KR20240034496A - Substrate treating apparatus - Google Patents

Abstract

Provided is a substrate processing device that can reduce the influence of harmonics and increase plasma process uniformity. The substrate processing apparatus includes a process chamber; A first electrode and a second electrode disposed inside the process chamber and generating plasma for processing the substrate; a first high-frequency power supply for applying high frequency to the first electrode; a first transmission line connecting the first high-frequency power source and the first electrode; and a first matching network installed on the first transmission line, wherein the first matching network includes a resonance circuit that generates resonance for harmonics related to high frequencies or harmonics related to plasma, and the resonance circuit has a specified frequency band. It creates resonance for harmonics associated with high frequencies.

Description

Substrate treating apparatus {Substrate treating apparatus}

The present invention relates to an apparatus for processing substrates to manufacture semiconductors. More specifically, it relates to a device for processing a substrate using plasma.

The semiconductor manufacturing process can be performed continuously within a semiconductor manufacturing facility and can be divided into pre-process and post-process. Semiconductor manufacturing facilities may be installed within a semiconductor manufacturing plant, defined as a fab, to manufacture semiconductors.

The preprocess refers to the process of completing a chip by forming a circuit pattern on a wafer. The pre-process is a deposition process that forms a thin film on a wafer, a photo lithography process that transfers photo resist onto a thin film using a photo mask, and a desired circuit on the wafer. Etching Process, which selectively removes unnecessary parts using chemicals or reactive gases to form a pattern, Ashing Process, which removes photoresist remaining after etching, and parts connected to the circuit pattern. It may include an ion implantation process to obtain the characteristics of an electronic device by implanting ions into the wafer, and a cleaning process to remove contaminants from the wafer.

Post-process refers to the process of evaluating the performance of a product completed through the pre-process. The post-process is the primary inspection process that checks the operation of each chip on the wafer to select good and defective products, including dicing, die bonding, wire bonding, and molding. The final product characteristics and reliability are determined through the package process, which cuts and separates each chip through marking, etc. to form the product, electrical characteristics inspection, and burn-in inspection. It may include the final inspection process, etc.

When processing a substrate (eg, a wafer) using an etching process to manufacture a semiconductor, plasma equipment such as capacitively coupled plasma (CCP) or inductively coupled plasma (ICP) may be used.

The plasma equipment applies high-frequency power to the upper or lower electrode to excite the process gas introduced into the process chamber into a plasma state, thereby forming an electromagnetic field in the internal space of the process chamber.

However, as the power applied to the electrode increases, the amplitude of harmonic components generated when high-frequency power is applied may increase, resulting in non-uniformity in the amount of etching between different areas of the substrate. It can be.

The technical problem to be solved by the present invention is to provide a substrate processing device that can reduce the influence of harmonics and increase plasma process uniformity.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

One aspect of the substrate processing apparatus of the present invention for achieving the above technical problem is a process chamber; a first electrode and a second electrode disposed inside the process chamber and generating plasma for processing a substrate; a first high frequency power supply for applying high frequency to the first electrode; a first transmission line connecting the first high-frequency power source and the first electrode; and a first matching network installed on the first transmission line, wherein the first matching network includes a resonance circuit that generates resonance for harmonics related to the high frequency or harmonics related to the plasma, and the resonance circuit creates resonance for harmonics associated with high frequencies in a specified frequency band.

The resonance circuit includes a variable element, and the variable element may be connected in parallel to the first high-frequency power supply.

The variable element may be variably controlled based on power efficiency in the process chamber.

The variable element includes the type or amount of process gas flowing into the process chamber, the amount of power applied to the first electrode, the gap between the first electrode and the second electrode, the volume of the process chamber, and the It may be variably controlled based on at least one factor of whether the ring assembly surrounding the substrate is installed in the process chamber.

The designated frequency band may be a 60 MHz frequency band.

The first high-frequency power source may not change its power amount over time.

The first electrode may be an electrostatic chuck that supports the substrate.

There may be a plurality of first high-frequency power sources, and the plurality of first high-frequency power sources may be connected in parallel to the first electrode and apply different frequency powers to the first electrode.

The first matching network may further include a filter that passes frequencies in a specified range.

In addition, another aspect of the substrate processing apparatus of the present invention for achieving the above technical problem is a process chamber; an electrostatic chuck disposed inside the process chamber and supporting a substrate; a shower head unit disposed inside the process chamber and introducing process gas for processing the substrate; a first high frequency power supply for applying high frequency to the electrostatic chuck; a first transmission line connecting the first high-frequency power source and the electrostatic chuck; and a first matching network installed on the first transmission line, wherein the electrostatic chuck functions as a lower electrode for generating plasma for processing the substrate when the high frequency is applied, and the shower head unit is grounded. It is connected to an electrode (GND) and functions as an upper electrode for generating the plasma, and the first matching network includes a resonance circuit that generates resonance for harmonics related to the high frequency or harmonics related to the plasma, and the resonance circuit The circuit creates resonance for harmonics associated with high frequencies in a specified frequency band.

Specific details of other embodiments are included in the detailed description and drawings.

1 is a cross-sectional view exemplarily showing the internal structure of a substrate processing apparatus according to an embodiment of the present invention.
Figure 2 is a cross-sectional view exemplarily showing the internal structure of a substrate processing apparatus according to another embodiment of the present invention.
Figure 3 is a diagram to explain the relationship between the power applied to the electrode and the current density of the harmonic frequency.
4 is a first example diagram schematically showing the internal structure of a substrate processing device including a first matching network.
Figure 5 is an example diagram of a resonance circuit including a variable element.
Figure 6 is a graph showing the difference in plasma uniformity by frequency.
FIG. 7 is a second exemplary diagram schematically showing the internal structure of a substrate processing device including a first matching network.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions thereof are omitted.

The present invention relates to a substrate processing device and method that can reduce the influence of harmonics generated when high-frequency power is applied to plasma equipment for substrate processing and increase plasma density and plasma process uniformity. Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is a cross-sectional view exemplarily showing the internal structure of a substrate processing apparatus according to an embodiment of the present invention.

According to FIG. 1, the substrate processing apparatus 100 includes a process chamber 110, a substrate support unit 120, a cleaning gas supply unit 130, a process gas supply unit 140, a shower head unit 150, and a plasma generation unit. It may be configured to include a unit 160, a liner unit 170, and a baffle unit 180.

The substrate processing apparatus 100 is a device that processes a substrate W (eg, a wafer) using plasma. The substrate processing apparatus 100 may process the substrate W using an etching process in a vacuum environment. However, this embodiment is not limited to this. The substrate processing apparatus 100 is also capable of processing the substrate W using a deposition process in a vacuum environment. Alternatively, the substrate processing apparatus 100 may process the substrate W using a dry cleaning process.

The process chamber 110 provides a space where a process for processing the substrate W using plasma, that is, a plasma process, is performed. This process chamber 110 may have an exhaust hole 111 at its lower portion.

The exhaust hole 111 may be connected to the exhaust line 113 on which the pump 112 is mounted. The exhaust hole 111 may discharge reaction by-products generated during the plasma process and gas remaining inside the process chamber 110 to the outside of the process chamber 110 through the exhaust line 113. In this case, the internal space of the process chamber 110 may be depressurized to a predetermined pressure.

The process chamber 110 may have an opening 114 formed on its side wall. The opening 114 may function as a passage through which the substrate W enters and exits the process chamber 110 . The opening 114 may be configured to be automatically opened and closed by, for example, the door assembly 115.

The door assembly 115 may include an outer door 115a and a door driver 115b. The outer door 115a is provided on the outer wall of the process chamber 110. This outer door 115a may be moved in the height direction of the substrate processing apparatus 100, that is, in the third direction 30, through the door driver 115b. The door driver 115b may operate using any one selected from a motor, hydraulic cylinder, and pneumatic cylinder.

The substrate support unit 120 is installed in the inner lower area of the process chamber 110. This substrate support unit 120 can support the substrate W using electrostatic force. However, this embodiment is not limited to this. The substrate support unit 120 can also support the substrate W using various methods such as mechanical clamping and vacuum.

When supporting the substrate W using electrostatic force, the substrate support unit 120 may include a base 121 and an electrostatic chuck (ESC) 122.

The electrostatic chuck 122 is a substrate support member that supports the substrate W placed on it using electrostatic force. This electrostatic chuck 122 is placed on the base 121 and may be made of a ceramic material.

The ring assembly 123 is provided to surround the outer edge area of the electrostatic chuck 122. This ring assembly 123 may include a focus ring (123a) and an edge ring (123b).

The focus ring 123a is formed inside the edge ring 123b and may be provided to surround the outer area of the electrostatic chuck 122. The focus ring 123a may serve to focus ions on the substrate W when a plasma process is performed inside the process chamber 110, and may be made of a silicon material.

The edge ring 123b is formed on the outside of the focus ring 123a and may be provided to surround the outer area of the focus ring 123a. The edge ring 123b may serve to prevent the side of the electrostatic chuck 122 from being damaged by plasma, and may be made of an insulating material, for example, quartz.

The heating member 124 and the cooling member 125 are provided to maintain the substrate W at the process temperature when a substrate processing process is performed inside the process chamber 110. The heating member 124 may be provided as a heating wire to increase the temperature of the substrate W, and may be installed, for example, inside the electrostatic chuck 122. The heating member 124 may not be provided within the substrate support unit 120.

The cooling member 125 may be provided as a cooling line through which a coolant flows to lower the temperature of the substrate W, and may be installed, for example, inside the base 121. The cooling member 125 may be supplied with refrigerant using a cooling device (Chiller; 126). The cooling device 126 may be installed separately outside the process chamber 110.

The cleaning gas supply unit 130 provides cleaning gas to remove foreign substances remaining in the electrostatic chuck 122 or the ring assembly 123. The cleaning gas supply unit 130 may provide, for example, nitrogen gas (N2 Gas) as a cleaning gas, and may include a cleaning gas source 131 and a cleaning gas supply line 132.

The cleaning gas supply line 132 transports the cleaning gas supplied by the cleaning gas supply source 131. This cleaning gas supply line 132 may be connected to the space between the electrostatic chuck 122 and the focus ring 123a, and the cleaning gas moves through the space to the edge portion of the electrostatic chuck 122 or the ring assembly 123. ) can remove foreign substances remaining on the upper part of the machine.

The process gas supply unit 140 supplies process gas to the internal space of the process chamber 110. This process gas supply unit 140 may provide process gas through a hole formed through the upper cover of the process chamber 110, or may provide process gas through a hole formed through the side wall of the process chamber 110. there is. The process gas supply unit 140 may include a process gas source 141 and a process gas supply line 142.

At least one process gas source 141 may provide a gas used to process the substrate W as a process gas, and may be provided in the substrate processing apparatus 100 . When a plurality of process gas sources 141 are provided in the substrate processing apparatus 100, the plurality of process gas sources 141 supply the same type of process gas to obtain the effect of providing a large amount of gas in a short time. It is also possible to supply different types of process gases.

The process gas supply line 142 transports the process gas provided by the process gas source 141 to the shower head unit 150. The process gas supply line 142 may be provided to connect the process gas source 141 and the shower head unit 150 for this purpose.

Meanwhile, although not shown in FIG. 1, the process gas supply unit 140 is used to distribute process gas to each module of the shower head unit 150 when the shower head unit 150 is divided into a plurality of modules. It may further include a process gas distributor and a process gas distribution line. The process gas distributor is installed on the process gas supply line 142 and can distribute the process gas supplied from the process gas source 141 to each module of the shower head unit 150. The process gas distribution line is configured to connect the process gas distributor and each module of the shower head unit 150, and can transfer the process gas distributed by the process gas distributor to each module of the shower head unit 150. .

The shower head unit 150 is disposed in the internal space of the process chamber 110 and may include a plurality of gas feeding holes. Here, a plurality of gas injection holes are formed penetrating the body surface of the shower head unit 150, and may be formed at regular intervals on the body. This shower head unit 150 can uniformly spray the process gas supplied through the process gas supply unit 140 onto the substrate W within the process chamber 110 .

The shower head unit 150 may be installed to face the electrostatic chuck 122 in the vertical direction (third direction 30) within the process chamber 110. In this case, the shower head unit 150 may be provided to have a larger diameter than the electrostatic chuck 122, or may be provided to have the same diameter as the electrostatic chuck 122. The shower head unit 150 may be made of silicone or metal.

Although not shown in FIG. 1, the shower head unit 150 may be divided into a plurality of modules. For example, the shower head unit 150 may be divided into three modules, such as a first module, a second module, and a third module. The first module may be placed at a location corresponding to the center zone of the substrate W. The second module is arranged to surround the outside of the first module, and may be arranged in a position corresponding to the middle zone of the substrate W. The third module is arranged to surround the outside of the second module, and may be arranged at a position corresponding to the edge zone of the substrate W.

The plasma generation unit 160 generates plasma from gas remaining in the discharge space. Here, the discharge space refers to a space located above the substrate W among the internal spaces of the process chamber 110.

The plasma generation unit 160 may generate plasma in the discharge space inside the process chamber 110 using a capacitively coupled plasma (CCP) source. For example, the plasma generating unit 160 uses the electrostatic chuck 122 as a first electrode (lower electrode) and the shower head unit 150 as a second electrode (upper electrode) to be installed inside the process chamber 110. Plasma can be generated in the discharge space.

However, this embodiment is not limited to this. The plasma generation unit 160 may generate plasma in the discharge space inside the process chamber 110 using an inductively coupled plasma (ICP) source. For example, the plasma generation unit 160 uses the electrostatic chuck 122 as a first electrode (lower electrode) and the antenna unit as a second electrode (upper electrode) to form a discharge space inside the process chamber 110. Plasma can also be generated.

Meanwhile, in FIG. 1 and FIG. 2 described later, it is explained that the first electrode is provided in the electrostatic chuck 122, but the present embodiment is not necessarily limited thereto. That is, the first electrode may be provided in the base 121 disposed below the electrostatic chuck 122.

The plasma generation unit 160 may be configured to include a first high-frequency power source 161, a first transmission line 162, and a second transmission line 164.

The first high-frequency power source 161 applies RF power to the first electrode. The first high-frequency power source 161 may serve as a plasma source that generates plasma within the substrate processing apparatus 100.

A single first high-frequency power source 161 may be provided in the substrate processing apparatus 100, but a plurality of first high-frequency power sources 161 may also be provided. When a plurality of first high-frequency power sources 161 are provided in the substrate processing apparatus 100, they may be arranged in parallel on the first transmission line 162.

Although not shown in FIG. 1, when a plurality of first high-frequency power sources 161 are provided in the substrate processing apparatus 100, the plasma generation unit 160 is a first matching unit electrically connected to the plurality of first high-frequency power sources. Additional networks may be included. Here, when frequency powers of different sizes are input from each first high-frequency power source, the first matching network may serve to match the frequency powers and apply them to the first electrode.

The first transmission line 162 connects the first electrode and GND. The first high-frequency power source 161 may be installed on this first transmission line 162.

Meanwhile, although not shown in FIG. 1, a first impedance matching circuit may be provided on the first transmission line 162 connecting the first high frequency power source 161 and the first electrode for the purpose of impedance matching. The first impedance matching circuit may act as a lossless passive circuit to maximize the transfer of electrical energy from the first high-frequency power source 161 to the first electrode.

Meanwhile, the second transmission line 164 may connect the second electrode and GND.

Although not shown in FIG. 1, the plasma generation unit 160 may be configured to further include a second high-frequency power source. The second high-frequency power source may be installed on the second transmission line 164, and a more detailed description will be provided later with reference to FIG. 2.

The liner unit (Liner Unit or Wall Liner) 170 is used to protect the inside of the process chamber 110 from arc discharge generated when process gas is excited or impurities generated during the substrate processing process. The liner unit 170 may be formed to cover the inner wall of the process chamber 110 for this purpose.

The liner unit 170 may include a support ring 171 on its upper portion. The support ring 171 protrudes from the top of the liner unit 170 in an outward direction (i.e., in the first direction 10) and may serve to secure the liner unit 170 to the process chamber 110. .

The baffle unit (180) serves to exhaust plasma process by-products, unreacted gases, etc. This baffle unit 180 may be installed in the space between the inner wall of the process chamber 110 and the substrate support unit 120, and may be provided in an annular ring shape. The baffle unit 180 may be provided with a plurality of through holes penetrating in an upward and downward direction (i.e., in the third direction 30) to control the flow of process gas.

As described above, the plasma generation unit 160 can not only generate plasma in the discharge space within the process chamber 110 using a CCP source, but also generate plasma in the discharge space within the process chamber 110 using an ICP source. It may occur. Below, the latter case will be explained.

Figure 2 is a cross-sectional view exemplarily showing the internal structure of a substrate processing apparatus according to another embodiment of the present invention. The following description refers to FIG. 2, and description of parts overlapping with FIG. 1 is omitted.

The plasma generation unit 160 may be configured to include a first high-frequency power source 161, a first transmission line 162, a second high-frequency power source 163, and a second transmission line 164.

The second high frequency power source 163 applies RF power to the second electrode. The second high-frequency power source 163 may serve to control the characteristics of plasma within the substrate processing apparatus 100. For example, the second high-frequency power source 163 may play a role in controlling ion bombardment energy within the substrate processing apparatus 100.

A single second high-frequency power source 163 may be provided in the substrate processing apparatus 100, but a plurality of second high-frequency power sources 163 may also be provided. When a plurality of second high-frequency power sources 163 are provided in the substrate processing apparatus 100, they may be arranged in parallel on the second transmission line 164.

Although not shown in FIG. 2, when a plurality of second high-frequency power sources 163 are provided in the substrate processing apparatus 100, the plasma generation unit 160 is a second matching device electrically connected to the plurality of second high-frequency power sources. Additional networks may be included. Here, when frequency powers of different sizes are input from each second high-frequency power source, the second matching network may serve to match the frequency powers and apply them to the second electrode.

Meanwhile, although not shown in FIG. 2, a second impedance matching circuit may be provided on the second transmission line 164 connecting the second high frequency power source 163 and the second electrode for the purpose of impedance matching. The second impedance matching circuit may act as a lossless passive circuit to ensure maximum transfer of electrical energy from the second high-frequency power source 163 to the second electrode.

When the second high-frequency power source 163 is installed on the second transmission line 164, the plasma generation unit 160 can apply multi-frequency to the substrate processing apparatus 100, and thus the substrate The substrate processing efficiency of the processing device 100 can be improved.

Meanwhile, like the second high-frequency power source 163, the first high-frequency power source 161 may also play a role in controlling the characteristics of plasma.

The antenna unit 190 serves to excite the process gas into plasma by generating a magnetic field and an electric field inside the process chamber 110. For this purpose, the antenna unit 190 may include an antenna 191 provided to form a closed loop using a coil, and may use RF power supplied from the second high-frequency power source 163.

The antenna unit 190 may be installed on the upper surface of the process chamber 110. In this case, the antenna 191 may be installed with the width direction (first direction 10) of the process chamber 110 in the longitudinal direction, and may be provided to have a size corresponding to the diameter of the process chamber 110. You can.

The antenna unit 190 may be formed to have a planar type structure. However, this embodiment is not limited to this. The antenna unit 190 can also be formed to have a cylindrical type. In this case, the antenna unit 190 may be installed to surround the outer wall of the process chamber 110.

Meanwhile, the antenna unit 190 may include a window module 192. The window module 192 may serve as an upper cover of the process chamber 110 that covers the upper part of the process chamber 110 when it is opened and seals the internal space of the process chamber 110.

The window module 192 may be formed as a dielectric window using an insulating material (eg, alumina (Al ₂ O ₃ )). The window module 192 may be formed to include a coating film on its surface to suppress particles from being generated when the plasma process proceeds inside the process chamber 110.

When measuring plasma in the process chamber 110 using a Langmuir probe (LP), as shown in FIG. 3, as the frequency power (Input Power) input to the lower electrode (first electrode) increases, It can be seen that the current density of the harmonic frequency increases. In Figure 3, (a) shows the case of 60 MHz frequency, (b) shows the case of 120 MHz frequency, and (c) shows the case of 180 MHz frequency. Figure 3 is a diagram to explain the relationship between the power applied to the electrode and the current density of the harmonic frequency.

As the frequency power applied to the lower electrode (first electrode) increases, the amplitude of the harmonic component may also increase, resulting in non-uniformity between the center area and the edge area of the substrate W or between different edge areas. Undesirable etching may occur.

In this embodiment, in order to solve the above problem, a parallel resonance circuit is added to the matching network, thereby reducing the influence of harmonics and increasing plasma density and plasma process uniformity. Below, this will be explained in detail.

4 is a first example diagram schematically showing the internal structure of a substrate processing device including a first matching network. The following description refers to FIG. 4.

As described above, the first matching network 210 may be installed on the first transmission line 162 connecting the first high-frequency power source 161 and the lower electrode 220. A resonance circuit (Resonance Circuit) 230 may be included in the first matching network 210. In the above, the lower electrode 220 is the first electrode described above, and in this embodiment, it may be the electrostatic chuck 122.

A plurality of first high-frequency power sources 161 may be installed to apply power of different frequencies to the lower electrode 220 . A plurality of first high-frequency power sources 161 may be connected to the lower electrode 220 in parallel. Hereinafter, the three first high-frequency power sources 240a, 240b, and 240c will be described as an example, but of course, the number of first high-frequency power sources 161 in this embodiment is not limited to this.

The a-th high-frequency power source 240a to the c-th high-frequency power source 240c may apply different frequency powers to the lower electrode 220. For example, the a-th high-frequency power source 240a may apply a first frequency power to the lower electrode 220, and the b-th high-frequency power source 240b may apply a second-frequency power to the lower electrode 220. And, the c high frequency power source 240c can apply the third frequency power to the lower electrode 220.

In the above, the first frequency power may have a value greater than the second frequency power, and the second frequency power may have a value greater than the third frequency power. For example, the first frequency power may be RF power with a frequency ranging from several MHz to several tens of MHz, the second frequency power may be RF power with a frequency ranging from hundreds of kHz to several MHz, and the third frequency power May be RF power with a frequency ranging from tens of kHz to hundreds of kHz.

The resonance circuit 230 generates resonance for harmonics. The resonance circuit 230 can control plasma and sheath by generating resonance for harmonics generated according to the non-linear characteristics of plasma. In this embodiment, the influence of harmonics can be reduced according to the role of the resonance circuit 230, and the effect of increasing plasma density and plasma process uniformity can be obtained.

As described above, the resonance circuit 230 may be included in the first matching network 210. The resonance circuit 230 may be provided in the form of a parallel resonance circuit within the first matching network 210. The resonance circuit 230 may be provided in the first matching network 210 in the form of, for example, an LC parallel resonance circuit or an RLC parallel resonance circuit.

The resonance circuit 230 may be configured to include a variable element. In this case, the resonance circuit 230 may generate resonance for each of a plurality of harmonics through the variable characteristics of the variable element. For example, the resonance circuit 230 may be provided in the first matching network 210 including a variable capacitor 230a as shown in FIG. 5 . The variable capacitor 230a may be connected in parallel with the lower electrode 220. Figure 5 is an example diagram of a resonance circuit including a variable element.

The resonance circuit 230 may have various circuit structures depending on the overall circuit characteristics of the substrate processing apparatus 100. That is, the resonance circuit 230 has a circuit structure that generates resonance for each of a plurality of harmonics according to the impedance characteristics of the lower electrode 220 as well as the first matching network 210 and the first transmission line 162. You can. The resonance circuit 230 may generate resonance for a corresponding frequency so that the impedance has a minimum value for that frequency.

Meanwhile, in this embodiment, the first matching network 210 may include a circuit structure other than the resonance circuit 230 to control plasma and sheath. In this embodiment, it goes without saying that any type of circuit structure can be employed in the first matching network 210 as long as the impedance within the process chamber 110 can be minimized and the uniformity of plasma distribution can be effectively controlled.

The resonance circuit 230 may generate resonance for harmonics of ultra-short waves. For example, the resonance circuit 230 can generate resonance for harmonics from the 2nd to the 5th order using a 60 MHz microwave as a fundamental wave. That is, the resonance circuit 230 can generate resonance for the first harmonic of 60 MHz, the second harmonic of 120 MHz, the third harmonic of 180 MHz, the fourth harmonic of 240 MHz, and the fifth harmonic of 300 MHz.

Figure 6 is a graph showing the difference in plasma uniformity by frequency. The graph of FIG. 6 shows how ultrashort harmonics among the plurality of frequency powers applied to the lower electrode 220 affect plasma distribution within the process chamber 110. In FIG. 6 , the x-axis represents the distance in the radial direction of the substrate W within the process chamber 110, and the y-axis represents the strength of the electric field. Here, the electric field strength can be expressed as a normalized value.

In Figure 6, (a) shows the electric field strength for each position of the substrate (W) for the first harmonic of 60 MHz, and (b) shows the electric field strength for each position of the substrate (W) for the first harmonic of 120 MHz, , (c) shows the intensity of the electric field for each position of the substrate (W) for the first harmonic of 180 MHz, (d) shows the strength of the electric field for each position of the substrate (W) for the first harmonic of 240 MHz, ( e) shows the intensity of the electric field for each position of the substrate (W) for the first harmonic of 300 MHz.

Referring to the electric field intensity at each location in the process chamber 110 for each harmonic in FIG. 6, the plasma distribution is calculated from the difference value between the electric field intensity in the center area and the electric field intensity in the edge area in the process chamber 110. It can be seen that it appears unevenly within. Therefore, by reducing the influence of harmonics, it may be possible to increase plasma density and plasma process uniformity.

As described above with reference to FIG. 3, according to the results of measuring plasma in the process chamber 110 using a Langmuir probe (LP), as the frequency power input to the lower electrode 220 increases, the current density of harmonics increases. It may rise and affect plasma uniformity. Therefore, in this embodiment, the plasma density and plasma process uniformity can be increased by only increasing power efficiency using the resonance circuit 230 without increasing the power applied from the plurality of first high-frequency power sources 161.

The resonance circuit 230 may generate resonance for harmonics in a specific frequency band. For example, the resonance circuit 230 may generate resonance for the first harmonic of 60 MHz. The resonance circuit 230 increases the power efficiency of only a specific frequency band, thereby achieving the effect of independently controlling impedance without the influence of harmonic frequencies.

When resonance is generated using a variable element such as the variable capacitor 230a, the resonance circuit 230 may control the variable element to increase only the power efficiency related to a specific frequency band. That is, the variable element can be variably controlled based on the power efficiency in the process chamber 110.

The variable element may be variably controlled based on conditions for the process gas, conditions for a plurality of high frequency powers, conditions for the process chamber 110, etc. Here, the conditions for the process gas are related to the process gas flowing into the process chamber 110 through the shower head unit 150 for plasma generation. For example, the type or amount of the process gas may be applicable. You can. In addition, the conditions for the plurality of high-frequency powers are related to the high-frequency power applied to the lower electrode 220 from the plurality of first high-frequency power sources 161 for plasma generation, and may include, for example, the amount of power. In addition, the conditions for the process chamber 110 include, for example, the gap between the upper and lower electrodes 220, the volume of the process chamber 110, and the ring assembly 123 within the process chamber 110. ) may be installed or not.

In this embodiment, the substrate processing apparatus 100 may further include a filter 250 in the first matching network 210 as shown in FIG. 7 to reduce the influence of harmonics. FIG. 7 is a second exemplary diagram schematically showing the internal structure of a substrate processing device including a first matching network.

The filter 250 may perform a filtering function that passes only frequencies within a specific range among the frequencies of the RF power output from the first matching network 210. For example, the filter 250 may be configured to include at least one type of filter among a low pass filter (LPF) and a high pass filter (HPF).

When the filter 250 includes a low-pass filter, it can block harmonic components of each frequency of RF power. The low-pass filter may be connected in series to the first high-frequency power supply 161.

When the filter 250 includes a high-pass filter, the resonance circuit 230 may contribute to generating resonance for harmonics generated by the non-linear characteristics of the plasma in the process chamber 110. The high-pass filter may be arranged together with the resonance circuit 230 and may be connected in parallel with the first high-frequency power source 161.

Referring to FIGS. 1 to 7, the first matching network 210 installed on the first transmission line 162 connecting the first high frequency power source 161 and the lower electrode 220 and the resonance circuit included therein ( 230) and the substrate processing device 100 have been described.

In this embodiment, by adding a parallel resonance circuit to the matching network, only power delivery in a specific frequency band (for example, 60 MHz) can be controlled. In this embodiment, through this, the efficiency characteristics for the HF applied frequency can be improved, the generation of additional harmonic components can be suppressed, and the plasma density can be increased at the same time.

In this embodiment, the HF Power is not increased to increase the plasma density, but only the 60 MHz power efficiency is increased, so that it can be controlled independently without the influence of the harmonic frequency. Additionally, in this embodiment, a variable element (eg, variable capacitor) may be inserted in parallel with the lower electrode to increase power efficiency and plasma density. Additionally, in this embodiment, the plasma resistance and plasma density of a specific frequency can be increased by using a resonance circuit of HF frequency. When the resonance circuit includes a variable capacitor, the resistance of the HF frequency can be changed by changing the value of the variable capacitor.

Although embodiments of the present invention have been described above with reference to the attached drawings, the present invention is not limited to the above embodiments and can be manufactured in various different forms, and can be manufactured in various different forms by those skilled in the art. It will be understood by those who understand that the present invention can be implemented in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

100: substrate processing device 110: process chamber
120: substrate support unit 122: electrostatic chuck
123: Ring assembly 130: Cleaning gas supply unit
140: Process gas supply unit 150: Shower head unit
160: Plasma generation unit 161: First high frequency power source
162: first transmission line 170: liner unit
180: Baffle unit 190: Antenna unit
210: first matching network 220: lower electrode
230: resonance circuit 230a: variable capacitor
240a: A high frequency power supply 240b: B high frequency power supply
240c: C high frequency power 250: Filter

Claims (10)

process chamber;
a first electrode and a second electrode disposed inside the process chamber and generating plasma for processing a substrate;
a first high frequency power supply for applying high frequency to the first electrode;
a first transmission line connecting the first high-frequency power source and the first electrode; and
It includes a first matching network installed on the first transmission line,
The first matching network includes a resonance circuit that generates resonance for harmonics associated with the high frequency or harmonics associated with the plasma,
A substrate processing device wherein the resonance circuit generates resonance for harmonics associated with high frequencies in a designated frequency band. According to claim 1,
The resonance circuit includes a variable element,
A substrate processing device wherein the variable element is connected in parallel to the first high-frequency power supply. According to claim 2,
A substrate processing device in which the variable element is variably controlled based on power efficiency in the process chamber. According to claim 3,
The variable element includes the type or amount of process gas flowing into the process chamber, the amount of power applied to the first electrode, the gap between the first electrode and the second electrode, the volume of the process chamber, and the A substrate processing device that is variably controlled based on at least one factor of whether a ring assembly surrounding a substrate is installed in the process chamber. According to claim 1,
A substrate processing device in which the specified frequency band is a 60 MHz frequency band. According to claim 1,
A substrate processing device in which the first high-frequency power source does not change the amount of power over time. According to claim 1,
The first electrode is an electrostatic chuck that supports the substrate. According to claim 1,
The first high frequency power source is plural,
A substrate processing device wherein a plurality of first high-frequency power sources are connected in parallel to the first electrode and apply different frequency powers to the first electrode. According to claim 1,
The first matching network further includes a filter that passes frequencies in a specified range. process chamber;
an electrostatic chuck disposed inside the process chamber and supporting a substrate;
a shower head unit disposed inside the process chamber and introducing process gas for processing the substrate;
a first high frequency power supply for applying high frequency to the electrostatic chuck;
a first transmission line connecting the first high-frequency power source and the electrostatic chuck; and
It includes a first matching network installed on the first transmission line,
The electrostatic chuck functions as a lower electrode to generate plasma for processing the substrate when the high frequency is applied,
The shower head unit is connected to a ground electrode (GND) and functions as an upper electrode for generating the plasma,
The first matching network includes a resonance circuit that generates resonance for harmonics associated with the high frequency or harmonics associated with the plasma,
A substrate processing device wherein the resonance circuit generates resonance for harmonics associated with high frequencies in a designated frequency band.

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