JP5567318B2 - Power supply system, substrate processing apparatus, semiconductor manufacturing apparatus, and deterioration diagnosis method - Google Patents

Description

  The present invention relates to a power supply system that supplies a reactive gas to the surface of a substrate carried into a processing furnace and supplies AC power to a substrate processing apparatus that performs a predetermined process.

  Conventionally, when a functional thin film is formed on the surface of a semiconductor substrate, a glass substrate or the like, the substrate reacts while heating the substrate in a heating furnace provided with a resistance heater which is a kind of heating element to be controlled. A chemical gas was supplied to cause a chemical reaction.

  FIG. 9 is a circuit diagram showing a configuration of a conventional power supply system 10 that supplies AC power to the substrate surface treatment apparatus. The power supply system 10 includes an AC power supply 11, a power receiving terminal block 12, a protective breaker (NFB) 13, a power transformer TR, a thyristor 16, a resistance heater 5, a thermocouple 8, and a temperature adjustment controller 15. Yes. The resistance heater 5 is made of molybdenum disilicide whose resistance value is very small at room temperature and increases when the temperature is high. The thyristor 16 is a switch element that controls the phase of the AC voltage transformed by the power transformer TR and applies it to the resistance heater 5. The thyristor 16 increases the AC power supplied to the resistance heater 5 when the temperature measured by the resistance heater 5 with the thermocouple 8 serving as the temperature detection means is lower than the set temperature of the furnace, while the furnace When the temperature is higher than the set temperature, the AC power supplied to the resistance heater 5 is reduced.

  The resistance heater 5 is easily deteriorated as it is used for a long time. If the resistance heater 5 is disconnected during the processing of the substrate, a film formation failure occurs. Therefore, it is necessary to discard the substrate or remove the defective thin film. Loss occurs.

  Therefore, the resistance voltage of the resistance heater 5 is calculated by measuring the AC voltage and AC current applied to the resistance heater 5 to calculate the resistance value of the resistance heater 5 and observing the change in the calculated resistance value. Techniques (Patent Document 1 and Patent Document 2) for predicting disconnection by grasping the state have been developed.

JP 2006-165200 A JP 2006-85907 A JP 2006-107013 A

However, in the techniques described in Patent Document 1 and Patent Document 2, since the AC voltage applied to the resistance heater is phase-controlled by a thyristor, the waveform is not a sine wave but shown by a solid line in FIG. It becomes a discontinuous waveform in which a part of the sine wave is missing. Here, FIG. 10B shows the timing at which the control signal is input to the thyristor. Further, in FIG. 10B, every half cycle of the AC power source, the period from when the control signal is input to the thyristor until the power source voltage becomes zero volts, that is, the period during which the AC voltage is applied to the resistance heater is shown as active power. The period A is displayed, while the period from when the power supply voltage is zero volts to when the control signal is input to the thyristor, that is, the period during which no AC voltage is applied to the resistance overheater is displayed as the reactive power period B. As is clear from FIG. 10, immediately after the control signal is input to the thyristor, a steep rise occurs in the waveform of the AC voltage applied to the resistance heater. At this time, the alternating current applied to the resistance heater does not follow the steep rise of the alternating voltage and increases more gradually than the alternating voltage. At this time, the alternating current applied to the resistance heater includes harmonic currents having various frequencies resulting from a sharp rise in the alternating voltage. This harmonic current is noise that disturbs the measured value of the alternating current by the ammeter.

  As described above, in the techniques described in Patent Document 1 and Patent Document 2, the alternating current applied to the resistance heater is delayed without following the steep rise of the alternating voltage. It is slightly smaller than the theoretical value derived from the value of. Further, since the harmonic current generated due to the steep rise of the AC voltage disturbs the measurement value of the AC current by the ammeter, the measurement value of the AC current fluctuates.

  Therefore, in the techniques described in Patent Document 1 and Patent Document 2, the AC voltage and AC current applied to the resistance heater are continuously measured, and the resistance value (measured resistance value) of the resistance heater is determined from the measured value. When the resistance heater's resistance value is measured using an AC voltage with a sinusoidal waveform when trying to determine the progress of deterioration of the resistance heater based on the calculated change over time of the measured resistance value. There is a problem that the actually measured resistance value is calculated to be slightly higher than that. Further, due to this problem, there is a problem that an increase in resistance value due to the progress of deterioration of the resistance heater appears relatively small and is overlooked. Furthermore, since the actual resistance value of the resistance heater is fluctuated due to the generation of the harmonic current, the change in resistance value due to the deterioration of the resistance heater is buried in this fluctuation. There is also a problem that it is difficult to accurately grasp the progress of deterioration of the heater, in particular, the progress of deterioration in the initial stage after the start of use.

  On the other hand, a power supply system (Patent Document 3) using a high-speed switching power control element has been developed. In the technique described in Patent Document 3, AC power supplied from the AC power supply 11 is supplied to the resistance heater using a high-speed switching element such as IGBT instead of the thyristor 16 shown in FIG.

  An object of the present invention is to provide a power supply system that can detect a change in resistance value due to deterioration of a resistance heater, and thus can accurately predict the replacement time of the resistance heater.

  According to one aspect of the present invention, a supply power regulator that controls a peak value of an AC voltage having a sine wave waveform, and a heating element that generates heat when an AC voltage controlled by the supply power regulator is applied. A measuring device for measuring an alternating voltage and an alternating current applied to the heating element, and calculating a resistance value of the heating element from a voltage value and a current value obtained by the measuring instrument, and based on the calculated resistance value And an arithmetic unit that performs deterioration diagnosis of the heating element.

  According to the present invention, it is possible to accurately grasp the progress of deterioration of the heating element and accurately predict the replacement time of the heating element. Further, since the substrate processing and the deterioration diagnosis of the resistance heater can be performed in parallel, the progress of deterioration in real time can be monitored.

It is a block diagram which shows the structure of the electric power supply system which concerns on one Embodiment of this invention. It is a circuit diagram which shows the structure of the principal part of the power supply regulator in FIG. It is a block diagram which shows the structure of the principal part of the power supply regulator in FIG. It is a figure explaining the control aspect of the alternating voltage by the power supply regulator shown in FIG. It is a flowchart which shows operation | movement of the resistance detection apparatus in FIG. It is a perspective view which shows the structure of the substrate processing apparatus provided with the electric power supply system which concerns on this invention. It is a figure which shows the cross section of the reactor in FIG. 6, and the structure of a substrate support. It is a figure which shows the measurement result of the in-furnace temperature in the Example which concerns on this invention, and the resistance value of a resistance heater. It is a block diagram which shows the structure of the electric power supply system provided with the conventional thyristor. It is a wave form diagram of the alternating voltage output from the electric power supply system of FIG.

<One Embodiment of the Present Invention>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a power supply system 100 according to an embodiment of the present invention. The power supply system 100 includes an AC power supply 101, a power receiving terminal block 102, a protective breaker (NFB) 103, a power transformer 104, a distribution terminal block 105, a resistance heater 106, a furnace 107, a power supply regulator 110, and voltage measurement. A line 128, a temperature adjustment controller 130, a resistance detection device 140, thermocouples 131 and 141, and a current transformer 142 are provided. The supply power regulator 110 includes an input side filter circuit 111, an IGBT converter 112, a current transformer 113, a voltage measurement line 123, a power fluctuation detection means feedforward circuit 114, a frequency conversion circuit 115, an output side filter circuit 116, a current. A transformer 117, a voltage measurement line 118, and a load fluctuation detection means feedback circuit 119 are provided. The resistance detection device 140 includes an A / D converter 143, a computing unit (CPU) 144, a heater manufacturing reference table 145, a heater temperature coefficient table 146, a DO output means 147, and a communication interface (I / F) 148. I have.

  The AC power supply 101 is a single-phase commercial power supply having a frequency of 50/60 Hz and an AC of 200 V, for example. The AC power supply 101 is connected to the power receiving terminal block 102 and supplies AC power to the resistance heater 106. The power receiving terminal block 102 is configured by a terminal that passes power from the AC power supply 101 to the resistance heater 106 side. The resistance heater 106 is a heating element selected from molybdenum disilicide, silicon carbide, carbon, iron-chromium-aluminum alloy, or nickel-chromium alloy.

  A power breaker 103 is connected to the power receiving terminal block 102, and a power transformer 104 is further connected. The power supplied from the AC power supply 101 is received by the power receiving terminal block 102 and then supplied to the power transformer 104 through the protective breaker 103.

  The protective breaker 103 is for preventing excessive electric power from being supplied to the resistance heater 106, and normally the AC power source 101 and the resistance heater 106 are in a conductive state. When excessive power is likely to be supplied to 106, conduction between AC power supply 101 and resistance heater 106 is interrupted.

The power transformer 104 converts the AC voltage of the AC power source 101 into a voltage that can be used by the resistance heater 106. The power transformed by the power transformer 104 is supplied to the IGBT converter 112 controlled by the frequency conversion circuit 115 via the input side filter circuit 111 and further connected to the distribution terminal block 105 via the output side filter circuit 116. The resistance heater 106 is supplied. Note that the power transformer 104 may not be used depending on the specifications of the resistance heater 106.

  The supply power regulator 110 supplies the output of the converter that performs high-speed switching operation to the resistance heater 106 as electric power, and the converter device includes an IGBT (Insulated-Gate) that is an element for controlling high-speed switching power. Bipolar transistor / insulated gate bipolar transistor) is used. The supplied power adjuster 110 applies an AC voltage obtained by switching the AC voltage directly by the IGBT converter 112 and performing pulse width modulation to the resistance heater 106. The waveform of the AC voltage applied to the resistance heater 106 by the supply power regulator 110 is a sine wave waveform without distortion shown in (e) voltage waveform C or (i) voltage waveform C of FIG. Therefore, the reactive power period B shown in FIG. 10 does not exist in the AC voltage applied to the resistance heater 106.

  The thermocouple 131 measures the temperature in the furnace 107 and outputs it to the temperature adjustment controller 130, and is for making the measured temperature of the resistance heater 106 coincide with the set temperature of the furnace 107. The thermocouple 131 is installed in a furnace 107 that is a vertical furnace, and outputs the thermoelectromotive force generated in the furnace 107 to the temperature adjustment controller 130 as data indicating the temperature in the furnace. In general, the thermocouple 131 is installed in the vicinity of the resistance heater 106.

  The thermocouple 141 is for measuring the temperature of the resistance heater 106 and performing a deterioration diagnosis of the resistance heater 106. The thermocouple 141 is installed in the vicinity of the resistance heater 106, and outputs the thermoelectromotive force generated by the heat generated by the resistance heater 106 to the resistance detector 140 as data indicating the temperature of the resistance heater 106. The thermocouple 141 may be configured of the same material as the thermocouple 131 and may be configured to be output to the temperature adjustment controller 130 as data indicating the temperature in the furnace 107 as well.

  The current transformer 142 measures the current flowing through the resistance heater 106 and converts it into an electrical signal, and outputs the electrical signal to the resistance detection device 140. The current transformer 142 is preferably installed closer to the resistance heater 106 than the distribution terminal block 105 in order to accurately measure load fluctuations.

  The temperature adjustment controller 130 controls on / off of the IGBT converter 112 based on the temperature corresponding to the thermoelectromotive force of the thermocouple 131 and the preset temperature of the resistance heater 106. The feedback control signal is output to the frequency conversion circuit 115. Further, the temperature adjustment controller 130 transmits the temperature corresponding to the thermoelectromotive force of the thermocouple 131 and the feedback control signal to a not-shown upper management device or the like via the communication interface 148. Specifically, the temperature adjustment controller 130 calculates the temperature difference (temperature fluctuation) between the temperature measured in the furnace 107 of the furnace 107 by the thermocouple 131 and the set temperature thereof, and the resistance heater according to the temperature fluctuation. The amount of power to be supplied to 106 is calculated, and the calculation result is output to the frequency conversion circuit 115 as a feedback control signal. Further, the temperature adjustment controller 130 outputs an alarm to the upper management device or the like via the communication interface 148 when detecting a temperature abnormality. In the present embodiment, as shown in FIG. 1, the temperature control is performed by the temperature adjustment controller 130 based on the temperature detected by the thermocouple 131, but a thermocouple 141 (not shown) can be substituted.

  The A / D converter 143 converts the measurement value of the AC voltage applied to the resistance heater 106 by the voltage measurement line 128, converts the measurement current value by the current transformer 142, and outputs from the thermocouple 141. The measured temperature value is converted and output to the computing unit 144.

  The heater temperature coefficient table 146 stores diagnosis reference data for deterioration diagnosis, that is, data such as the resistance temperature coefficient of the resistance heater 106, the length of the resistance heater 106, and the cross-sectional area of the resistance heater 106 as a set. Is memory.

  The heater manufacturing reference table 145 is a memory that stores a set of actual measurement data of the temperature and resistance value of the resistance heater 106 when the resistance heater 106 is manufactured (first time use). The heater manufacturing reference table 145 shows the resistance value (actually measured initial resistance value) of the resistance heater 106 calculated by the computing unit 144 based on the output from the A / D converter 143 when the resistance heater 106 is used for the first time. It is stored in association with the temperature at the time of measurement.

  In other words, the heater temperature coefficient table 146 is a memory that stores data used when calculating the theoretical resistance value of the resistance heater 106, while the heater manufacturing reference table 145 includes the resistance value of the resistance heater 106. It is a memory storing an initial value of temperature (actually measured initial value). Therefore, since both the heater manufacturing reference table 145 and the heater temperature coefficient table 146 store the same data, when the computing unit 144 performs the deterioration diagnosis of the resistance heater 106, it is alternatively. used.

  The computing unit 144 calculates the resistance value (measured resistance value) of the resistance heater 106 as needed based on the digital signal converted by the A / D converter 143. Further, the computing unit 144 accesses the heater manufacturing reference table 145 to acquire the actual measured initial resistance value of the resistance heater 106 associated with the temperature measured by the thermocouple 141, or accesses the heater temperature coefficient table 146. The data stored there is obtained, and the theoretical resistance value of the resistance heater 106 corresponding to the temperature measured by the thermocouple 141 is calculated using the obtained data. Then, the computing unit 144 compares the measured resistance value of the resistance heater 106 with the measured initial resistance value or the theoretical resistance value. The computing unit 144 transmits the comparison result to a higher-level management device or the like via the communication interface 148, and when the comparison result satisfies a predetermined condition, the resistance heater 106 is likely to be disconnected. And instructing the DO output means 147 to send an alarm. In the present embodiment, as shown in FIG. 1, the temperature control by the resistance detection device 140 is performed based on the temperature detected by the thermocouple 141, but a thermocouple 131 (not shown) can be substituted.

  The DO output means 147 outputs an alarm, for example, a warning sound for notifying the replacement of the resistance heater 106 in accordance with a command from the computing unit 144. The communication interface 148 is an interface that connects the computing unit 144 and the temperature adjustment controller 130 to a higher-level management device or the like.

  Next, the configuration, function, and operation of the input side filter circuit 111, the output side filter circuit 116, and the IGBT converter 112 will be described with reference to FIG.

The input side filter circuit 111 is a low-pass filter using LC as a filter system, and filter elements are arranged in the order of CLC. The coil L is divided into an input line and a common line and is inserted into L1-1 and L1-2. The capacitor C1-1 before the LC is installed for the purpose of removing harmonic noise riding on the sine wave waveform of the AC power supply and reducing loss, and is a capacitor with a very small capacity. It is desirable to be. The cut-off frequency of the low-pass filter is 1/10 to 1/40 of the switching frequency (the number of times the IGBT is turned on / off in one second and 20 kHz in this embodiment) from the viewpoint of the sine wave waveform and harmonic noise of the AC power supply. (500 Hz to 2 KHz). Therefore, the input side filter circuit 111 can cut off the harmonic noise and reliably supply the AC power of the target commercial frequency (50 or 60 Hz) to the resistance heater 106. The input-side filter circuit 111 suppresses electromagnetic noise generated by switching the IGBT converter 112 at high speed and high frequency. That is, the input-side filter circuit 111 can suppress induction of electromagnetic noise in the input line of the IGBT converter 112 connected to the AC power supply 101 side, and can prevent noise disturbance from occurring in the AC power supply 101.

  The output side filter circuit 116 is a low-pass filter using LC as a filter system, similarly to the input side filter circuit 111, and has filter elements arranged in the order of LCC. The coil L is inserted into the output line and the common line by being divided into L2-1 and L2-2. The capacitor C2-2 after the LC is a capacitor for removing harmonic noise riding on the sine wave waveform of the AC power supply, as described in the input-side filter circuit 111. Further, the cutoff frequency of this low-pass filter is similarly 500 Hz to 2 kHz. The output side filter circuit 116 smoothes (smooths) the output obtained by switching by the IGBT converter 112 and effectively removes harmonic noise contained in the output.

  The IGBT converter 112 includes a power IGBT converter 112a and a regeneration IGBT converter 112b. The IGBT converter 112 is a tabular arm type that separately performs switching of a positive voltage / current waveform and a negative voltage / current waveform. The power IGBT converter 112a is composed of a high-speed rectifier circuit FRD1 and a chopper section having an IGBT2. The chopper section includes an upper arm and a lower arm to which a chopper section PWM (Pulse Width Modulation / pulse width modulation) signal is applied. The regenerative IGBT converter 112b includes an IGBT 3 and a high-speed rectifier circuit FRD2. The IGBT 2 switches AC power directly at a high-speed and high-frequency basic carrier frequency. For example, the switch timing by the PWM system is the zero cross point of the AC voltage of the supply source, and the control signal (PWM signal) is matched with the zero cross point as a reference. Then, the IGBT converter 112 switches the AC voltage of the AC power supply 101 with the combined carrier frequency to obtain a pulse width modulated wave, and applies this to the resistance heater 106 via the output side filter circuit 116. The IGBT converter 112 can also change the frequency of the AC voltage substantially continuously using a frequency control method. In general, devices that control the rotational speed by frequency, such as induction motors, use a method that obtains stable rotation that improves the slip at the start of the motor by controlling the frequency variable width and the voltage applied to the induction motor, etc. It is done. In the present invention, since resistance addition is a control target, pulse width control is used.

  Next, the configuration, function, and operation of the power supply fluctuation detection means feedforward circuit 114, the frequency conversion circuit 115, the load fluctuation detection means feedback circuit 119, and the temperature adjustment controller 130 will be described with reference to FIG.

  The power fluctuation detection means feedforward circuit 114 detects the fluctuation of the AC voltage output from the input side filter circuit 111 and outputs a feedforward control signal corresponding to the fluctuation to the frequency conversion circuit 115. The power fluctuation detection means feedforward circuit 114 includes a current transformer 113 that measures the alternating current output from the input side filter circuit 111 and a voltage measurement line 123 that measures the output line voltage of the input side filter circuit 111. ing. The power supply fluctuation detection means feedforward circuit 114 detects the power supply fluctuation of the AC power supply, and the difference between the measured current value by the current transformer 113 and the set current and the difference between the measured voltage value by the voltage measurement line 123 and the set voltage. Ask for. The product (electric power) of these differences is the power supply fluctuation. This power supply fluctuation is input to the frequency conversion circuit 115 as a feedforward control signal.

The load fluctuation detecting means feedback circuit 119 detects fluctuations in the AC power supplied to the resistance heater 106 and outputs a feedback signal corresponding to the fluctuations to the frequency conversion circuit 115.
Output to. The load fluctuation detection means feedback circuit 119 is connected to a voltage measurement line 118 for measuring the output line voltage of the output side filter circuit 116 and a current transformer 117 for measuring an alternating current applied to the resistance heater 106. Yes. The load fluctuation detecting means feedback circuit 119 obtains the difference between the actually measured voltage value by the voltage measuring line 118 and the set voltage and the difference between the actually measured current value by the current transformer 117 and the set current. The product (electric power) of these differences becomes the load fluctuation. This load fluctuation is input to the frequency conversion circuit 115 as a feedback control signal.

  The frequency conversion circuit 115 controls the IGBT converter 112 by a pulse width modulation method according to the temperature variation, the power source variation, and the load variation. Specifically, the frequency conversion circuit 115 includes a feedforward control signal output from the power fluctuation detection means feedforward circuit 114, a feedback control signal output from the load fluctuation detection means feedback circuit 119, and a temperature adjustment controller 130. Based on the feedback control signal output from, the amount of power (target power amount) to be supplied to the resistance heater 106 is calculated. Next, the frequency conversion circuit 115 determines the duty ratio in the pulse width modulation method used in the IGBT converter 112 so that the peak value of the AC voltage output from the IGBT converter 112 becomes a value corresponding to the target electric energy. Adjust. Next, the frequency conversion circuit 115 inputs a gate control signal including the adjusted duty ratio to the gates of the IGBTs constituting the IGBT converter 112. Note that the frequency conversion circuit 115 inputs a gate control signal including a frequency corresponding to the target power amount to the IGBT converter 112 when the IGBT converter 112 controls the peak value of the AC voltage by the frequency control method. .

  In addition, the resistance value that can be actually measured for the resistance heater 106 in the power supply system 100 is smaller than the resistance value that can be actually measured for the resistance heater 5 in the conventional power supply system 10. That is, according to the power supply system 100, since an AC voltage having a sine wave waveform without distortion is output from the IGBT converter 112, fluctuations in the actually measured resistance value of the resistance heater 106 are reduced. Furthermore, since the fluctuation of the measured resistance value is reduced as the resistance value can be measured even with a small resistance value, an instantaneous change in the actually measured resistance value due to the deterioration of the resistance heater 106 can be detected.

  Further, the temperature adjustment controller 130 and the frequency conversion circuit 115 control the temperature of the resistance heater 106 to be the set temperature as follows.

  The temperature adjustment controller 130 calculates the temperature difference between the measured temperature in the furnace 107 and the set temperature, calculates the amount of electric power to be supplied to the resistance heater 106 according to this temperature difference, and the frequency conversion circuit 115. The operation result is output to. The frequency conversion circuit 115 inputs a gate control signal having a duty ratio corresponding to the output value from the temperature adjustment controller 130 to the IGBT converter 112. The IGBT converter 112 controls the peak value of the AC voltage output from the input side filter circuit 111 using a duty ratio corresponding to the gate control signal from the frequency conversion circuit 115, and the AC voltage whose peak value is controlled. Is applied to the resistance heater 106 via the output side filter circuit 116. Then, by applying an AC voltage whose peak value is controlled to the resistance heater 106, the AC current applied to the resistance heater 106 changes, and the temperature of the resistance heater 106 changes.

Thus, between the temperature adjustment controller 130 and the frequency conversion circuit 115, a closed loop of temperature fluctuation detection → control calculation → output of output value → temperature change → temperature fluctuation detection →. Feedback control is performed. Therefore, according to the power supply system 100, since the temperature of the furnace 107 is detected, the target power amount to be supplied to the resistance heater 106 is set by the temperature adjustment controller 130 and the frequency conversion circuit 115. Feedback control is possible. Furthermore, according to the power supply system 100, the resistance heater 10
6 is corrected, and a stable AC voltage is applied to the resistance heater 106. Therefore, the temperature of the resistance heater 106 can be kept constant.

  If the AC voltage of the AC power supply 101 fluctuates when the temperature of the resistance heater 106 is favorably feedback controlled, this fluctuation appears as a power fluctuation in the output of the input side filter circuit 111. This power fluctuation is measured by the current transformer 113 and the voltage measurement line 123 and detected by the power fluctuation detecting means feedforward circuit 114. The power fluctuation detection means feedforward circuit 114 that has detected the power fluctuation outputs a feedforward control signal corresponding to the power fluctuation to the frequency conversion circuit 115. The frequency conversion circuit 115 to which this feedforward control signal is input outputs a gate control signal including a duty ratio according to the difference between the actually measured power amount and the target power amount to the IGBT converter 112 according to this feedforward control signal. . By such a series of feedforward controls, the power supply fluctuation caused by the AC power supply 101 is corrected, and stable electric power is supplied to the resistance heater 106. Further, the response characteristic from the input side filter circuit 111 to the thermocouple 131 is improved by this feedforward control.

  In addition, when the temperature of the furnace 107 is favorably feedback-controlled, if a disturbance (for example, hitting the outside air) occurs in the resistance heater 106 or the property of the resistance heater 106 changes slightly, it is an IGBT converter. It appears as a change in resistance value 112 or a change in the amount of electric power provided to the resistance heater 106 (load change). That is, the AC voltage and AC current applied to the resistance heater 106 vary. This load fluctuation is measured by the current transformer 117 and the voltage measurement line 118, and is detected by the load fluctuation detecting means feedback circuit 119. A feedback control signal corresponding to the load fluctuation is input from the load fluctuation detecting means feedback circuit 119 to the frequency conversion circuit 115. The frequency conversion circuit 115 outputs a gate control signal including a duty ratio corresponding to the difference between the actually measured power amount and the set power amount to the IGBT converter 112 according to the feedback control signal. By inputting this gate control signal to the IGBT converter 112, feedback control based on load fluctuation is performed. Therefore, according to the power supply system 100, stable power supply to the resistance heater 106 becomes possible by correcting the load fluctuation.

  Such load fluctuation control has two steps, disturbance → power fluctuation detection, compared to temperature fluctuation control through three steps of disturbance → heater temperature change → thermocouple detection, and the thermocouple detection step can be omitted. Fast response characteristics.

  Next, referring to FIG. 3 as appropriate, the frequency conversion circuit 115 receives the feedforward control signal based on the power supply fluctuation, the feedback control signal based on the load fluctuation, and the feedback control signal based on the temperature fluctuation. The control process when outputting the gate control signal to the IGBT converter 112 will be described more specifically.

  The power fluctuation detection means feedforward circuit 114 DC converts the measured current value by the current transformer 113 and the measured voltage value by the voltage measurement line 123 from the effective value (RMS) by the AC / DC converters 114a and 114b, respectively. In 114c, current (DC) × voltage (DC) = primary side power is calculated and input to the frequency conversion circuit 115 as a primary side power supply fluctuation feedback signal FB1.

  The load fluctuation detecting means feedback circuit 119 DC converts the measured current value by the current transformer 117 and the measured voltage value by the voltage measurement line 118 from the effective value (RMS) by the AC / DC converters 119a and 119b, respectively, and the computing unit 119c. Current (DC) × voltage (DC) = secondary power is calculated and input to the frequency conversion circuit 115 as a secondary load fluctuation feedback signal FB2.

  The temperature adjustment controller 130 calculates a temperature difference between the measured temperature in the furnace 107 and the set temperature, calculates a target power amount to be supplied to the resistance heater 106 according to the temperature difference, and calculates the result. Is input to the frequency conversion circuit 115.

  The frequency conversion circuit 115 includes two power gain adjusters 115a and 115b and one power setting gain adjuster 115c therein, and each signal level can be adjusted individually by analog calculation or CPU calculation. Adjust the level. Each level-adjusted signal is input to the adder 115f and added. This addition is also performed by analog calculation or CPU calculation.

  In the configuration as described above, when the primary power supply fluctuation feedback signal FB1 and the secondary load fluctuation feedback signal FB2 are input to the frequency conversion circuit 115, respectively, the primary feedback power fluctuation signal FB1 and the secondary load fluctuation feedback signal are input. The gain of FB2 is adjusted by the power gain adjusters 115a and 115b, inverted by inverters 115d and 115e, respectively, and input to the adder 115f. The adder 115f compares the feedback signal FB1 ′ (FB2 ′) and the feedback signal FB1 (FB2) when outputting the power setting signal in advance. The difference is added to the power setting signal as power supply fluctuation (load fluctuation).

  When a power setting signal is input from the temperature adjustment controller 130 to the frequency conversion circuit 115, the power setting signal is input to the adder 115f after the gain is adjusted by the power setting gain adjuster 115c. When the power supply fluctuation or the load fluctuation occurs, the frequency conversion circuit 115 supplies the fluctuations of the primary-side power fluctuation feedback signal FB1 and the secondary-side load fluctuation feedback signal FB2 adjusted in gain as described above as power in the adder 115f. In addition to the setting signal, an optimum power setting signal is output as a gate control signal (IGBT frequency setting signal).

  As described above, the high-frequency and large-capacity IGBT converter 112 is used as an element constituting the high-speed switching power control semiconductor converter, and the feedback control with respect to the temperature fluctuation of the furnace 107, the feedforward control with respect to the power fluctuation, and the feedback with respect to the load fluctuation Since the control is incorporated, according to the power supply system 100, the temperature stability of the furnace 107 and the stability against power supply fluctuation and load fluctuation can be remarkably improved, and further the temperature stability of the resistance heater 106 can be improved. You can also.

  4 shows the switching operation of the main part of the supply power regulator 110 shown in FIG. 2, and the waveform of the AC voltage at each point ((a) to (e), (f) to (i)) shown in FIG. Is shown. Hereinafter, the function and operation of the IGBT converter 112 will be described in detail with reference to FIGS. 2 and 4 as appropriate.

An AC voltage having the waveform of (a) voltage waveform A of FIG. 4 is applied to the terminal block TB1 shown in FIG. Note that the input frequency of the PWM signal (gate control signal) to the IGBT converter 112 applied via the arm is fixed at 20 KHz (50 μsec). The chopper part PWM signals shown in FIGS. 4B and 4C are respectively applied to the upper arm and the lower arm of the IGBT 2 shown in FIG. The output waveform of the IGBT converter 112 shown in FIG. 2 is (d) voltage waveform B in FIG. This is because the AC power supply 101 is energized only when the IGBT 2 is ON (when the PWM signal is applied), while the energization from the AC power supply 101 is interrupted when the IGBT 2 is OFF. The output waveform of the IGBT converter 112 is smoothed by the output side filter circuit 116. By this smoothing, an AC voltage having a commercial frequency having a sine wave waveform without distortion as shown in (e) voltage waveform C of FIG. 106 is applied. in this way,
The peak value of the AC voltage applied to the resistance heater 106 can be controlled by changing the ON period of the IGBT 2. Therefore, by adjusting the duty ratio of the PWM signal input to the IGBT 2, only the peak value of the AC voltage applied to the resistance heater 106 is changed in the range of 0 to 100% without changing the frequency of the AC power supply 101. Can be controlled.

  Note that the pulse width of the chopper PWM signal applied to the upper arm and lower arm of the IGBT 2 is as shown in (f) and (g) of FIG. 4 from the pulse widths shown in (b) and (c) above. In this case, the waveform of the AC voltage output from the IGBT converter 112 is the waveform shown in (h) voltage waveform B of FIG. Further, since (h) voltage waveform B in FIG. 4 is smoothed by output-side filter circuit 116, the waveform of AC voltage applied to output-side filter circuit 116 is shown in (i) voltage waveform C in FIG. It becomes a sine wave waveform. Note that (i) the peak value of the voltage waveform C in FIG. 4 is larger than the peak value of the (e) power waveform C in FIG. 4 reflecting the difference in the pulse width of the PWM signal input to the IGBT 2. Yes. Incidentally, in one embodiment of the present invention, since the IGBT 2 incorporated in the IGBT converter 112 is directly switched to the AC power supply 101, no diode full-wave rectifier circuit is required on the input side of the IGBT converter 112. It is.

  The IGBT 2 that is a switching element constituting the IGBT converter 112 is a bipolar power transistor combined with a voltage-driven gate, and has low gate drive power consumption and is suitable for high-speed switching. Further, it is a large-capacity element that operates at a high frequency, and its on-voltage is significantly smaller than that of a MOSFET (SSR). The IGBT 2 is preferably controlled at a high frequency in order to reduce reactive power.

  FIG. 5 is a flowchart showing the operation of the resistance detection device 140 when the resistance detection device 140 performs deterioration diagnosis of the resistance heater 106.

  First, in step S110, the arithmetic unit 144 accesses the reference table 145 at the time of heater manufacture, and checks whether the actually measured initial resistance value of the resistance heater 106 is stored in the reference table 145 at the time of heater manufacture. If the measured initial resistance value is stored in the heater manufacturing reference table 145, the computing unit 144 acquires the measured initial resistance value from the heater manufacturing reference table 145 and stores it in the built-in memory, and then the operation of step S130. I do. On the other hand, when the actual initial resistance value of the resistance heater 106 is not stored in the heater manufacturing reference table 145, the computing unit 144 performs the operation of step S120.

Next, in step S120, the arithmetic unit 144 accesses the heater temperature coefficient table 146 to determine deterioration diagnosis data, that is, the resistance temperature coefficient of the resistance heater 106, the length of the resistance heater 106, and the disconnection of the resistance heater 106. Get area data. The computing unit 144 that has acquired the deterioration diagnosis data calculates the theoretical resistance value _Rth in the set temperature range of the resistance heater 106 and stores it in the built-in memory. The theoretical resistance value _Rth of the resistance heater 106 is defined as follows. The resistance temperature coefficient at an arbitrary temperature T ° C. is ρ _T , the length of the resistance heater 106 is L, and the sectional area of the resistance heater 106 is S. It is calculated from the equation “R _th = ρ _T × L / S”.

  Next, in step S130, the computing unit 144 calculates an actual resistance value of the resistance heater 106 from the measured values of the AC voltage and the AC current applied to the resistance heater 106 converted by the A / D converter 143. . The computing unit 144 always provides the calculated actual resistance value of the resistance heater 106 to the upper management device or the like via the communication interface 148.

Then, in step S140, the calculator 144, the reference resistance value one of the theoretical resistance value _{R th} calculated at actual initial resistance value or the step S120 of acquired resistance heater 106 at step S110, and the reference resistance value A difference from the actually measured resistance value of the resistance heater 106 calculated in step S130 is calculated.

  Next, in step S150, the computing unit 144 determines whether the difference calculated in step S140 exceeds a predetermined threshold. If the difference calculated in step S140 exceeds a predetermined threshold, the computing unit 144 determines that the resistance heater 106 has a high risk of disconnection, that is, has reached the replacement time, and outputs an alarm to the DO output means 147. Order to do. The DO output unit 147 that has received a command from the computing unit 144 activates an alarm device such as a speaker to notify the administrator of the power supply system 100 that the resistance heater 106 has reached the replacement time.

  FIG. 6 is a perspective view showing a configuration of a semiconductor manufacturing apparatus 610 provided with the power supply system 100 according to an embodiment of the present invention. The semiconductor manufacturing apparatus 610 is a batch type vertical heat treatment apparatus, and includes a housing 612 in which a main part is arranged.

  A reaction furnace 640 (furnace 107) is disposed on the upper side on the back side in the housing 612. A substrate support 630 loaded with a plurality of substrates 754 is inserted into the reaction furnace 640, and heat treatment is performed.

  FIG. 7 is a view showing a cross section of the reaction furnace 640 and the substrate support 630 inserted into the reaction furnace 640. The reaction furnace 640 includes a reaction tube 742 made of quartz. The reaction tube 742 has a cylindrical shape with its upper end closed and its lower end open. A quartz adapter 744 is disposed below the reaction tube 742 so as to support the reaction tube 742. A reaction vessel 743 is formed by the reaction tube 742 and the adapter 744. A resistance heater 106 is disposed around the reaction tube 742 except for the adapter 744 in the reaction vessel 743. The resistance heater 106 is composed of five sections labeled H5, H4, H3, H2, and H1 in order from the vicinity of the contact point between the reaction tube 742 and the adapter 744 in the vertical upward direction. Each of the resistance heaters 106 of each of the sections H1 to H5 is independently temperature controlled, and is individually replaced with a new resistance heater 106 as necessary. That is, the power supply systems 100 that operate individually are installed in the sections H1 to H5, respectively.

  The lower part of the reaction vessel 743 is opened to insert the substrate support 630. The open portion (furnace port portion) is sealed by the furnace port seal cap 748 coming into contact with the lower surface of the lower end flange of the adapter 744. The furnace port seal cap 748 supports the substrate support 630 and is provided so as to be movable up and down together with the substrate support 630. The substrate supporter 630 supports a large number of, for example, 25 to 100 substrates 754 in a substantially horizontal state with a plurality of gaps and is loaded into the reaction tube 742.

  The adapter 744 is provided with a gas supply port 756 and a gas exhaust port 759 that are integrated with the adapter 744. A gas introduction pipe 760 is connected to the gas supply port 756, and an exhaust pipe 762 is connected to the gas exhaust port 759.

  The processing gas introduced from the gas introduction pipe 760 to the gas supply port 756 is supplied into the reaction pipe 742 via the gas introduction path 764 and the nozzle 766 provided in the side wall portion of the adapter 744.

Next, the operation of the semiconductor manufacturing apparatus 610 will be described. In the following description, the operation of each component of the semiconductor manufacturing apparatus 610 is controlled by the controller 770.

  First, when a pod 616 containing a plurality of substrates 754 is set on the pod stage 614, the pod transfer device 618 transfers the pod 616 from the pod stage 614 to the pod shelf 620 and stocks it. Next, the pod transfer device 618 transfers the pod 616 stocked on the pod shelf 620 to the pod opener 622 and sets it. After the pod opener 622 opens the lid of the pod 616, the substrate number detector 624 confirms the number of substrates 754 accommodated in the pod 616.

  Next, the tweezer 632 of the substrate transfer machine 626 takes out the substrate 754 from the pod 616 at the position of the pod opener 622 and transfers it to the notch aligner 628. The notch aligner 628 detects and aligns the notches while rotating the substrate 754. Next, the tweezer 632 of the substrate transfer machine 626 takes out the substrate 754 from the notch aligner 628 and transfers it to the substrate support 630.

  In this way, when one batch of substrates 754 is transferred to the substrate support 630, the substrate support 630 loaded with a plurality of substrates 754 is inserted into the reaction tube 742 set to about 600 ° C., for example. A furnace port seal cap 748 seals the reactor 640. Next, after the temperature of the reaction furnace 640 is raised to the heat treatment temperature, a processing gas is introduced into the reaction tube 742 from the gas introduction tube 760 through the gas supply port 756, the gas introduction path 764, and the nozzle 766. When the substrate 754 is heat-treated, the temperature in the reaction furnace 640 is maintained at 1000 ° C., for example.

  When the heat treatment of the substrate 754 is completed, for example, the temperature in the reaction furnace 640 is lowered to about 600 ° C., and then the substrate support 630 is unloaded from the reaction tube 742. The substrate support 630 is held in place until all the substrates 754 supported by the substrate support 630 are cooled to room temperature.

  Next, when the substrate 754 of the substrate support 630 that has been placed on standby is cooled to a predetermined temperature, the substrate transfer device 626 takes out the substrate 754 from the substrate support 630 and sets the empty pod 616 that is set in the pod opener 622. To be transported and stored.

  Next, the pod transfer device 618 transfers the pod 616 containing the substrate 754 to the pod shelf 620 or the pod stage 614, and a series of processes is completed.

(Effects of one embodiment according to the present invention)
The resistance heater 106 has a characteristic that the measured resistance value gradually increases and the occurrence rate of disconnection increases as the usage time increases. That is, the amount of change in the actually measured resistance value of the resistance heater 106 can be a good index indicating the occurrence rate of disconnection of the resistance heater 106.

Therefore, according to the power supply system 100, the resistance detector 110 uses the resistance heater 140 to control the peak value while maintaining the sinusoidal waveform of the AC voltage and remove harmonic noise from the AC voltage. A change in the actually measured resistance value 106 is detected with high resolution. Then, since the change in the measured resistance value of the resistance heater 106 is detected with high resolution, it is possible to grasp the deterioration of the resistance heater 106 in detail and accurately. In particular, when the measured resistance value of the resistance heater 106 is low, the amount of change in the measured resistance value caused by the deterioration of the resistance heater 106 seems to be relatively large, so the progress of the deterioration of the resistance heater 106 is more accurately detected. Be grasped. Therefore, since the resistance heater 106 has a low resistance value at medium and low temperatures, the resistance heater 106 monitors the amount of change in the actually measured resistance value at medium and low temperatures, so that the progress of deterioration of the resistance heater 106 is more accurately detected. Can grasp.

  As described above, according to the power supply system 100, it is possible to perform accurate deterioration diagnosis based on an objective standard rather than subjective deterioration diagnosis based on an operator's experience. Therefore, the resistance heater 106 is installed before disconnection occurs. It will be possible to replace it reliably.

  Further, according to the power supply system 100, since the change in the measured resistance value of the resistance heater 106 can be detected with high resolution, the progress of deterioration of the resistance heater 106 can be accurately grasped from the initial stage after the start of use. Can do. Therefore, according to the power supply system 100, it is not necessary to prepare the spare resistance heater 106 and replace it periodically, and the resistance heater 106 is suddenly disconnected within the lifetime prediction range period and the substrate is removed. The problem that the processing work must be interrupted is less likely to occur.

  Furthermore, according to the power supply system 100, it is possible to reliably prevent defective heating during substrate processing due to disconnection of the resistance heater 106, thereby preventing occurrence of lot defects during substrate processing and improving substrate processing productivity. be able to. In particular, when the furnace 107 is a vertical furnace, the productivity is remarkably improved.

  Further, according to the power supply system 100, the difference between the actually measured resistance value of the resistance heater 106 and the reference resistance value transmitted from the computing unit 144 via the communication interface 148 is monitored using a higher-level management device or the like. be able to. Here, in the process in which the measured resistance value of the resistance heater 106 gradually increases, an instantaneous peak appears in the measured resistance value, and the appearance frequency and maximum value of the peak are the deterioration of the resistance heater 106. It increases with progress. Therefore, the deterioration diagnosis of the resistance heater 106 can be performed by measuring the appearance frequency and the maximum value of the peak while monitoring the difference between the actually measured resistance value of the resistance heater 106 and the reference resistance value. The deterioration diagnosis by measuring the appearance frequency and the maximum value of this peak is particularly useful for deterioration diagnosis in the initial stage after the resistance heater 106 is used at a low temperature or when the resistance heater 106 is used.

  Further, according to the supply power adjuster 110, the electromagnetic noise generated in the IGBT converter 112 is suppressed by the input-side filter circuit 111, so that it is difficult for the electromagnetic noise to be mixed into the AC voltage from the AC power supply AC power supply 101. Therefore, according to the power supply system 100, it is possible to prevent occurrence of a failure due to electromagnetic noise included in the AC voltage. Moreover, according to the power supply system 100, it can suppress that electromagnetic noise is induced | guided | derived to the input cable from AC power supply 101 to IGBT converter 112. FIG. Furthermore, according to the power supply system 100, harmonic noise included in the output of the IGBT converter 112 is suppressed by the output-side filter circuit 116, so that harmonic noise included in the AC voltage applied to the resistance heater 106. Can be attenuated.

  Further, according to the power supply system 100, the regenerative IGBT converter 112b regenerates the back electromotive force generated outside the IGBT converter 112 and returns it to the AC power supply 101, so that the energy efficiency of the AC power supply 101 is greatly increased. Can be improved. In particular, since the IGBT converter 112 performs a switching operation at a high speed and a high frequency, the number of occurrences of the counter electromotive force is large, and power regeneration is frequently performed.

Further, according to the power supply system 100, the power supply fluctuation is reflected in the control of the peak value of the AC voltage in the IGBT converter 112 by the feedforward control, and the load fluctuation and the temperature fluctuation are reflected by the feedback control. The temperature stability of 106 can be improved. In other words, in addition to the feedback control based on the temperature fluctuation of the furnace 107 by the temperature adjustment controller 130, the power supply system 100 includes the feedforward control based on the power fluctuation by the power fluctuation detection means feedforward circuit 114 and the load fluctuation. By simultaneously performing feedback control based on load fluctuations by the detection means feedback circuit 119, the resistance of the resistance heater 106 can be maintained even when the resistance heater 106 is at a low intermediate temperature or when the power supplied to the resistance heater 106 is small. The value can be measured accurately. Therefore, according to the power supply system 100, since stable power control is possible, the usability is improved.

  Further, according to the power supply system 100, since the IGBT converter 112, which is a high-speed switching element, is used, it has excellent temperature response and does not depend on the correction of the phase advance capacitor, so that electromagnetic noise is generated. Since it is a difficult structure, it is suitable as a component of an instrumentation line that dislikes electromagnetic noise. Therefore, it is possible to prevent problems such as malfunction and damage of each component of the power supply system 100 and attraction of malfunction to peripheral devices.

  Further, according to the power supply system 100, since electromagnetic noise generated in the IGBT converter 112 is removed by the input side filter circuit 111, mixing of electromagnetic noise into the AC power supply 101 can be effectively suppressed. Furthermore, according to the power supply system 100, since harmonic noise included in the AC voltage output from the IGBT converter 112 is removed by the output-side filter circuit 116, a sine wave waveform without distortion from the supply power regulator 110. Therefore, it is possible to save the power of the entire system. Therefore, the measured resistance value of the resistance heater 106 can be accurately calculated even at a low temperature.

  According to the semiconductor manufacturing apparatus 610, since the power supply system 100 is provided, the temperature stability in the reaction furnace 640 can be improved, and as a result, a high-performance semiconductor device can be manufactured.

  Further, according to the semiconductor manufacturing apparatus 610, the deterioration diagnosis of the resistance heater 106 can always be performed regardless of the standby state after the substrate support 630 is inserted into the reaction tube 742 and before the substrate 754 is heated. Therefore, it is not necessary to separately provide a time for diagnosing deterioration of the resistance heater 106, and the productivity of substrate processing can be improved.

(Modification of one embodiment according to the present invention)
In an embodiment according to the present invention, the feedback control signal based on the temperature fluctuation of the resistance heater 106 detected by the temperature adjustment controller 130 is fed to the feed based on the power fluctuation detected by the power fluctuation detecting means feedforward circuit 114. The case where the feedback control signal based on the load fluctuation detected by the forward control signal and the load fluctuation detection means feedback circuit 119 is added by the frequency conversion circuit 115 and then input to the IGBT converter 112 has been described. The case is not limited. For example, by partially modifying an embodiment according to the present invention, the frequency conversion circuit 115 may change the feedback control signal based on the temperature variation to the feedforward control signal based on the power source variation or the feedback control signal based on the load variation. Any of these may be added and input to the IGBT converter 112. When the feedforward control signal based on the power supply fluctuation is added, the IGBT converter 112 outputs an AC voltage corrected so as to cancel the power supply fluctuation, so that the power supplied to the resistance heater 106 is stabilized. On the other hand, when the feedback control signal based on the load fluctuation is added, the IGBT converter 112 outputs an AC voltage corrected so as to cancel the load fluctuation, so that the voltage change caused by the operation of the supply power regulator 110 Is suppressed, and the power supplied to the resistance heater 106 is stabilized.

Further, although not explicitly shown in one embodiment of the present invention, for example, the A / D converter 143 and the arithmetic unit 144, or the temperature adjustment controller 130 and the communication interface 148 are connected via a data communication line. May be. Thus, when each component in the power supply system 100 is connected via a data communication line, the design flexibility of the power supply system 100 is remarkably increased. Can be enlarged.

  In one embodiment according to the present invention, when one reactor 640 is temperature-controlled separately for each of the five sections H1 to H5, that is, one power supply system 100 is installed in each of the sections H1 to H5. Although the case has been described, the present invention is not limited to this case. For example, the temperature may be controlled by one power supply system 100 without dividing one reactor 640 into sections. Further, when controlling the temperature of a plurality of reactors 640 of the same type at the same time, for example, using one reactor 640 as a sample, the power supply system 100 is installed only in the reactor 640 of this sample, and the other reactors 640 have You may make it supply electric power on the same conditions as the reaction furnace 640 of a sample.

  In the embodiment of the present invention, the case where the furnace 107 and the reaction furnace 640 are vertical furnaces has been described. However, the present invention is not limited to this case. For example, the furnace 107 and the reaction furnace 640 are horizontal. A furnace or a single wafer furnace may be used.

  In one embodiment of the present invention, the supply power regulator 110 includes a current transformer 117 and a voltage measurement line 118, while the resistance detector 140 is a voltage disposed in front of the current transformer 142 and the distribution terminal block 105. Although the case where it is connected to the measurement line 128 has been described, the present invention is not limited to this case. For example, the supply power regulator 110 and the resistance detection device 140 share the current transformer and the voltage measurement line. It may be configured.

Example 1
The substrate 754 loaded on the substrate support 630 was heat-treated in the reaction tube 742 using the semiconductor manufacturing apparatus 610 provided with the power supply system 100 according to the embodiment of the present invention. Specific heating conditions in this heat treatment are as follows.

(1) The substrate support 630 holding the substrate 754 is inserted into the reaction tube 742 at room temperature and sealed.
(2) Next, the set temperature of the resistance heater 106 is set to 100 ° C. to 380 ° C., and this temperature range is set so as to reciprocate in a cycle of 1 hour. An AC voltage having a sinusoidal waveform with a controlled high value and without distortion is applied.
(3) Next, the set temperature of the resistance heater 106 is corrected to 750 ° C. 10 hours after the energization of the resistance heater 106 is started from the supply power regulator 110.
(4) Next, after 1 hour has elapsed since the set temperature of the resistance heater 106 is corrected to 750 ° C., the set temperature of the resistance heater 106 is again set to 100 ° C. to 380 ° C., and this temperature range is cycled for 1 hour. Set to go back and forth.
(5) Next, after the set temperature of the resistance heater 106 is reset to 100 ° C. to 380 ° C. and 10 hours have elapsed, the set temperature of the resistance heater 106 is corrected again to 750 ° C.
(6) Next, after 1 hour has elapsed since the set temperature of the resistance heater 106 is re-corrected to 750 ° C., the set temperature of the resistance heater 106 is again set to 100 ° C. to 380 ° C., and this temperature range is set to 1 hour. Reconfigure to reciprocate at periodic intervals.
(7) Next, after the set temperature of the resistance heater 106 is reset to 100 ° C. to 380 ° C., after 5 hours have elapsed, the supply of AC power from the supply power regulator 110 to the resistance heater 106 is stopped, and the reaction The tube 742 and the substrate 754 are radiated to return to room temperature.

  In Example 1, the heat treatment steps (1) to (7) are repeated in principle. However, when the steps (5) and (6) are not performed or after the step (6) (5 ) Step and (6) step may be repeated.

  The resistance heater 106 used in Example 1 was an unused product and was not deteriorated at all. In the first embodiment, the computing unit 144 accesses the heater temperature coefficient table 146 to calculate the theoretical resistance value of the resistance heater 106 for each temperature, and uses the calculated theoretical resistance value as the reference resistance value. In the first embodiment, the computing unit 144 constantly calculates the difference between the resistance value measured and the reference resistance value of the resistance heater 106-H3, that is, the resistance heater 106 disposed in the central section of the reaction furnace 640. Continued.

(Comparative Example 1)
In Comparative Example 1, the substrate 754 was heat-treated under the same heating conditions as in Example 1 by replacing the supply power regulator 110 in the reaction furnace 640 used in Example 1 with the thyristor 16 in the conventional power supply system 10. . Also in Comparative Example 1, an unused resistance heater 106 was used, and the theoretical resistance value of the resistance heater 106 was used as a reference resistance value. Furthermore, also in the comparative example 1, the computing unit 144 continuously calculated the difference between the actually measured resistance value and the theoretical resistance value of the resistance heater 106-H3.

(Contrast between Example 1 and Comparative Example 1)
FIG. 8 shows the difference between the measured temperature (upper line segment) of the resistance heater 106-H3 in Example 1 and Comparative Example 1, and the measured resistance value and the theoretical resistance value of the resistance heater 106-H3 at the time of measurement. (Lower line segment). In FIG. 8, the left side shows the result of the heat treatment by the comparative example 1, that is, the phase control method, while the right side from the center shows the result of the heat treatment by the example 1, that is, the voltage peak value control method.

  From the graph of FIG. 8, the difference between the measured resistance value and the theoretical resistance value of the resistance heater 106-H3 in Comparative Example 1 is the difference between the measured resistance value and the theoretical resistance value of the resistance heater 106-H3 in Example 1. It can be seen that it is larger than the difference. As described above, the reason why the actually measured resistance value of the resistance heater 106 in the comparative example 1 is relatively larger than the theoretical resistance value is that the alternating current applied to the resistance heater 106 in the phase control method of the comparative example 1. This is probably because the voltage waveform is not a sinusoidal waveform but a distorted waveform having a steep rise, and the alternating current cannot follow the distorted waveform of the alternating voltage and is delayed.

  Further, it can be seen from the graph of FIG. 8 that an instantaneous peak is formed in the line segment of the difference between the actually measured resistance value and the theoretical resistance value of the resistance heater 106-H3 in the first embodiment. This peak is considered to be caused by the deterioration of the resistance heater 106, and in the line segment actually showing Example 1 in FIG. 8, this peak appears as the usage time of the resistance heater 106-H3 increases. As the frequency increases, the maximum value of this peak increases.

  Therefore, according to the power supply system 100 according to the embodiment of the present invention, by continuously monitoring the appearance frequency of the peak and the maximum value of the peak, the progress of deterioration of the resistance heater 106 can be accurately determined. I can grasp it. In particular, according to the power supply system 100, since the difference between the measured resistance value and the theoretical resistance value of the resistance heater 106 is relatively small, the occurrence of the peak shown in FIG. easy. Therefore, in the power supply system 100 according to an embodiment of the present invention, a threshold value regarding a difference between the actually measured resistance value and the theoretical resistance value of the resistance heater 106 is set in advance, and the peak shown in FIG. If the frequency is exceeded, it may be diagnosed that the resistance heater 106 has deteriorated and the replacement time has been reached.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

The first aspect is
Current detection means for detecting a current value of a control target (heating element) provided in the semiconductor manufacturing apparatus;
Voltage detection means for detecting a voltage value of the control object;
Resistance value calculating means for calculating a resistance value of the control object based on a current value detected by the current detecting means and a voltage value detected by the voltage detecting means;
An arithmetic unit that uses the resistance value calculated by the resistance value calculating means for diagnosis of deterioration of the controlled object;
A resistance detection apparatus comprising: a transmission means that transmits the resistance value calculated by the resistance value calculation means as diagnostic reference data used for deterioration diagnosis of a control target provided in another semiconductor manufacturing apparatus via a communication line; ,
A power converter (IGBT converter) that converts the AC voltage of the AC power source into an AC voltage corresponding to the duty ratio of the control signal and applies the AC voltage to the control target;
A power supply system comprising: a regenerative converter (IGBT converter) that regenerates a back electromotive force generated by a switching operation of the power converter and returns it to the AC power supply.

A second aspect is the power supply system according to the first aspect,
The supply power regulator is
Temperature fluctuation detecting means for detecting temperature fluctuation of the controlled object;
A power fluctuation detecting means for detecting a power fluctuation of the AC power from the power supplied from the AC power to the power converter;
Load fluctuation detecting means for detecting a load fluctuation from the electric power supplied from the power converter to the controlled object;
The frequency of the control signal corresponding to the amount of power to be supplied to the control object to be applied to the supply power regulator is determined according to the detection results of the temperature fluctuation detection means, the power supply fluctuation detection means, and the load fluctuation detection means. And a frequency varying means for controlling.

The third aspect is
Temperature measuring means for measuring the temperature of the controlled object;
A heater temperature coefficient table storing data used to calculate the theoretical resistance value of the control object;
A heater creation reference table storing the measured initial resistance value of the control object together with temperature data;
A reference resistance value corresponding to the temperature of the control object measured by the temperature measuring means is calculated from data stored in the heater temperature coefficient table, or actually stored in the heater creation time reference table Whether the initial resistance value is acquired, the measured resistance value of the controlled object is further calculated from the measured values of the AC voltage and the alternating current applied to the controlled object, and the calculated measured resistance value and the reference resistance value are calculated. And a computing unit for comparing with the resistance detector.

The fourth aspect is
An input side filter circuit for removing harmonic noise contained in the AC voltage;
A power fluctuation detecting means feedforward circuit for detecting a power fluctuation of the output from the input side filter circuit and outputting a feedforward control signal for canceling the detected power fluctuation;
An IGBT converter that controls a peak value of a sinusoidal waveform of the AC voltage output from the input side filter circuit;
An output side filter circuit for removing harmonic noise contained in the AC voltage output from the IGBT converter;
A load fluctuation detecting means feedback circuit for detecting a power fluctuation of the output from the output side filter circuit and outputting a feedback control signal for canceling the detected power fluctuation (load fluctuation);
A temperature adjustment control signal for eliminating a temperature difference between a measured temperature of a controlled object (heating element) to which the AC voltage output from the output side filter circuit is applied and a set temperature of the controlled object; and the feedforward control signal And a frequency conversion circuit that causes the IGBT converter to adjust the peak value of the sine wave waveform of the AC voltage in accordance with the feedback control signal.

The fifth aspect is
A temperature measuring step in which the temperature measuring means measures the temperature of the controlled object (heating element);
An arithmetic unit obtains data for calculating the theoretical resistance value of the controlled object from the heater temperature coefficient table and calculates the theoretical resistance value corresponding to the measured temperature in the temperature measuring step, or a heater creation reference table A reference resistance value acquisition step of acquiring an actual measured initial resistance value of the controlled object corresponding to the measurement temperature in the temperature measurement step, or
An actual resistance value calculating step for calculating an actual resistance value of the control object from a measurement value of the AC voltage and the AC current applied to the control object;
A resistance value comparison step for comparing the reference resistance value of the control target calculated or acquired in the reference resistance value acquisition step with the actual resistance value calculated in the actual resistance value calculation step;
A deterioration diagnosis method for a control object, comprising: a deterioration diagnosis step for performing deterioration diagnosis of the control object by determining whether the comparison result in the resistance value comparison step exceeds a predetermined threshold. .

According to a sixth aspect, in the fifth aspect,
An alarm transmission step in which an alarm for prompting replacement of the control object is transmitted when the arithmetic unit determines that the comparison result in the resistance value comparison step exceeds a predetermined threshold;
An exchange step of exchanging the controlled object when the alarm is transmitted.

The seventh aspect is
A semiconductor manufacturing apparatus equipped with a power supply system for controlling a resistance heater installed in a reaction furnace for heat-treating a substrate,
Temperature measuring means (thermocouple) for measuring the temperature of the controlled object;
A heater temperature coefficient table storing data used to calculate the theoretical resistance value of the control object;
A heater creation reference table storing the measured initial resistance value of the control object together with the measured temperature;
The reference resistance value corresponding to the temperature measured by the temperature measuring unit is calculated from the data stored in the heater temperature coefficient table, or the measured initial resistance stored in the heater creation reference table The actual resistance value of the control object is calculated from the measured values of the alternating voltage and the alternating current applied to the control object, and the calculated actual resistance value and the reference resistance value are obtained. A resistance detection device comprising a computing unit for comparison;
An input side filter circuit for removing harmonic noise contained in the AC voltage;
A power fluctuation detecting means feedforward circuit for detecting a power fluctuation of the output from the input side filter circuit and outputting a feedforward control signal for canceling the detected power fluctuation;
An IGBT converter that controls a peak value of a sinusoidal waveform of the AC voltage output from the input side filter circuit;
An output side filter circuit that removes harmonic noise contained in the AC voltage output from the IGBT converter;
A load fluctuation detecting means feedback circuit for detecting a power fluctuation of the output from the output side filter circuit and outputting a feedback control signal for canceling the detected power fluctuation (load fluctuation);
A control signal for temperature adjustment that eliminates a temperature difference between the measured temperature of the controlled object to which the AC voltage output from the output-side filter circuit is applied and the set temperature of the controlled object, the feedforward control signal, and the A frequency converter circuit that adjusts the peak value of the sine wave waveform of the AC voltage in response to a feedback control signal;
Is a semiconductor manufacturing apparatus.

The eighth aspect is
A resistance heater that generates heat when an alternating voltage with a controlled peak value is supplied;
A thermocouple for detecting temperature fluctuations of the resistance heater;
A power fluctuation detecting means feedforward circuit for detecting a power fluctuation from an AC voltage and an AC current before the peak value is controlled;
A load fluctuation detecting means feedback circuit for detecting a load fluctuation from an AC voltage and an AC current applied to the resistance heater;
A frequency conversion circuit that outputs a control signal according to the temperature variation, the power source variation, and the load variation;
An IGBT converter for controlling a peak value while maintaining a sinusoidal waveform of an AC voltage by a pulse width modulation method according to the control signal;
A current transformer for measuring an alternating current applied to the resistance heater;
A voltage measurement line for measuring an AC voltage applied to the resistance heater;
Resistance detection for calculating an actual resistance value of the resistance heater from the measured current value by the current transformer and the measured voltage value by the voltage measurement line, and performing deterioration diagnosis of the resistance heater based on the calculated actual resistance value Equipment,
It is a power supply system provided with.

  The power supply system according to the present invention and the substrate processing apparatus including the power supply system can be applied not only to thin film formation processing on a semiconductor substrate, a glass substrate, etc., but also to annealing processing and oxidation / reduction processing.

DESCRIPTION OF SYMBOLS 100 Electric power supply system 106 Resistance heating heater 107 Furnace 110 Supply electric power regulator 112 IGBT converter 114 Power supply fluctuation | variation detection means Feedforward circuit 115 Frequency conversion circuit 119 Load fluctuation detection means feedback circuit 130 Temperature adjustment controller 144 Calculator 145 Heater manufacture Time reference table 146 Heater temperature coefficient table

Claims (9)

A power supply regulator comprising at least a power IGBT converter for controlling a peak value of an AC voltage of an AC power supply having a sine wave waveform;
A resistance heater that generates heat when an AC voltage controlled by the supply power regulator is applied;
A measuring instrument for measuring the alternating voltage and alternating current applied to the resistance heater ;
An arithmetic unit that calculates the resistance value of the resistance heater from the voltage value and the current value obtained by the measuring device, and performs deterioration diagnosis of the resistance heater based on the calculated resistance value;
Temperature measuring means for measuring the temperature of the resistance heater;
A heater temperature coefficient table storing data used to calculate the theoretical resistance value of the resistance heater;
A resistance detection device comprising: a heater creation reference table storing measured initial resistance values of the resistance heater together with temperature data;
With
The supply power regulator is
By adjusting the duty ratio of the gate control signal input to the power IGBT converter, the peak value is controlled while maintaining the sinusoidal waveform of the AC voltage without changing the frequency of the AC power supply ,
The calculator is
A reference resistance value corresponding to the temperature of the resistance heater measured by the temperature measuring means is calculated from data stored in the heater temperature coefficient table or stored in the heater creation time reference table. The actual resistance value of the object to be controlled is calculated from the measured values of the alternating voltage and alternating current applied to the resistance heater by acquiring the actual measured initial resistance value, and the calculated actual resistance value and the reference resistance are calculated. A power supply system , wherein a difference from the value is compared with a predetermined threshold value smaller than 4Ω to determine whether the threshold value is exceeded . The supply power regulator is
Power supply system according to claim 1, and a regenerating IGBT converter back to the AC power supply back EMF regeneration to a caused by the switching operation of the IGBT converter for the power. The supply power regulator is
Temperature fluctuation detecting means for detecting temperature fluctuation of the resistance heater ;
Power fluctuation detection means for detecting a power fluctuation of the AC power supply from the power supplied from the AC power supply to the power IGBT converter;
A load fluctuation detecting means for detecting a load fluctuation from the electric power supplied from the power IGBT converter to the resistance heater ;
The frequency of the control signal according to the amount of power to be supplied to the resistance heater applied to the supply power regulator according to the detection results of the temperature fluctuation detection means, the power fluctuation detection means, and the load fluctuation detection means Frequency variable means for controlling
A power supply system according to claim 1 or 2. The supply power regulator is
An input side filter circuit for removing harmonic noise contained in the AC voltage;
A power fluctuation detecting means feedforward circuit for detecting a power fluctuation of the output from the input side filter circuit and outputting a feedforward control signal for canceling the detected power fluctuation;
An IGBT converter for power that controls the peak value of the sine wave waveform of the AC voltage output from the input side filter circuit;
An output-side filter circuit that removes harmonic noise contained in the AC voltage output from the power IGBT converter;
A load fluctuation detecting means feedback circuit for detecting a power fluctuation of the output from the output side filter circuit and outputting a feedback control signal for canceling the detected power fluctuation;
A temperature adjustment control signal for eliminating a temperature difference between the measured temperature of the resistance heater to which the AC voltage output from the output side filter circuit is applied and the set temperature of the resistance heater , the feedforward control signal, And a frequency conversion circuit that causes the power IGBT converter to adjust the peak value of the sine wave waveform of the AC voltage according to the feedback control signal;
The power supply system according to claim 1, comprising: A substrate processing apparatus including a power supply system according to any one of claims 1 to 4. The substrate processing apparatus according to claim 5 , wherein at least one of the semiconductor substrate and the glass substrate is configured to perform any one of thin film formation processing, annealing processing, and oxidation processing. A semiconductor manufacturing apparatus provided with a power supply controller for controlling a resistance heater installed in a reaction furnace for heat-treating a substrate,
Temperature measuring means for measuring the temperature of the controlled object;
A heater temperature coefficient table storing data used to calculate the theoretical resistance value of the control object;
A heater creation reference table storing the measured initial resistance value of the control object together with the measured temperature;
The reference resistance value corresponding to the temperature measured by the temperature measuring unit is calculated from the data stored in the heater temperature coefficient table, or the measured initial resistance stored in the heater creation reference table The actual resistance value of the control object is calculated from the measured values of the alternating voltage and the alternating current applied to the control object, and the calculated actual resistance value and the reference resistance value are obtained. A resistance detection device comprising a computing unit for comparison;
An input side filter circuit for removing harmonic noise contained in the AC voltage of the AC power supply;
A power fluctuation detecting means feedforward circuit for detecting a power fluctuation of the output from the input side filter circuit and outputting a feedforward control signal for canceling the detected power fluctuation;
An IGBT converter for power that controls the peak value of the sine wave waveform of the AC voltage output from the input side filter circuit;
An output side filter circuit for removing harmonic noise contained in the AC voltage output from the power IGBT converter;
A load fluctuation detecting means feedback circuit for detecting a power fluctuation of the output from the output side filter circuit and outputting a feedback control signal for canceling the detected load fluctuation;
A control signal for temperature adjustment that eliminates a temperature difference between the measured temperature of the controlled object to which the AC voltage output from the output-side filter circuit is applied and the set temperature of the controlled object, the feedforward control signal, and the A frequency conversion circuit that causes the power IGBT converter to adjust a peak value of a sine wave waveform of the AC voltage in accordance with a gate control signal calculated from a feedback control signal;
Supply for controlling the peak value while maintaining the sinusoidal waveform of the AC voltage without changing the frequency of the AC power supply by adjusting the duty ratio of the gate control signal input to the power IGBT converter A power regulator;
Equipped with,
The arithmetic unit, the difference between the reference resistance value and the measured resistance value, a semiconductor manufacturing device to determine if exceeds a 4Ω smaller predetermined threshold value. A degradation diagnosis method for a semiconductor manufacturing apparatus according to claim 7 ,
A temperature measuring step in which the temperature measuring means measures the temperature of the controlled object;
An arithmetic unit obtains data for calculating the theoretical resistance value of the controlled object from the heater temperature coefficient table and calculates the theoretical resistance value corresponding to the measured temperature in the temperature measuring step, or a heater creation reference table A reference resistance value acquisition step of acquiring an actual measured initial resistance value of the controlled object corresponding to the measurement temperature in the temperature measurement step, or
An actual resistance value calculating step for calculating an actual resistance value of the control object from a measurement value of the AC voltage and the AC current applied to the control object;
A resistance value comparison step for comparing the reference resistance value of the control target calculated or acquired in the reference resistance value acquisition step with the actual resistance value calculated in the actual resistance value calculation step;
A deterioration diagnosis step of performing a deterioration diagnosis of the control object by determining whether the comparison result in the resistance value comparison step exceeds a predetermined threshold value less than 4Ω by the computing unit;
A deterioration diagnosis method having An alarm transmission step in which an alarm for prompting replacement of the control object is transmitted when the arithmetic unit determines that the comparison result in the resistance value comparison step exceeds a predetermined threshold value less than 4Ω ;
The deterioration diagnosis method according to claim 8 , further comprising: an exchange step of exchanging the control target when the alarm is transmitted.