KR20070055010A - Dry etching apparatus - Google Patents

Abstract

Dry etching apparatus is disclosed. Dry etching apparatus of the present invention, the etching process chamber is performed the etching process of the semiconductor wafer; Etch end point detector (EPD, End Point Detector) detachably coupled to one side of the etching process chamber, for detecting the end point of the etching process for the semiconductor wafer; And a coupling monitoring unit provided in at least one of the etching process chamber and the etching end point detector to monitor whether the etching process chamber and the etching end point detector are coupled to each other. According to the present invention, the etching process may be performed only when the etching end point detector is coupled to the etching process chamber, so that the etching process is performed without the etching end point detector being coupled to the conventional etching process chamber, thereby forming the semiconductor wafer as a desired film quality. It cannot be etched, and therefore, a phenomenon in which wafer defects or process defects occur can be reliably prevented.

Dry Etching Equipment, Etching, Etching Chamber, Etch End Point Detector (EPD), Coupling Monitoring Unit, Semiconductor Wafer

Description

Dry Etching Equipment {Dry Etching Apparatus}

1 is a schematic block diagram of a dry etching apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a state in which an etching end point detector is coupled to an etching process chamber in the dry etching apparatus of FIG. 1.

3 is an enlarged cross-sectional view of the coupling monitoring unit of the dry etching apparatus of FIG.

4 is a graph illustrating a detection frequency of light having a specific wavelength emitted from an etching process chamber as the etching process of the dry etching apparatus of FIG. 1 progresses.

FIG. 5 is a perspective view illustrating a state in which an etching end point detector is separated from an etching process chamber in the dry etching apparatus of FIG. 2.

6 is an enlarged cross-sectional view of the coupling monitoring unit of the dry etching apparatus of FIG. 5.

* Explanation of symbols for the main parts of the drawings

1: dry etching apparatus 10: etching process chamber

15: window 20: etching end point detector (EPD)

22: filter 24: monochromator

26 photoelectric amplifier tube (PMT) 30 control unit

40: coupling monitoring unit 42: push switch

44: compression spring 46: sensor

50: display unit E: end of etching

The present invention relates to a dry etching apparatus, and more particularly, to a dry etching apparatus that allows an etching process to proceed only when an etching end point detector is coupled to an etching process chamber.

The etching process of the semiconductor wafer is divided into wet etching and dry etching. A wet etching process generally involves placing a wafer in an etching solution (liquid) so that it is etched by liquid-solid chemistry, which is typically difficult to control and underetch, which is etched under the mask. Undercut) is one cause of the degradation of the resolution of the etching model, and the line width that can be etched is limited. In addition, there is a disadvantage that a problem that must deal with the additionally generated etching solution occurs. Therefore, at present, a lot of dry etching processes are used that can compensate for the disadvantages of the wet etching process.

Dry etching is a process in which etching is performed by physical action by ion bombardment on the surface of the wafer, chemical reaction of reactants generated in plasma, or physical and chemical action simultaneously. Physical dry etching is a phenomenon in which the surface wear is caused by the momentum when the ions are accelerated by the electric field towards the material to be etched and then collided, which includes ion beam etching (or ion beam milling). )), Sputter etching, and radio-frequency (RF) etching.

On the other hand, chemical dry etching refers to etching proceeding by supplying reactive species generated in the plasma to the surface of the material to be etched, whereby a chemical reaction occurs between the reactive species and the surface atoms, thereby generating volatile gas. In this case, isotropic etching takes place as well as wet etching. The difference from wet etching is that the reactor is in a vacuum and therefore easier to move from the surface of the volatile product, i.e., to remove it.

Physical and chemical dry etching involves ions, electrons, or photons impinging on the surface of the material to be etched by a physical method such as acceleration through an electric field to first activate the surface materials, Etching occurs when chemical reactions with species produce volatile gases. In this case, the ions themselves may also be reactants.

The dry etching process described above is performed in an etching process chamber, and the etching process chamber is provided with a wafer chuck for mounting a wafer therein, and a gas feed throw for injection of a predetermined gas at one upper end thereof. (gas feedthrough) is installed, and one side wall is formed with a window for mounting an end point detector (EPD).

In order for the dry etching process to form a desired fine pattern on the wafer, it is very important to selectively remove the unnecessary wafer film quality. An etching end point detector is used to detect the removal of the wafer film quality. Detect the end point.

On the other hand, if the dry etching process of the semiconductor wafer is repeated for a considerable number of times, the polymer generated in the film quality on the wafer surface during the etching process is deposited on the inner wall of the etching process chamber. In addition, when the deposited polymer falls on the semiconductor wafer, it may cause defects. In addition, it is necessary to perform regular cleaning to remove the polymer inside the etching process chamber. Regular PM maintenance is needed to prevent this. The periodic cleaning operation or the periodic PM operation as described above is performed after the etching end point detector is separated from the etching process chamber.

However, in the conventional dry etching apparatus, the etching end point detector must be separated from the etching process chamber, and after performing regular cleaning or periodic PM operation, the etching end point detector must be coupled to the etching process chamber before the etching process is performed again. Nevertheless, due to the carelessness of the user, the etching process of the semiconductor wafer is often performed without the etching end point detector being coupled to the etching process chamber again. There is a problem that causes defects and process defects.

Accordingly, an object of the present invention, in order to solve such problems in the prior art, the etching process can proceed only when the etching end point detector is coupled to the etching process chamber, the etching end point detector is not coupled to the conventional etching process chamber An etching process is performed in a state so that a semiconductor wafer cannot be etched to a desired film quality, and thus a dry etching apparatus capable of reliably preventing a phenomenon in which wafer defects or process defects occur is provided.

The object is, according to the present invention, an etching process chamber in which the etching process of the semiconductor wafer is performed; An etch end point detector (EPD, End Point Detector) detachably coupled to one side of the etch process chamber to detect an end point of the etch process with respect to the semiconductor wafer; And a coupling monitoring unit provided in at least one of the etching process chamber and the etching end point detector to monitor whether the etching process chamber and the etching end point detector are coupled to each other.

The controller may further include a controller configured to receive a signal about an end point of the etching process of the semiconductor wafer from the etching end point detector and generate a control signal for stopping the etching process.

Here, when the etching end point detector is not coupled to the etching process chamber, the controller stops the etching process based on a signal output from the coupling detecting unit.

The coupling monitoring unit may include: a push switch coupled to an opposite wall portion of the etching process chamber of the etching end point detector to be accessible and retracted toward the etching process chamber; An elastic member coupled to the etching end point detector to elastically bias the push switch toward the etching process chamber; And a sensor configured to sense a predetermined retracted position at which the push switch is retracted from the etching process chamber when the etching end point detector is coupled to the etching process chamber.

In this case, the elastic member may be a compression spring elastically deformed between the push switch and the sensor.

The display apparatus may further include a display unit configured to externally display whether the etching end point detector is coupled to the etching process chamber based on a result of detecting whether the etching process chamber and the etching end point detector are coupled to each other.

In this case, the display unit is preferably at least one of a monitor, a lamp, and a buzzer.

In addition, the coupling monitoring unit may be a contact sensor provided on an opposing wall portion of the etch end point detector and the etch process chamber which are in contact with each other to output an electrical signal to the controller when the etch end point detector and the etch process chamber are in contact with each other. .

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

1 is a schematic block diagram of a dry etching apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view illustrating a state where an etching end point detector is coupled to an etching process chamber in the dry etching apparatus of FIG. 1, and FIG. 3. 2 is an enlarged cross-sectional view of the coupling monitoring unit of the dry etching apparatus of FIG. 2. FIG. 4 is a graph illustrating a detection frequency of light having a specific wavelength emitted from an etching process chamber as the etching process of the dry etching apparatus of FIG. 1 is used. FIG. 5 is an etching end point detector of the etching process chamber of the dry etching apparatus of FIG. 2. Is a perspective view illustrating a separated state, and FIG. 6 is an enlarged cross-sectional view of the coupling monitoring unit of the dry etching apparatus of FIG. 5. As shown in these drawings, the dry etching apparatus 1 according to the embodiment of the present invention includes an etching process chamber 10, an etching end point detector 20, a coupling monitoring unit 40, and a controller ( 30 and a display unit 50.

The etching process chamber 10 is subjected to an etching process of the semiconductor wafer, and includes a cover 12 and a main body 13. The cover 12 is provided with a cover handle 14 and a locker 11, and the main body 13 is provided with a window 15 and screwing holes 17a and 17b. In addition, a wafer chuck (not shown) in which the semiconductor wafer is seated, a vacuum pump (not shown) for discharging gas therein, and a gas feed thrower may be provided in the etching process chamber 10. (Not shown) and the like are installed. When the etching process is performed in the etching process chamber 10, the film 65 applied to the surface of the semiconductor wafer 60 reacts with the injected gas and the plasma 69 to be etched to etch the upper surface of the semiconductor wafer 60. The desired pattern is formed.

The window 15 serves to emit light emitted from the inside of the etching process chamber 10 to the outside, and is provided with a material that can transmit light.

Etch end point detector 20 is detachably coupled to the window 15 provided in the etching process chamber 10, to detect the end point of the etching process for the semiconductor wafer 60, the etch end point detector 20 is a filter ( 22, a monochromator 24, and a photo amplifier tube 26.

The filter 22 is installed on the side where the etching end point detector 20 is in contact with the etching process chamber 10, and when the etching end point detector 20 is coupled to the etching process chamber 10, the filter 22 of the etching process chamber 10 is formed. It is in close contact with the window 15 located on one wall. The filter 22 receives the light generated when the etching process is performed in the etching process chamber 10 and sends the light to the monochromator 24.

The monochromator 24 is provided inside the etching end point detector 20 and selectively passes only light having a specific wavelength among the light received through the filter 22 to the photoamplification tube tube 26. send.

The photoelectric amplifier tube 26 is positioned inside the etch stop detector 20 and converts light of a specific wavelength received from the monochromator 24 into an electrical signal corresponding to the specific wavelength.

The etching end point detector 20 detects an end point of the etching process based on the electrical signal thus converted.

Meanwhile, the coupling monitoring unit 40 monitors whether the etching end point detector 20 is coupled to the etching process chamber 10, and the push switch 42 and the push switch 42 installed in the etching end point detector 20. Compression spring 44 for elastically biasing toward the etching process chamber 10, and a sensor 46 for sensing the position of the push switch 42.

The push switch 42 is installed in the etching end point detector 20. At the rear end of the push switch 42, the push switch 42 is elastically biased toward the etching process chamber 10 so that the push switch 42 protrudes from the etching end point detector 20 toward the etching process chamber 10. There is a spring 44. Then, when the compression spring 44 is in the retracted position, it is pressed by the push switch 42 and provided with a sensor 46 capable of sensing that the push switch 42 is in the retracted position. In the case where the etching end point detector 20 is separated from the etching process chamber 10, the push switch 42 may include the push switch 42 of the etching end point detector 20 as shown in detail in FIGS. 5 and 6. It is in the approaching position protruding a certain distance from the installation surface. However, when the etching end point detector 20 is coupled to the etching process chamber 10, the push switch 42 that protrudes is in a retracted position inserted into the etching end point detector 20.

The controller 30 receives the sensor 46 signal from the coupling monitoring unit 40 and the semiconductor wafer inside the etching process chamber 10 when the etch stop detector 20 is not coupled to the etching process chamber 10. By preventing the etching process, the etching process is performed while the etching end point detector 20 is not coupled to the etching process chamber 10, thereby preventing wafer defects and process defects that have occurred in the past. In addition, the control unit 30 outputs a signal to the display unit 50 when the etching end point detector 20 is not coupled to the etching process chamber 10, and the display unit 50 displays the state so that the user can display the etching process chamber 10. Etch end point detector (20) to check the combined state.

The display unit 50 displays the result of detecting whether the etching process chamber 10 and the etching end point detector 20 are coupled to the outside, and may be selected from a monitor, a lamp, and a buzzer. In this embodiment, a lamp (not shown) is used.

By this configuration, it will be described the operation of the dry etching apparatus according to an embodiment of the present invention.

When the semiconductor wafer 60 is seated on the wafer chuck (not shown) inside the etching process chamber 10, the cover 12 is brought into close contact with the main body 13 using the handle 14 and fixed with the rocker 11. After that, the user operates the dry etching apparatus 1 to proceed with the etching process. When the user operates the dry etching apparatus 1, the coupling monitoring unit 40 monitors whether the etching end point detector 20 is coupled to the etching process chamber 10. When the etching end point detector 20 is attached to the window 15 provided on one side of the etching process chamber 10, the push switch 42 installed in the etching end point detector 20 touches the outer wall of the etching process chamber 10. Since the pressure acts on the push switch 42, the compression spring 44 is compressed, and the push switch 42 is moved to the retracted position.

Therefore, when the push switch 42 is in the retracted position, the rear end of the push switch 42 is in contact with the sensor 46, and the sensor 46 signals a signal indicating that the push switch 42 is in the retracted position. Output to the control unit 30. Receiving a signal from the sensor 46 indicating that the push switch 42 is in the retracted position, the control unit 30 outputs a control signal for proceeding the etching process of the semiconductor wafer 60.

When the etching process is performed, a vacuum pump (not shown) is operated to bring the interior of the etching process chamber 10 to a predetermined vacuum state, and then a predetermined gas is etched through a gas feed throw (not shown). It is introduced into the chamber 10. In addition, a process of selectively removing the film 65 applied to the surface of the semiconductor wafer 60 through the plasma 69 generated by applying a high frequency power source is performed. ) And the film 65 applied to the surface of the wafer react with each other and light is emitted through the window 15 located on the wall of the etching process chamber 10.

Light emitted through the window 15 is received by the filter 22 in close contact with the window 15, and the received light detects only a specific wavelength by the operation of the monochromator 24. do. The light of the detected specific wavelength is converted into an electrical signal corresponding to the specific wavelength through the photo amplifier tube 26.

The etch end point detector 20 compares the detection frequency of a specific wavelength with a pre-input reference value based on the electric signal converted as described above, and when it is determined that the compared value is equal to or less than the reference value, the etch end point E is reached. (E) detects and outputs a signal to the controller 30 to stop the etching process.

Looking at the determination process of the etching end point (E) in detail, as the etching proceeds, the film quality 65 trapped on the wafer surface is removed by the plasma 69 generated by applying a high frequency power source, thereby etching The frequency of a specific wavelength according to the component of the film 65 removed from the light generated in the process chamber 10 is increased (A section).

However, as the etching proceeds and the specific film quality 65 to be removed decreases, the frequency of specific wavelengths of light generated in the etching process chamber is also reduced (B section). As the etching process proceeds, if the frequency of a specific wavelength continues to decrease and falls below the etching end point E, which is a previously input value, the etching end point detector 20 determines that the etching end point E has been reached and controls the signal. Output to 30 to terminate the progress of the dry etching process.

On the other hand, if the dry etching process of the semiconductor wafer is repeated for a considerable number of times, polymer generated in the film quality 65 on the wafer surface during the etching process is deposited on the inner wall of the etching process chamber 10. In addition, when the deposited polymer falls on the semiconductor wafer, it may cause defects. In addition, the etching process chamber 10 may have to be periodically cleaned to remove the polymer inside the etching process chamber 10. Periodic PM (Prevent Maintenance) work is required to prevent internal and external abnormalities, and regular cleaning work or regular PM work is performed after separating the etching end point detector 20 from the etching process chamber 10. Same as one.

Therefore, after performing a regular cleaning operation or a regular PM operation, before the etching process is performed again, the etching end detector 20 must be coupled to the etching process chamber 10. Is pushed to the outside from the mounting surface on the etch end point detector 40, the sensor 46 is pushed. A signal indicating that the switch 42 is in the approaching position is output to the controller 30, and the controller 30 thereby inhibits the progress of the etching process in the etching process chamber 10.

As a result, the etching process does not proceed in the state where the etching end point detector 20 is not coupled to the etching process chamber 10, thereby preventing wafer defects or process defects that have occurred in the past. In addition, the control unit 30 outputs a signal indicating that the etch stop point detector 20 is not coupled to the etching process chamber 10 to the display unit 50, so that the display unit 50 can check it from the outside. Indicates.

In the above-described embodiment, the coupling monitoring unit 40 is described above in the case of the push switch 42, the coupling monitoring unit 40 is in contact with the etching end point detector 20 and the etching process chamber 10 mutually It may be a contact sensor provided in the opposite wall portion to output a signal to the control unit 30 to detect the coupling when the coupling monitoring unit 40 and the etching end point detector 20 is in contact.

In addition, in the above-described embodiment, although the elastic member of the coupling monitoring unit 40 is shown as a compression spring 44, rubber having elastic force in addition to the compression spring 44 may be possible.

As described above, the present invention is not limited to the described embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention, which will be apparent to those skilled in the art. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

As described above, according to the present invention, the etching process may be performed only when the etching end point detector is coupled to the etching process chamber, and the etching process is performed without the etching end point detector being coupled to the conventional etching process chamber. It is not possible to etch the wafer into the desired film quality, and thus a phenomenon in which wafer defects or process defects occur can be reliably prevented.

Claims (8)

An etching process chamber in which an etching process of the semiconductor wafer is performed; An etch end point detector (EPD, End Point Detector) detachably coupled to one side of the etch process chamber to detect an end point of the etch process with respect to the semiconductor wafer; And And a coupling monitoring unit provided in at least one of the etching process chamber and the etching end point detector to monitor whether the etching process chamber and the etching end point detector are coupled to each other. The method of claim 1, And a controller configured to receive a signal about an end point of the etching process of the semiconductor wafer from the etching end point detector and generate a control signal for stopping the etching process. The method of claim 2, And the control unit stops the etching process based on a signal output from the coupling detecting unit when the etching end point detector is not coupled to the etching process chamber. The method of claim 3, The coupling monitoring unit, A push switch coupled to an opposing wall portion of the etch process chamber of the etch end point detector to be accessible and retracted toward the etch process chamber; An elastic member coupled to the etching end point detector to elastically bias the push switch toward the etching process chamber; And And a sensor for sensing a predetermined retreat position from which the push switch is retracted from the etching process chamber when the etching end point detector is coupled to the etching process chamber. The method of claim 4, wherein The elastic member is a dry etching apparatus, characterized in that the compression spring elastically deformed between the push switch and the sensor. The method of claim 4, wherein And a display unit configured to externally display whether the etching end point detector is coupled to the etching process chamber based on a result of detecting whether the etching process chamber and the etching end point detector are coupled to each other. The method of claim 6, And the display unit is at least one of a monitor, a lamp and a buzzer. The method of claim 3, The coupling monitoring unit, And a contact sensor provided at opposite wall portions of the etch end point detector and the etch process chamber to contact the etch end point detector and the etch process chamber to output an electrical signal to the controller when the etch end point detector and the etch process chamber are in contact with each other.

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