JPH07122148B2 - Electrode etching state detection method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for accurately detecting the etching state of electrodes such as liquid crystals.

[0002]

2. Description of the Related Art Various methods have been conventionally used for etching electrodes to prevent over-etching.
For example, when forming a transparent electrode on a transparent substrate such as liquid crystal, the progress of dry etching cannot be visually recognized because both the substrate and the electrode are transparent, and the important etching end point to prevent overetching can be visually observed. It was extremely difficult to confirm.

Therefore, a method conceived is a method of continuously monitoring a specific gas component during etching by a mass spectrometer connected to a chamber. This is because the mass spectrometer is very expensive, and thus the apparatus cost is high. There is a problem that it becomes too high, and there is also a drawback that the detection speed is slow because of an indirect means such as gas analysis.

Further, it is desirable that the etching progresses uniformly on the entire substrate at the same time, but in some cases, the etching progresses partially unevenly, and the gas analysis method can only know the entire etching state. However, there is also a problem that it is not possible to detect uneven etching.

[0005]

The problems to be solved by the present invention are as follows.
The first is to directly detect the etching state and to detect the etching end point in real time, and the second is to accurately detect the etching state for each portion of the substrate.

[0006]

A method for detecting an etching state of an electrode according to the present invention accurately detects an etching end point in real time and detects the etching state of each part of a substrate.
With the method of detecting accurately, the lower electrode in the chamber (5)
(2) each individually irradiation location of infrared or laser for the installed substrate (1) in the infrared or laser irradiation with the irradiation location with a plurality of locations set on
On the other side of the substrate (1) after passing through the etching portion through a plurality of band pass filters (Fa) which superimpose the modulated signal specified on the above and selectively pass the infrared ray or the laser beam on which the modulated signal is superimposed. The amount of exposure of infrared or laser light that appears on the surface of the chamber
It is detected through the observation window (7) provided in (5) .

An electrode etching state detecting device for realizing the detecting method according to claim 1 is, as described in claim 2 , "infrared rays embedded in the lower electrode (2) in the chamber (5). Infrared rays or laser beams emitted from the infrared ray emitter (19) or the laser irradiator while the light emitter (19) or the laser irradiator is embedded in a plurality of places
It is assumed that each individually specified modulation signal is superposed, and an exposure detection device (F) for detecting the exposure amount from the substrate (1 ) is desired in the observation window (7) of the chamber (5).
A plurality of band-pass filters (Fa) that are arranged on a fixed position and that selectively pass infrared rays or laser beams with modulated signals superimposed thereon are installed in the exposure detection device (F). is there. In addition, this detection method
The electrode (4) to which the detection device can be applied is "transparent electrode or
Aluminum electrode ”.

[0008]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic perspective view showing the overall flow of the apparatus of the present invention, (A) loader, (B) substrate supply standby space,
(C) is an etching apparatus main body, (D) is a substrate discharge standby space, (E) is an unloader, (F) is an exposure detection apparatus,
(G) is an air supply system, and (H) is an exhaust system.

An outline of the flow of the substrate (1) will be explained.
The substrate (1) is set in the loader (A) in a cassette (not shown). In the loader (A), each time the substrate (1) is taken out one by one, it rises by one step, and when the cassette becomes empty, the loader (A) descends to the bottom dead center and is reloaded into a new cassette.

One substrate (1) unloaded from the loader (A) is waiting in the substrate supply waiting space (B) for the etching apparatus main body (C) to be empty, and the substrate (1) sent in before. ) Waiting for the end of etching. When the etching is completed and sent out and the etching apparatus main body (C) becomes empty, the waiting substrate (1) is sent in.

When the substrate (1) is fed into the etching apparatus body (C), it is fixed on the lower electrode (2) and then
A voltage is applied between the upper electrode (3) and the lower electrode (2), an arc is generated between the upper electrode (3) and the substrate (1), electrodes applied on the upper surface of the substrate (1) Etching (4). When the etching is completed, it is sent to the next substrate unloading waiting space (D). This etching operation will be described later in detail.

The etching-completed substrate (1 ') carried out to the substrate carry-out standby space (D) is inserted into the empty space of the cassette set in the unloader (E). When the insertion of the substrate (1 ') is completed, the unloader (E) descends by one step and waits for the insertion of the next substrate (1'). When the cassette is thus filled with the etching-completed substrate (1 ′), the cassette is replaced with an empty cassette, and the unloader (E) moves up to wait for the supply of the substrate (1 ′).

FIG. 3 is a detailed XX cross section of the etching apparatus main body (C) according to the present invention. A T-section electrode (2) is mounted on the bottom of the vacuum chamber (5), and an upper electrode (3) is mounted on a ceiling plate (3a) covering the ceiling surface of the vacuum chamber (5). The ceiling plate (3a) can be opened together with the upper electrode (3) if necessary, and the inside of the chamber (5) can be released. Ceiling board (3
An air intake system (G) is installed in a) so that a gas required for etching work is appropriately supplied. Further, a magnet (6) is mounted on the upper surface of the ceiling plate (3a), and the ceiling plate (3) is installed along the guide rail (6a).
a) It reciprocates above.

An observation window (7) is provided in front of the vacuum chamber (5 ).
Is provided so that the inside can be observed through the window glass (7a). Further, a substrate loading port (8) and a substrate loading port (9) are provided on both sides of the vacuum chamber (5), from which the vacuum chamber (5) of the substrate (1) is provided.
And out of to is carried out. In FIG. 3, the substrate loading port (8)
Is drawn.

At the center of the lower electrode (2) at the bottom of the vacuum chamber (5), there is a substrate clamp device (1) guided by a guide bar (10) suspended from the lower electrode (2).
1) is installed and a commercially available lifting cylinder (11a)
It is designed to go up and down.

(12) is an elevating plate mounted on the elevating cylinder (11a), and elevating bars (13) provided at four corners of the lower electrode (2) are fixed to the elevating plate (12). The upper end portion of the elevating bar (13) projects from the lower electrode (2), and a clamp (14) is installed between the two elevating bars (13). This clamp (14) is for clamping the side end of the substrate (1).

At the four corners of the lower electrode (2), substrate elevating pins (15) are installed inside the elevating bar (13) and are urged downward by the springs (16) in the retracted direction. The substrate lifting pins projecting consistent with (15) <br/> pin (17) is installed in the elevating plate (12), protrudes against the spring (16) Pin (17) a lower electrode (2 ) To a certain height.

The lower electrode (2) has a double structure and a cooling water passage (18) is formed therein to cool the lower electrode (2).

A plurality of through holes are formed in the lower electrode (2) at regular intervals, and an infrared light emitting device (19) or a laser irradiating device for irradiating an infrared ray or a laser beam is embedded. In this embodiment, it is embedded in multiple locations.
It As the infrared light emitter (19), for example, an infrared light emitting diode or the like is used.

Modulation signals individually specified are superimposed on the plurality of infrared light emitters (19) or laser irradiators . (20) is modulated superimposition device for superimposing the infrared or laser of the individual <br/> modulate signals individual infrared emitters (19) or laser irradiator. Thereby, the etching state of the substrate (1) can be partially grasped by detecting the infrared ray or the laser beam having a specific wavelength through the bandpass filter .

The exposure detection device (F) selectively detects the detection part (21), the measurement part (23) and the modulated irradiation light.
It is composed of a bandpass filter (Fa) that allows the light to pass through and an amplifier (22) thereof. In the case of the present embodiment, the detection unit (21) is installed so as to face the observation window (7) , the etching of the substrate (1) proceeds, the etching portion is exposed, and the vacuum chamber (5) overflows. The intensity of infrared rays and laser beams is observed. The amount of exposure increases as the etching progresses, and when the etching is completed, as shown in FIG.
The exposure amount becomes constant as shown in FIG. The end point of etching can be found by detecting where the exposure amount becomes constant. Although the detection part (21) of the exposure detection device (F) can be installed in the upper electrode (3), infrared rays are better observed through the observation window (7) as in this embodiment. It was possible to catch the increase of laser beam and laser beam remarkably.

Infrared rays and laser beams have different characteristics.
Te The constant has been modulated signal is superimposed, to the photodetector (F) is placed a band-pass filter (Fa) is by the quantity corresponding to the modulating signal, this
These are individually and selectively detected.

The substrate (1) is, for example, a glass plate or a transparent quartz plate used for liquid crystals, and an electrode (4) is formed on the entire upper surface thereof.
Are uniformly formed, and a masking layer (4a) having an appropriate pattern is formed on the electrode (4). The electrode (4) may be any as long as it does not pass infrared rays or laser beams in a non-etched state and allows infrared rays or laser beams to pass as the etching progresses. In this case, a transparent electrode made of an ITO film grown to 1,0024 strom is used. Further, it is not limited to this, and an aluminum electrode or the like may be used.

Then, the etched substrate (1 ') is carried out from the etching apparatus body (C), and the unetched substrate (1) is carried into the vacuum chamber (5) from the substrate carry-in port (8). At this time, the substrate clamp device (1
1) is located at the top dead center, the clamp (14) is waiting at the upper position shown by the phantom line, and the substrate elevating pin (15) projects from the upper surface of the lower electrode (2) to carry in the substrate (1). Waiting for In this state, when the substrate (1) is loaded and placed on the substrate lifting pins (15), the lifting cylinder (11)
a) actuates to operate the clamp (14) and the board lifting pin (1
5) Lower and. The substrate elevating pin (15) is first immersed in the lower electrode (2), and the substrate (1) is placed on the lower electrode (2).
Let stand. In this state, the clamp (14) continues to descend, and finally the side end of the substrate (1) is clamped. At this time, the protrusion pin (17) is separated from the lower end of the substrate elevating pin (15). This is the state shown in FIG. The gas required for dry etching is supplied from the gas supply system (G) into the vacuum chamber (5), and the exhaust gas consumed is discharged from the exhaust system (H).

In this state, the magnet (6) is moved onto the substrate (1), and a voltage is applied between the upper and lower electrodes (2) and (3) so that the substrate (1) and the upper electrode (3) are connected. A plasma is generated between the masking layer (4a) of the electrode (4 ).
The part exposed from is dry-etched. During this time, infrared rays (or a laser beam from a laser radiator) are emitted from the infrared emitter (19) of the lower electrode (2) to the lower surface of the substrate (1). As the dry etching progresses, infrared rays (or laser beams) are gradually exposed from the etching location to the upper surface side of the substrate (1),
Leak into the vacuum chamber (5). This is detected by the exposure detection device (F) through the observation window (7) .

As the etching progresses, the exposure amount increases,
With the completion of etching, the increase in exposure dose stops and the maximum value is maintained. The point showing the maximum value is the etching end point, and the end point of the etching can be accurately known in real time by detecting the increase amount of infrared rays (or laser beam).

Further, a plurality of infrared ray emitters (19) are installed and infrared rays or laser beams for individually irradiating the respective parts of the substrate (1) are superposed with respective specified modulation signals, Appear in the vacuum chamber (5) through each etching portion of the substrate (1) through a plurality of bandpass filters that selectively pass infrared or laser light with superimposed separate modulation signals. When detecting the exposure amount of infrared rays or laser beams, it is possible to know the etching state of each part of the substrate (1) in real time and accurately by knowing the intensity of each infrared ray or laser beam of the detected wavelength. It can be confirmed that the etching of the entire surface of the substrate (1) is completed by confirming that the intensity of the infrared ray or laser beam of the wavelength shows the maximum value. One in which it is possible to eliminate the etching irregularity.

When the etching is completed in this way, the voltage application between the upper and lower electrodes (2) and (3) is stopped to stop the generation of plasma, and then the magnet (6) is moved.

Then, the lifting cylinder (11a) is operated to first push up the clamp (14) to release the substrate (1), and then the ejecting pin (17) is moved to the substrate lifting pin (1).
5) It abuts and pushes it up to float the etching-completed substrate (1 ′). In this state, the substrate (1 ') is unloaded from the vacuum chamber (5). In the above embodiments, dry etching by plasma was mainly described, but the present invention is not limited to this, and it goes without saying that dry etching by RIE, ECR or other methods is also included.

[0030]

As described above, since the present invention has the structure as set forth in claim 1, the end point of etching can be accurately detected in real time even if it is invisible such as a transparent electrode. Moreover, through the observation window of the chamber
Thus, it is possible to detect the progress of etching by dividing the entire surface of the substrate into parts, and it is possible to prevent uneven etching by detecting infrared rays or laser beams of all wavelengths.

[Brief description of drawings]

FIG. 1 is a schematic flow chart of a substrate of the present invention.

FIG. 2 is a block diagram of a measurement system of the present invention.

FIG. 3 is a sectional view taken along line XX of the vacuum chamber of the present invention.

FIG. 4 is an enlarged cross-sectional view showing an etched state of the substrate of the present invention.

FIG. 5 is an infrared detection graph according to the present invention.

[Explanation of symbols]

(1) ... Substrate (2) ... Lower electrode (3) ... Upper electrode (4) ... Electrode (19) ... Infrared light emitter (F) ... Exposure detection device (Fa) ... Bandpass filter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-160173 (JP, A) JP-A-57-116342 (JP, A) JP-A-58-25478 (JP, A) JP-A-63- 244847 (JP, A) Actual development Sho 55-29549 (JP, U)

Claims (2)

[Claims] 1. Installed on a lower electrode in a chamber.
Superimposing the modulated signals are separately identified in the infrared or laser irradiation with the irradiation location while multiple locations set the irradiation location of infrared or laser to the substrate which is, infrared or laser by superimposing the modulated signal pieces exposure amount of infrared or laser passes through the etched portion appears at the other surface of the substrate through a plurality of bandpass filters for selectively passing
A method for detecting the etching state of an electrode, which is characterized by detecting through an observation window provided in the chamber separately . 2. An infrared emitting device or a laser irradiating device embedded in a lower electrode in a chamber has a plurality of embedding positions, and infrared rays or a laser beam emitted from the infrared emitting device or the laser irradiating device is individually specified.
Assuming that the modulated signals are superimposed, an exposure detection device that detects the amount of exposure from the substrate is installed in the chamber observation window.
7. A plurality of band pass filters, which are arranged at a position facing the above, and which selectively pass infrared rays or laser beams on which the module signal is superimposed, are installed in the exposure detection apparatus. 2. The etching state detecting device for an electrode according to 2 .