JP2001176851A - Dry etching system and method for detecting end point of dry etching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the end point of dry etching of a semiconductor film formed on a transparent substrate, by monitoring advance of dry etching from the back side of the transparent substrate. SOLUTION: The dry etching system 15 comprises upper and lower electrodes 2, 3 disposed oppositely in a reaction chamber 1, and a transparent substrate provided with a material being etched and mounted on the lower electrode 3, where plasma 8 is generated with high frequency power between the upper and lower electrodes 2, 3, in order to dry etch the material being etched. The dry etching system 15 further comprises members 5b, 5b for introducing plasma light generated in the reaction chamber 1 to the outside through openings 3a, 3a made in the etching material, the transparent substrate and the lower electrode 3, a detector 9 for detecting variation of the plasma light introduced by the members 5b, 5b, and a section 10 for determining the end point of dry etching, based on the detection results of the detector 9 and stopping high frequency power supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dry etching apparatus and a dry etching end point detecting method.
In particular, in the manufacture of a liquid crystal display device, a dry film that detects the end point of dry etching by monitoring the progress of dry etching of a metal film, a semiconductor film, an insulating film, and the like formed on a transparent substrate from the back surface of the transparent substrate. The present invention relates to an etching apparatus and a dry etching end point detection method.

[0002]

2. Description of the Related Art In recent years, with the development of flat panel displays, array elements have been refined. Among them, in a liquid crystal display device, a polysilicon thin film transistor with a built-in drive circuit is used.
nsistor (hereinafter referred to as "polysilicon TFT") is being actively developed. Therefore, in pattern processing of a metal film, a semiconductor film, and the like constituting the polysilicon TFT, a shift from a conventional wet etching method to a dry etching method, which is excellent when finer processing is performed, is progressing.

Here, a conventional dry etching apparatus will be described with reference to FIG. FIG. 7 is a schematic diagram showing a configuration of a conventional dry etching apparatus.

A conventional dry etching apparatus 30 includes a lower electrode 33 for mounting an array substrate 36 in the process of forming a polysilicon TFT in a reaction chamber 31, and a lower electrode 33.
An upper electrode 32 parallel to the upper electrode 3 is provided.
2 is grounded, and the lower electrode 33 is connected to a high frequency power supply 37. By applying high-frequency power to the lower electrode 33 by the high-frequency power supply 37, the reaction chamber 3
1. A plasma 38 is generated in 1.

The inside of the reaction chamber 31 is evacuated by a vacuum evacuation system (not shown).
The etching gas is introduced through the etching gas introduction pipe 34.

The metal film and the semiconductor film formed on the array substrate 36 are physically or chemically removed (dry-etched) by ions or radicals generated in the plasma. Usually, dry etching is performed after a specific photoresist pattern is formed on the film.

On the side wall of the reaction chamber 31, an internal observation window 35 made of a transparent material such as quartz is provided. Plasma light generated during the dry etching process is introduced into the photodetector 39 through the internal observation window 35. The introduced plasma light is split into light of each wavelength by a spectral prism (not shown), and light of a specific wavelength among the wavelengths passes through the interference filter 40 and the lens 41,
The light is detected by the optical sensor 42. The optical sensor 42 outputs an electric signal corresponding to the detected light emission intensity to the determination unit 43 connected to the optical sensor 42.

[0008] The determination unit 43 includes an A / D converter 44 and C
It comprises a PU 45, a ROM 46, a RAM 47 and the like. Said A
The / D converter 44 converts an electric signal output from the optical sensor 42 into a digital signal.
The digital signal output from the D converter 44 is stored.
The ROM 46 stores a program for detecting the end point of dry etching of a metal film, a semiconductor film, or the like in the process of dry etching the array substrate 36.

During the etching of the metal film and the semiconductor film formed on the array substrate 36, the CPU 4
5 is a RAM 4 based on a control program in the ROM 46.
The data (digital signal) of the change in the intensity of the light of the specific wavelength stored in 7 is monitored. Then, when the change in the intensity of the monitored light of the specific wavelength becomes saturated (constant), the CPU 45 determines that the dry etching has been completed, and stops the supply of the gas into the high-frequency power supply 37 and the reaction chamber 31. I do.

More specifically, when the object to be etched is SiO2 as an insulating film and the etching gas is a CF-based gas, a CO gas is generated during the etching process. The CO gas emits light when excited in plasma,
The emitted light passes through the internal observation window 35 and is split into light of each wavelength by a spectral prism (not shown). Of the respective wavelengths, light of a specific wavelength passes through the interference filter 40 and the lens 41 and passes through the optical sensor. 42 is detected. The light sensor 42
Outputs an electric signal corresponding to the detected intensity of light of a specific wavelength to the determination unit 43, and the electric signal is stored in the RAM 47. When the change in the electric signal stored in the RAM 47 becomes constant, the CPU 45 determines that the dry etching of the SiO 2 film has been completed, and stops the supply of the gas into the high-frequency power supply 37 and the reaction chamber 31.

In recent years, the number of pixels formed on an array substrate has been increasing with the increase in screen size and definition of liquid crystal display devices. Above all, in the case of a polysilicon TFT, since the array element region and the driver element region are formed by the same process, there is a strong demand for uniform processing of each element to be miniaturized, and furthermore, stability of the process. Therefore, it is necessary to accurately detect the end point of dry etching.

Various studies and developments have been made on a method of accurately monitoring an etching end point by a dry etching apparatus. For example, a method is provided in which a diffraction pattern is provided on a polysilicon film surface, a laser beam is irradiated on the surface, and the diffraction light is monitored by a photodetector to detect the end point of etching (Japanese Patent Application Laid-Open No. 5651515) A method of detecting the processing end point by monitoring the passing ultrasonic wave and the simultaneously oscillated ultrasonic wave that is not passed, and detecting the processing end point by the delay of the ultrasonic pulse and the fluctuation of the intensity difference between them (Japanese Patent Laid-Open No. 200539), a method of detecting the end point of etching by applying a direct current bias to the electrode on which the etching material is placed, and detecting the ion current flowing into the electrode (Japanese Patent Application Laid-Open No. Sho 59-43881). Method for measuring potential (Japanese Unexamined Patent Publication No.
-74843).

[0013]

The above-mentioned polysilicon TF
In T, since each of the constituent layers is a thin film, excessive etching in dry etching must be avoided.
Therefore, an additional etching process is performed for the purpose of just etching (etching of an amount equal to the film thickness of the material to be etched).

However, in the above method, the polysilicon TFT is taken out of the etching apparatus between the just etching and the additional etching, and the visual inspection, the film thickness measurement, and the continuity check are carried out. Etching must be performed. At that time, since the polysilicon TFT is once exposed to the atmosphere, the surface of the etching remaining film is deteriorated, and there is a problem that it is extremely difficult to achieve stability and reproducibility of additional etching.
Since the opening of the contact hole formed by etching affects the display characteristics of the liquid crystal display device,
Accurately detecting the end point of etching is a very important task.

[0015]

According to the present invention, in order to solve the above-mentioned problems, an end point of dry etching is detected by detecting a change in plasma light in a reaction chamber from a back surface of a transparent substrate constituting an array substrate by a detector. To provide a dry etching apparatus and a dry etching end point detecting method capable of detecting a dry etching.

That is, according to the first aspect of the present invention, a transparent substrate having a first electrode and a second electrode facing the first electrode in a reaction chamber and having a material to be etched formed on the first electrode is provided. In a dry etching apparatus for mounting, generating plasma by high frequency power between the first electrode and the second electrode, and dry-etching the material to be etched, the material to be etched, the transparent substrate, and the first electrode are connected to each other. Through, a light deriving unit that guides plasma light generated in the reaction chamber to the outside of the reaction chamber, a detecting unit that detects a light change of the plasma light guided by the light deriving unit, and a detection result obtained by the detecting unit. , Determine the end point of dry etching,
Determining means for stopping high frequency power.

According to the above configuration, the plasma light is guided to the detecting means by the light deriving means via the material to be etched, the transparent substrate, and the first electrode, and the detecting means detects a light change of the plasma light and makes a judgment. In the means, the end point of the dry etching can be determined based on the detection result obtained by the detecting means, and the high frequency power can be stopped to terminate the dry etching.

Therefore, unlike the conventional dry etching apparatus which monitors the surface of the substrate and detects a change in the plasma atmosphere, the dry etching apparatus is not affected by the environmental influence of the reaction chamber and is directly exposed to the material to be etched. And the end point of the dry etching can be accurately determined. In addition, it is possible to provide a dry etching apparatus which does not need to take out a material to be etched from the dry etching apparatus and perform a visual inspection, a film thickness measurement, and a continuity check.

According to a second aspect of the present invention, a first substrate and a second electrode facing the first electrode are provided in a reaction chamber, and a transparent substrate on which a material to be etched is formed is placed on the first electrode. Then, in a dry etching apparatus for generating plasma between the first electrode and the second electrode by high-frequency power and dry-etching the material to be etched, the dry etching apparatus includes the material to be etched, the transparent substrate, and the first electrode. A plurality of light deriving means for guiding plasma light generated in the reaction chamber to the outside of the reaction chamber, a detecting means for detecting a light change of the plasma light guided by the plurality of light deriving means, and a plurality of light beams obtained by the detecting means. A determination unit for determining an end point of the dry etching based on the detection result and stopping the high-frequency power.

With the above-described configuration, the light change of the plasma light at a plurality of locations can be detected by the plurality of light deriving means by the detecting means. Therefore, when dry-etching a material to be etched formed on a large-sized substrate used for a liquid crystal display device, variations in etching speed at a plurality of locations on the substrate and an etching time difference caused by an influence of an etching pattern are caused. A corresponding etching process can be performed, and a reliable etching process can be constructed.

Further, since the dry etching apparatus can perform uniform etching in the substrate while measuring the etching level in the etching process of the multilayer thin film, it is possible to perform an appropriate processing in a unit of single wafer processing. You can.

According to a third aspect of the present invention, a transparent substrate having a first electrode and a second electrode facing the first electrode in which a material to be etched is formed is placed on the first electrode. A method for detecting an end point of dry etching using a dry etching apparatus for generating plasma by high-frequency power between a first electrode and a second electrode to dry-etch a material to be etched, wherein the material to be etched, A detection step of detecting plasma light in the reaction chamber guided by the light extraction means through the transparent substrate and the first electrode by the detection means; and determining an end point of the dry etching based on a detection result obtained by the detection means. Judge by means,
An end point determining step of stopping the high frequency power.

According to the method, the plasma light is guided to the detecting means by the light guiding means through the material to be etched, the transparent substrate, and the first electrode, and the detecting means comprises:
The light change of the plasma light is detected, the judging means judges that the dry etching is completed by the light change of the plasma light, and stops the supply of the high-frequency power supply and the gas to the reaction chamber to automatically end the etching. be able to. Unlike the conventional dry etching method in which the observation from the substrate surface or the change in the plasma atmosphere is detected, the above method does not depend on the environmental influence of the reaction chamber and directly monitors the material to be etched. The end point can be accurately detected.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A dry etching apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
However, some parts are shown enlarged or reduced for ease of explanation.

FIG. 1 is a schematic diagram showing a configuration of a dry etching apparatus according to an embodiment of the present invention. In the dry etching apparatus 15, a lower electrode 3 on which the array substrate 6 is mounted and an upper electrode 2 parallel to the lower electrode 3 are provided in the reaction chamber 1. The upper electrode 2 is grounded, and the lower electrode 3 is connected to a high frequency power supply 7, which generates a plasma 8 in the reaction chamber 1.
The inside of the reaction chamber 1 is configured to be evacuated by a vacuum evacuation system (not shown).

An etching gas is introduced into the reaction chamber 1 through an etching gas introduction pipe 4, so that the etching gas is ejected from an upper electrode 2 having a large number of holes on the lower surface.

The lower electrode 3 is provided with a plurality (two in FIG. 1) of openings 3a, 3a.
One end sides of the cylindrical light guide members 5b and 5b are arranged in 3a, and the openings 3a and 3a and the light guide members 5b and 5b constitute light guide means. In addition, the light guide member 5b
The other end of 5 b protrudes out of the reaction chamber 1, and guides the plasma light in the reaction chamber 1 to the photodetector 9 via the array substrate 6. Instead of providing the openings 3a, the lower electrode 3 may be a transparent electrode.

At a position below the light guide members 5b (FIG. 1), a light detector 9 as a detecting means is provided. Although not shown, the light detector 9 includes a spectral prism, an interference filter, a lens, an optical sensor, and the like. When monitoring a light change occurring during the dry etching process, more specifically, when monitoring the light intensity of a specific wavelength of the plasma light, the plasma light is applied to the etching target material forming the array substrate 6. (Insulating film, semiconductor film, electrode film), glass substrate, and light guiding member 5b
-Introduced into the photodetector 9 via 5b. The introduced plasma light is separated into light of each wavelength by a spectral prism provided in the photodetector 9, and light of a specific wavelength among the wavelengths is detected by a light sensor through an interference filter and a lens. Is done.

When monitoring the light intensity of the plasma light in the reaction chamber 1, the light intensity of the plasma light is detected by an optical sensor without passing through a spectral prism, an interference filter or a lens.

The optical sensor outputs an electric signal corresponding to the detected light intensity or the light intensity of a specific wavelength to a judging unit 10 as judging means connected to the photodetector 9.

The determination unit 10 includes an A / D converter 11 and C
It includes a PU 12, a ROM 13, a RAM 14, and the like. A / D
The converter 11 receives the electric signal output from the photodetector 9 and converts it into a digital signal. The RAM 14 stores the digital signal output from the A / D converter 11.

The ROM 13 stores a program for detecting the end point of the dry etching of the metal film, the semiconductor film and the like in the dry etching of the array substrate 6.
The ROM 13 stores in advance the light intensity (preset value) of the plasma light detected by the photodetector 9 when the etching of the metal film is completed.

In the etching process of the array substrate 6, the CPU 12 monitors the light intensity stored in the RAM 14 or the data of the light intensity of a specific wavelength based on the control program of the ROM 13. And the CPU 12
Determines the end point of dry etching based on the monitored light intensity or the light intensity of a specific wavelength.
Then, the supply of gas into the reaction chamber 1 is stopped.

Incidentally, the light detector 9 is provided with the light guide members 5b and 5b.
b, the etched portions at a plurality of places (two places in FIG. 1) of the array substrate 6 are monitored, and the light intensity monitored at the two places or the light intensity at a specific wavelength on the substrate Detection corresponding to the variation of the end point of dry etching is possible.

(Embodiment 1) Next, Embodiment 1 will be described. A method of detecting the end point of the dry etching of the array substrate 6 by monitoring the light intensity of the plasma light in the reaction chamber 1 by the dry etching apparatus 15 configured as described above will be described with reference to FIGS. This will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view for explaining a dry etching process of a semiconductor film by the dry etching apparatus of the present invention, and FIG. 3 is a schematic cross-sectional view for explaining a dry etching process of a metal film by the dry etching apparatus of the present invention. is there.

First, as shown in FIG. 2A, an array substrate 6 is placed on a transparent glass substrate 16 by, for example,
Insulating film 17 made of SiO2 by plasma CVD
Is formed, and an amorphous silicon thin film is formed on the insulating film 17 by a plasma CVD method, and is irradiated with high energy density ultraviolet rays such as an excimer laser to crystallize the amorphous silicon into polycrystalline silicon. Thus, a semiconductor film (silicon film) 18 is formed. Further, a photoresist 19 is formed in a pattern on the semiconductor film 18 by photolithography.

The light transmittance of the glass substrate 16 is 9
It needs to be 8% or more. This is because, when a glass substrate having a light transmittance lower than 98% is used, the display performance and the load on the backlight increase, and the power consumption increases. Under such conditions, the semiconductor film 18 as an etched portion and the transparent insulating film (for example, SiOx, SiNx, TaOx, A
By monitoring (IOx) and the like from the back surface of the glass substrate 16, it is possible to reliably detect the light intensity of the plasma light generated during the etching.

The array substrate 6 thus formed is placed on the lower electrode 3 of the dry etching apparatus 15 shown in FIG. 1, and the inside of the reaction chamber 1 is evacuated by a vacuum evacuation system (not shown). A predetermined degree of vacuum is set.

Thereafter, an etching gas is introduced into the reaction chamber 1 from the upper electrode 2 having a large number of holes on the lower surface through an etching gas introduction pipe 4. Then, when the pressure in the reaction chamber becomes constant, high-frequency power is applied from the high-frequency power source 7 to the lower electrode 3 to generate plasma 8 in the reaction chamber 1 and start etching of the array substrate 6.

By performing the etching process,
As shown in FIG. 2B, the semiconductor film 18 is etched into the same shape as the photoresist 19. After that, the photoresist 19 is removed.

In the dry etching of the semiconductor film 18, the glass substrate 1
6, the reaction chamber 1 via the insulating film 17 and the semiconductor film 18
The light intensity of the plasma light inside is monitored by the light detector 9.

Specifically, in the ROM 13 (shown in FIG. 1), the light intensity at the etching end point of the semiconductor film 18 (that is, the light intensity was detected by the photodetector 9 via the glass substrate 16 and the insulating film 17 in advance). Data of plasma light intensity).

Therefore, during the dry etching of the semiconductor film 18, the glass substrate 16, the insulating film 17,
The light intensity of the plasma light is detected by the photodetector 9 through
The data is converted into digital data by the A / D converter 11,
The digital data is stored in the RAM 14. RAM1
When the digital data (data of the light intensity of the plasma light) stored in the memory 4 coincides with the light intensity data at the etching end point stored in the ROM 13 in advance, the CP
U12 determines that the dry etching of the semiconductor film 18 has been completed, and stops the supply of the gas into the high-frequency power supply 7 and the reaction chamber 1.

Next, a method for detecting the end point of dry etching of a metal film (gate electrode) will be described. FIG. 3 (a)
As shown in FIG. 1, a gate insulating film 20 made of SiO2 is formed on the semiconductor film 18 of the array substrate 6 by a plasma CVD method or the like, and a metal film 21 made of Al or the like is formed on the entire surface of the gate insulating film 20 by a sputtering method. Etc.
Further, a photoresist 22 is formed in a pattern on the metal film 21 by lithography.

Next, the array substrate 6 constructed as described above is used.
Then, the dry etching process is started by the dry etching apparatus 15 shown in FIG.

By performing the dry etching process, the metal film 21 is etched into the same shape as the photoresist 22, as shown in FIG. After that, the photoresist 22 is removed.

The dry etching of the metal film 21 is performed in the same manner as the dry etching of the semiconductor film 18. That is, at the same time as the start of the dry etching, the light intensity of the plasma light in the reaction chamber 1 is detected by the photodetector 9 via the glass substrate 16, the insulating film 17, the semiconductor film 18, the gate insulating film 20, and the metal film 21. Monitor.

The ROM 13 stores the light intensity (ie, the glass substrate 16 and the insulating film 1) at the etching end point of the metal film 21 in advance.
7, the data of the light intensity of the plasma light detected by the photodetector 9 via the semiconductor film 18 and the gate insulating film 20).

Therefore, during the dry etching process, the light intensity of the plasma light is detected by the photodetector 9 via the glass substrate 16, the insulating film 17, the semiconductor film 18, the gate insulating film 20, and the metal film 21, and the A / A The data is converted into digital data by the D converter 11, and the digital data is stored in the RAM 14. When the digital data (data of the light intensity of the plasma light) stored in the RAM 14 matches the data of the light intensity at the etching end point stored in the ROM 13 in advance, the CPU 12 performs the dry etching of the metal film 21. When it is determined that the process has been completed, the supply of gas into the high-frequency power supply 7 and the reaction chamber 1 is stopped.

(Embodiment 2) In Embodiment 2, a method for detecting the end point of dry etching when a contact hole is opened will be described with reference to FIG. FIG. 4 is a schematic sectional view for explaining formation of a contact hole by the dry etching apparatus of the present invention.

As shown in FIG. 4A, the array substrate 6
The impurity ions are implanted into the semiconductor film 18 by ion implantation using the metal film (gate electrode) 21 formed in the first embodiment as a mask, and the source region 18b, the channel region 18a, the drain An area 18c has been created. An interlayer insulating film 23 made of a silicon nitride film or the like is formed on the metal film 21 by PECVD or the like. On the interlayer insulating film 23, a photoresist 24 is formed in a pattern by lithography.

Next, the array substrate 6 configured as described above is used.
Is started by the dry etching apparatus 15 shown in FIG.

By performing the dry etching process, contact holes 25 reaching the surface of the semiconductor film 18 are opened in the interlayer insulating film 23 and the gate insulating film 20 as shown in FIG. After that, the photoresist 24 is removed.

In the dry etching process for opening the contact holes 25, the glass substrate 16, the insulating film 17, and the
The light intensity of a specific wavelength of the plasma light in the reaction chamber 1 is monitored by the photodetector 9 via the semiconductor film 18, the gate insulating film 20, and the interlayer insulating film 23.

FIG. 5 is a graph showing the relationship between the thickness of the semiconductor film and the light transmittance when a contact hole is formed by the dry etching apparatus of the present invention. The graph is obtained by detecting the light intensity of plasma light by the photodetector 9 in advance through the glass substrate 16, the insulating film 17, and the semiconductor film 18 having the changed thickness. From FIG. 5, it can be seen that the transmittance of light having a wavelength of about 550 nm changes most due to a change in the thickness of the semiconductor film. Therefore, it is understood that the transmittance of light having a wavelength of 550 nm can be easily measured through the semiconductor film.

Therefore, during the dry etching process, the light transmittance (light intensity) of plasma light having a wavelength of 550 nm is detected by the photodetector 9 via the glass substrate 16, the insulating film 17, and the semiconductor film 18. . The light transmittance at a wavelength of 550 nm does not change during the dry etching of the insulating films 20 and 23, but the transmittance changes when the dry etching is further advanced (when the semiconductor film 18 is over-etched). Therefore, the setting is made such that when the change in transmittance becomes 10% (arbitrary value), it is determined as the etching end point (end of the contact hole forming step). In the range of the wavelength to be measured, the wavelength of 550 nm having the largest change in transmittance is best,
It is convenient to use light having a wavelength of m, but there is no particular limitation.

That is, the dry etching for forming the contact holes 25 is proceeded, and as shown in FIG.
e) is dry-etched, and the light detector 9 detects the transmittance of light having a wavelength of 550 nm, which changes most by the change in the film thickness 18d of the semiconductor film 18 in that case. Thereafter, the data is converted into digital data by the A / D converter 11, and the digital data is stored in the RAM 14.

When the change of the digital data (data of the light transmittance of the plasma light having a wavelength of 550 nm) stored in the RAM 14 becomes 10%, the CPU 12 determines the etching end point (the opening of the contact holes 25, 25 is completed). ), And the supply of gas into the high-frequency power supply 7 and the reaction chamber 1 is stopped. The change in the transmittance is determined when the end point of the dry etching is 10%, but is not limited thereto, and is determined by the configuration of the dry etching apparatus and the dry etching speed.

(Other Matters) The metal film 21 (gate electrode) is made of Al, Ta, Ti, W, Mo, Cr, Cu.
The gate insulating film 20 and the interlayer insulating film 23 are made of any of highly transparent SiO2, SiNx, TaOx, AlOx, an organic film, or a combination thereof.

Further, the insulating film 17, the gate insulating film 20, and the interlayer insulating film 23 must have transparency even when observed from the back surface of the glass substrate 16, like the glass substrate 16 which is a transparent substrate. In the embodiment, the transmitted light of the plasma light is measured through the member to be etched, the glass substrate, and the like. Alternatively, the reflected light is measured by irradiating the back surface of the glass substrate with light. Other things are possible.

In the present invention, the light guide member 5b
5b are provided at two locations, but when detecting the end point of dry etching of a large-area, high-definition substrate such as used in a liquid crystal display device, a plurality (three or more) of light guide members 5b, 5b Are provided, and a plurality of etched portions are monitored, and detection corresponding to variation in the end point of dry etching on the substrate is possible.

[0062]

As described above, the end point of the dry etching can be detected by monitoring the plasma light in the reaction chamber from the back surface of the transparent substrate constituting the array substrate via the material to be etched. Unlike the conventional method of observing from the substrate surface or detecting changes in the plasma atmosphere, the detection method directly monitors the material to be etched without being affected by the environmental influence of the reaction chamber, so that dry etching can be accurately performed. Can be detected.

Further, by using a plurality of monitoring points, for example, in an etching process for a substrate having a large area such as a liquid crystal display device, a variation in an etching rate on the substrate and an etching time difference caused by an influence of an etching pattern are provided. It is possible to correspond to. For this reason,
A stable and reliable etching process can be constructed, and a large-area and high-definition liquid crystal display device can be realized. Therefore, a high-performance liquid crystal display device with stable panel characteristics can be realized very easily.

[Brief description of the drawings]

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

FIG. 2 is a schematic cross-sectional view for explaining a dry etching process of a semiconductor film by the dry etching apparatus of the present invention.

FIG. 3 is a schematic cross-sectional view for explaining a dry etching process of a metal film by the dry etching apparatus of the present invention.

FIG. 4 is a schematic cross-sectional view for explaining formation of a contact hole by the dry etching apparatus of the present invention.

FIG. 5 is a graph showing the relationship between the thickness of a semiconductor film and the light transmittance when a contact hole is formed by the dry etching apparatus of the present invention.

FIG. 6 is a schematic diagram illustrating over-etching of a semiconductor film when forming a contact hole.

FIG. 7 is a schematic diagram showing a configuration of a conventional dry etching apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction chamber 2 Upper electrode 3 Lower electrode 3a Opening 4 Gas introduction tube 5b Light guide member 6 Array substrate 7 High frequency power supply 8 Plasma 9 Photodetector 10 Judgment unit 11 A / D converter 12 CPU 13 ROM 14 RAM 15 Dry etching Device 16 Glass substrate 17 Insulating film 18 Semiconductor film 19 Photoresist 20 Gate insulating film 21 Metal film 22 Photoresist 23 Interlayer insulating film 24 Photoresist 25 Contact hole

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G043 AA03 BA01 BA03 CA02 DA05 EA15 GA07 GA10 GB12 JA03 JA05 LA01 NA06 4K057 DA14 DB01 DB04 DB05 DD01 DJ03 DM03 DN01 5F004 AA09 BA04 CB16 DB00 DB02 DB03 DB09 DB10 EA01

Claims (3)

[Claims] A first electrode having a first electrode and a second electrode facing the first electrode in a reaction chamber, a transparent substrate on which a material to be etched is formed is placed on the first electrode; A plasma generated by high-frequency power between the first electrode and the second electrode, and dry-etching the material to be etched, wherein the plasma is generated in the reaction chamber through the material to be etched, the transparent substrate, and the first electrode. A light deriving unit that guides the plasma light to the outside of the reaction chamber; a detecting unit that detects a light change of the plasma light guided by the light deriving unit; and determining an end point of the dry etching based on a detection result obtained by the detecting unit. And a determining means for stopping high frequency power. 2. A first electrode having a first electrode and a second electrode facing the first electrode in a reaction chamber, a transparent substrate on which a material to be etched is formed is placed on the first electrode, and a first electrode is provided. A plasma generated by high-frequency power between the first electrode and the second electrode, and dry-etching the material to be etched, wherein the plasma is generated in the reaction chamber through the material to be etched, the transparent substrate, and the first electrode. A plurality of light deriving means for guiding the plasma light to the outside of the reaction chamber, a detecting means for detecting a light change of the plasma light guided by the plurality of light deriving means, and a plurality of detection results obtained by the detecting means,
A determination means for determining an end point of the dry etching and stopping the high frequency power. 3. A first electrode having a first electrode and a second electrode facing the first electrode in a reaction chamber, and a transparent substrate on which an etching target material is formed is placed on the first electrode. A method for detecting an end point of dry etching using a dry etching apparatus that generates plasma by high frequency power between the first electrode and the second electrode and dry-etches the material to be etched, wherein the material to be etched, the transparent substrate, and the first A detecting step of detecting plasma light in the reaction chamber guided by the light deriving means by the detecting means through the electrode of the electrode, and determining the end point of the dry etching by the determining means based on the detection result obtained by the detecting means; An end point determining step of stopping power, a method for detecting an end point of dry etching.