JP5374109B2 - Heating vacuum processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise a temperature of a heating lamp without generating an inrush current and noise. <P>SOLUTION: When the temperature of the heating lamp 15 is raised from room temperature, it is raised by using a phase control from the room temperature up to a change temperature and by using a cycle control from the change temperature up to a treatment temperature. When the temperature of the heating lamp 15 is lowered from the treatment temperature to the minimum temperature lower than the change temperature, it is raised up to the treatment temperature by the cycle control. When a filament of the heating lamp is at the room temperature wherein it has a low resistance, the inrush current is not generated since the phase control is used, and when the filament of the heating lamp is at a higher temperature than the change temperature, the noise is not generated since the cycle control is used. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a heating vacuum processing method for processing a processing target object in a vacuum atmosphere, such as a sputtering process, a vapor deposition process, and an etching process, and more particularly to a technique for heating the processing target object with a heating lamp.

  A semiconductor wafer or a liquid crystal glass substrate is used as a processing target, and a thin film is formed on the processing target by sputtering or vapor deposition, or a thin film on the processing target is patterned by etching or the like.

  When such treatment is performed, the object to be treated is heated and subjected to heat vacuum treatment. In addition to using a resistance heating element that generates heat by energization as a heating device, a heating lamp that can be disposed as a treatment object is provided. It is used as a heating device.

  In the case of a heating lamp, the energization amount is controlled by cycle control that combines a half-wave that is conductive for the entire period of 180 degrees and a half-wave that is blocked for the entire period of 180 degrees, and the object to be processed is heated to a predetermined processing temperature. Heat vacuum processing is performed.

However, including a holder for holding the object to be processed in a vacuum chamber in which heat vacuum processing is performed, and in addition to those, if a cycle control is performed while the heating lamp is at room temperature, a large inrush current flows, and the control device Or the heating power supply may be destroyed.
The following Patent Document 1 is known as a heating method for controlling the energization amount of the resistance heating coil, and the following Patent Document 2 is known as a heating method for heating with a heating lamp.
JP-A-10-294285 JP 2002-190552 A

  When the heating lamp is heated and heat rays are radiated, the resistance value of the heating lamp is high, but when the temperature of the heating lamp is at room temperature, the resistance value of the heating lamp is low, so the temperature of the heating lamp at room temperature The reason why the inrush current is generated when the voltage is increased is that such a resistance value is low. Particularly, when the cycle control in which the half wave of the AC voltage is applied to the heating lamp is performed, the voltage of the half wave is reduced. It was found that an inrush current occurs when a large voltage at the peak position is applied.

On the other hand, when performing phase control for conducting a part of the half-wave, inrush current does not occur if the part after the peak position of the half-wave is partially conducted, but the circuit switches from interruption to conduction while voltage is applied. There was a disadvantage that noise was generated.
This noise, as a harmonic, affects the supply power supply side, and there is a concern of affecting not only this apparatus but also other devices.

In order to solve the above-described problems, the present invention carries a processing object into a vacuum chamber, holds the processing target with a holder in the vacuum chamber, and controls the AC voltage output from the heating power source by a control device. Applied to the heating lamp, radiates heat rays from the heating lamp, irradiates and heats the object to be processed and the holder disposed in the vacuum chamber in a vacuum atmosphere, and vacuums the object to be processed. A heating vacuum processing method for processing, wherein a minimum temperature higher than room temperature, a processing temperature higher than the minimum temperature, and a change temperature between the minimum temperature and the processing temperature are set in advance, and the processing measuring the temperature of the object by the sensor, when the temperature of the processing object was measured in room temperature, until said processing object reaches the changing temperature, some of the half-wave for conducting the middle of 180 degrees combination Allowed to warm to the processing object by controlling the radiation of heat rays of the heating lamp by phase control, after the temperature of the processing object of measurement has reached the change temperature, 180 degrees entire period conductive to have half The temperature of the object to be processed is increased by controlling the radiation of the heat rays of the heating lamp by cycle control combining a wave and a half-wave that is cut off for a whole period of 180 degrees, and the processing temperature is increased. This is a heating vacuum processing method for performing vacuum processing.
Further, the present invention provides a heating vacuum processing method in which the energizing time of the heating lamp is lengthened in the phase control, and the ratio of a half wave that is conductive for 180 degrees in the cycle control is increased in the cycle control. It is.
In the present invention, the object to be processed is carried into the vacuum chamber, the object to be processed is held by the holder in the vacuum chamber, and the AC voltage output from the heating power source is controlled by the control device and applied to the heating lamp. The heating lamp radiates heat rays from the heating lamp, irradiates and heats the object to be processed and the holder disposed in the vacuum chamber in a vacuum atmosphere, and heats and vacuums the object to be processed In this method, a minimum temperature higher than room temperature, a processing temperature higher than the minimum temperature, and a change temperature between the minimum temperature and the processing temperature are set in advance, and the temperature of the processing object is set. When the temperature of the object to be processed is measured at a sensor and the temperature of the object to be processed is room temperature, the heating is performed by phase control that combines a part of a half wavelength that conducts from the middle of 180 degrees until the object to be processed reaches the change temperature. The temperature of the object to be processed is controlled by controlling the radiation of the heat rays of the amplifier, and after the change temperature is reached, the half wave that is conducted for the entire period of 180 degrees and the half wave that is blocked for the entire period of 180 degrees are combined A heating vacuum processing method for controlling the radiation of the heat rays of the heating lamp by cycle control to raise the temperature of the object to be processed to a temperature higher than the change temperature, and performing vacuum treatment at the treatment temperature, When the sensor determines that the object has fallen from a temperature higher than the minimum temperature to a temperature lower than the minimum temperature, the processing object is controlled by controlling the radiation of the heat ray of the heating lamp by the cycle control. This is a heating vacuum processing method for raising the temperature.
Moreover, this invention is the heating vacuum processing method which attaches the said sensor to the said holder or the said vacuum chamber, measures the temperature of the said holder or the said vacuum chamber, and makes it the temperature of the said process target object.

  Since the heating lamp is heated by phase control when the temperature is low and the resistance is low, no inrush current is generated, and after the heating lamp is heated, the heating lamp is heated by cycle control, so noise is not generated. .

First, the method of the present invention using a heating lamp will be described.
Reference numeral 1 in FIG. 1 denotes a film forming apparatus, which includes a carry-in chamber 11, a heating chamber 12, a processing chamber 13, and a carry-out chamber 14.
Each chamber 11-14 has vacuum tanks 51-54, and the vacuum exhaust systems 21-24 are connected to each vacuum tank 51-54 so that each vacuum exhaust can be carried out individually.

  In the film forming apparatus 1, a processing target such as a semiconductor substrate or a liquid crystal glass substrate is heated in a vacuum chamber of the heating chamber 12 in a vacuum atmosphere, and then a thin film is formed on the surface in the vacuum chamber 53 of the processing chamber 13. It is supposed to be.

  The heating vacuum processing method will be described. First, the inside of the vacuum chamber 52 of the heating chamber 12 and the vacuum chamber 53 of the processing chamber 13 are evacuated in advance, and the object to be processed is placed in the vacuum chamber 51 of the carry-in chamber 11. Then, the vacuum chamber 51 in the carry-in chamber 11 is evacuated, the vacuum chambers 51 and 52 in the heating chamber 12 are connected, and the object to be processed is carried into the vacuum chamber 52 in the heating chamber 12.

  In the vacuum chamber 52 of the heating chamber 12, a plurality of heating lamps 15 are arranged on the ceiling side and the bottom surface side, and the holder 18 that holds the object to be processed at a position between the heating lamps 15 on the ceiling side and the bottom surface side. Is arranged. The loaded processing object is held by the holder 18.

Reference numeral 7 in FIG. 1 is a processing object, and the heating lamp 15 is arranged in parallel on the front surface side and the back surface side of the processing object 7.
The configuration of the heating lamp 15 is shown in FIG. The heating lamp 15 includes an elongated glass tube 31 and a filament 32 disposed in the glass tube 31, and individual electrodes 33 are disposed at both ends of the elongated glass tube 31, and the individual electrodes 33 are disposed at both ends of the filament 32. It is connected to.

As shown in FIG. 4, the individual electrodes 33 of a plurality of prescribed numbers (here, 4) of heating lamps 15 are respectively connected to a common electrode 34 and are arranged in parallel to constitute a module 16.
A plurality of modules 16 are arranged in the heating chamber 12, and the positional relationship between the plurality of heating lamps 15 arranged and the processing object 7 is shown in FIG. A plurality of modules 16 are arranged so that both surfaces of the processing object 7 are covered by the heating lamp 15.

Two modules 16 are made into one set, and two sets of control devices 17 and one set of voltage converters 27 are provided in this set.
The voltage converter 27 has a primary winding 41 and a secondary winding 42, the heating power supply 29 is connected to both ends of the primary winding 41, and the AC voltage output from the heating power supply 29 is applied to both ends of the primary winding 41. Is applied.

The primary winding 41 and the secondary winding 42 are magnetically coupled, and an AC voltage is induced in the secondary winding 42 by the AC voltage applied to the primary winding 41.
Both ends of the secondary winding 42 are respectively connected to one common electrode 34 of one module 16 via another control device 17.

  The other common electrode 34 of each module 16 is connected to the terminal of the secondary winding 42 opposite to the terminal to which each module 16 is connected via the control device 17. Is connected to both ends of the secondary winding 42, and the voltage induced in the secondary winding 42 is applied to the series circuit of the module 16 and the control device 17.

A center tap (center portion of the secondary winding 42) 28 is taken out from the secondary winding 42, and the center tap 28 is connected to the ground potential.
The voltage of the center tap 28 is set to be half the voltage across the secondary winding 42. Therefore, when the voltage V is induced across the secondary winding 42, One end of the secondary winding 42 is configured to have a potential of + V / 2, and the other end is configured to have a potential of −V / 2.

  A bidirectional switch 43 is provided in the control device 17, and all or part of the AC voltage output from the heating power supply 29 is converted by the voltage conversion device 27 when the bidirectional switch 43 is turned on as will be described later. The voltages of + V / 2 and -V / 2 are applied to both ends of the heating lamp 15.

  The vacuum chamber 52 of the heating chamber 12 is connected to the ground potential, and no potential difference of magnitude V occurs between the heating lamp 15 or the control device 17 and the vacuum chamber 52, and a maximum potential difference of ± V / 2. Therefore, no discharge is generated between the vacuum chamber 52 and the heating lamp 15 or the like.

  The operation of the bidirectional switch 43 will be described. The bidirectional switch 43 is configured by connecting two thyristors 45 a and 45 b in parallel in the opposite direction, and the bidirectional switch 43 is configured in the control device 17. A switch controller 44 connected to the gate terminals of the two thyristors 45a and 45b is provided.

  The switch controller 44 allows current to flow through the gate terminal (current flows into the gate terminal or current flows out from the gate terminal), and between the anode terminal and the cathode terminal of the thyristors 45a and 45b where the current flows through the gate terminal. And conducting current from the anode terminal to the cathode terminal.

  The end portion of the secondary winding 42 connected to the control device 17 is connected to a portion where the anode terminal and the cathode terminal of the bidirectional switch 43 element are connected. On the other hand, the portion where the anode terminal and the cathode terminal on the opposite side of the bidirectional switch 43 element are connected is connected to the common electrode 34 of the heating lamp 15.

When the heating lamp 15 is connected to the secondary winding 42 via the conductive thyristors 45a and 45b, a voltage induced at both ends of the secondary winding 42 is applied to each heating lamp 15, and each module 16 A current flows through the filament 32 of the heating lamp 15.
The filament 32 is heated by this electric current, and when it reaches a high temperature, heat rays (infrared rays) are radiated to irradiate the processing object 7. Due to the heat rays, the temperature of the processing object 7 rises.

  A sensor 19 is attached in the vicinity of the holder 18, and the temperature of the holder 18 rises when heat rays are emitted from the heating lamp 15 of each module 16. The temperature change is detected by the sensor 19.

  The temperature of the holder 18 and the temperature of the processing object 7 held by the holder 18 are substantially the same. When the temperature of the holder 18 is detected by the sensor 19 and the temperature is obtained by the temperature measuring device 20, the sensor 19. The temperature of the holding tool 18 detected by the above is set as the temperature of the processing object 7, and the switch controller 44 controls the bidirectional switch 43 as follows.

  5 indicates the relationship between the temperature (vertical axis) and the time (horizontal axis) of the processing object 7 heated in the heating chamber 12. First, the processing disposed in the heating chamber 12. The object 7 is raised to a processing temperature d that is similar to the temperature maintained in the processing chamber 13 and higher than the room temperature, and the processing temperature d is maintained in the processing chamber 13 subsequent to the heating chamber 12. A vacuum process such as film formation is performed as it is.

  In a state where the use of the film forming apparatus 1 is stopped and the vacuum chamber 52 and the holder 18 of the heating chamber 12 are at room temperature a (FIG. 5), first, before the processing object 7 is carried into the heating chamber 12. Or after carrying in, the vacuum chamber and the holder 18 of the heating chamber 12 are raised to the processing temperature d.

  The method for energizing the heating lamp 15 by the control device 17 is such that the current in the bidirectional switch 43 flows when the half-wavelength period between zero V and zero V of the AC voltage generated in the secondary winding 42 is 180 degrees. One thyristor 45a, 45b (or both thyristors) is turned on for the entire 180 degrees, and the half-wave applied to the heating lamp 15 and the thyristors 45a, 45b (or both thyristors) through which current flows are cut off for the entire 180 degrees. In the meantime, a current is caused to flow through the heating lamp 15 by cycle control combining with a half wavelength of the AC voltage not applied to the heating lamp 15, or a thyristor 45a in which the current in the bidirectional switch 43 flows from the middle of the half wavelength. , 45b (or both thyristors), the half-wave of the AC voltage generated in the secondary winding 42 is conducted from the middle of 180 degrees, and a part of the half-wave is It is possible to perform any of the control of carrying out the phase control to match viewing.

When the half wavelength of the AC voltage of the secondary winding 42 is applied to the heating lamp 15 by cycle control, the voltage at the center position of the half wavelength is also applied to the heating lamp 15.
Since the voltage at the center position of the half wavelength is the largest peak voltage among the AC voltages, when the heating lamp 15 is at room temperature and the resistance value of the filament 32 is low, an inrush current is generated when the peak voltage is applied. Resulting in.

  Therefore, when the temperature of the heating lamp 15 is raised from room temperature, the bidirectional switch 43 is turned on at a position after the peak voltage (the thyristors 45a and 45b on which the current in the bidirectional switch 43 flows, or both thyristors 45a and 45b). When a current is passed through the heating lamp 15 by a phase control method that interrupts (automatically) when the subsequent AC voltage is zero V, no inrush current occurs.

In the case of such a phase control method, the temperature of the heating lamp 15 rises as the period during which the voltage is applied to the heating lamp 15 is lengthened. 6 (a) and 6 (b) is a voltage generated in the secondary winding 42, and s ₁ and s ₂ are applied to the heating lamp 15 during phase control, respectively. It is a voltage period. Since s ₁ <s ₂ , the heating lamp 15 has a higher temperature when applied during the period s ₂ than when the voltage V is applied to the heating lamp 15 during the period s _1. .

However, when the voltage is generated in the secondary winding 42, conduction occurs, and noise is generated.
Therefore, it is necessary to change the voltage application to the heating lamp 15 from phase control to cycle control.

  A change temperature c lower than the processing temperature d and higher than the room temperature a is set in advance as a temperature to shift from phase control to cycle control when the heating lamp 15 is heated, and the temperature of the heating lamp 15 is changed by phase control. When the sensor 19 detects that the temperature has risen, raised from room temperature a, and reached the change temperature c, the phase control is terminated, and the half wavelength of conduction and cutoff is combined by cycle control, and the ratio of the half wavelength to conduct is determined. The temperature of the heating lamp 15 is increased by increasing the temperature. For example, FIG. 6 (c) shows a conduction period of 40%, FIG. 6 (d) shows 60%, and FIG.

As shown in FIG. 5, the heating of the heating lamp 15 at room temperature a is started by phase control at time t ₀ , changes to temperature c at time t ₁ and changes to cycle control, and the processing temperature at time t _2. c has been reached.
When the processing object 7 is not arranged in the heating chamber 12, the processing object 7 is carried into the heating chamber 12 when the sensor 19 detects that the processing temperature c has been reached.

In this case, since the temperature of the processing object 7 carried into the heating chamber 12 is the room temperature a, the temperatures of the surrounding holder 18 and the vacuum chamber 52 are lowered.
Therefore, when the temperature of the vacuum chamber 52 of the heating chamber 12 or the temperature of the holder 18 is detected by the sensor 19, the temperature is lower than the processing temperature d, so the conduction half wavelength of cycle control is increased and the processing temperature d is increased. Return to. When the temperature is higher than the processing temperature d, the conduction half wavelength is decreased.

Next, when the carrying of the processing object 7 into the heating chamber 12 is stopped for a long time, the energization to the heating lamp 15 is stopped. From the time t ₃ when the energization is stopped, the temperature of the holder 18 and vacuum chamber 52 is lowered, the temperature detected by the sensor 19 slide into reduced.

The minimum temperature b that is higher than the room temperature a but lower than the change temperature c is set in advance, and the temperature detected by the sensor 19 due to the temperature drop of the processing object 7 and other members such as the holder 18 and the vacuum chamber 52. When the temperature reaches the minimum temperature b, the cycle control is resumed at the time t ₄ , the cycle temperature is returned to the processing temperature d (time t ₅ ), and the heat ray is emitted from the heating lamp 15. For example, as shown in FIG. 6D, 100% conduction can be achieved.

Even when the heating lamp 15 is at the minimum temperature b, the resistance value of the filter 32 of the heating lamp 15 is higher than that at the room temperature a, so that no inrush current is generated.
The processing object 7 heated to the processing temperature d in the heating chamber 12 is moved to the processing chamber 13 and is disposed on the surface of the heater 25 disposed in the processing chamber 13. While d is maintained, the target 26 in the processing chamber 13 is sputtered, and a thin film is formed on the surface of the processing object 7.

  The processing object 7 on which the thin film is formed is transferred to the unloading chamber 14 in a vacuum atmosphere, the space between the processing chamber 13 and the processing chamber 13 is closed, and the atmosphere is introduced into the vacuum chamber 54 of the unloading chamber 14. 7 is taken out into the atmosphere.

  When the control device 17 performs cycle control operation, current flows through the primary and secondary windings 41 and 42 continuously for a half-wavelength period of positive voltage, or continuously for only a half-wavelength period of negative voltage. When current flows, only positive or negative current in the same direction flows in the primary and secondary windings 41 and 42, and only magnetic flux in the same direction is generated, which may cause coil burning.

  Accordingly, the control device 17 of the present invention alternately conducts the positive half-wave period and the negative half-wave period, and an AC voltage of ± V / 2 is applied to the primary and secondary windings 41 and 42. When operated in this manner, an alternating current flows through the primary and secondary windings 41 and 42 so that the coil is not burned out.

  In the above embodiment, the film formation process by sputtering has been described as the vacuum process. However, the vacuum process includes not only sputtering but also other film formation processes such as CVD and vapor deposition. In addition, a vacuum process such as a process that is not a film forming process such as etching or an annealing process performed in the heating chamber 12 is also included.

  Furthermore, in the above embodiment, the sensor 19 is mounted near the holder 18 and the temperature of the holder 18 is set as the temperature of the processing object 7. However, the temperature of the processing object 7 can be directly measured or a vacuum chamber can be used. It is also possible to measure the temperature of the object 7 to be the temperature of the processing object 7.

The figure for demonstrating the film-forming apparatus with which this invention is applied Diagram for explaining the positional relationship between modules and processing objects Heating lamp Block diagram for applying voltage to heating lamp Graph showing the temperature of the heating lamp (a), (b): Phase control (c)-(e): Cycle control

Explanation of symbols

7 ... Processing object 15 ... Heating lamp 18 ... Holder 19 ... Sensor 29 ... Heating power source 52 ... Vacuum chamber

Claims (4)

Bring the object to be processed into the vacuum chamber,
Holding the object to be processed by a holder in the vacuum chamber,
The AC voltage output from the heating power source is controlled by a control device, applied to the heating lamp, radiates heat rays from the heating lamp, and the processing object and the holder arranged in the vacuum chamber in a vacuum atmosphere A heating vacuum processing method in which the object to be processed is vacuum processed,
Preliminarily set a minimum temperature higher than room temperature, a processing temperature higher than the minimum temperature, and a change temperature between the minimum temperature and the processing temperature,
The measured by the sensor temperature of the processing object, if the temperature of the processing object was measured in room temperature, until said processing object reaches the change temperature, one half wavelength for conducting the middle of 180 degrees The temperature of the object to be processed is controlled by controlling the radiation of the heat rays of the heating lamp by phase control combining the parts,
After the measured temperature of the object to be processed reaches the change temperature, the heating lamp is controlled by a cycle control that combines a half-wave that is on for 180 degrees and a half-wave that is off for 180 degrees. A heating vacuum processing method in which radiation of heat rays is controlled to raise the temperature of the object to be processed to a temperature higher than the change temperature and to perform vacuum treatment at the treatment temperature. In the phase control, the energization time of the heating lamp is lengthened,
The heating vacuum processing method according to claim 1, wherein in the cycle control, a ratio of a half-wave that is conductive for a full period of 180 degrees is increased. Bring the object to be processed into the vacuum chamber,
Holding the object to be processed by a holder in the vacuum chamber,
The AC voltage output from the heating power source is controlled by a control device, applied to the heating lamp, radiates heat rays from the heating lamp, and the processing object and the holder arranged in the vacuum chamber in a vacuum atmosphere A heating vacuum processing method in which the object to be processed is vacuum processed,
Preliminarily set a minimum temperature higher than room temperature, a processing temperature higher than the minimum temperature, and a change temperature between the minimum temperature and the processing temperature,
When the temperature of the object to be processed is measured by a sensor and the temperature of the object to be processed is at room temperature, a part of the half wavelength that conducts from the middle of 180 degrees until the object to be processed reaches the change temperature. Control the radiation of the heat rays of the heating lamp by combined phase control to raise the temperature of the object to be processed,
After reaching the change temperature, the processing object is controlled by controlling the radiation of the heat rays of the heating lamp by cycle control that combines a half-wave that is conductive for the entire period of 180 degrees and a half-wave that is blocked for the entire period of 180 degrees. It is a heating vacuum processing method in which the temperature of the product is increased to a temperature higher than the change temperature, and vacuum processing is performed at the processing temperature ,
When the sensor measures that the object to be processed has fallen from a temperature higher than the minimum temperature to a temperature lower than the minimum temperature, the process control is performed by controlling the radiation of the heat rays of the heating lamp by the cycle control. vacuum processing method pressurized heat Ru warmed objects. The heating vacuum according to any one of claims 1 to 3 , wherein the sensor is attached to the holder or the vacuum chamber, and the temperature of the holder or the vacuum chamber is measured to obtain the temperature of the object to be processed. Processing method.

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