KR102175086B1 - Apparatus for treating substrate and method for treating apparatus - Google Patents

Abstract

Disclosed is a substrate treating device capable of removing harmonics caused by the nonlinearity of plasma in the substrate treating device. According to the present invention, the substrate treating device may comprise: a process chamber having a treatment space therein; a support unit supporting a substrate in the treatment space; a gas supply unit supplying a process gas into the treatment space; a plasma source generating plasma from the process gas; a sensor sensing harmonics in the treatment space during a process; a distortion signal generation unit generating a distortion signal by receiving harmonic information from the sensor; a power generation unit applying the distortion signal to an impedance matching unit; and an impedance matching unit matching impedance between the power generation unit and the process chamber. Each of the power generation unit and the distortion signal generation unit may be provided in a corresponding number. Alternatively, the distortion signal generation unit may be connected to a high-frequency power source having a frequency at which the harmonics is generated above 100 MHz among high-frequency power sources included in the power generation unit.

Description

Substrate processing apparatus and substrate processing method {APPARATUS FOR TREATING SUBSTRATE AND METHOD FOR TREATING APPARATUS}

The present invention relates to a substrate processing apparatus and a substrate processing method. More specifically, the present invention relates to a substrate processing apparatus and a substrate processing method capable of removing harmonics generated in a substrate processing process.

In order to manufacture a semiconductor device, a desired pattern is formed on the substrate by performing various processes such as photolithography, etching, ashing, ion implantation, thin film deposition, and cleaning. Among them, the etching process is a process of removing a selected heating region from among the films formed on the substrate, and wet etching and dry etching are used. Among them, an etching apparatus using plasma is used for dry etching.

In general, to form a plasma, an electromagnetic field is formed in an inner space of a process chamber, and the electromagnetic field excites a process gas provided in the process chamber into a plasma state. Plasma refers to an ionized gas state composed of ions, electrons, and radicals. Plasma is created by very high temperatures, strong electric fields, or RF electromagnetic fields.

In a capacitively coupled plasma processing apparatus using radio frequency (RF), an upper electrode and a lower electrode are arranged in parallel in a processing container, and a substrate to be processed (semiconductor wafer, glass substrate, etc.) is typically placed on the lower electrode. , A high frequency of a frequency suitable for plasma generation (usually 13.56 MHz or higher) is applied to the upper or lower electrode. By the application of this high frequency, electrons are accelerated by a high frequency electric field generated between two electrodes facing each other, and plasma is generated by collisional ionization between the electrons and the processing gas. A thin film is deposited on the substrate or a material or thin film on the surface of the substrate is chipped by a gas phase reaction or a surface reaction of radicals or ions contained in the plasma. In order to improve the processing quality of the substrate, it is necessary to form a uniform plasma in the process chamber.

1 shows a substrate processing apparatus in the prior art. The substrate processing apparatus according to the prior art may include an upper RF power source 441, an upper electrode 410, a lower electrode 220, and a lower RF power source 222. In addition, it may include an upper impedance matching unit 442 and a lower impedance matching unit 225 connected to the upper and lower RF power, respectively.

The upper RF power 441 may provide first RF power, and the upper electrode 410 may generate plasma by receiving the first RF power. The lower electrode 220 may be disposed to face the upper electrode 410. The lower RF power source 222 may be connected to the lower electrode 220. The lower RF power supply 222 provides second RF power, through which ionic particles contained in the plasma may move to the lower electrode 220.

In the substrate processing apparatus according to the prior art, only a circuit for performing impedance matching between a high frequency power source and a chamber was included, and it was difficult to remove harmonics generated by this.

In addition, even though the harmonics can be removed, the first, second, and third harmonics must be removed because the harmonics have a characteristic that greatly decreases after the third order. Harmonics cannot be attenuated simultaneously, and only one harmonic can be selectively attenuated. As a result, harmonics are not completely removed, and thus the plasma density in the chamber is not uniformly treated.

An object of the present invention is to provide a substrate processing apparatus capable of removing harmonics generated due to nonlinearity of plasma in the substrate processing apparatus.

An object of the present invention is to provide a substrate processing apparatus capable of removing harmonics through a distortion signal generator included in the substrate processing apparatus.

The problem to be solved by the present invention is not limited to the above-described problems, and the problems that are not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings. .

An apparatus for processing a substrate is disclosed.

A substrate processing apparatus according to the present invention includes: a process chamber having a processing space therein; A support unit supporting a substrate in the processing space; A gas supply unit for supplying a process gas into the processing space; A plasma source for generating plasma from the process gas; A sensor for sensing harmonics in the processing space during a process; A distortion signal generator for generating a distortion signal by receiving harmonic information from the sensor; A power generator for applying the distortion signal to an impedance matching unit; And an impedance matching unit that matches impedance between the power generation unit and the process chamber.

Each of the power generation unit and the distortion signal generation unit may be provided in a corresponding number.

The distortion signal generator may be connected to a high frequency power source having a frequency at which harmonics are generated at 100 MHz or higher among high frequency power sources included in the power generator.

The distortion signal generator may include some of a nonlinear generator circuit, a phase shift circuit, a size adjustment circuit, and an amplifier.

The distortion signal generator may sense a harmonic measured from the sensor, generate a signal having the same magnitude as the always sensed harmonic and opposite in phase, and transmit it to the power generator.

The power generator may generate power by mixing a distortion signal transmitted from the distortion signal generator with a main signal that is a signal for forming plasma in the process chamber.

The harmonic may be a harmonic generated due to nonlinearity in the plasma.

The harmonic may be a harmonic generated by a high frequency RF power included in the power generating unit.

According to another embodiment of the present invention, a method for processing a substrate is disclosed.

What is claimed is: 1. A method of processing a substrate in a substrate processing apparatus that is connected to an RF power source to generate plasma in a process chamber, the method comprising: determining whether a harmonic is generated; Generating a distortion signal capable of removing the harmonics when it is determined that the harmonics have occurred; It may include; transmitting the generated distortion signal to a power transmission unit.

The power transmission unit may include generating power by mixing a main signal that is a signal for forming a plasma in the process chamber and the distortion signal, and applying it to the process chamber.

Forming a plasma through the power generated by the power transmission unit in the process chamber; Sensing a harmonic at an output end of the process chamber; And when the harmonic is sensed, repeating generating and applying a distortion signal corresponding to the sensed harmonic, and repeating until the harmonic is not sensed.

When the harmonic is not sensed, not generating a distortion signal.

In the present invention, a substrate processing apparatus capable of removing harmonics generated due to nonlinearity of plasma in the substrate processing apparatus is provided.

In the present invention, harmonics may be removed through the distortion signal generator included in the substrate processing apparatus.

According to the present invention, it is possible to improve and optimize plasma nonlinearity caused by harmonics.

The effects of the present invention are not limited to the above-described effects, and effects that are not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings.

1 is a diagram showing the configuration of a substrate processing apparatus according to the prior art.
2 is an exemplary diagram showing a substrate processing apparatus according to an embodiment of the present invention.
3 is a diagram showing the configuration of a substrate processing apparatus according to an embodiment of the present invention.
4 is a diagram showing the configuration of a substrate processing apparatus according to another embodiment of the present invention.
5 is a diagram illustrating an example of a distortion signal generator according to an embodiment of the present invention.
6 is a diagram illustrating a method of removing harmonics using a distortion signal generator according to the present invention.
7 is a flowchart of a substrate processing method according to the present invention.

Other advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments to be described later in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only this embodiment is intended to complete the disclosure of the present invention, and to provide ordinary knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

Even if not defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly accepted by universal technology in the prior art to which this invention belongs. Terms defined by general dictionaries may be construed as having the same meaning as the related description and/or the text of this application, and not conceptualized or excessively formalized, even if not clearly defined herein. Won't.

The terms used in the present specification are for describing exemplary embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification,'includes' and/or various conjugated forms of this verb, for example,'includes','includes','includes','includes', etc. refer to the mentioned composition, ingredient, component, Steps, operations and/or elements do not preclude the presence or addition of one or more other compositions, components, components, steps, operations and/or elements. In the present specification, the term'and/or' refers to each of the listed components or various combinations thereof.

2 is an exemplary diagram illustrating a substrate processing apparatus 10 according to an embodiment of the present invention.

Referring to FIG. 2, the substrate processing apparatus 10 processes a substrate W using plasma. For example, the substrate processing apparatus 10 may perform an etching process on the substrate W. The substrate processing apparatus 10 includes a chamber 100, a substrate support unit 200, a gas supply unit 300, a plasma generating unit 400, and a heating unit 500.

The chamber 100 has a space 101 formed therein. The inner space 101 is provided as a space for performing plasma processing on the substrate W. Plasma treatment on the substrate W includes an etching process. An exhaust hole 102 is formed on the bottom surface of the chamber 100. The exhaust hole 102 is connected to the exhaust line 121. The reaction by-products generated in the process and the gas remaining in the chamber 100 may be discharged to the outside through the exhaust line 121. The internal space 101 of the chamber 100 is depressurized to a predetermined pressure by the exhaust process.

A substrate support unit 200 is located inside the chamber 100. The substrate support unit 200 supports the substrate W. The substrate support unit 200 includes an electrostatic chuck for adsorbing and fixing the substrate W using electrostatic force. The substrate support unit 200 includes a dielectric plate 210, a lower electrode 220, a heater 230, a support plate 240, and an insulating plate 270.

The dielectric plate 210 is located at the upper end of the substrate support unit 200. The dielectric plate 210 is provided with a disk-shaped dielectric. A substrate W is placed on the upper surface of the dielectric plate 210. The upper surface of the dielectric plate 210 has a radius smaller than that of the substrate W. Therefore, the edge region of the substrate W is located outside the dielectric plate 210. A first supply passage 211 is formed in the dielectric plate 210. The first supply flow path 211 is provided from the top surface to the bottom surface of the dielectric plate 210. A plurality of first supply passages 211 are formed to be spaced apart from each other, and are provided as passages through which a heat transfer medium is supplied to the bottom surface of the substrate W. A separate electrode for adsorbing the substrate W to the dielectric plate 210 may be embedded in the dielectric plate 210. Direct current may be applied to the electrode. An electrostatic force acts between the electrode and the substrate by the applied current, and the substrate W may be adsorbed to the dielectric plate 210 by the electrostatic force.

The lower electrode 220 is connected to the lower power supply unit 221. The lower power supply 221 applies power to the lower electrode 220. The lower power supply unit 221 includes a lower RF power supply 222 and a lower impedance matching unit 225. A plurality of lower RF power sources 222 may be provided, or only one may be selectively provided. The lower RF power source 222 mainly controls ion bombardment energy. According to an example, the lower RF power supply 222 may generate a frequency power of 13.56 MHz. The lower impedance matching unit 225 is electrically connected to the lower RF power supply 222, matches frequency powers of different sizes, and applies them to the lower electrode 220.

The heater 230 is electrically connected to an external power source (not shown). The heater 230 generates heat by resisting a current applied from an external power source. The generated heat is transferred to the substrate W through the dielectric plate 210. The substrate W is maintained at a predetermined temperature by the heat generated by the heater 230. The heater 230 includes a spiral-shaped coil. The heater 230 may be buried in the dielectric plate 210 at uniform intervals.

A support plate 240 is positioned under the dielectric plate 210. The lower surface of the dielectric plate 210 and the upper surface of the support plate 240 may be bonded by an adhesive 236. The support plate 240 may be made of aluminum. The upper surface of the support plate 240 may be stepped so that the center region is positioned higher than the edge region. The center region of the upper surface of the support plate 240 has an area corresponding to the bottom surface of the dielectric plate 210 and is bonded to the bottom surface of the dielectric plate 210. A first circulation passage 241, a second circulation passage 242, and a second supply passage 243 are formed in the support plate 240.

The first circulation passage 241 is provided as a passage through which the heat transfer medium circulates. The first circulation flow path 241 may be formed in a spiral shape inside the support plate 240. Alternatively, the first circulation flow path 241 may be arranged such that ring-shaped flow paths having different radii have the same center. Each of the first circulation flow paths 241 may communicate with each other. The first circulation passages 241 are formed at the same height.

The second circulation passage 242 is provided as a passage through which the cooling fluid circulates. The second circulation passage 242 may be formed in a spiral shape inside the support plate 240. Alternatively, the second circulation passage 242 may be arranged such that ring-shaped passages having different radii from each other have the same center. Each of the second circulation passages 242 may communicate with each other. The second circulation passage 242 may have a larger cross-sectional area than the first circulation passage 241. The second circulation passages 242 are formed at the same height. The second circulation passage 242 may be located below the first circulation passage 241.

The second supply passage 243 extends upward from the first circulation passage 241 and is provided as an upper surface of the support plate 240. The second supply passage 243 is provided in a number corresponding to the first supply passage 211 and connects the first circulation passage 241 and the first supply passage 211.

The first circulation passage 241 is connected to the heat transfer medium storage unit 252 through a heat transfer medium supply line 251. The heat transfer medium storage unit 252 stores a heat transfer medium. The heat transfer medium contains an inert gas. According to an embodiment, the heat transfer medium includes helium (He) gas. The helium gas is supplied to the first circulation flow path 241 through the supply line 251, and is supplied to the bottom of the substrate W through the second supply flow path 243 and the first supply flow path 211 in sequence. The helium gas serves as a medium through which heat transferred from the plasma to the substrate W is transferred to the substrate support unit 200. Ion particles contained in the plasma are attracted by the electric force formed in the substrate support unit 200 and move to the substrate support unit 200, and in the process of moving, they collide with the substrate W to perform an etching process. Heat is generated in the substrate W while the ion particles collide with the substrate W. Heat generated from the substrate W is transferred to the substrate support unit 200 through helium gas supplied to the space between the bottom surface of the substrate W and the upper surface of the dielectric plate 210. Accordingly, the substrate W can be maintained at a set temperature.

The second circulation passage 242 is connected to the cooling fluid storage unit 262 through a cooling fluid supply line 261. The cooling fluid storage unit 262 stores the cooling fluid. A cooler 263 may be provided in the cooling fluid storage unit 262. The cooler 263 cools the cooling fluid to a predetermined temperature. Alternatively, the cooler 263 may be installed on the cooling fluid supply line 261. The cooling fluid supplied to the second circulation passage 242 through the cooling fluid supply line 261 circulates along the second circulation passage 242 to cool the support plate 240. Cooling of the support plate 240 cools the dielectric plate 210 and the substrate W together to maintain the substrate W at a predetermined temperature.

An insulating plate 270 is provided under the support plate 240. The insulating plate 270 is provided in a size corresponding to the support plate 240. The insulating plate 270 is positioned between the support plate 240 and the bottom surface of the chamber 100. The insulating plate 270 is made of an insulating material, and electrically insulates the support plate 240 and the chamber 100.

The focus ring 280 is disposed in the edge region of the substrate support unit 200. The focus ring 200 has a ring shape and is disposed along the circumference of the dielectric plate 210. The upper surface of the focus ring 280 may be stepped so that the outer portion 280a is higher than the inner portion 280b. The inner upper surface 280b of the focus ring 280 is positioned at the same height as the upper surface of the dielectric plate 210. The inner portion 280b of the upper surface of the focus ring 280 supports the edge region of the substrate W positioned outside the dielectric plate 210. The outer portion 280a of the focus ring 280 is provided to surround the edge region of the substrate W. The focus ring 280 expands the electric field formation region so that the substrate W is located at the center of the plasma region. Accordingly, plasma is uniformly formed over the entire area of the substrate W, so that each area of the substrate W can be uniformly etched.

The gas supply unit 300 supplies process gas to the chamber 100. The gas supply unit 300 includes a gas storage unit 310, a gas supply line 320, and a gas inlet port 330. The gas supply line 320 connects the gas storage unit 310 and the gas inlet port 330, and supplies the process gas stored in the gas storage unit 310 to the gas inlet port 330. The gas inlet port 330 is connected to the gas supply holes 412 formed in the upper electrode 410.

The plasma generation unit 400 excites the process gas remaining in the chamber 100. The plasma generating unit 400 includes an upper electrode 410, a distribution plate 420, and an upper power supply.

The upper electrode 410 is provided in the shape of a disk and is positioned above the substrate support unit 200. The upper electrode 410 includes an upper plate 410a and a lower plate 410b. The upper plate 410a is provided in a disk shape. The upper plate 410a is electrically connected to the upper RF power source 441. The upper plate 410a excites the process gas by applying the first RF power generated from the upper RF power source 441 to the process gas remaining in the chamber 100. The process gas is excited and converted to a plasma state. The bottom surface of the upper plate 410a is stepped so that the center region is higher than the edge region. Gas supply holes 412 are formed in the center region of the upper plate 410a. The gas supply holes 412 are connected to the gas inlet port 330 and supply process gas to the buffer space 414. A cooling passage 411 may be formed inside the upper plate 410a. The cooling passage 411 may be formed in a spiral shape. Alternatively, the cooling passage 411 may be arranged so that ring-shaped passages having different radii from each other have the same center. The cooling flow path 411 is connected to the cooling fluid storage unit 432 through a cooling fluid supply line 431. The cooling fluid storage unit 432 stores cooling fluid. The cooling fluid stored in the cooling fluid storage unit 432 is supplied to the cooling flow path 411 through the cooling fluid supply line 431. The cooling fluid circulates through the cooling flow path 411 and cools the upper plate 410a.

The lower plate 410b is located under the upper plate 410a. The lower plate 410b is provided in a size corresponding to the upper plate 410a, and is positioned to face the upper plate 410a. The upper surface of the lower plate 410b is stepped so that the center region is positioned lower than the edge region. The upper surface of the lower plate 410b and the lower surface of the upper plate 410a are combined with each other to form a buffer space 414. The buffer space 414 is provided as a space where the gas supplied through the gas supply holes 412 temporarily stays before being supplied into the chamber 100. Gas supply holes 413 are formed in the central region of the lower plate 410b. A plurality of gas supply holes 413 are formed at a predetermined interval. The gas supply holes 413 are connected to the buffer space 414.

The distribution plate 420 is located under the lower plate 410b. The distribution plate 420 is provided in a disk shape. Distribution holes 421 are formed in the distribution plate 420. The distribution holes 421 are provided from the top to the bottom of the distribution plate 420. The distribution holes 421 are provided in a number corresponding to the gas supply holes 413 and are located corresponding to the points where the gas supply holes 413 are located. The process gas remaining in the buffer space 414 is uniformly supplied into the chamber 100 through the gas supply holes 413 and the distribution holes 421.

The upper power supply unit applies RF power to the upper plate 410a. The upper power supply unit 440 includes an upper RF power source 441 and an upper impedance matching unit 442.

The heating unit 500 heats the lower plate 410b. The heating unit 500 includes a heater 510, a second upper power source 520, and a filter 530. The heater 510 is installed inside the lower plate 410b. The heater 510 may be provided in an edge region of the lower plate 410b. The heater 510 may include a heating coil, and may be provided to surround the central region of the lower plate 410b. The second upper power source 520 is electrically connected to the heater 510. The second upper power source 520 may generate DC power. Alternatively, the second upper power source 520 may generate AC power. The second frequency power generated from the second upper power source 520 is applied to the heater 510, and the heater 510 generates heat by resisting the applied current. The heat generated by the heater 510 heats the lower plate 410b, and the heated lower plate 410b heats the distribution plate 420 positioned below it to a predetermined temperature. The lower plate 420 may be heated to a temperature of 60°C to 300°C. The filter 530 is electrically connected to the second upper power 520 and the heater 510 in a section between the second upper power 520 and the heater 510.

Hereinafter, a substrate processing apparatus including a circuit capable of removing harmonics proposed by the present invention is disclosed.

3 is a diagram showing the configuration of a substrate processing apparatus according to an embodiment of the present invention.

The substrate processing apparatus 10 according to FIG. 3 may include a sensor 600, a distortion signal generation unit 700, a power generation unit 800, and an impedance matching unit 900 in the substrate processing apparatus according to FIG. 2. have.

The sensor 600 is connected to the output terminal of the process chamber 100 to sense harmonics generated due to nonlinearity of plasma in the process chamber 100. The sensor 600 may sense the output of the process chamber 100. The sensor 600 may be a VI sensor. A plurality of sensors 600 may be provided to sense various harmonics due to plasma nonlinearity in the process chamber 100. The harmonics sensed by the sensor 600 may be transmitted to the distortion signal generator 700.

The distortion signal generator 700 may generate a distortion signal according to a result of a harmonic signal transmitted from the sensor 600. When a harmonic transmitted from the sensor 600 is sensed, the distortion signal generator 700 may generate a distortion signal corresponding thereto. The distortion signal generator 700 may not generate a distortion signal when harmonics received from the sensor are not sensed.

When the distortion signal is generated, the distortion signal generator 700 applies the generated distortion signal to the power generator 800. When the distortion signal is not generated, the distortion signal generator 700 applies a general signal to the power generator 800. The general signal may be a signal that does not contain a distortion signal.

A plurality of distortion signal generators 700 may be provided. A plurality of distortion signal generators 700 may be provided to apply a distortion signal to each of the plurality of power generators 800.

The power generation unit 800 may apply power to the impedance matching unit 900 and the process chamber 100 based on a signal applied from the distortion signal generation unit 700.

The power generation unit 800 may include a plurality of RF power sources 810, 820, and 830. According to the example of FIG. 3, the power generation unit 800 may include three RF power sources. Any one of the three RF power sources may be a high frequency power source. The other two of the three RF power supplies may be low-frequency power supplies. However, the RF power source may be provided as a power source having various frequencies. Among a plurality of RF power sources, a high frequency power source may be used for plasma generation. Among a plurality of RF power sources, a low frequency power source may be used to control ion bombardment energy.

The distortion signal generation unit 700 and the power generation unit 800 may be provided in corresponding numbers, respectively.

Referring to FIG. 3, it can be seen that the distortion signal generation unit 700 is connected to the power sources 810, 820, and 830 included in the power generation unit 800 in a one-to-one correspondence. Since the size of the harmonics generated due to the nonlinearity of the plasma in the chamber may vary, a distortion signal is generated to adjust the signal levels of the plurality of power sources 810, 820, and 830 included in the power generation unit 800, respectively. I can.

4 is a diagram showing the configuration of a substrate processing apparatus according to another embodiment of the present invention.

According to another embodiment of FIG. 4, the distortion signal generator 700 may be connected only to any one 810 of a plurality of RF power sources included in the power generator 800. The generation of harmonics in the substrate processing apparatus is not only caused by nonlinearity of plasma in the chamber, but may also be generated by high frequency RF power.

In the conventional substrate processing apparatus, due to a center-peak phenomenon that occurs when a high frequency of 100 MHz or higher is applied, there is a problem that the electron density is unbalanced between the center and the edge. An imbalance has occurred. Therefore, there is also a need to block and adjust the high frequency over 100MHz generated from the RF power supply.

According to the exemplary embodiment of FIG. 4, a center peak phenomenon may occur due to harmonics generated by high frequency power. According to the exemplary embodiment of FIG. 4, the highest frequency among three RF power sources included in the power generation unit is a power source having a frequency of 60 MHz. Since the harmonic of the RF power supply 810 generates harmonics exceeding 100 MHz, there is a concern that a center peak phenomenon may occur.

As shown in FIG. 4, when the harmonic of the frequency of the RF power included in the power generator 800 exceeds 100 MHz, the distortion signal generator 700 is configured to be connected only to the corresponding power source 810, thereby reducing the load of unnecessary circuits. Can be, and there is an effect that faster signal processing is possible. In addition, in this embodiment, the distortion signal generator 700 connected to the RF power source may generate a distortion signal that removes harmonics of the corresponding distortion signal, so that the distortion signal is more easily generated.

5 is a diagram illustrating an example of a distortion signal generator 700 according to an embodiment of the present invention.

The distortion signal generator 700 may include a non-linearity generation circuit, a variable phase shift circuit, a variable size adjustment circuit, and an AMP amplifier. The components of the distortion signal generation unit 700 shown in FIG. 5 are only an example, and the distortion signal generation unit 700 according to the present invention is not limited to this configuration. The distortion signal generator 700 may include components capable of various signal processing at the level of knowledge of a person skilled in the art.

6 is a diagram illustrating a method of removing harmonics by using the distortion signal generator 700 according to the present invention.

Referring to FIG. 6, the method of removing harmonics in the distortion signal generator 700 according to the present invention can be roughly divided into four steps.

The sensor 600 connected to the process chamber 100 may detect harmonics. According to the leftmost graph of FIG. 6, the blue signal is the original frequency signal, and the red signal is the harmonic signal generated by nonlinearity of plasma in the chamber. The sensor 600 may transmit these detection signals to the distortion signal generator 700.

The distortion signal generator 700 may generate a signal based on harmonics detected by the sensor 600. This is shown in the second picture from the left of FIG. 6. When there is no detected harmonic, the distortion signal is not generated and transmitted to the power generation unit 800. When there is a detected harmonic signal as shown in FIG. 6, a distortion signal for attenuating it is generated. The distortion signal may be generated to have the same magnitude as the detected harmonic signal and have a phase opposite. The distortion signal may be determined in consideration of the frequencies of the RF power sources 810, 820, and 830 connected to the distortion signal generator 700. According to an example, it is assumed that the frequency of the RF power connected to the distortion signal generator 700 is 60 MHz and the harmonic detected by the sensor is 120 MHz. In this case, the distortion signal generation unit 700 may generate a distortion signal in which the size of the RF power connected to the distortion signal generation unit 700 is double and the phase is opposite.

When the distortion signal is generated as described above, the power generation unit 800 generates power based on the input distortion signal. This is shown in the third picture from the left of FIG. 6. In this case, the original frequency signal may be applied as it is, and power may be generated by adding a distortion signal to the original frequency signal. According to FIG. 6, the frequency of the power applied by the power generator 800 may be a result of a sum of an original frequency signal and a distortion signal generated by the distortion signal generator. The original frequency signal may be a signal for forming plasma in a process chamber.

If the harmonic signal is not detected by the sensor connected to the chamber, the distortion signal generator 700 will not generate a distortion signal and apply a general signal to the power generator 800. According to this, the power generation unit 800 will apply only the frequency corresponding to the original frequency signal.

When the result of combining the original frequency signal and the distortion signal as described above is applied to the chamber, the harmonic signals cancel each other with the distortion signal generated by the distortion signal generator, and finally, only the frequency corresponding to the original frequency signal may remain. . This is shown in Figure 4 from the left of FIG. 6. Therefore, when the output of the chamber is sensed as a result of removing the harmonics, it can be seen that the harmonics are removed and only the original frequency signal remains.

Although not shown in FIG. 6, if the output of the chamber is sensed by the sensor in the last step, there is a possibility that the harmonics may be detected again due to the generation of additional harmonics.

In such a case, by repeating the steps of the first to third drawings of FIG. 6 again, the harmonic removal operation may be repeatedly performed by adjusting the power of the distortion signal generator and the power generator.

7 is a flowchart of a substrate processing method according to the present invention.

In the substrate processing method according to the present invention, it is first determined whether or not harmonics are generated. The harmonic may be a harmonic generated due to nonlinearity of plasma or may be a harmonic generated due to high frequency RF power. Harmonics can be sensed through a sensor connected to the output terminal of the chamber.

If harmonics are not sensed, the substrate processing method of the present invention may be terminated.

If a harmonic is sensed, it means that a harmonic has occurred, and it must be removed.

When harmonics are generated, a distortion signal may be generated in consideration of the magnitude and phase of the detected harmonics. The distortion signal may be generated within a range capable of removing the harmonics. According to an example, the distortion signal may generate a signal having the same magnitude as the detected harmonic and having a phase opposite.

When the distortion signal is generated as described above, it is transmitted to the power generator 800. The power generation unit 800 may add the received distortion signal and a main signal corresponding to a frequency for forming a plasma in the process chamber and apply it to the chamber. In this process, the impedance matching unit 900 may match the impedance between the chamber and the power.

After applying the signal transmitted from the power generation unit 800 to the plasma chamber, it is determined whether or not harmonics have occurred again. When the harmonics are removed through the application of the distortion signal, the harmonics are not detected, and the procedure may be terminated.

If there are additional harmonics generated during the processing, harmonics of which the magnitude and phase are modified may be additionally detected. In such a case, harmonics can be removed by repeating the substrate processing method according to the present invention.

According to the present invention, it is possible to attenuate the harmonics by detecting the harmonics of plasma detected by the sensor connected to the output terminal of the process chamber, and generating a distortion signal based on this. According to the present invention, not only the first harmonic but also the second, third, and fourth harmonics can be simultaneously attenuated depending on whether or not a distortion signal is set, thus providing greater flexibility than conventional processing devices. Through this, the electron density can be increased, and the etch rate can be increased. In addition, it is possible to improve the density imbalance between the center and the edge of the substrate. Through this, the uniformity of the plasma can be improved.

It should be understood that the above embodiments have been presented to aid understanding of the present invention, and do not limit the scope of the present invention, and various deformable embodiments are also within the scope of the present invention. The drawings provided in the present invention are merely showing an optimal embodiment of the present invention. The technical protection scope of the present invention should be determined by the technical idea of the claims, and the technical protection scope of the present invention is not limited to the literal description of the claims itself, but a scope that has substantially equal technical value. It should be understood that it extends to the invention of.

10: substrate processing apparatus
100: chamber
600: sensor
700: distortion signal generator
800: power generation unit
900: impedance matching unit

Claims (12)

In the apparatus for processing a substrate,
A process chamber having a processing space therein;
A support unit supporting a substrate in the processing space;
A gas supply unit for supplying a process gas into the processing space;
A plasma source for generating plasma from the process gas;
A sensor connected to an output terminal of the process chamber and sensing harmonics in the processing space during a process;
A distortion signal generator for generating a distortion signal by receiving harmonic information from the sensor;
A power generator that generates power corresponding to the distortion signal and applies it to an impedance matching unit; And
Including an impedance matching unit for matching the impedance between the power generation unit and the process chamber,
A plurality of the power generation unit and the distortion signal generation unit are provided in a corresponding number, respectively,
The plurality of power generators include a plurality of RF power sources,
A substrate processing apparatus including a portion of the distortion signal generator, a nonlinear generator circuit, a phase shift circuit, a size adjustment circuit, and an amplifier.
delete The method of claim 1,
The distortion signal generator is a substrate processing apparatus connected to a high-frequency power source having a frequency at which a harmonic is generated above 100 MHz among high-frequency power included in the power generator.
delete The method of claim 1,
The distortion signal generator senses the harmonics measured from the sensor and
A substrate processing apparatus that generates a signal having the same magnitude as the always sensed harmonic and whose phase is opposite to that of the signal to be transmitted to the power generator.
The method of claim 5,
The power generation unit
A substrate processing apparatus for generating power by mixing a distortion signal received from the distortion signal generator and a main signal that is a signal for forming plasma in the process chamber.
The method of claim 1,
The harmonics are harmonics generated due to nonlinearity in plasma.
The method of claim 3,
The harmonic is a harmonic generated by a high frequency RF power included in the power generating unit.
In the method of processing a substrate using the substrate processing apparatus according to claim 1,
Determining whether or not harmonics are generated;
Generating a distortion signal capable of removing the harmonics when it is determined that the harmonics have occurred;
Transmitting the generated distortion signal to a power transmission unit; substrate processing method comprising a.
The method of claim 9,
And generating power by mixing the main signal and the distortion signal, which is a signal for forming a plasma in the process chamber, and applying the power to the process chamber.
The method of claim 10,
Forming a plasma through the power generated by the power transmission unit in the process chamber;
Sensing a harmonic at an output end of the process chamber; And
When the harmonic is sensed, repeating generating and applying a distortion signal corresponding to the sensed harmonic, and repeating until the harmonic is not sensed.
The method of claim 11,
And not generating a distortion signal when the harmonics are not sensed.

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