JP4955436B2 - Light source device and exposure apparatus using the same - Google Patents

Description

  The present invention relates to a light source device having a discharge lamp and capable of emitting light having a uniform illuminance over a long period of time, and an exposure apparatus using such a light source device.

  A light source device using a discharge lamp is actively used in an industrial process for processing an object using light, such as a photoresist exposure process in a semiconductor manufacturing process or a printed circuit board production process. Light source devices used in such industrial processes are particularly required to be able to emit light with uniform illuminance over a long period of time. However, discharge lamps used in light source devices deteriorate with increasing usage time. Since the illuminance is reduced, it is not easy to meet this requirement.

Therefore, research for meeting this requirement has been conducted for a long time, and the light source device of Patent Document 1 is known as a result. This light source device comprises a plurality of discharge lamps, and when the light source device is new, the necessary light intensity is ensured by lighting a smaller number of discharge lamps than the total number, and the usage time of the light source device When a predetermined time elapses, the remaining discharge lamp is additionally lit to compensate for the decrease in illuminance due to the deterioration of the discharge lamp.
JP 2005-227465 A

  Since there are “individual differences” in each of the discharge lamps, there is a possibility that defective discharge lamps may be mixed, such as electrode consumption is very fast, or the envelope is damaged very early and causes “light loss”. It cannot be completely eliminated. For this reason, as in the prior art (Patent Document 1), if the discharge lamp is additionally lit at a predetermined time while ignoring the possibility that a defective discharge lamp is mixed, the illuminance is likely to be excessive or insufficient, and the illuminance uniformity There was a limit to raising In other words, even if some defective discharge lamps cause “illuminance reduction” or “light loss” at an early stage, additional discharge lamps cannot be turned on until a predetermined time elapses, and are emitted from the light source device. Insufficient illuminance of light occurs. On the contrary, when the light source device emits light with sufficient illuminance even after a predetermined usage time has elapsed, if the discharge lamp is additionally lit, the illuminance of light emitted from the light source device becomes excessive. Existed.

  The present invention has been developed in view of such problems of the prior art. Therefore, a main problem of the present invention is to provide a light source device capable of continuously emitting light with uniform illuminance over a long period of time and an exposure apparatus using the same.

According to the first aspect of the present invention, “a plurality of discharge lamps 30, a reflector 31 provided in each of the discharge lamps 30 and reflecting light emitted from each of the discharge lamps 30 in the same direction, and a discharge lamp” The lamp unit 18 includes an abnormality determination unit 28 that individually measures the voltage applied to the lamp 30, determines the abnormality of the discharge lamp 30 individually based on the voltage, and outputs an abnormality signal S3 when the abnormality is determined. And a function of individually energizing or interrupting the discharge lamp 30, energizing other discharge lamps 30 in a state where at least one spare discharge lamp 30 is de-energized during startup, and , together with blocking the determined energization of the discharge lamp 30 and abnormality based on the abnormality signal S3, equipped with a lighting control device 22 for energizing the spare lamp 30 energized was blocked before, abnormal-format The means 28 is configured so that the measured voltage obtained by individually measuring the voltage applied to the discharge lamp 30 is larger than the reference voltage set higher than the convergence voltage value, or the current measured voltage applied to the discharge lamp 30 and the predetermined voltage. The light source device 10 is characterized in that the discharge lamp 30 is determined to be abnormal when the difference from the measured voltage measured before time is negative .

  According to the present invention, based on the voltage applied to the discharge lamp 30, the abnormality determination means 28 has reached the end of its life due to the consumption of the electrode (remarkably, the discharge lamp 30 has lost its light due to damage to the envelope container 30 c). Individually determined as “abnormal”, the lighting control device 22 cuts off the power supply to the discharge lamp 30 determined to be abnormal by the abnormality determination means 28 and energizes the standby discharge lamp 30.

  Thereby, there is no possibility that some of the discharge lamps 30 are insufficient in illuminance or continue to operate the light source device 10 while the illuminance is lowered due to the loss of light. On the other hand, under normal lighting in which illuminance shortage or light loss does not occur as described above, the automatic additional lighting of the discharge lamp 30 with the passage of a predetermined time is not performed, so the illuminance of light emitted from the light source device 10 becomes excessive. There is nothing. Therefore, the light source device 10 according to the present invention can emit light with uniform illuminance continuously over a long period of time.

In this specification, “illuminance” (irradiance) refers to energy [mW / cm ² ] received per ^{second by} an area of 1 cm ² .

  The voltage value supplied to the discharge lamp 30 increases as the usage time elapses immediately after the start of use of the discharge lamp 30, but thereafter, the voltage value gradually increases with the elapse of the usage time. (This voltage value is referred to as “convergence voltage value”). However, in the “abnormal” discharge lamp 30 described above, a rapid increase in voltage value is observed in a short time.

The present invention utilizes such characteristics of the discharge lamp 30, and when the measured voltage obtained by individually measuring the voltage applied to the discharge lamp 30 is higher than the reference voltage V1 set higher than the convergence voltage value. The discharge lamp 30 is determined to be abnormal. Further, the difference between the current measured voltage and the measured voltage measured a predetermined time before the present is calculated, and the discharge lamp 30 is determined to be abnormal when the difference is negative. Thereby, the defective discharge lamp 30 can be detected reliably.

The invention described in claim 2 is described as follows: “The light source device 10 according to claim 1, the support 14 for supporting the exposure object X exposed by the light emitted from the light source device 10, and the light source device 10. And an optical system 16 that guides the emitted light to the exposure object X supported by the support base 14 ”.

  According to the present invention, light having a uniform illuminance is continuously emitted from the light source device 10 over a long period of time. The time required for the exposure of the object X can be made constant over a long period of time. Therefore, it is possible to minimize the waiting time and the occurrence probability of the traffic jam in the steps before and after the exposure step by making the timing of placing the exposure object X on the support base 14 and the timing of transporting it to the next processing step constant.

  According to the present invention, it is possible to provide a light source device capable of continuously emitting light with uniform illuminance over a long period of time. Further, it is possible to provide an exposure apparatus in which the exposure time of the exposure object is constant for a long time.

  The present invention will be described below with reference to the drawings. FIG. 1 is a view showing an outline of an exposure apparatus 12 in which a light source device 10 according to the present invention is incorporated. The exposure device 12 is for exposing a resist layer X as an “exposure target” formed on the printed circuit board P, and supports the light source device 10 and the resist layer X together with the printed circuit board P. The base 14 and the optical system 16 that irradiates the resist layer X with the light emitted from the light source device 10 as parallel light are roughly configured.

  The light source device 10 is for emitting light (ultraviolet light or visible light close to ultraviolet light) necessary for exposure at a predetermined illuminance. The light source device 10 includes a lamp unit 18, an illuminance meter 20, a lighting control device 22, and the like. It has.

In this specification, “illuminance” (irradiance) refers to energy [mW / cm ² ] received per ^{second by} an area of 1 cm ² .

  As shown in FIG. 2, the lamp unit 18 includes a plurality of lamp devices 24, a power supply device 26, and an abnormality determination unit 28. Further, the lamp unit 18 includes a block-shaped holder 29 that holds the plurality of lamp devices 24 in order to emit light from the plurality of lamp devices 24 in the same direction.

  Each of the lamp devices 24 includes a discharge lamp 30 and a reflector 31 that reflects light emitted from the discharge lamp 30 in a predetermined direction.

  As shown in FIG. 3, the discharge lamp 30 is a direct current lighting type short arc high pressure lamp, and includes a spherical light emitting portion 30a and sealed portions 30b formed by a shrink seal method at both ends thereof. 30c, an electrode rod 30d, a molybdenum foil 30e embedded in the sealing portion 30b, a lead rod 30f welded to the molybdenum foil 30e, mercury sealed in the light emitting portion 30a and other necessary sealing materials.

  Inside each sealing part 30b in the envelope container 30c, one end of the electrode bar 30d protruding into the light emitting part 30a, one end of the lead bar 30f protruding outward, the other end of the electrode bar 30d and the lead bar Molybdenum foil 30e that electrically connects the other end of 30f is disposed, and at one end of each electrode rod 30d, an anode 30h and a cathode 30i that constitute a pair of electrodes 30g are arranged at a predetermined interval (hereinafter, referred to as a It is connected with a gap (referred to as “distance L between electrodes”).

  As shown in FIG. 2, the power supply device 26 is a ballast for supplying a current necessary for supplying constant power to the discharge lamp 30 constituting the lamp device 24, and includes a ballast power unit 32 and a ballast control unit. 33. The lamp unit 18 includes the same number of power supply devices 26 as the lamp device 24.

  When the ballast power unit 32 receives the energization signal S1 from the lighting control device 22, the ballast power unit 32 performs a switching operation according to the pulse width signal from the ballast control unit 33, thereby releasing the power necessary for lighting the discharge lamp 30. When power is supplied to the electric lamp 30 or when an energization cutoff signal S2 is received from the lighting control device 22, the electric power supply to the discharge lamp 30 is stopped.

  In addition, the ballast controller 33 can supply a current necessary for supplying a constant power to the discharge lamp 30 in consideration of variations in the voltage supplied to the discharge lamp 30 and changes in voltage over time. Thus, the ballast power unit 32 is controlled.

  The abnormality determination unit 28 is a unit that determines whether or not each discharge lamp 30 has an abnormality, and is measured by a measurement circuit 34 that measures a voltage value supplied from the power supply device 26 to the discharge lamp 30, and the measurement circuit 34. A comparison circuit 36 that compares the measured voltage value with a preset reference voltage V1 and outputs an abnormal signal S3 if the measured voltage value is greater than the reference voltage V1. The lamp unit 18 has the same number of abnormality determination means 28 as the lamp device 24.

  As shown in FIG. 1, the illuminometer 20 is mounted on the light emission axis of the light source device 10 and facing the lamp unit 18 on the back surface of the reflecting mirror 54 constituting the optical system 16. The illuminance of light emitted from the light source device 10 is measured. The actual illuminance measured by the illuminometer 20 is output to the lighting control device 22 as the illuminance value S4.

  The lighting control device 22 is a device that individually energizes or interrupts the discharge lamp 30, and includes an integrated light meter 38, a sequencer 40, and a computer processing device 42 as shown in FIG. 4. .

  The integrated light meter 38 includes a determination circuit 44 that determines whether there is an abnormality based on the illuminance value S4 output from the illuminometer 20, and an integrating circuit 46 that calculates the light amount by integrating the illuminance value S4. Yes.

In this specification, the term "amount" refers to the energy area of 1 cm ² was received within the predetermined time [mJ / cm ^2].

  The determination circuit 44 determines whether the illuminance value S4 sent from the illuminometer 20 is higher or lower than the preset appropriate illuminance value, or the difference between the illuminance value S4 and the appropriate illuminance value is emitted from one discharge lamp 30. It is determined whether or not the illuminance of the emitted light is comparable. When the illuminance value S4 sent from the illuminometer 20 is higher than the appropriate illuminance value and the difference between the illuminance value S4 and the appropriate illuminance value is about the same as the illuminance of the light emitted from one discharge lamp 30, The determination circuit 44 transmits an illuminance abnormality high signal S5 to the sequencer 40. Conversely, the illuminance value S4 sent from the illuminometer 20 is lower than the appropriate illuminance value, and the illuminance value S4 and the appropriate illuminance value are set. When the difference is approximately the same as the illuminance emitted from one discharge lamp 30, the determination circuit 44 outputs an illuminance abnormality low signal S 6 to the sequencer 40.

  The integrating circuit 46 is a circuit that receives the illuminance value S4 from the illuminometer 20 and integrates the illuminance value S4 to calculate the amount of light, and resets the integrated value when receiving the integration start signal S7 from the sequencer 40. Integration of the illuminance value S4 is started. When the light amount reaches a preset value, the integration circuit 46 ends the integration of the illuminance value S4 and outputs an integration end signal S8 to the sequencer 40.

  The sequencer 40 includes an abnormality signal S3 output from the comparison circuit 36 of the abnormality determination unit 28, an illuminance abnormality high signal S5 or an illuminance abnormality low signal S6 output from the determination circuit 44 of the integrated light quantity meter 38, and an integration circuit 46. The output integration end signal S8 and the illuminance abnormality high signal S12 or the illuminance abnormality low signal S13 output from the computer processing device 42 are received, and the energization signal S1 or the energization interruption is supplied to each power supply device 26 based on these signals. The control unit 40a that outputs the signal S2, the set standby time that is preset as the time from when the discharge lamp 30 starts to light until the illuminance stabilizes, and which lamp device 24 is lit when the light source device 10 is activated, A storage unit 40b for storing a lamp device use setting in advance which lamp device 24 is to be turned off, and counting time It is equipped with a timer 40c.

  That is, when the abnormality signal S3 is given from the comparison circuit 36 included in the abnormality determination unit 28 of the lamp unit 18 to the sequencer 40, the sequencer 40 sends the energization cutoff signal S2 to the power supply device 26 corresponding to the abnormality determination unit 28. At the same time, an energization signal S1 is sent to the power supply device 26 corresponding to the standby discharge lamp 30 that has been extinguished until then.

  Further, when the illuminance abnormality high signal S5 is given to the sequencer 40 from the determination circuit 44 of the integrating light quantity meter 38, the sequencer 40 selects one discharge lamp 30 from the discharge lamps 30 that are lit, and the discharge lamp 30 Is sent to the power supply device 26 corresponding to On the other hand, when the illuminance abnormality low signal S6 is given to the sequencer 40, the sequencer 40 selects one discharge lamp 30 from the discharge lamps 30 that are not lit, and the power supply device 26 corresponding to the selected discharge lamp 30. An energization signal S1 is sent to

  Further, the sequencer 40 outputs an open signal S10 or a close signal S11 to the exposure control shutter 50 included in the optical system 16 in order to expose the resist layer X with an appropriate amount of light.

  When the sequencer 40 outputs the open signal S10 to the exposure control shutter 50, the timer 40c starts counting time at the same time as transmitting the integration start signal S7 to the integration circuit 46. When the sequencer 40 receives the integration end signal S8 from the integration circuit 46, the sequencer 40 outputs the closing signal S11 to the exposure control shutter 50, and the timer 40c ends the time counting. That is, the timer 40c counts the exposure time of the resist layer X. Then, the sequencer 40 outputs the exposure time value S9 counted from the transmission of the integration start signal S7 to the reception of the integration end signal S8 to the computer processing device 42 and resets the count of the timer 40c.

  The computer processing device 42 compares the exposure time value S9 received from the sequencer 40 with a preset appropriate exposure time, and determines the presence or absence of a problem in the exposure time value S9, and stores the exposure time value S9. It is comprised with the memory | storage part 42b. When the exposure time value S9 is shorter than the appropriate exposure time, the computer processing device 42 outputs an illuminance abnormality high signal S12 to the sequencer 40. Conversely, when the exposure time value S9 is longer than the appropriate exposure time, the computer processing device 42 transmits an illuminance abnormality low signal S13 to the sequencer 40.

  The exposure time data stored in the storage unit 42b is accumulated as data indicating the operation history of the exposure apparatus 12. By accumulating exposure time data in this way, in the unlikely event that an exposure failure occurs, the operating status of the exposure apparatus 12 is analyzed by referring to past exposure time data, and the cause of the failure occurrence is investigated. can do.

  As shown in FIG. 1, the support base 14 supports the printed circuit board P, and a well-known configuration can be employed as appropriate.

  The optical system 16 is for guiding the light emitted from the light source device 10 to the resist layer X of the printed circuit board P supported by the support base 14 as parallel light, and the illuminance distribution of the light emitted from the light source device 10. Is uniform, that is, light that does not cause unevenness in illuminance on the irradiated surface when irradiated on a flat surface, and light emitted from the light source device 10 (in this embodiment) , The light after passing through the integrator 52), the exposure control shutter 50 for controlling the opening and closing of the light emission path, the reflection mirror 54 for refracting the optical path of the light that has passed through the exposure control shutter 50, and the reflection by the reflection mirror 54 And a concave mirror 56 that guides the light to the support base 14 as parallel light. In addition, a through hole 58 is provided at substantially the center of the reflecting mirror 54, and the illuminometer 20 is attached to a position on the back surface of the reflecting mirror 54 where light that has passed through the through hole 58 can be received. . Accordingly, the illuminance meter 20 can receive a part of light emitted from the light source device 10 and having a uniform illuminance distribution by passing through the integrator 52 and measure the illuminance.

  In addition, the structure of the optical system 16 shown here is an example, and is not limited to the structure of a present Example. For example, the configuration may be such that the light emitted from the light source device 10 is reflected by the reflecting mirror 54 and then enters the integrator 52, and the configuration can be appropriately changed according to the target optical path. It is. In addition to the louver system as shown in FIG. 1, the exposure control shutter 50 is formed of a material that does not allow light to pass through, and has a rotating disk (having a hole through which light emitted from the light source device 10 passes). For example, a method of rotating a not-shown) by a predetermined rotation control device can be used.

  When the lighting control device 22 is activated, an energization signal S1 is transmitted from the sequencer 40 to a predetermined number of power supply devices 26, the lamp device 24 is turned on, and light emitted from the lamp device 24 (in this embodiment) , Mainly ultraviolet light) will be emitted forward. The illuminance required by the exposure apparatus 12 according to the present embodiment is an amount that can be covered by light emitted from the three lamp devices 24. Therefore, of the five lamp devices 24 included in the light source device 10, in principle, the three lamp devices 24 may be turned on at the same time, and the remaining two lamp devices 24 are kept off as a spare.

  The light emitted from the light source device 10 passes through the integrator 52 and becomes light with a uniform illuminance distribution. When the set standby time preset in the storage unit 40b of the sequencer 40 has elapsed as the time from when the discharge lamp 30 starts to light until the amount of light stabilizes, the sequencer 40 integrates the integrating circuit 46 of the integrating photometer 38. In addition to outputting the integration start signal S7, an open signal S10 is transmitted to the exposure control shutter 50 to open the exposure control shutter 50. At the same time, the timer 40c starts counting time.

  Then, the light from the integrator 52 passes through the exposure control shutter 50 opened in response to the open signal S10 from the sequencer 40. Further, the light that has passed through the exposure control shutter 50 is reflected by the reflecting mirror 54 toward the concave mirror 56.

  At this time, part of the light traveling toward the reflecting mirror 54 passes through a through hole 58 provided in the reflecting mirror 54 and irradiates the illuminometer 20. The illuminometer 20 measures the illuminance based on the light that has passed through the through-hole 58 and outputs the measured illuminance value S4 to the integrated light meter 38 of the lighting control device 22. In addition, the output illuminance value S4 is determined by the determination circuit 44 of the integrated light meter 38 to determine whether there is an abnormality, and is integrated by the integration circuit 46.

  The light reflected by the reflecting mirror 54 toward the concave mirror 56 is converted into parallel light by the concave mirror 56 and reflected toward the support base 14. The light reflected toward the support table 14 is applied to the resist layer X of the printed circuit board P placed on the support table 14 through a mask M on which a circuit pattern is formed.

  When the light quantity value integrated in the integration circuit 46 reaches a preset value, the integration circuit 46 transmits an integration end signal S8 to the sequencer 40. Upon receiving the integration end signal S8, the sequencer 40 outputs a close signal S11 to the exposure control shutter 50, closes the exposure control shutter 50, blocks light that irradiates the resist layer X, and transmits an integration start signal S7. After that, the exposure time value S9 counted by the timer 40c is output to the computer processing device 42 until the integration end signal S8 is received. The computer processing device 42 that has received the exposure time value S9 determines whether or not the exposure time value S9 is within a preset appropriate exposure time, and outputs the exposure time value S9 to the storage unit 42b as exposure time data. .

  Thus, when the exposure with respect to one resist layer X is complete | finished, the printed circuit board P under the mask M is replaced | exchanged for an unprocessed thing, and exposed similarly.

  When the abnormality determination unit 28 that measures the voltage value supplied to the lighting discharge lamp 30 detects the abnormality of the discharge lamp 30 while the resist layer X is exposed, the abnormality determination unit 28 uses the sequencer 40. Output an abnormal signal S3. Upon receiving this abnormality signal S3, the sequencer 40 sends an energization cutoff signal S2 to the power supply device 26 that supplies power to the discharge lamp 30 in which an abnormality has occurred, and at the same time, the power corresponding to the standby discharge lamp 30 that has been turned off. An energization signal S1 is sent to the supply device 26. Thereby, since the discharge lamp 30 in which an abnormality has occurred is turned off and a new discharge lamp 30 is turned on, the number of light-emitting discharge lamps 30 does not change when viewed from the light source device 10 as a whole. The discharge lamp 30 in which an abnormality has occurred is replaced by an operator at an appropriate time, and the replaced discharge lamp 30 is turned off as a spare discharge lamp 30 until another abnormality occurs in another discharge lamp 30 next time. To maintain.

  As described above, the abnormality determination unit 28 determines the abnormality of the discharge lamp 30 based on the voltage value supplied from the power supply device 26 to the discharge lamp 30 of the lamp device 24. That is, the voltage value supplied to the discharge lamp 30 increases as the usage time elapses immediately after the start of use of the discharge lamp 30, as shown by A in FIG. As the time elapses, the voltage gradually converges to a predetermined voltage value (this voltage value is referred to as a converged voltage value). Such a phenomenon occurs because, when the discharge lamp 30 is used for a long time, the electrode 30g is consumed, the interelectrode distance L is increased, and the voltage value necessary for maintaining the discharge state is increased.

  However, among the many discharge lamps 30, there are defective discharge lamps 30 in which the electrodes are consumed very quickly or the envelope 30 c is damaged and loses light very early. As for the relationship between the voltage value and the usage time in such a defective discharge lamp 30, as shown in FIG.

  Therefore, a voltage value larger than the convergence voltage value is set as the reference voltage V1, and the measured voltage value is compared with the reference voltage V1. As a result of the comparison, if the measured voltage value is larger, the discharge lamp 30 has already lost light or is likely to lose light immediately, so it is determined to be “abnormal”.

  As described above, in the light source device 10 according to the present embodiment, the individual discharge lamps 30 are individually determined to be abnormal, the energization to the discharge lamp 30 determined to be abnormal is interrupted, and the spare discharge lamp 30 is energized. Therefore, there is no fear that the light source device 10 will continue to operate without realizing that the illuminance of the light emitted from the light source device 10 has decreased, and conversely, the illuminance shortage of the light emitted from the light source device 10 occurs. Under normal lighting, since the automatic additional lighting of the discharge lamp 30 is not performed as a predetermined time elapses, the light amount emitted from the light source device 10 does not become excessive or insufficient.

  Therefore, the light source device 10 according to the present embodiment can emit light with uniform illuminance continuously for a long time.

  Further, the illuminance value S4 emitted from the light source device 10 is larger than the appropriate illuminance value, and the difference between the illuminance value S4 and the appropriate illuminance value is comparable to the illuminance of light emitted from one discharge lamp 30. The determination circuit 44 of the integrated light meter 38 that detects the illuminance outputs an abnormal illuminance high signal S5 to the sequencer 40. The sequencer 40 that has received the abnormal illuminance high signal S5 from the determination circuit 44 selects one discharge lamp 30 from the discharge lamps 30 that are lit, and cuts off the power supply to the power supply device 26 corresponding to the discharge lamp 30. The signal S2 is output. As a result, the number of discharge lamps 30 to be turned on decreases, so that the illuminance of the light emitted from the light source device 10 decreases, and the excessive illuminance falls within the appropriate light quantity value. Conversely, the illuminance value S4 emitted from the light source device 10 is smaller than the appropriate illuminance value, and the difference between the illuminance value S4 and the appropriate illuminance value is about the same as the illuminance of light emitted from one discharge lamp 30. When the determination circuit 44 detects this, the illuminance abnormality low signal S6 is output to the sequencer 40. The sequencer 40 that has received the illuminance abnormality low signal S6 from the determination circuit 44 selects one discharge lamp 30 from the discharge lamps 30 that are not lit, and supplies an energization signal to the power supply device 26 corresponding to the discharge lamp 30. S1 is output. Thereby, since the number of the discharge lamps 30 to light up increases, the illumination intensity of the light irradiated from the light source device 10 increases, and the illumination intensity that was too small falls within the appropriate light quantity value.

  Thereby, the abnormality of each discharge lamp 30 is grasped by the voltage value, and not only the preset number of discharge lamps 30 can always be lit, but also the illuminance itself of the light emitted from the light source device 10 is measured, An optimal number of discharge lamps 30 can be turned on.

  Furthermore, since the light received by the illuminometer 20 has the illuminance distribution made uniform by the integrator 52, the installation position of the illuminometer 20 must be "aligned with the central axis of the light of the light source device 10", for example. The same illuminance can be measured no matter where the illuminance meter 20 is installed as long as it is a position where the light from the light source device 10 can be received. That is, the position adjustment of the illuminometer 20 can be easily performed.

  Further, the computer 42 that detects that the exposure time value S9 output from the sequencer 40 is longer than the appropriate exposure time (that is, the illuminance of the light emitted from the light source device 10 is low) The illuminance abnormality low signal S13 is output. The sequencer 40 that has received the illuminance abnormality low signal S13 from the computer processing device 42 selects one discharge lamp 30 from the discharge lamps 30 that are extinguished, and energizes the power supply device 26 corresponding to the discharge lamp 30. The signal S1 is output. As a result, the number of discharge lamps 30 to be lit increases, and the time until the amount of light integrated in the integration circuit 46 reaches a preset value by increasing the illuminance of the light emitted from the light source device 10. Since it is shortened, the exposure time value S9 falls within the appropriate exposure time. Conversely, the computer processing device 42 that has detected that the exposure time value S9 is shorter than the appropriate exposure time (that is, that the illuminance of the light emitted from the light source device 10 is high) signals the illuminance abnormality high signal to the sequencer 40. S12 is output. The sequencer 40 that has received the abnormal illuminance high signal S12 from the computer processing device 42 selects one discharge lamp 30 from the discharge lamps 30 that are lit, and supplies power to the power supply device 26 corresponding to the discharge lamp 30. A shut-off signal S2 is output. As a result, the number of discharge lamps 30 that are turned on decreases, and the illuminance of the light emitted from the light source device 10 decreases, so that the time until the amount of light integrated in the integration circuit 46 reaches a preset value. Since it becomes longer, the exposure time value S9 falls within the appropriate exposure time.

  Thereby, the validity of the illuminance of the light emitted from the light source device 10 can be determined based on the exposure time, and the optimum number of lamp devices 24 can be turned on.

  According to the exposure apparatus 12 according to the present embodiment, light having a uniform illuminance is continuously emitted from the light source device 10 over a long period of time, so that the exposure time X is irradiated with light from the light source device 10 (tact). Time), that is, the time required for exposure of the exposure object X can be made constant. Therefore, it is possible to minimize the waiting time and the occurrence probability of the traffic jam in the steps before and after the exposure step by making the timing of placing the exposure object X on the support base 14 and the timing of transporting it to the next processing step constant.

  The discharge lamp 30 shown in FIG. 3 is a double-end type DC lighting system lamp, but instead of this, an AC lighting system lamp or a single-end type lamp may be used. Further, the discharge lamp 30 is not limited to a short arc type discharge lamp in which mercury is sealed in a sealed container 30c, and a ultraviolet light, a metal halide lamp in which a metal halide material such as sodium or scandium is sealed as a luminescent material, Alternatively, visible light may be emitted. In addition, quartz glass or translucent ceramic may be used as the material of the envelope container 30c.

  In this embodiment, when the measured voltage value supplied to the discharge lamp 30 is higher than the reference voltage V1 set higher than the convergence voltage value, it is determined that the discharge lamp 30 is “abnormal”. The method of determining that the discharge lamp 30 is “abnormal” is not limited to this. Based on the voltage value when the discharge lamp 30 is first lit (referred to as “initial voltage value”), the initial voltage value is set to a predetermined voltage. There are a method in which a value increased by a number is used as a reference voltage V1, and a method in which a value increased by a predetermined ratio from the initial voltage value is used as a reference voltage V1. Also, the difference between the current measured voltage value and the measured voltage value measured a predetermined time before the present time is calculated, and the difference is larger than the predetermined value (that is, the voltage value has increased rapidly), or The discharge lamp 30 may be determined to be “abnormal” when the difference is negative (that is, the voltage value has decreased with the passage of time of use). By using this determination method, it is possible to detect a case where the voltage value of the discharge lamp 30 moves as indicated by C in FIG. That is, in some discharge lamps 30, the envelope 30 c expands due to heat during use. When such expansion occurs, the voltage value decreases for a short period of time, and then the discharge lamp 30 is lost. Lights and the voltage value becomes zero. Therefore, by calculating the difference between the current measured voltage value and the measured voltage value after the lapse of a predetermined time, not only the “abnormal” type in which the voltage value increases rapidly but also the “abnormal” type in which the voltage value decreases. Can also be detected.

  Further, it is determined whether the illuminance value S4 sent from the illuminometer 20 is higher or lower than a preset appropriate illuminance value, and the light emitted from the light source device 10 is controlled by controlling the number of discharge lamps 30 to be lit. However, when the illuminance value S4 sent from the illuminometer 20 is higher than the preset appropriate illuminance value, the amount of power supplied to the discharge lamp 30 is reduced, and conversely, When the illuminance value S4 is lower than a preset appropriate illuminance value, the illuminance of light emitted from the light source device 10 may be made constant by increasing the amount of power supplied to the discharge lamp 30. Furthermore, the control of the number of discharge lamps 30 to be lit and the control of the amount of power supplied to the discharge lamp 30 may be combined.

  In addition, the illuminometer 20 is arranged on the back surface of the reflecting mirror 54 constituting the optical system 16, but only while the exposed printed circuit board P is replaced with a new printed circuit board P, another illuminance meter 20 is disposed immediately above the mask M. The illuminance meter 20 may be arranged to measure the illuminance of light irradiated on the mask M, and the illuminance measured by the illuminometer 20 on the back surface of the reflecting mirror 54 may be corrected based on the illuminance. In this way, based on the illuminance in the vicinity of the resist layer X that is the actual exposure object, the illuminance measurement system of the illuminometer 20 disposed on the back surface of the reflecting mirror 54 is enhanced, and more accurate exposure time management is performed. It can be carried out.

  The functions of the lighting control device 22 are shared by the integrating light meter 38, the sequencer 40, and the computer processing device 42, but all the functions necessary for the lighting control device 22 are combined into one device. The functions may be shared by more apparatuses than in the present embodiment. Moreover, you may comprise so that the lighting control apparatus 22 may bear the function of the abnormality determination means 28. FIG.

  Further, the angle with respect to the holder 29 is adjusted for each lamp device 24 so that the optical axis of the lamp device 24 passes through the center of the integrator 52. However, as shown in FIG. A light guide unit 64 including a reflection mirror 60 and a semi-reflection mirror (half mirror) 62 is used to focus the optical axis R of each lamp device 24 so that the focused optical axis R passes through the center of the integrator 52. May be.

  Moreover, although the light source device 10 according to the invention is used for the exposure device 12, the light source device 10 capable of emitting a uniform amount of light over a long period of time can be applied to any industrial process using light.

It is a figure which shows the exposure apparatus concerning this invention. It is a figure which shows a light source unit. It is a figure which shows a discharge lamp. It is a figure which shows a lighting control apparatus. It is a figure which shows the relationship between the voltage value supplied to a discharge lamp, and the use time of the said discharge lamp. It is a figure which shows the other Example regarding a some lamp | ramp, an integrator, and a position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Light source device 12 ... Exposure apparatus 14 ... Support stand 16 ... Optical system 18 ... Lamp unit 20 ... Illuminance meter 22 ... Illumination control device 24 ... Lamp device 26 ... Power supply device 28 ... Abnormality determination means 30 ... Discharge lamp 38 ... Integration Light meter 40 ... Sequencer 42 ... Computer processing unit 50 ... Exposure control shutter 52 ... Integrator 54 ... Reflective mirror 56 ... Concave mirror

Claims (2)

A plurality of discharge lamps, a reflector provided in each of the discharge lamps and reflecting light emitted from each of the discharge lamps in the same direction, and a voltage applied to the discharge lamp are individually measured. A lamp unit having an abnormality determining means for individually determining abnormality of the discharge lamp based on the voltage and outputting an abnormality signal when it is determined to be abnormal, and energizing the discharge lamp individually, or energizing It has a function of shutting off, and at the time of start-up, the other discharge lamp is energized in a state where the energization of at least one spare discharge lamp is shut off, and the discharge that has been determined to be abnormal based on the abnormal signal. It has a lighting control device that cuts off the power of the electric lamp and energizes the spare discharge lamp that has been cut off until then ,
The abnormality determination unit is configured such that when a measurement voltage obtained by individually measuring a voltage applied to the discharge lamp is larger than a reference voltage set higher than a convergence voltage value, or a current measurement voltage applied to the discharge lamp. And the measured voltage measured a predetermined time before is negative, the discharge lamp is determined to be abnormal . A light source device according to claim 1;
A support base for supporting an exposure object exposed by light emitted from the light source device;
An exposure apparatus comprising: an optical system that guides light emitted from the light source device to the exposure object supported by the support base .

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