the wafer at the second stage position, the unwanted matter on the wafer front surface may be removed at the first stage position.

Further, in the above-mentioned embodiment, an example of the object to be subjected to the plasma etching treatment is shown, but the present invention is not limited to this and can be applied to other materials.

Further, the means for removing the unnecessary substances on the back surface of the wafer is not limited to the ashing process, and it is also possible to use a means for alternately repeating vacuum suction and purging with an inert gas.

In the above description, the case where the invention made by the present inventor is mainly applied to the plasma etching which is the field of application which is the background of the invention has been described, but the invention is not limited thereto. The present invention can be applied at least under the condition of removing unnecessary substances attached to the back surface of the wafer.

[0048]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

Since a processing chamber for accommodating the semiconductor substrate on which the desired processing has been completed and removing the unwanted matter attached to the back surface of this semiconductor substrate is provided, the unwanted matter attached to the back surface of the wafer is removed after the etching processing is completed. It becomes possible to do.

Since the ashing chamber is provided for carrying in the semiconductor substrate after the etching process and removing the unwanted matter attached to the back surface of the semiconductor substrate, the unwanted matter attached to the back surface of the wafer is removed after the etching process is completed. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a semiconductor manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a step in the etching process by the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing another step of the etching process by the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a step in the ashing process performed by the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 5 is a sectional view showing another step of the ashing process by the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 6 is a schematic view showing a first stage of an ashing process by the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 7 is a schematic view showing a second stage of the ashing process step by the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 8 is a configuration diagram showing a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

FIG. 9 is a schematic diagram showing a main part of a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... Plasma etching processing chamber, 2 ... Ashing processing chamber, 3, 21, 38 ... Container, 4 ... Anode electrode, 5, 5
A ... Reactant gas introducing pipe, 6, 6A ... Adjusting valve, 7 ... Bottom plate, 8, 24 ... Exhaust pipe, 9, 26 ... Pressure adjusting valve, 10
… Gate, 11… Gate valve, 12… Insulation plate, 13…
Etching electrode, 14 ... Blocking capacitor, 1
5, 23 ... High frequency power supply, 16 ... Electrostatic adsorption plate, 17 ... Wafer, 18 ... DC power supply, 19 ... Helium cooling tube, 20 ... Thermometer, 22 ... Electrode, 25 ... Vacuum pump, 27 ... Ashing electrode, 28 ... Heater, 29 ... Thermometer, 30 ... Push-up pin, 31 ... Push-up mechanism, 32 ... Insulating film, 33 ... Photoresist, 34 ... Contact hose, 35 ... Unnecessary object,
37 ... Inversion chamber, 39 ... Wafer inversion stage, 40 ... Rotation axis, 41 ... Clamper.

Claims (5)

[Claims] 1. A semiconductor manufacturing apparatus comprising a processing chamber for accommodating a semiconductor substrate on which desired processing has been completed and for removing unnecessary substances adhering to the back surface of the semiconductor substrate. 2. A plasma etching processing chamber for accommodating a semiconductor substrate and performing a plasma etching process, and a semiconductor substrate which is integrally coupled to the plasma etching processing chamber and has undergone the plasma etching process and which is carried in to the semiconductor substrate. A semiconductor manufacturing apparatus, comprising: an ashing processing chamber that removes unnecessary substances attached to the back surface. 3. The semiconductor manufacturing apparatus according to claim 2, wherein the plasma etching processing chamber has an electrostatic attraction plate that supports the semiconductor substrate. 4. The semiconductor manufacturing according to claim 2, wherein the ashing processing chamber has an ashing electrode that supports the semiconductor substrate, and a pin member that separates the semiconductor substrate from the ashing electrode. apparatus. 5. The ashing processing chamber includes a reversing chamber that carries in the semiconductor substrate, inverts the front and back surfaces of the semiconductor substrate in advance, and transfers the inverted semiconductor substrate to the ashing processing chamber. The semiconductor manufacturing apparatus according to claim 2 or 3.