JP6240532B2 - Electrostatic chuck temperature control method - Google Patents

Description

  The present invention relates to an electrostatic chuck and a temperature control method for the electrostatic chuck.

  In substrate processing such as etching, the etching rate and the like are controlled by controlling the temperature of the substrate. In order to locally control the temperature of the substrate, a method of dividing the substrate into a plurality of zones and independently controlling the temperature for each zone has been proposed (see, for example, Patent Document 1). ). When controlling the temperature of the substrate, a plurality of temperature sensors are arranged on the inner wall of the chamber and the like, and the temperature of the substrate is controlled based on the sensor value of each temperature sensor (see, for example, Patent Document 2). ).

  In recent years, a heater built-in type electrostatic chuck has been proposed in which a heater is incorporated in the electrostatic chuck and the electrostatic chuck (ESC: Electrostatic Chuck) is heated by the heater to enhance the temperature control responsiveness. In the electrostatic chuck with a built-in heater, the electrostatic chuck is divided into a plurality of zones, and the temperature is controlled independently by a heater provided for each zone. Moreover, it may be required to arrange a plurality of heaters on the outer periphery of the electrostatic chuck and to locally control the temperature of the outer periphery of the substrate.

JP 2004-1111819 A Japanese Patent Laid-Open No. 06-242840

  However, if there is a difference in the set temperature to be controlled between adjacent zones, a zone that is controlled to a higher temperature (hereinafter also referred to as a “high temperature zone”) and a zone that is controlled to a lower temperature than the high temperature zone (hereinafter referred to as a “low temperature zone”). The heat is transferred to (also referred to as “heat leak”). At this time, there may be a region in the low temperature zone that is difficult to lower at low temperatures, particularly on the high temperature zone side.

  When the low temperature zone is affected by the heat leakage from the high temperature zone and is controlled to a temperature higher than the set temperature of the low temperature zone, the output value of the heater decreases. As a result, the output value of the heater may become zero. When the output value of the heater becomes zero, temperature control using the heater becomes impossible.

  To solve the above problem, in one aspect, in an electrostatic chuck that is divided into a plurality of zones and is capable of controlling the temperature for each zone, the electrostatic chuck and the electrostatic chuck capable of accurately controlling the temperature for each zone It is an object of the present invention to provide a temperature control method.

In order to solve the above problems, according to one aspect, a method of controlling the temperature electrostatic chuck which is divided into a plurality of zones for each zone, one temperature sensor is provided for each said zone, said temperature sensor for each zone is arranged in a range transmission of heat generated by the temperature control of the adjacent zone is suppressed, the heater of each zone which belongs temperature sensor based on by that measurement of the temperature sensor for each of the zones When controlling the value to be applied, the value applied to the heater in each zone is higher than that in each zone according to the difference between the temperature measured by the temperature sensor in each zone and the set temperature set in each zone. There is provided an electrostatic chuck temperature control method for controlling so as not to become 0 (zero) by heat generated by temperature control by the heaters belonging to adjacent zones .
According to another aspect, there is provided a method for controlling the temperature of an electrostatic chuck divided into a plurality of zones for each zone, wherein one or more temperature sensors are provided for each zone, and two are provided in the same zone. In the case where the above temperature sensors are provided, a temperature sensor arranged in a range in which the transfer of heat generated by the temperature control of the adjacent zone is suppressed is selected, and one is selected for each selected temperature sensor or each zone. when controlling the value to be applied to the heater of each zone which belongs temperature sensor based on the measurement that by the temperature sensor provided, the set temperature and the set temperature and the zones measured by the temperature sensor in each zone The value applied to the heater in each zone according to the difference between the two values must be 0 (zero) due to the heat generated by the temperature control by the heater belonging to the adjacent zone having a higher temperature than each zone. To control such a temperature control method of the electrostatic chuck is provided.

  According to one aspect, in an electrostatic chuck that is divided into a plurality of zones and capable of temperature control for each zone, temperature control can be performed accurately for each zone.

The figure which shows an example of the whole structure of the plasma processing apparatus concerning one Embodiment. The figure which shows the comparative example of arrangement | positioning of the temperature sensor of an electrostatic chuck. The figure for demonstrating the influence of the heat leak in the comparative example of FIG. The figure which shows an example of arrangement | positioning of the temperature sensor of the electrostatic chuck concerning 1st Embodiment. The figure which shows an example of arrangement | positioning of the temperature sensor of the electrostatic chuck concerning 2nd Embodiment. The figure which shows an example of arrangement | positioning of the temperature sensor of the electrostatic chuck concerning a modification. The figure which shows an example of arrangement | positioning of the temperature sensor of the electrostatic chuck concerning a modification. The figure which shows an example of the temperature control processing flow concerning one Embodiment. The figure which shows an example of the zone division | segmentation of the electrostatic chuck concerning one Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, in this specification and drawing, about the substantially same structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[Overall configuration of plasma processing apparatus]
First, an overall configuration of a plasma processing apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an example of the overall configuration of a plasma processing apparatus according to an embodiment. FIG. 1 shows a longitudinal section of a plasma processing apparatus according to an embodiment.

  The plasma processing apparatus 1 has a cylindrical chamber 10 made of metal such as aluminum or stainless steel. The chamber 10 is grounded. Inside the chamber 10, the substrate is subjected to plasma processing such as etching. Here, a parallel plate type (capacitively coupled plasma (CCP)) plasma processing apparatus in which a lower electrode and an upper electrode are opposed to each other in the chamber 10 and gas is supplied from the upper electrode into the chamber is taken as an example. I will give you a description.

  In the chamber 10, a mounting table 104 for mounting a semiconductor wafer W (hereinafter referred to as a wafer W) as an example of a substrate is provided. The mounting table 104 is made of a material such as aluminum Al, titanium Ti, or silicon carbide SiC. On the upper surface of the mounting table 104, an electrostatic chuck 106 for electrostatically attracting the wafer W is disposed. A focus ring 108 made of, for example, silicon is disposed on the peripheral edge of the electrostatic chuck 106 in order to improve the in-plane uniformity of etching.

  The electrostatic chuck 106 has a structure in which a chuck electrode 106a is sandwiched between insulators 106b. A DC voltage source 34 is connected to the chuck electrode 106a, and a DC voltage is applied to the electrode 106a from the DC voltage source 34, whereby the wafer W is attracted to the electrostatic chuck 106 by Coulomb force.

  A high frequency power supply 32 is connected to the mounting table 104 via a matching unit 33. The high frequency power supply 32 applies a high frequency power suitable for generating plasma inside the chamber 10, for example, high frequency power of 60 MHz to the mounting table 104. In this way, the mounting table 104 also functions as a lower electrode.

  A shower head 25 is provided on the ceiling of the chamber 10 via a shield ring 40 that covers the periphery of the chamber 10. A gas inlet 45 for introducing gas from the gas supply source 15 is formed in the shower head 25. A diffusion chamber 50 for diffusing the gas introduced from the gas inlet 45 is provided inside the shower head 25. The gas diffused in the diffusion chamber 50 is supplied into the chamber 10 through a number of gas supply holes 55. With this configuration, the shower head 25 also functions as an upper electrode having a ground potential. Thereby, the high frequency power from the high frequency power supply 32 is capacitively applied between the mounting table 104 and the shower head 25.

  An exhaust port is formed at the bottom of the chamber 10, and the exhaust port is connected to the exhaust device 62. The exhaust device 62 has a vacuum pump (not shown) and depressurizes the processing space in the chamber 10 to a predetermined degree of vacuum.

  A plurality of heaters 116 a, 116 b and 116 c (hereinafter collectively referred to as “heater 116”) are embedded in the electrostatic chuck 106. The heater 116a is provided in the center zone (see FIG. 9A) when the electrostatic chuck 106 is divided into a plurality of zones (regions), the heater 116b is provided in the middle zone, and the heater 116c is provided in the edge zone. It has been. A desired current flows from each AC power source 44 to each heater 116.

  In addition, a coolant channel 104 a is formed inside the mounting table 104. A refrigerant is circulated and supplied to the refrigerant flow path 104a from a chiller unit (not shown) via pipes 104b and 104c.

  According to this configuration, the wafer W can be adjusted to a desired temperature by cooling with the coolant flowing through the coolant channel 104a and heating by the heater 116. Further, these temperature controls are performed based on a command from the control unit 100.

  The control unit 100 includes a CPU (Central Processing Unit) 105, a ROM (Read Only Memory) 110, and a RAM (Random Access Memory) 115. The CPU 105 executes plasma processing according to various recipes stored in the ROM 110 or the RAM 115. The recipe includes process time, which is device control information for process conditions, processing chamber temperature (upper electrode temperature, processing chamber sidewall temperature, set temperature of each electrostatic chuck zone, etc.), pressure (gas exhaust), high frequency Electric power, voltage, various gas flow rates, heat transfer gas flow rates, and the like are described. Note that the function of the control unit 100 may be realized by operating using software, or may be realized by operating using hardware. The main configuration of the entire configuration of the plasma processing apparatus 1 according to the present embodiment has been described above.

(Temperature control for each zone)
Next, a configuration for performing temperature control for each zone of the electrostatic chuck 106 will be described. The electrostatic chuck 106 is temperature-controlled for each zone. For this purpose, each of the heaters 116a, 116b, 116c is provided with temperature sensors 60a, 60b, 60c.

  Sensor values detected by the temperature sensors 60 a, 60 b and 60 c are sent to the temperature measuring device 65. The temperature measuring device 65 measures the temperature of each zone (center, middle, edge) from each sensor value. The temperature measuring device 65 notifies the controller 100 of the measured temperature of each zone at the present time.

  The control unit 100 calculates the difference between the measured temperature of each zone at the present time and the set temperature of each zone. Thus, the control unit 100 calculates a current value necessary for controlling the temperature of each zone to the set temperature according to how far the temperature of each zone currently deviates from the set temperature, and the thyristor The circuit 70 is instructed to perform feedback control of a necessary current value.

  The thyristor circuit 70 is a transistor having a switching function for diverting a current output from the AC power supply 44, and can cope with high power. The thyristor circuit 70 divides the current output from the AC power supply 44 in accordance with an instruction from the control unit 100 and supplies it to the heaters 116a, 116b, and 116c. The heater filter F is provided between the heaters 116 a, 116 b, 116 c and the thyristor circuit 70, and removes the high frequency power applied from the high frequency power supply 32. The heater filter F is connected to the heaters 116a, 116b, and 116c via power supply lines 71a, 71b, and 71c.

(Heat leakage in temperature control for each zone)
Next, heat leakage in the temperature control for each zone of the electrostatic chuck 106 will be described. If there is a difference in the set temperature to be controlled between adjacent zones, a “heat leak” in which heat is transferred from the high temperature zone to the low temperature zone may occur. At this time, there is a portion where it is difficult to lower the temperature in the low-temperature zone adjacent to the high-temperature zone, and the sensor value to be detected may vary depending on the arrangement of the temperature sensor even in the same zone.

  For example, as shown in FIG. 9A, temperature control and heat leakage for each zone when the electrostatic chuck 106 is divided from the center into three concentric zones such as a center zone, a middle zone, and an edge zone will be described. To do. Here, as shown in FIG. 2, the temperature sensors 60a, 60b, and 60c are respectively disposed in the radial center of the heaters 116a, 116b, and 116c provided in the center zone, the middle zone, and the edge zone, respectively. Is assumed.

  A desired current is supplied to the heaters 116a, 116b, and 116c via the feeder lines 71a, 71b, and 71c. Thereby, the temperature of the electrostatic chuck 106 can be raised for each zone by the current flowing through the resistance patterns of the heaters 116a, 116b, and 116c.

  A refrigerant having a desired temperature is circulated and supplied to the refrigerant flow path 104 a inside the mounting table 104. By controlling the temperature of the refrigerant, it is possible to mitigate a rapid temperature increase caused by the heat generated by the heater 116 and suppress the transfer of heat between the zones.

  However, the electrostatic chuck 106 has a zone structure that does not thermally separate the heaters 116a, 116b, and 116c, and the cooling capacity by the refrigerant is not so high as to completely eliminate the transfer of heat between the zones. For this reason, after the heat transfer between the zones, the temperature control for each zone is performed by the control unit 100.

  For example, as shown in FIG. 3, when the set temperature of the edge zone is 60 ° C., the set temperature of the middle zone is 40 ° C., and the set temperature of the center zone is 40 ° C., the setting to be controlled between the edge zone and the middle zone There is a difference in temperature. In this case, heat leaks from the edge zone of the high temperature zone to the middle zone of the low temperature zone, and it becomes difficult for the temperature of the middle zone to be lowered on the edge zone side. When affected by heat leakage in this way, the measurement temperature in the edge zone is 60 ° C., the measurement temperature in the middle zone is 45 ° C., and the measurement temperature in the center zone is 40 ° C. At this time, the temperature sensor 60b in the middle zone that is affected by the heat leak detects a temperature of 45 ° C. that is 5 ° C. higher than the set temperature 40 ° C. Therefore, the output value of the heater 116b in the middle zone is It may be controlled to a lower value than when the preset temperature is controlled to 40 ° C. In this way, if the output value of the heater 116b in the middle zone is too low, the output value of the heater 116b may become zero.

  When the output values of the heaters 116a, 116b, and 116c become zero as described above, the temperature control of the zone becomes impossible, and individual differences occur in the temperature inside the electrostatic chuck 106, and the temperature control of the electrostatic chuck can be performed. There is a risk of disappearing. For this reason, the control part 100 needs to control so that the output value of each heater 116a, 116b, 116c may not become 0 (zero).

<First Embodiment>
Therefore, in the electrostatic chuck 106 according to the first embodiment of the present invention, the temperature sensor is arranged in a range that is not affected by heat leakage in the temperature control for each zone, or in which heat transfer is suppressed. Below, arrangement | positioning of a temperature sensor is demonstrated, referring FIG.

  In the electrostatic chuck 106 according to the first embodiment, the arrangement of the temperature sensor is optimized so as not to be affected by the heat leakage generated between the high temperature zone and the low temperature zone, or to suppress the influence of heat. FIG. 4 shows an example of the arrangement of the temperature sensor of the electrostatic chuck 106 according to the first embodiment.

  When the set temperature of the edge zone is 60 ° C., the set temperature of the middle zone is 40 ° C., and the set temperature of the center zone is 40 ° C., there is a difference in the set temperature to be controlled between the edge zone and the middle zone. It is difficult for the zone to cool down with respect to the set temperature. Therefore, in consideration of heat leakage from the edge zone of the high temperature zone to the middle zone of the low temperature zone, the temperature sensor 60b disposed in the middle zone is located far from the adjacent edge zone and is affected by the heat leakage. It is arrange | positioned in the range which is not received or heat transfer is suppressed. In this example, the temperature sensor 60b arranged in the middle zone is arranged at the inner end of the middle zone opposite to the edge zone of the high temperature zone.

  As an example of placing a temperature sensor in a range that is not affected by heat leakage or in which heat transfer is suppressed, a temperature sensor provided in a low temperature zone among adjacent zones with different set temperatures is used to prevent heat leakage from the high temperature zone. It may be arranged in a low temperature zone range excluding a range controlled to a temperature higher than the set temperature of the low temperature zone due to the influence. In FIG. 4, a ring-shaped range having a width A in the radial direction from the inner end side of the middle zone is a range that is not affected by heat leakage or heat transfer is suppressed. What is necessary is just to arrange | position the sensor 60b.

  As another example of placing the temperature sensor in a range that is not affected by heat leakage or in which heat transfer is suppressed, the temperature sensor provided in the low temperature zone among the adjacent zones having different set temperatures is arranged on the opposite side of the high temperature zone. It is mentioned to arrange | position in the edge part (position furthest away from a high temperature zone) or its vicinity. As another example of arranging the temperature sensor in a range that is not affected by heat leakage or in which heat transfer is suppressed, a temperature sensor provided in a zone sandwiched between two adjacent zones is installed in two adjacent zones. You may arrange | position in the position close | similar to the low temperature zone of the two zones adjacent to those high temperature zones.

  As described above, in the electrostatic chuck 106 according to the first embodiment, the position of the temperature sensor provided in the low temperature zone among the adjacent zones having different set temperatures is optimized. In this manner, by disposing the temperature sensor in the low temperature zone away from the high temperature zone, it is not affected by heat leakage from the high temperature zone, or the influence of heat can be suppressed.

  In the present embodiment, the temperature sensor 60b disposed in the middle zone is not affected by heat leakage from the adjacent edge zone, or is disposed in a range where heat transfer is suppressed. Therefore, the temperature sensor 60b in the middle zone is not affected by heat leakage or suppresses the influence of heat, and therefore does not detect a temperature higher than the original temperature. Thereby, it is possible to avoid that the output value of the heater 116b in the middle zone is lower than the value that should be originally controlled. As a result, the output value of the heater 116b can be prevented from becoming 0, and the heater 116b can be controlled so as not to become uncontrollable.

Second Embodiment
Next, the arrangement of the temperature sensor of the electrostatic chuck 106 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 shows an example of the arrangement of the temperature sensor of the electrostatic chuck according to the second embodiment. Also by the electrostatic chuck 106 according to the second embodiment, the temperature control for each zone is not affected by heat leakage, or the influence of heat is suppressed, and the temperature control can be performed accurately for each zone. .

  The electrostatic chuck 106 according to the second embodiment is provided with two temperature sensors for a zone having two or more adjacent zones, and switches the temperature sensor to be used according to the process. For example, as shown in FIG. 5, the middle zone has two adjacent zones. In contrast, the edge zone and the center zone have only one adjacent zone. Therefore, in the electrostatic chuck 106 according to the second embodiment, two temperature sensors are provided for the middle zone having two or more adjacent zones. Specifically, the temperature sensor 60b1 is disposed at or near the inner end of the middle zone, and the temperature sensor 60b2 is disposed at or near the outer end of the middle zone.

  In the case where a plurality of temperature sensors are provided in the same zone, the control unit 100 determines that the output value of the heater in the zone to which the temperature sensor belongs is adjacent to the adjacent zone whose temperature is higher than that zone. A temperature sensor arranged in a range that does not become zero due to heat generated by temperature control by the heater is selected.

  For example, the temperature sensor selected may be a temperature sensor on the side farther from the high temperature zone among two or more adjacent zones. The control unit 100 specifies a high temperature zone from two or more adjacent zones according to the set temperature of each zone set in the recipe stored in the RAM 115, and is on the side far from the specified high temperature zone. A temperature sensor can be selected. In this way, the control unit 100 selects a temperature sensor used in the process before the process.

  For example, in FIG. 5, the set temperature of the edge zone is 40 ° C., the set temperature of the middle zone is 40 ° C., and the set temperature of the center zone is 60 ° C. In this case, the control unit 100 selects the temperature sensor 60b2 on the side away from the center zone of the high temperature zone of the adjacent zones as the temperature sensor used for the next process in the middle zone. As a result, the temperature sensor 60b2 in the middle zone is not affected or suppressed by the heat leakage, and thus does not detect a temperature higher than the original temperature. Thereby, it is possible to avoid that the output value of the heater 116b in the middle zone is lower than the value that should be originally controlled. As a result, the output value of the heater 116b can be prevented from becoming 0, and the heater 116b can be controlled so as not to become uncontrollable.

<Modification>
Next, the arrangement of the temperature sensor of the electrostatic chuck 106 according to the modification of the present invention will be described with reference to FIGS. 6 and 7 show an example of the arrangement of the temperature sensor of the electrostatic chuck according to the modification of the present invention. Also by the electrostatic chuck 106 according to the modification, the temperature control for each zone is not affected or suppressed by the heat leakage, and the temperature control can be accurately performed for each zone.

  In FIG. 6, the temperature sensor 60a in the center zone and the temperature sensor 60b in the middle zone are disposed at the radial center of the heater 116a and the heater 116b provided in each zone. On the other hand, the temperature sensor 60c in the edge zone is disposed at the outer end portion of the heater 116c provided in the edge zone.

  As described above, the temperature sensor 60c is arranged at the outer end portion that is not affected by the heat leakage from the adjacent zone or the heat transfer is suppressed with respect to the edge zone. Thereby, the temperature control of the edge zone can be performed with high accuracy.

  Further, in FIG. 7, in addition to the temperature sensor 60c in the edge zone being disposed at the outer end of the heater 116c provided in the edge zone, two temperature sensors 60b1 and 60b2 are provided in the middle zone. Has been placed. The center zone temperature sensor 60a is disposed at the center in the radial direction of the heater 116a, but may be disposed at the center in the radial direction of the heater 116a.

  In this way, two temperature sensors are arranged in a zone sandwiched between two or more other zones, and as described in the second embodiment, two temperature sensors are provided according to the set temperature of the adjacent zone. It is preferable to use by switching. If there are multiple zones sandwiched between two or more other zones, place two temperature sensors in each of the multiple zones sandwiched between two or more other zones and switch between them. It is preferable to use it.

  According to such a configuration, the temperature sensor is disposed at the outer end portion with respect to the edge zone, and the influence of heat leakage from the adjacent zone is exerted on the zone sandwiched between two or more other zones. The temperature sensor is selected so as not to receive heat or to be in a range where heat transfer is suppressed. Thereby, a temperature sensor can be set to the position which is not influenced by the heat leak from an adjacent zone, or heat transfer is suppressed. Thereby, temperature control of each zone can be performed accurately.

  The arrangement of the temperature sensor of the electrostatic chuck 106 according to the modification of the present invention has been described above. In FIGS. 6 and 7, the electrostatic chuck 106 and the focus ring 108 are configured separately. In this case, heat is hardly exchanged between the electrostatic chuck 106 and the focus ring 108 in a vacuum state.

  On the other hand, when the electrostatic chuck 106 and the focus ring 108 are integrally formed, heat is transferred between the electrostatic chuck 106 and the focus ring 108. Therefore, in this case, it is preferable to optimize the arrangement of the temperature sensor of the focus ring 108 in the same manner as the electrostatic chuck 106 by using the methods shown in the first and second embodiments and the modified examples.

[Temperature control method]
Next, an example of a temperature control method using the electrostatic chuck 106 according to the present embodiment will be described with reference to FIG. FIG. 8 is an example of a temperature control processing flow according to the present embodiment. This temperature control process is mainly executed by the control unit 100.

  In the case of the electrostatic chuck 106 according to the second embodiment, before starting this temperature control process, from the plurality of temperature sensors in the middle zone, from the adjacent zone on the high temperature side according to the temperature setting of the adjacent zone. A temperature sensor arranged in a range that is not affected by heat or in which heat transfer is suppressed is selected in advance.

  First, the temperature measuring device 65 measures the temperature of each zone based on the sensor value acquired from the temperature sensor 60 installed in each zone (step S100). Next, the control unit 100 acquires the measured temperature from the temperature measuring device 65, and calculates the difference between the measured temperature of each zone and the set temperature of each zone (step S102).

  Next, the control unit 100 calculates the output value of the heater 116 in each zone based on the difference between the calculated measured temperature and the set temperature (step S104).

  Next, the control unit 100 determines whether or not the calculated output value of the heater 116 is equal to 0 (hereinafter, including an approximate value of 0) (step S106). When the calculated output value of the heater 116 is equal to 0, the control unit 100 returns to step S100 without performing zone temperature control (feedback control) by applying the calculated output value of the heater 116 to the heater 116. .

  On the other hand, when the output value of the heater 116 provided in each zone is not equal to 0, the control unit 100 instructs the heater 116 to apply the calculated output value of the heater 116 to control the temperature of the zone (feedback control). ) Is executed (step S108), and the process returns to step S100.

  Heretofore, an example of the temperature control method according to the present embodiment has been described. According to this, the output value of the heater 116 for each zone is controlled based on the sensor value detected by the temperature sensor 60 for each zone provided in the electrostatic chuck 106 of the present embodiment. At that time, the output value of the heater 116 is controlled so as not to become zero. Thereby, the uncontrollability of the heater 116 can be avoided.

[Electrostatic chuck zone]
Finally, an example of zone division in the electrostatic chuck 106 according to the present embodiment will be described with reference to FIG. FIG. 9 shows an example of zone division of the electrostatic chuck 106 according to the present embodiment.

  FIG. 9A shows an example in which the electrostatic chuck 106 is concentrically divided into three zones (center, middle, and edge) as described above. However, the zone of the electrostatic chuck 106 is not limited to a concentric zone. For example, FIG. 9B shows an example in which the electrostatic chuck 106 is divided into a large number of zones in a matrix shape. For example, as shown in FIG. 9C, the concentric zones may be further subdivided and divided into fan-shaped zones, or may be divided into other shapes and other numbers of zones. .

  As mentioned above, although the electrostatic chuck and the temperature control method of the electrostatic chuck have been described in the above embodiment, the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention. is there. Moreover, it is possible to combine the above-described embodiments and modification examples as long as they do not contradict each other.

  For example, in the electrostatic chuck according to the present invention, a space such as a recess for installing the temperature sensor is formed to be larger than the size of the temperature sensor, and the temperature sensor can be moved in the space. You may enable it to adjust the position of a temperature sensor within the space.

  For example, in the electrostatic chuck according to the present invention, the number of temperature sensors in each zone is not necessarily limited to two. Three or more temperature sensors may be arranged in the radial direction of the electrostatic chuck, for example, and the temperature may be detected by any of the arranged temperature sensors.

  However, if the number of temperature sensors arranged in each zone is too large, it becomes difficult to maintain the uniformity of the surface temperature of the electrostatic chuck 106, resulting in an increase in cost. Therefore, the number of temperature sensors in each zone is preferably up to two.

  Further, in the electrostatic chuck according to the present invention, the temperature sensor can be arranged horizontally to widen the detection range of the temperature in the zone by one temperature sensor.

  The electrostatic chuck and the electrostatic chuck temperature control method according to the present invention can be applied not only to a capacitively coupled plasma processing apparatus but also to other semiconductor manufacturing apparatuses. Other semiconductor manufacturing equipment includes inductively coupled plasma (ICP), CVD (Chemical Vapor Deposition) equipment using a radial line slot antenna, Helicon Wave Plasma (HWP) equipment, electronic It may be a cyclotron resonance plasma (ECR) apparatus or the like.

The substrate processed by the semiconductor manufacturing apparatus according to the present invention is not limited to a wafer, and may be a large substrate for a flat panel display, an EL element, or a substrate for a solar cell, for example. Further, the embodiment disclosed in the present application may further include the following forms.
[Appendix 1]
An electrostatic chuck divided into a plurality of zones and capable of temperature control for each zone,
A heater arranged for each of the zones;
A temperature sensor provided for each of the zones,
The temperature sensor for each zone has a higher value applied to the heater of each zone according to the difference between the temperature measured by the temperature sensor of each zone and the set temperature set for each zone. It is arranged in a range that does not become 0 (zero) due to heat generated by temperature control by the heater in the adjacent zone.
Electrostatic chuck.
[Appendix 2]
An electrostatic chuck divided into a plurality of zones and capable of temperature control for each zone,
A heater arranged for each of the zones;
One or more temperature sensors provided for each zone;
When a plurality of temperature sensors are provided in the same zone, the temperature of each zone is determined according to the difference between the temperature measured by the temperature sensor of each zone and the set temperature set for each zone. A selection means for selecting a temperature sensor disposed in a range in which a value applied to the heater does not become zero due to heat generated by temperature control by the heater in the adjacent zone higher than the zone;
An electrostatic chuck.
[Appendix 3]
When the electrostatic chuck and the focus ring installed outside the electrostatic chuck are integrated, and the focus ring is provided with a heater and a temperature sensor, the temperature is measured by the temperature sensor of the focus ring. A value to be applied to the heater of the focus ring according to the difference between the temperature and the set temperature set for the focus ring is generated by temperature control by the heater belonging to an adjacent zone that is higher in temperature than the heater of the focus ring. Placed in a range that does not become 0 (zero) due to heat
The electrostatic chuck described in appendix 1.

1: Plasma processing apparatus 10: Chamber 15: Gas supply source 25: Shower head (upper electrode)
28: Exhaust device 32: High frequency power supply 44: AC power supply 60, 60a, 60b, 60c: Temperature sensor 65: Temperature measuring device 70: Thyristor circuit 100: Control unit 104: Mounting table (lower electrode)
104a: Refrigerant flow path 106: Electrostatic chuck 108: Focus ring 116, 116a, 116b, 116c: Heater

Claims (3)

A method of controlling the temperature of an electrostatic chuck divided into a plurality of zones for each zone,
One temperature sensor is provided for each said zone, a temperature sensor for each of the zones is arranged in a range transmission of heat generated by the temperature control of the adjacent zone is suppressed,
When controlling the value to be applied to the heater of each zone which belongs temperature sensor based on the measurement that by the temperature sensor for each of the zones, a set temperature set in the temperature and the respective zones measured by the temperature sensor in each zone The value applied to the heater in each zone according to the difference between and is controlled so as not to become 0 (zero) due to the heat generated by the temperature control by the heater belonging to the adjacent zone having a temperature higher than each zone .
Electrostatic chuck temperature control method. A method of controlling the temperature of an electrostatic chuck divided into a plurality of zones for each zone,
When one or more temperature sensors are provided for each zone, and two or more temperature sensors are provided in the same zone, they are arranged in a range in which the transfer of heat generated by the temperature control of the adjacent zone is suppressed. Select the temperature sensor
When controlling the value to be applied to the heater of each zone which belongs temperature sensor based on the measurement that by the that one temperature sensor is provided for each of the selected temperature sensor or the zone, measured by the temperature sensor in each zone The value applied to the heater of each zone according to the difference between the set temperature and the set temperature set for each zone is due to the heat generated by the temperature control by the heater belonging to the adjacent zone having a higher temperature than each zone. Control so as not to become 0 (zero) ,
Electrostatic chuck temperature control method. When the electrostatic chuck and the focus ring installed outside the electrostatic chuck are integrated, and the focus ring is provided with a heater and a temperature sensor , based on the measurement by the temperature sensor of the focus ring. When controlling the value to be applied to the heater of the focus ring, it is applied to the heater of the focus ring according to the difference between the temperature measured by the temperature sensor of the focus ring and the set temperature set to the focus ring. The value is controlled so as not to become 0 (zero) due to heat generated by temperature control by the heater belonging to an adjacent zone having a temperature higher than that of the heater of the focus ring.
The temperature control method of the electrostatic chuck according to claim 1 or 2.

Images