JPH09246174A - Aligner and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always accurately control predetermined exposure amount irrespective misfiring during the exposure by oscillating a pulse laser by giving an oscillation command signal, detecting the exposure amount at each one pulse of the laser, and detecting the oscillation failure of the pulse laser according to the detected value. SOLUTION: An applied voltage is given to a laser output controller 10 by a controller 9, a laser oscillation command signal is outputted to a pulse laser 1 to conduct the pulse generation at the laser 1. On the other hand, the controller 9 reads the output value of an integrator 8 for integrating the generated pulse output at each pulse of the laser detected by a sensor 7, and measures the exposure energy value of the generated pulse. The oscillation failure of the laser 1 is detected by the measured exposure energy value. Thus, predetermined exposure amount control accuracy can be always obtained irrespective of the occurrence of misfiring during the exposure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus and method using a pulse laser, and more particularly to improvement of exposure amount control accuracy and exposure efficiency.

[0002]

2. Description of the Related Art The semiconductor device technology has been highly integrated and miniaturized, and in recent years, a pulse laser such as an excimer laser has been used as a light source in the far ultraviolet region in an exposure apparatus used in a lithography process for manufacturing a semiconductor device. in use. Such an exposure apparatus irradiates a wafer coated with a resist with a laser pulse through a reticle or an imaging optical system to perform an image projection of a circuit pattern image drawn on the reticle as one shot exposure operation. To do. The total energy of a plurality of laser pulses irradiated during this exposure is the exposure amount of one shot, and in order to always keep the resolving power and the line width of the circuit pattern of the reticle imaged on the wafer constant between shots. Stable exposure amount control with little variation in exposure amount is required. Therefore, for example, as disclosed in JP-A-5-62876, there is used a control method of detecting the exposure energy of each pulse of a laser and controlling the exposure energy of each pulse so as to obtain a target exposure amount. The exposure energy for each pulse of the pulsed laser changes according to the setting parameter value (for example, applied voltage) given to the laser device at the time of pulse oscillation of the laser, so the exposure energy is controlled by changing the setting value for each pulse. It is possible.

[0003]

However, a pulsed laser device such as an excimer laser does not always obtain the same exposure energy even if the same applied voltage value is continuously given for each pulse, and it is always 5% or more for each pulse. A phenomenon in which the laser does not always oscillate even when a pulse oscillation command is given to the laser (misfire) due to deterioration of the gas used in the laser device, etc. ) Occurs, and finally falls into a state where oscillation is impossible. This phenomenon can be prevented by replacing the gas in the laser device at a proper time and maintaining a fresh state, but the gas replacement work takes about 10 minutes at a time, During that time, since the oscillation operation cannot be performed, the throughput of the exposure apparatus is deteriorated. Also, in order to reduce the amount of gas consumed, the number of gas exchange operations should be minimized.

According to the exposure amount control method of JP-A-5-62876, in the exposure amount control for one shot consisting of a plurality of laser pulse oscillations, the difference between the target total exposure amount and the exposure amount accumulated up to the present time is used. Calculate the average energy per residual pulse from the residual exposure and the number of residual pulses,
Using this as the target energy for the next pulse, compare this target energy value with the exposure energy obtained in the previous pulse, and set the applied voltage to the laser device so that the exposure energy of the next pulse matches the target energy. It is attempted to realize the exposure amount control by repeating the operation of changing the parameter value for each pulse until the remaining pulse number becomes zero.

For example, if the target energy is compared with the exposure energy of the previous pulse, and if the target energy is larger, the applied voltage value given to the laser device in the next pulse is set to a value larger than the previous pulse. When the energy is smaller, control is performed to make the applied voltage value of the next pulse a smaller value.

Here, when a misfire phenomenon occurs by giving an oscillation command to a certain n-th pulse during exposure,
The detection value of the exposure energy of the n-th pulse becomes zero, and therefore the remaining exposure amount is the same as that after the (n-1) th pulse oscillation, but the remaining pulse number is the oscillation command for the n-th pulse. One pulse is reduced by giving. Therefore, the calculated value of the average energy of the remaining pulse becomes larger than that after the (n-1) th pulse oscillation. Now, assuming that the nth pulse in which the misfire phenomenon occurs is the last pulse of the exposure operation, the target energy of the nth pulse is equal to the residual exposure amount. The exposure energy of is zero due to the misfire phenomenon. However, the exposure operation of this shot is completed by giving the oscillation command to the last pulse.
Therefore, the above-described shot has an exposure amount shortage error of the same amount as the target energy value of the nth pulse.

Even if the nth pulse in which the misfire phenomenon occurs is not the final pulse, the target energy of the next (n + 1) th pulse has a larger value than that of the nth pulse, as described above. The applied voltage value has a set range, and the controllable range is also limited to the exposure energy amount of one pulse.

Normally, in a pulse laser device, oscillation is performed by giving the minimum value of the settable applied voltage to the exposure energy of the pulse obtained when giving the maximum value of the settable applied voltage. The value of the exposure energy at that time is about 50%. If the target energy value of the (n + 1) th pulse exceeds the value of the exposure energy that oscillates by applying the settable maximum applied voltage, the target energy value of the (n + 1) th pulse cannot be realized, and the n + 1th pulse is actually realized. The pulse energy obtained by the pulse is smaller than the target energy, and the energy error due to this shortage is such that the target energy of the next (n + 2) th pulse is made larger than the target energy of the (n + 1) th pulse, so that an exposure amount error occurs at each pulse oscillation. Will be accumulated.

As described above, in order to improve the throughput of the exposure apparatus and reduce the gas consumption, the misfire phenomenon during the exposure operation, which may occur by reducing the number of gas exchange operations of the laser apparatus, is conventionally generated by one shot. However, there was a problem that the exposure amount control accuracy of 1 was deteriorated.

The present invention has been made in view of the above-mentioned problems in the prior art, and always has a constant exposure amount control accuracy regardless of whether a misfire phenomenon occurs during exposure, and a gas of a laser device. An object of the present invention is to provide an exposure apparatus having a deterioration state detection function.

[0011]

In order to achieve the above object, according to the present invention, an oscillation command signal is generated when a pattern on a master plate is projected and exposed on a substrate by causing a pulse laser to emit a plurality of pulses. Is applied to excite a pulse laser whose exposure amount is controlled, the exposure amount of each pulse of the laser is detected, and the oscillation abnormality of the pulse laser is detected by the detection value of the exposure amount of 1 pulse. .

Further, in the exposure method of projecting and exposing the pattern on the original plate on the substrate by making the pulsed laser emit pulsed light a plurality of times, the pulsed laser whose exposure amount is controlled is excited by giving an oscillation command signal, The elapsed time from the generation time of the oscillation command signal is counted in synchronism with the pulse oscillation timing, and the pulse laser oscillation abnormality is detected when the synchronization signal is not generated within a certain elapsed time from the oscillation command signal generation time.

Alternatively, the abnormal detection of the pulse laser oscillation based on the detected value of the exposure amount of one pulse and the abnormal detection of the pulse laser oscillation due to the synchronization signal not being generated within a certain elapsed time from the generation time of the oscillation command signal are detected. combine.

Further, when the laser oscillation abnormality is detected, the number of times the oscillation command signal is given to the laser output control means is increased or the exposure operation is stopped depending on the detection frequency of the laser oscillation abnormality.

With the above structure, a stable and proper exposure amount can be obtained even if the pulse oscillation is not always normally performed due to a change with time such as deterioration of a gas in a pulse laser such as an excimer laser. It is possible to detect the occurrence of changes over time.

[0016]

In order to achieve the above object, according to one embodiment of the present invention, the occurrence of misfire phenomenon is detected by the detection value of the exposure energy for each laser pulse in the exposure control. By changing the number of remaining pulses, it is possible to control the exposure amount of one shot with higher accuracy, and it is possible to detect the deterioration of the laser gas in the exposure device by detecting the misfire phenomenon. It is the one.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows the schematic arrangement of a reduction projection type exposure apparatus according to the first embodiment of the present invention. In the figure,
Reference numeral 1 is a pulsed laser light source that emits laser light, for example, in which a gas such as KrF is enclosed. This light source emits pulsed light having a wavelength in the far ultraviolet region. An illumination optical system 2 is composed of a beam shaping optical system, an optical integrator, a collimator, and a mirror (none of which is shown). The beam shaping optical system is for shaping the laser beam into a desired shape, and the optical integrator is for making the light distribution characteristics of the light flux uniform.
Reference numeral 3 denotes a reticle illuminated by the illumination optical system 2 on which a circuit pattern of a semiconductor element for printing is formed. Four
Is arranged so that the circuit pattern image of the reticle 3 is reduced by a reduction optical system and is image-projected onto the wafer 5.

A half mirror 6 is arranged on the optical path from the illumination optical system 2, and a part of the exposure light illuminating the reticle 3 is reflected by the mirror 6 and taken out. A photosensor 7 for ultraviolet light is arranged on the optical path of the reflected light of the mirror 6, and generates an output corresponding to the intensity of the reflected light of the mirror 6 corresponding to the intensity of the exposure light. The output of the sensor 7 is converted into exposure energy per pulse by an integration circuit 8 that performs integration for each pulse oscillation of the pulse laser 1, and is input to a controller 9 that performs calculation processing of integrated exposure amount. The controller 9 outputs an appropriate applied voltage value and a laser oscillation command signal to the laser output control device 10 based on the calculation result. The exposure energy of the pulse laser 1 is controlled by the laser output control device 10 according to the applied voltage, and the cumulative exposure amount of the circuit pattern image of the reticle 3 printed on the wafer 5 is controlled by repeating these operations.

However, in the excimer laser, the exposure energy for each pulse is 5% or more for each pulse even if a plurality of oscillation command signals are continuously supplied from the controller 9 while the same applied voltage value is being supplied to the laser output controller 10. There is a characteristic with uncontrollable variation of about 10%. On the other hand, in order to manufacture a semiconductor device of stable quality, it is necessary that the pattern line width of the circuit pattern image of the reticle 3 printed on the wafer 5 does not vary between printing exposures and is therefore constant. The stability of the cumulative exposure amount control accuracy required for each printing exposure shot is about 1%. Therefore, one shot exposure is performed by laser oscillation of several tens of pulses so that the variation amount of the exposure energy for each pulse becomes sufficiently small with respect to the exposure amount control accuracy.

In the exposure apparatus of this embodiment, the exposure energy is measured for each pulse, and the integrated exposure amount from the start of printing exposure is calculated. Then, the average value of the remaining exposure amount obtained by subtracting the integrated exposure amount from the total exposure amount to be exposed per one remaining pulse number is calculated, and the exposure energy of the pulse to be oscillated next approaches the average value. The controller 9 changes the applied voltage applied to the laser output control device 10.

FIG. 2 shows the exposure sequence of the exposure apparatus of FIG. 1 in detail.

When the exposure sequence is started, first, in step 201, the total exposure amount Dt desired to be obtained in the present exposure is set. Next, in step 202, the total number of pulses Pt oscillating in the main exposure sequence is calculated from the total exposure amount Dt and the standard exposure energy Ds of one pulse.
Next, at step 203, the cumulative exposure amount Dp (= 0), which is the sum of the exposure energies of the respective pulses obtained up to the present in the main exposure sequence, and the remaining oscillation pulse number P (= Pt) in the main exposure sequence. Then, the value of the average exposure energy Dm (Dt / Pt) in the remaining pulse is set or calculated to the initial value shown in parentheses. Next, step 204, which is an operation newly added in the exposure sequence of the present embodiment.
Then, the number of occurrences Pm of misfires generated in the main exposure shot is set to an initial value 0. Next, step 205
Then, the voltage Va applied to the laser output control device 10 at the first output pulse is calculated by the relational expression V = f (D) between the voltage V and the exposure energy D.

After that, the exposure is controlled by actually oscillating the pulse. In step 206, the applied voltage value calculated in step 205 is set as the average applied voltage value Va, and the controller 9 sets it in the laser output control device 10 to output a laser oscillation command signal and perform pulse oscillation. Next, in step 207, the controller 9 measures the exposure energy value D of the pulse that has just oscillated by reading the output value of the integrator 8 that integrates the oscillation pulse output detected by the sensor 7. Next, in step 208, which is a newly added operation in the sequence of the present embodiment, the exposure energy value D measured in step 207 is compared with the misfire determination value Dε1, and if D <Dε1, a mistake is made. It is determined that a fire has occurred, and the process proceeds to step 216. On the other hand, when D> Dε1 or D = Dε1, it is determined that there is no misfire, and the process proceeds to step 209. Here, as the misfire determination value Dε1, from the exposure energy value obtained when pulse oscillation is performed by setting the minimum applied voltage value that can be set in the laser output control device 10,
Set a sufficiently small value.

Now, assuming that normal laser oscillation is performed instead of misfire in step 208, the operation after step 209 will be described first. Step 2
At 09, the exposure energy D measured at step 207 is added to the accumulated exposure amount Dp so far to obtain a new accumulated exposure amount Dp, and the remaining pulse number P is decremented. Next, in step 210, it is determined whether or not the remaining pulse number P is 0. If it is 0, oscillation of all exposure pulses has been completed, so the exposure sequence is terminated, and if it is not 0, the process proceeds to step 211. .

In step 211, a value obtained by subtracting the integrated exposure amount Dp from the total exposure amount Dt, that is, the remaining exposure amount is divided by the number of remaining pulses P to calculate an average exposure energy value Dm per one remaining pulse. Next, in step 212, the average exposure energy Dm calculated in step 211
And the exposure energy D obtained by measurement in step 207
When the absolute value of the difference is smaller than the determination condition value Dε2, the process returns to step 206 and pulse oscillation is performed with the same applied voltage value. On the other hand, if it is larger than Dε2, the process proceeds to step 213, and it is determined whether the value of Dm-D is positive or negative. When Dm-D> 0, the exposure energy value desired to be obtained by the subsequent oscillation pulse is larger than the exposure energy value obtained by actually performing the pulse oscillation, so the routine proceeds to step 214, where the applied voltage set value Va is set. The preset change amount dV is added, and this is added to the new Va
And On the other hand, when Dm-D <0, on the contrary, since it is desired to obtain an exposure energy smaller than the actually obtained exposure energy value in the subsequent pulse oscillation, the process proceeds to step 215 and Va is subtracted by dV. And set a new Va. After the process of step 214 or step 215, the process returns to step 206 and pulse oscillation is repeated.

Next, the operation performed when it is determined that misfire has occurred as a result of the determination of the exposure energy in step 208 will be described. Steps 216 to 219 are operations added to the exposure sequence of this embodiment. In step 216, a warning signal indicating the occurrence of misfire is generated. This signal informs the user of the exposure apparatus that the state of the gas inside the pulse laser 1 has deteriorated to the extent that the misfire phenomenon occurs. Next, at step 217, the misfire occurrence count Pm is incremented. next,
In step 218, the number of times misfire occurs Pm is compared with the misfire limit value P _L. If it does not exceed P _L , the process returns to step 206 and pulse oscillation is repeated.
On the other hand, if P _L is exceeded, it is determined that misfires occur frequently and it is difficult to continue the exposure sequence.
In step 219, an error signal is generated, the exposure is interrupted, and the process is terminated.

In step 217, if the number of misfire occurrences Pm is less than or equal to the number of misfire limit values P _L and the process returns to step 206, the number of remaining pulses P
The pulse oscillation is performed again under the same conditions without performing the decrement processing of 1 or changing the applied voltage setting value Va.

FIGS. 3 to 5 show examples of transitions of the laser pulse generation timing and the integrated exposure amount when the exposure is actually performed in the exposure sequence shown in FIG. The vertical axis represents the integrated exposure amount and the horizontal axis represents time, which shows the timing of generation of the laser pulse oscillation command signal. In both cases, the value of the total exposure amount Dt is set to D5 ', and this is executed with the value of the total pulse number Pt being 5 pulses. In the figure, the numbers on the horizontal axis show the oscillation timing of the laser oscillation command signal or laser pulse from the start of exposure. The symbols D1 to D5 on the vertical axis are the cumulative exposure amounts actually obtained from the first pulse to the fifth pulse oscillation, and the symbols D1 'to D5' are the first pulse to the fifth pulse. It shows the amount obtained by adding the average exposure energy calculated value when the pulse oscillation command signal is output to the accumulated exposure amount up to that point.

FIG. 3 shows an exposure dose profile when the misfire phenomenon does not occur. The average exposure energy is calculated before outputting the oscillation command signal of the first pulse.
The total exposure amount D5 'is divided by the total pulse number 5 to obtain the value of D1'. In order to realize the same exposure energy, the voltage applied value to the laser is set to Va, and the oscillation command signal of the first pulse is output (timing 1 in the figure). Actually, the exposure energy of D1 smaller than D1 'was obtained due to the deterioration of the gas inside the laser. The average pulse energy value of the remaining pulses here is obtained by dividing the remaining exposure amount D5'-D1 by the number of remaining pulses 4 to obtain the value of D2'-D1. The pulse energy value D1 obtained by the oscillation of the first pulse is compared with the next average exposure energy value D2'-D1. Since the average exposure energy value is large, the applied voltage setting value is Va + dV,
The oscillation command signal of the second pulse is output (timing 2 in the figure). Thereafter, similar processing is performed, and the applied voltage set values of the oscillation command signals of the third, fourth, and fifth pulses are respectively Va + 2dV and Va + with respect to the applied voltage set value Va of the first pulse.
The exposure is completed by setting and outputting 3dV and Va + 4dV, and performing pulse oscillation. In the example of FIG. 3, the shortage of the actual exposure energy with respect to the average exposure energy per pulse is corrected by increasing the applied voltage setting value by dV for each pulse.

FIG. 4 is an exposure dose profile when the misfire phenomenon occurs in the third pulse. Until the output of the oscillation command signal of the third pulse (timing (3) in the figure), the same as in FIG. 3, but the laser did not oscillate and the exposure energy could not be obtained. Therefore, it is determined that the misfire phenomenon has occurred, the misfire warning signal is generated, the remaining pulse number is 3, the average exposure energy value is D3′−D2, the applied voltage setting value is Va + 2 dV, and the oscillation command signal is again output. Output (timing 3 in the figure). Here, normal pulse oscillation is obtained, and D3-D
An exposure energy of 2 was obtained. Hereinafter, the fourth and fifth normal pulse oscillations make it possible to obtain an integrated exposure amount equivalent to that of the exposure sequence shown in FIG. 3, and the occurrence of a misfire phenomenon causes a warning signal to be obtained. It is possible to know the deterioration of the gas in the device.

FIG. 5 shows a step 20 which is a means for detecting misfire occurrence in the exposure sequence shown in FIG.
8 is an exposure amount profile when the misfire phenomenon occurs in the third pulse similarly to the example of FIG. 4 in the conventional exposure sequence except the process of No. Since misfire determination is not performed in this exposure sequence, 0 is set for the oscillation command signal of the third pulse.
Assuming that the exposure energy was obtained, the integrated exposure amount D3 is the same value as D2. Next, the average exposure energy to be obtained in the fourth pulse is calculated, and the value of D4'-D3 is obtained. However, since this value exceeds the value calculated in the examples of FIGS. As a result of comparison with the obtained exposure energy value, the applied voltage setting value of the fourth pulse is V
a + 3dV, the applied voltage setting value of the fifth pulse is Va + 4d
The oscillation command signal is output as V and the exposure is completed,
The integrated exposure dose D5 obtained here is the target total exposure dose D5 '.
As a result, the amount of misfire is insufficient, an exposure amount error occurs, and deterioration of the laser gas cannot be detected.

(Second Embodiment) FIG. 6 shows the schematic arrangement of a reduction projection type exposure apparatus according to the second embodiment of the present invention. This exposure apparatus has a laser oscillation synchronization signal output from the pulse laser 1 to the controller 9 in addition to the exposure apparatus shown in FIG. 1. The controller 9 sets the applied voltage to the laser output control apparatus 10. When the value and the oscillation command signal are output, the signal output is obtained in synchronization with the timing when the pulse oscillation of the laser actually occurs. Therefore, if the controller 9 generates the integration timing of the integration circuit 8 that integrates the output of the sensor 7 that detects the intensity of the exposure light in order to measure the exposure energy for each pulse from the laser oscillation synchronization signal, the laser pulse More accurate integration timing can be obtained for oscillation, and more accurate exposure energy can be measured.

FIG. 7 shows an exposure sequence of the exposure apparatus of FIG. 6 using the laser oscillation synchronization signal. Step 501 among the steps of each exposure operation shown in FIG.
2 to 519 are the same as the operations of steps 201 to 219 of the exposure sequence of FIG.
Since step 520 and step 521 are newly added in the present embodiment, only the operations before and after this additional operation will be described here.

At step 506, the additional voltage setting value Va is set in the laser output control device 10 and the laser oscillation command signal is output. Next, in step 520, it is determined whether or not the laser oscillation synchronization signal has been output. If the synchronization signal has not yet been output, the process proceeds to step 521, and the progress since the laser oscillation command signal was output in step 506. It is determined whether or not the time has exceeded the time limit set time. If not, the process proceeds to step 520 again. When the laser oscillation synchronization signal is output from the pulse laser 1,
From step 520 to step 507, the controller 9 gives an integration command to the integration circuit 8, reads the output value of the integration circuit 8, and measures the exposure energy value D. By the above operation, the laser oscillation synchronization signal (laser oscillation synchronized with the laser oscillation synchronization signal) and the integration timing are synchronized with each other to improve accuracy.

When the misfire phenomenon occurs due to the deterioration of the gas inside the pulse laser 1, the laser oscillation synchronization signal may not be output. Therefore, in step 521 during standby for the laser oscillation synchronization signal, the elapsed time from the time when the laser oscillation command signal is output is set to a value sufficiently larger than the time when the laser oscillation synchronization signal is generated when normal pulse oscillation is performed. If the time limit set value is exceeded, it is determined that the time is a misfire, the process proceeds to step 516, and the same misfire process as in the first embodiment is performed. As a result, the occurrence of the misfire phenomenon can be detected from the timing of generation of the laser oscillation synchronization signal and the exposure energy value.

[0036]

As described above, according to the present invention,
Even if pulse oscillation is not always performed normally due to changes over time such as deterioration of gas in a pulse laser such as an excimer laser, a stable and appropriate exposure amount can be obtained and the occurrence of changes over time can be detected. Is possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an exposure apparatus according to a first embodiment of the present invention.

2 is a flowchart showing an exposure sequence in the exposure apparatus of FIG.

FIG. 3 is an explanatory diagram showing a change in integrated exposure amount in the apparatus of FIG.

FIG. 4 is an explanatory diagram showing a change in integrated exposure amount when a misfire phenomenon occurs in the apparatus of FIG.

FIG. 5 is an explanatory diagram showing changes in integrated exposure in a conventional exposure apparatus.

FIG. 6 is a schematic configuration diagram of an exposure apparatus according to a second embodiment of the present invention.

7 is a flowchart showing an exposure sequence in the exposure apparatus of FIG.

[Explanation of symbols]

1: pulsed laser, 2: illumination optical system, 3: reticle,
4: Reduction optical system, 5: Wafer, 6: Half mirror, 7:
Sensor, 8: integrating circuit, 9: controller, 10: laser output control device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/30 515B 527

Claims (10)

[Claims] 1. An exposure apparatus for projecting and exposing a pattern on an original plate onto a substrate by causing a pulsed laser to emit a pulsed light a plurality of times, and a laser output control means for pulse-oscillating the pulsed laser by giving an oscillation command signal, and a laser. An exposure apparatus comprising: an exposure amount detecting means for detecting the exposure amount for each pulse, and detecting the oscillation abnormality of the pulse laser based on the detection value of the exposure amount for one pulse. 2. An exposure apparatus for projecting and exposing a pattern on an original plate onto a substrate by causing a pulsed laser to emit a pulsed light a plurality of times, and a laser output control means for pulse-oscillating the pulsed laser by giving an oscillation command signal, and a laser. Of the pulse oscillation timing, and the counting means for counting the elapsed time from the generation time of the oscillation command signal. An exposure apparatus which detects abnormal oscillation of a laser. 3. An exposure apparatus for projecting and exposing a pattern on an original plate onto a substrate by causing a pulsed laser to emit light a plurality of times, and a laser output control means for pulse-oscillating the pulsed laser by giving an oscillation command signal, and a laser. The exposure amount detecting means for detecting the exposure amount of each pulse, the synchronizing signal detecting means synchronized with the pulse oscillation timing of the laser, and the counting means for counting the elapsed time from the generation time of the oscillation command signal. Exposure value or
An exposure apparatus which detects an oscillation abnormality of a pulse laser by not generating a synchronization signal within a certain elapsed time from the oscillation command signal generation time. 4. The exposure apparatus according to claim 1, wherein the number of times of generation of the oscillation command signal given to the laser output control means is increased by the number of times of laser oscillation abnormality detection. 5. The exposure apparatus according to any one of claims 1 to 4, wherein the exposure operation is stopped depending on the detection frequency of laser oscillation abnormality. 6. An exposure method for projecting and exposing a pattern on an original plate onto a substrate by causing a pulsed laser to emit a plurality of pulses to excite a pulsed laser whose exposure amount is controlled by giving an oscillation command signal, The exposure method is characterized by detecting the exposure amount for each pulse and detecting the oscillation abnormality of the pulse laser by the detection value of the exposure amount for one pulse. 7. An exposure method for projecting and exposing a pattern on an original plate onto a substrate by causing a pulsed laser to emit light a plurality of times to excite the pulsed laser whose exposure amount is controlled by giving an oscillation command signal. The pulse laser oscillation abnormality is detected by counting the elapsed time from the oscillation command signal generation time in synchronism with the pulse oscillation timing of and the synchronization signal is not generated within a certain elapsed time from the oscillation command signal generation time. And an exposure method. 8. An exposure method for projecting and exposing a pattern on an original plate onto a substrate by causing a pulsed laser to emit a plurality of pulses to excite a pulsed laser whose exposure amount is controlled by giving an oscillation command signal, The exposure amount of each pulse is detected, the elapsed time from the generation time of the oscillation command signal is counted in synchronization with the pulse oscillation timing of the laser, and it is constant from the detection value of the exposure amount of one pulse or the oscillation command signal generation time. The exposure method is characterized by detecting the oscillation abnormality of the pulse laser by not generating a synchronization signal within the elapsed time. 9. The exposure method according to claim 6, wherein the number of generations of the oscillation command signal given to the laser output control means is increased by the number of times of laser oscillation abnormality detection. 10. The exposure operation is stopped according to the detection frequency of the laser oscillation abnormality.
The exposure method according to any one of 1.