Patent Application
20250167751
The present application claims priority to Korean Patent Application No. 10-2023-0162225, filed Nov. 21, 2023, the entire contents of which is incorporated by reference herein for all purposes.
The present disclosure relates to a microwave heat treatment apparatus and an impedance matching method between a microwave power supply and a chamber in the microwave heat treatment apparatus.
A semiconductor manufacturing process, which is a process for manufacturing a semiconductor device on a substrate (e.g., a wafer), includes, for example, exposure, deposition, etching, ion implantation, and cleaning. In order to perform each manufacturing process, semiconductor manufacturing equipment for performing each process is provided in a clean room of a semiconductor manufacturing plant, and the process is performed on a substrate introduced into the semiconductor manufacturing equipment.
In the semiconductor manufacturing process, processes using plasma, such as etching and deposition, are widely used. The plasma treatment process is performed by seating the substrate in a lower part of a plasma treatment space and applying voltage by an antenna located at an upper part of the plasma treatment space along with the supply of gas for plasma treatment. Meanwhile, technology in which microwaves are applied from above for heat treatment of the substrate is also being introduced.
A microwave heat treatment apparatus performs heat treatment on a substrate by applying microwave power from a microwave power supply located at an upper part thereof to a chamber in which the substrate is located. In order to efficiently transmit the microwave power to the chamber while minimizing reflected power, impedance matching between the microwave power supply and the chamber is required.
In order to achieve impedance matching, a tuner circuit is provided on an electrical path between the microwave power supply and the chamber. Generally, the tuner circuit measures reflected power of the power supplied to the chamber from the microwave power supply, determines an impedance tuning value at which the reflected power is minimized, and adjusts the impedance of the tuner circuit to match the impedance tuning value. Impedance adjustment is mainly performed using an element having impedance varied by mechanical manipulation. A mechanical vacuum capacitor, which is a variable capacitor having capacitance adjusted by a mechanical driving apparatus (e.g., a motor), may be used as the impedance variable element.
In the case of heat treatment using microwaves, the substrate is heated to a target temperature within 1 second at the earliest, but it takes 0.2 seconds to 0.6 seconds for measurement of the reflected power, calculation of the impedance tuning value, and operation of the driving apparatus for adjusting the impedance of the tuner circuit. Thus, when a conventional impedance matching method is applied in the microwave heat treatment apparatus, the impedance tuning process takes a long time compared to the overall process time, resulting in a decrease in power transmission efficiency.
Therefore, the present disclosure has been made in view of the above problems, and it is an object of the present disclosure to provide a microwave heat treatment apparatus and an impedance matching method capable of quickly performing impedance matching.
The objects of the present disclosure are not limited to the aforementioned object, and other unmentioned objects will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains based on the following description.
In accordance with an aspect of the present disclosure, the above and other objects can be accomplished by the provision of an impedance matching method between a microwave power supply and a chamber in a microwave heat treatment apparatus, the impedance matching method including initially adjusting the impedance of a tuner circuit between the microwave power supply and the chamber based on pre-matching data for a heat treatment process, applying microwave power to the chamber from the microwave power supply through the tuner circuit having the initially adjusted impedance, measuring process data related to the impedance of the chamber to which the microwave power has been applied, determining an impedance tuning value of the tuner circuit by comparing the process data and the pre-matching data, and adjusting the impedance of the tuner circuit based on the impedance tuning value.
In the embodiment of the present disclosure, the pre-matching data may include a set of impedance tuning values corresponding to process conditions related to the heat treatment.
In the embodiment of the present disclosure, the process conditions may include the frequency of the microwave power supply, the height of a support pin configured to support a substrate in the chamber, and the temperature of the chamber.
In the embodiment of the present disclosure, the step of initially adjusting the impedance of the tuner circuit may include adjusting the impedance of the tuner circuit using one of the impedance tuning values included in the set.
In the embodiment of the present disclosure, the process data may include the height of the support pin configured to support the substrate in the chamber and the temperature of the chamber.
In the embodiment of the present disclosure, the step of determining an impedance tuning value for the tuner circuit by comparing the process data and the pre-matching data may include determining whether the process data is included in an internal division region of the pre-matching data, determining an impedance tuning value corresponding to the process data through regression analysis of the pre-matching data if the process data is included in the internal division region of the pre-matching data, and determining an impedance tuning value of the tuner circuit at which reflected power is minimized by measuring the reflected power from the chamber if the process data is included in an external division region of the pre-matching data.
In the embodiment of the present disclosure, the step of determining whether the process data is included within a range of the pre-matching data may include setting the internal division region based on points corresponding to the height of the support pin and the temperature of the chamber included in the pre-matching data and determining whether the point corresponding to the height of the support pin measured in the chamber and the temperature of the chamber is included in the internal division region.
In the embodiment of the present disclosure, the internal division region may be set by a convex hull algorithm or a concave hull algorithm.
In the embodiment of the present disclosure, the step of determining an impedance tuning value corresponding to the process data through regression analysis of the pre-matching data may include selecting points adjacent to the point corresponding to the measured height of the support pin and the measured temperature of the chamber and determining the impedance tuning value through weighted average of impedance tuning values corresponding to the points adjacent to the point.
In the embodiment of the present disclosure, the process data included in the external division region of the pre-matching data and the impedance tuning value of the tuner circuit at which the reflected power is minimized may be added to the pre-matching data.
In accordance with another aspect of the present disclosure, there is provided a microwave heat treatment apparatus including a chamber having a treatment space defined therein, a power supply device configured to supply thermal energy to the chamber, and a controller configured to control the power supply device. The power supply device includes a microwave power supply configured to provide thermal energy to the treatment space and a tuner circuit including a plurality of impedance elements provided on a power path between the chamber and the microwave power supply. The controller includes a processor configured to adjust the output of the microwave power supply and the impedance of the tuner circuit and a memory configured to store data related to matching of the tuner circuit. The processor initially adjusts the impedance of the tuner circuit based on pre-matching data for a heat treatment process stored in the memory, applies microwave power to the chamber from the microwave power supply through the tuner circuit having the initially adjusted impedance, measures process data related to the impedance of the chamber to which the microwave power has been applied, determines an impedance tuning value of the tuner circuit by comparing the process data and the pre-matching data, and adjusts the impedance of the tuner circuit based on the impedance tuning value.
In accordance with a further aspect of the present disclosure, there is provided a microwave heat treatment apparatus including a chamber having a treatment space for a substrate defined therein, a power supply device configured to supply thermal energy to the chamber, and a controller configured to control the power supply device. The power supply device includes a microwave power supply configured to provide thermal energy to the treatment space and a tuner circuit including a plurality of impedance elements provided on a power path between the chamber and the microwave power supply. The chamber includes a chuck installed at a lower part of the chamber, a support pin installed above the chuck, the support pin being configured to support the substrate, a temperature sensor configured to measure the temperature in the chamber, and a height sensor configured to measure the height of the support pin. The controller includes a processor configured to adjust the output of the microwave power supply and the impedance of the tuner circuit and a memory configured to store data related to matching of the tuner circuit. The processor initially adjusts the impedance of the tuner circuit based on pre-matching data including a set of impedance tuning values corresponding to process conditions related to heat treatment stored in the memory, the process conditions including the frequency of the microwave power supply, the height of the support pin configured to support the substrate in the chamber, and the temperature of the chamber, applies microwave power to the chamber from the microwave power supply through the tuner circuit having the initially adjusted impedance, measures process data including the height of the support pin and the temperature of the chamber from the height sensor and the temperature sensor, determines whether the point corresponding to the height of the support pin measured in the chamber and the temperature of the chamber is included in an internal division region set based on points corresponding to the height of the support pin and the temperature of the chamber included in the pre-matching data, determines an impedance tuning value corresponding to the process data through regression analysis of the pre-matching data if the process data is included in the internal division region of the pre-matching data, determines an impedance tuning value of the tuner circuit at which reflected power is minimized by measuring the reflected power from the chamber if the process data is included in an external division region of the pre-matching data, adjusts the impedance of the tuner circuit based on the impedance tuning value, and adds the process data included in the external division region of the pre-matching data and the impedance tuning value of the tuner circuit at which the reflected power is minimized to the pre-matching data and stores the pre-matching data having the impedance tuning value added thereto in the memory if the process data is included in the external division region of the pre-matching data.
The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the embodiments. The present disclosure may, however, be embodied in many different forms, and should not be construed as being limited to the embodiments set forth herein.
Parts irrelevant to description of the present disclosure will be omitted to clearly describe the present disclosure, and the same or similar constituent elements will be denoted by the same reference numerals throughout the specification.
In addition, constituent elements having the same configurations in several embodiments will be assigned with the same reference numerals and described only in the representative embodiment, and only constituent elements different from those of the representative embodiment will be described in the other embodiments.
Throughout the specification, when a constituent element is said to be “connected” or “coupled” to another constituent element, the constituent element and the other constituent element may be “directly connected” or “directly coupled” to each other, or may be “indirectly connected” or “indirectly coupled” to each other with one or more intervening elements interposed therebetween. In addition, throughout the specification, when a constituent element is referred to as “including” another constituent element, the constituent element should not be understood as excluding other elements, so long as there is no special conflicting description, and the constituent element may include at least one other element.
Unless otherwise defined, all terms used herein, which include technical or scientific terms, have the same meanings as those generally appreciated by those skilled in the art. The terms, such as ones defined in common dictionaries, should be interpreted as having the same meanings as terms in the context of pertinent technology, and should not be interpreted as having ideal or excessively formal meanings unless clearly defined in the specification.
The present disclosure relates to a microwave heat treatment apparatus 1 and an impedance matching method between a microwave power supply 270 and a chamber 10 in the microwave heat treatment apparatus 1, and more particularly to a microwave heat treatment apparatus 1 and an impedance matching method capable of performing impedance tuning at a high speed.
The microwave heat treatment apparatus 1 according to the embodiment of the present disclosure includes a chamber 10 having a treatment space PZ for the substrate W defined therein, a power supply device 20 configured to supply thermal energy to the chamber 10, and a controller 30 configured to control the power supply device 20.
The chamber 10 includes a chuck 110 installed at a lower part of the chamber 10 and a support pin 120 configured to support the substrate W above the chuck 110. In addition, the chamber 10 includes a height sensor 140 configured to measure the height of the support pin 120 and a temperature sensor 130 configured to measure the temperature of the treatment space PZ in the chamber 10.
The chuck 110, which is configured to support the substrate W, is located in the chamber 10, and the substrate W may be supported by the support pin 120 coupled to the chuck 110. A heater and a cooling channel configured to adjust the temperature of the substrate W may be formed in the chuck 110. In addition, a lower electrode configured to generate plasma in the treatment space PZ may be located in the chuck 110.
The support pin 120 supports the substrate W thereunder. Three or more support pins 120 may be provided to stably support the substrate W. The support pin 120 may be upwardly or downwardly moved by a driving mechanism (e.g., a motor) provided thereunder. That is, the height of the support pin 120 may be changed. The height of the support pin 120 may be determined to be a height at which heat treatment of the substrate W is optimized. A height sensor 140 configured to measure the height of the support pin 120 is installed in the vicinity of the support pin 120. The height sensor 140 may be a light sensor that is installed on the chuck 110 and measures the height of the support pin 120 by radiating light. Alternatively, the height sensor 140 may be a sensor that is mounted to a motor configured to upwardly or downwardly move the support pin 120 and measures the height of the support pin 120 based on the driving amount of the motor. The temperature sensor 130 measures the temperature of the treatment space PZ in the chamber 10. The data measured by the temperature sensor 130 and the height sensor 140 is provided to a processor 310. Temperature information measured by the temperature sensor 130 and height data measured by the height sensor 140 are subsequently included in process data.
Outside the microwave heat treatment apparatus 1, an inner space is formed by an outer wall 210, and the treatment space PZ of the chamber 10 is hermetically sealed by an inner support 212 provided inside the outer wall 210. In addition, the inner support 212 may support a support member 220 thereunder. The treatment space PZ is formed by the inner support 212, the support member 220, and a window 230.
The power supply device 20 includes a microwave power supply 270 configured to provide thermal energy to the treatment space PZ and a tuner circuit 290 including a plurality of impedance elements provided on a power path between the chamber 10 and the microwave power supply 270. The power supply device 20 applies power required for treatment of the substrate W in the treatment space PZ. The power supply device 20 may broadly include a plasma power supply device configured to apply power for forming a plasma and a microwave power supply device configured to apply microwaves for heat treatment of the substrate W.
The plasma power supply device may broadly include an upper electrode 250 and an RF power supply 280 configured to provide RF power to the upper electrode 250. Although not shown in detail, a matching circuit for impedance matching and a circuit for power transmission may be provided between the RF power supply 280 and the upper electrode 250. The upper electrode 250 may be disposed above the window 230. When treatment gas for treating the substrate W is supplied via a gas supply line 260, a plasma is formed in the treatment space PZ by the upper electrode 250 and the lower electrode provided at the chuck 110. The plasma formed by the plasma power supply device may etch a specific material of the substrate W.
The microwave power supply device provides power for heat treatment of the substrate W to the plasma treatment space PZ. The microwave power supply device may broadly include a microwave power supply 270, a tuner circuit 290, a microwave waveguide 246, and a microwave antenna 240. Microwaves generated by the microwave power supply 270 are transmitted to the microwave antenna 240 via the tuner circuit 290 and the waveguide 246.
The microwave antenna 240 may emit the microwaves into the treatment space PZ. The microwaves may also be emitted into a normal pressure space above the antenna, but heating by microwave absorption does not occur because a metal plate configured to reflect microwaves is located above the antenna. In this specification, microwaves refer to electromagnetic waves having a frequency band of 300 MHz to 300 GHz, which are shorter than radio waves and longer than infrared waves. Microwaves may be used to heat the substrate W because the microwaves have the property of penetrating specific materials while reacting with other specific materials.
The tuner circuit 290 includes a plurality of impedance elements provided on the power path between the chamber 10 and the microwave power supply 270. The tuner circuit 290 may adjust the impedance of an electrical path between the microwave power supply 270 and the chamber 10 such that the maximum power efficiency is achieved from the microwave power supply 270 to the chamber 10. The tuner circuit 290 may include a plurality of variable impedance elements (a variable capacitor and a variable inductor).
The controller 30 controls the overall operation of the microwave heat treatment apparatus 1. In particular, the controller 30 may adjust the output of the microwave power supply 270 and the impedance of the tuner circuit 290, and may store data necessary for operation of the microwave heat treatment apparatus 1. The controller 30 includes a processor 310 configured to adjust the output of the microwave power supply 270 and the impedance of the tuner circuit 290 and a memory 320 configured to store data related to matching of the tuner circuit 290. An impedance tuning method described below may be performed by the controller 30.
The processor 310 may perform computation and data processing for operation of the microwave heat treatment apparatus 1. The processor 310 may be constituted by one or more treatment circuits. The processor 310 may control the microwave heat treatment apparatus 1 by executing instructions configured to drive an operating system (OS) and associated programs of the microwave heat treatment apparatus 1. The processor 310 may be a central processing unit (CPU) or a dedicated processor designed for the microwave heat treatment apparatus 1.
The memory 320 stores data and instructions for operation of the microwave heat treatment apparatus 1. The memory 320 may be organized hierarchically. The memory 320 may include cache memory, volatile memory such as dynamic random access memory (DRAM), and non-volatile memory such as a solid state device (SSD) or hard disk drive (HDD).
In steps of adjusting the impedance (S22, S25, and S28), the processor 310 operates the motor (the driving mechanism) to adjust the variable impedance element to match the calculated impedance tuning value. In steps of detecting feedback (S23 and S26), an operation to measure the reflected power level according to the changed impedance of the tuner circuit 290 is performed. The heat treatment time of the substrate using microwaves generally takes 1 second to 3 seconds, and since it takes 0.2 seconds to 0.6 seconds to measure the reflected power level and drive the motor for impedance adjustment, it takes too much time for impedance matching. The present disclosure provides an impedance matching method capable of shortening the time for impedance matching in the heat treatment process for the substrate W using microwaves.
Regression analysis is a method of predicting future values based on previously learned or measured values. Models for regression analysis may vary, and, for example, linear regression may be used. According to the present disclosure, the processor 310 may determine an impedance tuning value for the current process based on process condition-specific impedance tuning data (pre-matching data) obtained through multiple processes. In this case, the time required for impedance tuning may be reduced compared to the case in which the reflected power is fed back to determine an impedance matching value, as in conventional impedance matching.
In step S410, the processor 310 initially adjusts the impedance of the tuner circuit 290 between the microwave power supply 270 and the chamber 10 based on the pre-matching data 1000 for the heat treatment process. The pre-matching data 1000 includes a set of impedance tuning values corresponding to process conditions related to the heat treatment. The process conditions include the frequency 1100 of the microwave power supply 270, the height 1200 of the support pin 120, which supports the substrate in the chamber 10, and the temperature 1300 of the chamber 10.
In step S420, the processor 310 applies microwave power to the chamber 10 from the microwave power supply 270 through the tuner circuit 290 having the initially adjusted impedance. The processor 310 may drive the microwave power supply 270 such that microwave power is supplied to the chamber 10 through the tuner circuit 290 having the impedance initially adjusted in step S410.
In step S430, the processor 310 measures process data related to the impedance of the chamber 10 to which the microwave power has been applied. The process data includes the height of the support pin 120, which supports the substrate W in the chamber 10, and the temperature of the chamber 10. The processor 310 may obtain the height of the support pin 120 measured by the height sensor 140 and the temperature of the chamber 10 measured by the temperature sensor 130.
In step S440, the processor 310 may determine an impedance tuning value of the tuner circuit 290 by comparing the process data to the pre-matching data 1000. After initial impedance matching, the processor 310 acquires the process data while the microwave power is applied to the chamber 10, and compares the process data to the pre-matching data 1000 to determine an impedance tuning value for further impedance tuning.
In step S610, the processor 310 determines whether the process data is included in the internal division (ID) region of the pre-matching data 1000.
In step S620, if the process data is included in the internal division (ID) region of the pre-matching data 1000, the processor 310 determines an impedance tuning value corresponding to the process data through regression analysis of the pre-matching data 1000.
Referring to
In step S630, if the process data is included in the external division (ED) region of the pre-matching data 1000, the processor 310 determines an impedance tuning value of the tuner circuit 290 at which reflected power is minimized by measuring the reflected power from the chamber 10. If the measured process data deviates from the range of the pre-matching data 1000, the processor 310 may calculate an impedance tuning value based on the measurement of the reflected power in the same manner as a conventional matching method. Referring to
In step S450, the processor 310 adjusts the impedance of the tuner circuit 290 based on the impedance tuning value determined in step S440.
As is apparent from the above description, according to the present disclosure, it is possible to quickly achieve impedance matching by initially adjusting the impedance of the tuner circuit in advance using the pre-matching data and subsequently readjusting the impedance based on the result of comparison between the measured process data and the pre-matching data.
The effects of the present disclosure are not limited to the aforementioned effect, and other unmentioned effects will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the above description.
It will be appreciated that the above embodiments and the accompanying drawings clearly illustrate only a part of the technical ideas included in the present disclosure and that all modifications and specific embodiments that can be readily inferred by those skilled in the art within the scope of the technical ideas included in the description and drawings of the present disclosure are included within the scope of the rights of the present disclosure.
Accordingly, the idea of the present disclosure is not to be limited to the embodiments described above, and it will be understood that not only the claims hereinafter described but also all equivalents or equivalent variations thereto fall within the scope of the idea of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0162225 | Nov 2023 | KR | national |
