Time assignment method and laser device

Abstract

A timestamping method for applying timestamps to a plurality of pulse data of a laser device that burst-oscillates pulsed laser beams, wherein: a first processor that includes a real-time system receives a first light emission trigger signal from a laser irradiation device, and calculates a time interval between a previously received second light emission trigger signal and the first light emission trigger signal using the real-time system; and a second processor receives the time interval from the first processor, and, if the time interval is less than a set value, applies a timestamp to the pulse data of a pulsed laser beam that corresponds to the first light emission trigger signal, in which timestamp the time interval is added to a timestamp that is applied to the pulse data of a pulsed laser beam that corresponds to the second light emission trigger signal.

Description

Technical Field

[0001] The present disclosure relates to a time-stamping method and a laser device.

Background Art

[0002] In recent years, in semiconductor exposure apparatuses, as semiconductor integrated circuits are miniaturized and highly integrated, an improvement in resolution has been demanded. For this reason, the wavelength of light emitted from an exposure light source has been shortened. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs laser light having a wavelength of about 248 nm and an ArF excimer laser device that outputs laser light having a wavelength of about 193 nm are used.

[0003] [[ID=I6]]The spectral linewidth of the spontaneous emission light of a KrF excimer laser device and an ArF excimer laser device is as wide as 350 to 400 pm. Therefore, when a projection lens is configured with a material that transmits ultraviolet light such as KrF and ArF laser light, chromatic aberration may occur. As a result, the resolution may decrease. Therefore, it is necessary to narrow the spectral linewidth of the laser light output from the gas laser device until chromatic aberration can be ignored. For this reason, a narrowbanding module (Line Narrowing Module: LNM) including a narrowbanding element (etalon, grating, etc.) may be provided in the laser resonator of the gas laser device to narrow the spectral linewidth. Hereinafter, a gas laser device whose spectral linewidth is narrowed is referred to as a narrowbanded gas laser device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] A time assignment method relating to one aspect of this disclosure is a time assignment method for assigning time to multiple pulse data of a laser device that burst-oscillates pulsed laser light, wherein a first processor including a real-time system receives a first light emission trigger signal from a laser irradiation device, measures the time interval between the second light emission trigger signal received immediately before and the first light emission trigger signal using the real-time system, and the second processor receives the time interval from the first processor, and if the time interval is less than a set value, assigns to the pulse data of the pulsed laser light corresponding to the first light emission trigger signal a time obtained by adding the time interval to the time assigned to the pulse data of the pulsed laser light corresponding to the second light emission trigger signal.

[0006] Another aspect of the present disclosure relates to a method for assigning time to multiple pulse data of a laser device that burst-oscillates pulsed laser light, wherein a first processor including a real-time system receives a first light emission trigger signal from a laser irradiation device, measures the time interval between the first light emission trigger signal and a second light emission trigger signal received immediately before using the real-time system, and if the second processor receives the time interval from the first processor and does not receive a time assignment signal from the laser irradiation device, the second processor assigns a time to the pulse data of the pulsed laser light corresponding to the first light emission trigger signal by adding the time interval to the time of the pulse data of the pulsed laser light corresponding to the second light emission trigger signal.

[0007] A laser device relating to another aspect of the present disclosure is a laser device that outputs pulsed laser light in response to a light emission trigger signal received from a laser irradiation device, and includes a first processor that receives a first light emission trigger signal from the laser irradiation device and measures the time interval between a second light emission trigger signal received immediately before and the first light emission trigger signal in a real-time system, and a second processor that receives the time interval from the first processor and, if the time interval is less than a set value, assigns to the pulse data of the pulsed laser light corresponding to the first light emission trigger signal a time obtained by adding the time interval to the time of the pulse data of the pulsed laser light corresponding to the second light emission trigger signal. [Brief explanation of the drawing]

[0008] Some embodiments of this disclosure are described below, merely as examples, with reference to the accompanying drawings. [Figure 1] Figure 1 schematically shows the configuration of the laser apparatus in the comparative example. [Figure 2] Figure 2 shows an example of burst oscillation by a laser device. [Figure 3] Figure 3 is a flowchart showing an example of the processing procedure of a data acquisition processor related to a comparative example. [Figure 4] Figure 4 is a diagram showing an example of pulse data received by the data acquisition processor. [Figure 5] Figure 5 is a diagram showing an example of pulse data stored by the data acquisition processor. [Figure 6] Figure 6 is a chart showing an example of burst data. [Figure 7] Figure 7 shows the timing chart for transmitting and receiving pulse data in a laser device according to a comparative example. [Figure 8] Figure 8 is a graph showing the oscillation start times for each burst from burst No. 470 to 490. [Figure 9] Figure 9 is a timing chart of pulse data transmission and reception in the laser device according to Embodiment 1. [Figure 10]Figure 10 is a diagram showing an example of pulse data received by the data acquisition processor according to Embodiment 1. [Figure 11] Figure 11 is a flowchart showing an example of the processing procedure of the data acquisition processor according to Embodiment 1. [Figure 12] Figure 12 is a graph showing the oscillation start times for each burst No. 470 to 490 in the laser device according to Embodiment 1. [Figure 13] Figure 13 schematically shows the configuration of the laser device according to Embodiment 2. [Figure 14] Figure 14 is a timing chart of pulse data transmission and reception in the laser device according to Embodiment 2. [Figure 15] Figure 15 is a flowchart showing an example of the processing procedure of the data acquisition processor according to Embodiment 2. Embodiment

[0009] -table of contents- 1. Explanation of Terms 2. Description of the laser apparatus related to the comparative example 2.1 Configuration 2.2 Operation 2.3 Challenges 3. Embodiment 1 3.1 Configuration 3.2 Operation 3.3 Action and Effects 4. Embodiment 2 4.1 Configuration 4.2 Operation 4.3 Action and Effects 5. Others The embodiments of this disclosure will be described in detail below with reference to the drawings. The embodiments described below are examples of the disclosure and are not intended to limit the scope of this disclosure. Furthermore, not all configurations and operations described in each embodiment are necessarily essential to the configurations and operations of this disclosure. The same reference numerals are used for identical components, and redundant descriptions are omitted.

[0010] 1. Explanation of Terms A "real-time system" refers to an operating system (RTOS: Real-Time OS) or a programmable logic device (PLD) that has functions and characteristics for executing time-constrained processing. Real-time systems are often used for controlling embedded systems such as industrial equipment and transportation machinery.

[0011] A "non-real-time OS" is a non-critical OS (Operating System) with a margin in processing time, also referred to as a GPOS (General Purpose Operating System). Non-real-time OSs generally have rich functions and excellent flexibility, and can construct a system at a relatively low cost.

[0012] 2. Description of the laser device according to the comparative example 2.1 Configuration FIG. 1 schematically shows the configuration of a laser device 10 according to the comparative example. The comparative example of the present disclosure is a form recognized by the applicant as being known only to the applicant, and is not a known example recognized by the applicant. The laser device 10 includes an LNM 12, an output coupler (OC) 14, a chamber 16, a charger 18, a pulse power module (PPM) 20, a monitor module 22, a laser processor 24, and a data collection processor 26.

[0013] The LNM 12 includes prisms 30 and 31 and a grating 32. The prisms 30 and 31 are arranged to expand the beam output from the chamber 16 so that the expanded beam is incident on the grating 32 at a predetermined angle. The wavelength dispersion direction of the grating 32 is arranged to be perpendicular to the discharge direction between the electrodes 34a and 34b in the chamber 16. The grating 32 is retrofitted so that the incident angle and the diffraction angle of the beam are the same angle.

[0014] The OC 14 is a partial reflection mirror and is arranged to form an optical resonator together with the LNM 12. The reflectivity of the OC 14 may be, for example, 20% to 30%.

[0015] Chamber 16 is positioned on the optical path of the optical resonator and includes a pair of electrodes 34a and 34b, and windows 36 and 37 through which pulsed laser light passes. Electrodes 34a and 34b are positioned opposite each other in the direction perpendicular to the plane of the paper in Figure 1. In Figure 1, the direction perpendicular to the plane of the paper is defined as the V direction. The direction of propagation of the pulsed laser light output from OC14 is defined as the Z direction, and the direction perpendicular to the Z and V directions is defined as the H direction.

[0016] Chamber 16 is filled with excimer laser gas. The excimer laser gas includes, for example, a rare gas, a halogen gas, and a buffer gas. The rare gas may be Ar or Kr gas. The halogen gas may be F2 gas. The buffer gas may be Ne gas.

[0017] Charger 18 is electrically connected to charge a charging capacitor (not shown) in PPM 20. PPM 20 includes a switch 39 and a charging capacitor (not shown), and is connected to electrode 34a via a feedthrough (not shown). Electrode 34b is connected to a grounded chamber 16.

[0018] The monitor module 22 includes a beam splitter BS1, a beam splitter BS2, an energy detector 42, and a spectrum detector 44. The beam splitter BS1 is positioned on the optical path of the pulsed laser light output from OC14, and is positioned so that the pulsed laser light reflected by the beam splitter BS1 is incident on the beam splitter BS2.

[0019] The beam splitter BS2 is positioned such that pulsed laser light reflected by the beam splitter BS2 is incident on the energy detector 42, and pulsed laser light that has passed through the beam splitter BS2 is incident on the spectrum detector 44.

[0020] The energy detector 42 includes a focusing lens (not shown) and a photosensor. The photosensor may be a photodiode with excellent fast response and resistance to ultraviolet light. The spectral detector 44 may be a spectrometer including an etalon (not shown) and an image sensor for measuring interference fringes generated by the etalon.

[0021] The laser processor 24 is a processing unit that includes a CPU (Central Processing Unit), main memory, and auxiliary memory. The laser processor 24 is a real-time system. The laser processor 24 functions as the main control system for the laser device 10.

[0022] The data acquisition processor 26 is a processing unit that includes a CPU, main memory, and auxiliary memory. The OS of the data acquisition processor 26 is a non-real-time OS. The data acquisition processor 26 performs processing to collect data such as pulse data related to pulsed laser light output from the laser device 10 and burst data generated in burst units of burst oscillation. The data acquisition processor 26 is connected to an external monitoring device 52 via a communication network 50.

[0023] The external monitoring device 52 includes a CPU, main memory, auxiliary memory, a display device such as a liquid crystal display (LCD) or an organic electroluminescent (EL) display, and an input device such as a keyboard or voice input device. The external monitoring device 52 acquires data collected by the data acquisition processor 26 and performs processing such as monitoring the operation of the laser device 10, presenting various data information, data analysis, and presenting analysis information.

[0024] Furthermore, the external monitoring device 52 may be connected to a centralized management system (not shown) via a communication network 50, and data may be transmitted from the external monitoring device 52 to the centralized management system. The external monitoring device 52 may be connected to multiple laser devices, including other laser devices not shown in Figure 1, not just the laser device 10.

[0025] The communication network 50 is a communication network capable of transmitting information by wire, wireless, or a combination thereof. The communication network 50 may be a wide area network or a local area network.

[0026] The laser device 10 is connected to a laser irradiation device such as an exposure device 60 or a laser processing device (not shown). In Figure 1, an exposure device 60 is shown as an example. In this case, the laser processor 24 is connected to the exposure device processor 62 of the exposure device 60. The exposure device processor 62 is a processing unit that includes a CPU, main memory, and auxiliary memory, and controls the operation of the exposure device 60.

[0027] 2.2 Operation The laser processor 24 receives a light emission trigger signal and target data such as target pulse energy and target spectral linewidth from a laser irradiation device such as an exposure device 60 or a laser processing device. The laser processor 24 sets the charging voltage of the charger 18 so that the pulse energy of the pulsed laser light output from the laser device 10 becomes the target pulse energy.

[0028] The laser processor 24 then transmits a light emission trigger signal to the PPM 20. In synchronization with this light emission trigger signal, the switch 39 in the PPM 20 turns ON, and the charge of the charging capacitor, which has been charged at the charging voltage Vhv, is transferred to the electrode 34a via a feedthrough (not shown) or the like.

[0029] When a discharge occurs between electrodes 34a and 34b in chamber 16, the laser gas is excited, and pulsed laser light with a wavelength of ultraviolet wavelength from 150 nm to 380 nm, narrowed by the optical resonator composed of OC14 and LNM12, is output from OC14.

[0030] The pulsed laser light output from OC14 is incident on the monitor module 22. The pulse energy of the pulsed laser light is then detected by the energy detector 42. The spectral linewidth of the pulsed laser light is also detected by the spectrum detector 44. The data detected by the energy detector 42 and the spectrum detector 44 are transmitted to the laser processor 24. The laser processor 24 receives the light emission trigger signal and target data from the exposure apparatus 60 in real time and transmits data such as pulse energy to the data acquisition processor 26.

[0031] The pulsed laser light that has passed through the monitor module 22 is incident on the exposure apparatus 60.

[0032] Figure 2 shows an example of burst oscillation by the laser device 10. As shown in Figure 2, the laser device 10 performs burst oscillation, which alternates between oscillation periods and pause periods. The oscillation period is the period during which pulsed laser light is continuously emitted. The pause period is the period during which oscillation is paused. Note that the lengths of the oscillation period and the pause period do not need to be constant.

[0033] Figure 3 is a flowchart showing an example of the processing procedure of a data acquisition processor 26 in a comparative example. In step S10, the data acquisition processor 26 receives pulse data from the laser processor 24 in accordance with the timing of the light emission trigger signal. The pulse data received by the data acquisition processor 26 includes at least one of pulse energy, wavelength, and spectral linewidth.

[0034] Figure 4 shows an example of pulse data received by the data acquisition processor 26. The data acquisition processor 26 receives pulse data for each pulse, including pulse energy, wavelength, and spectral linewidth. The pulse number (pulse No.) shown in Figure 4 represents the number within the oscillation period.

[0035] In step S20 of Figure 3, the data acquisition processor 26 assigns a reception time to the received pulse data. At this time, the reception time assigned to the pulse data is assigned by a non-real-time OS.

[0036] Subsequently, in step S30, the data acquisition processor 26 saves the pulse data along with the time it was assigned. An example of pulse data saved by the data acquisition processor 26 is shown in Figure 5. For each pulse of the burst oscillation, the data acquisition processor 26 saves the pulse data along with the time it was received. For each oscillation period of the burst oscillation, pulse data as shown in Figure 5 is saved.

[0037] In step S40, the data acquisition processor 26 determines whether a burst delimiter has been detected. A burst delimiter is, for example, when the pulse number (pulse No.) included in the pulse data is "1". This is because the pulse number of each burst starts from "1". In other words, pulse number "1" means that it is the first pulse that starts the oscillation of each burst. For this reason, the data acquisition processor 26 determines that a burst delimiter has been detected when it receives pulse data in which the pulse number is 1.

[0038] If the result of step S40 is a Yes, that is, if the data acquisition processor 26 detects a burst delimiter, the data acquisition processor 26 proceeds to step S42.

[0039] In step S42, the data acquisition processor 26 calculates the start time of the burst oscillation, the end time of the oscillation, the average, maximum, and minimum values ​​of the pulse energy, the average, maximum, and minimum values ​​of the wavelength, etc., from the pulse data within the burst, using a group of pulses representing the oscillation period of the burst oscillation as a unit. It then creates burst data containing this data and stores the burst data in the auxiliary storage device, linking it to the burst number (burst No.). An example of burst data is shown in Figure 6.

[0040] The oscillation start time may be the time assigned to the pulse data of pulse number "1", which is the first pulse in the burst. The oscillation end time may be the time assigned to the pulse data of the last pulse in the burst. The data acquisition processor 26 may be configured to create and store burst data that includes at least one of the multiple data shown in Figure 6. In addition, the data acquisition processor 26 may create burst data that is not limited to the burst data shown in Figure 6, but also includes pulse energy variation, wavelength variation, average value, maximum value, minimum value and variation of spectral linewidth, etc.

[0041] In step S44, the data acquisition processor 26 determines whether or not it has received a data acquisition request from the external monitoring device 52.

[0042] If the result of the determination in step S44 is a Yes determination, that is, if the data acquisition processor 26 receives a data acquisition request from the external monitoring device 52, the data acquisition processor 26 proceeds to step S46.

[0043] In step S46, the data acquisition processor 26 transmits pulse data and burst data to the external monitoring device 52.

[0044] After step S46, proceed to step S48.

[0045] If the determination result in step S40 is No, that is, if the data acquisition processor 26 does not detect a burst delimiter, the data acquisition processor 26 skips steps S42 to S46 and proceeds to step S48.

[0046] Furthermore, if the determination result in step S44 is No, that is, if the data acquisition processor 26 does not receive a data acquisition request from the external monitoring device 52, the data acquisition processor 26 skips step S46 and proceeds to step S48.

[0047] In step S48, the data acquisition processor 26 determines whether or not to terminate data acquisition. If the result of the determination in step S48 is No, that is, if the data acquisition processor 26 does not terminate data acquisition, the data acquisition processor 26 returns to step S10 and repeats the process from step S10 to step S48 until data acquisition is terminated.

[0048] If the result of step S48 is a Yes, that is, if the data acquisition processor 26 terminates data acquisition, the flowchart in Figure 3 is terminated.

[0049] The external monitoring device 52 sends a data acquisition request to the data acquisition processor 26 and acquires pulse data and burst data from the data acquisition processor 26 at any time and stores them.

[0050] The external monitoring device 52 displays the data acquired from the data acquisition processor 26 on a display device and performs data analysis.

[0051] 2.3 Challenges Figure 7 shows a timing chart of pulse data transmission and reception in the laser device 10 according to the comparative example. The laser processor 24 transmits the pulse data of each pulsed laser beam oscillated in response to the light emission trigger signal to the data acquisition processor 26 at a timing synchronized with the light emission trigger signal.

[0052] The data acquisition processor 26 assigns a reception time to the data received from the laser processor 24 for each pulse. However, the OS of the data acquisition processor 26 is a non-real-time OS, and a delay occurs in the time assignment depending on the processing performed when the pulse data is received, which can result in insufficient accuracy in the time assigned to each pulse. The problem addressed by this disclosure is to assign a time close to the timing of the light emission trigger signal to each pulse data in a non-real-time OS.

[0053] Figure 8 shows the oscillation start times for bursts No. 470 to 490. Note that the oscillation period and pause period for each burst shown in Figure 8 are constant. However, in the graph in Figure 8, the line connecting the oscillation start times for each burst number is not a straight line. This is because there is a delay in the time (reception time) assigned to the pulse data.

[0054] Furthermore, in the example shown in Figure 8, bursts No. 480 and No. 481 have the same oscillation start time. In this case, judging by the oscillation start time could lead to misjudging the order of the bursts. This error would affect the data analysis performed by the external monitoring device 52. For example, when analyzing the exposure results from the exposure apparatus 60, the analysis would be performed using data from a different pulsed laser beam than the one used for exposure.

[0055] 3. Embodiment 1 3.1 Configuration The configuration of the laser device according to Embodiment 1 may be the same as the configuration of the laser device 10 described in Figure 1.

[0056] 3.2 Operation In the laser device according to Embodiment 1, the processing performed by the data acquisition processor 26 differs from the processing in the comparative example (Figure 3).

[0057] Figure 9 shows a timing chart of pulse data transmission and reception in the laser device according to Embodiment 1. The laser processor 24 receives an emission trigger signal from the exposure device 60 and measures the time interval of the emission trigger signal. The time interval of the emission trigger signal is sometimes called the "emission trigger signal interval". Since the laser processor 24 is a real-time system, the measurement error of the measured emission trigger signal interval is small. The data acquisition processor 26 receives pulse data, including the emission trigger signal interval data, from the laser processor 24 in accordance with the timing of the emission trigger signal. The data acquisition processor 26 receives pulse data for each pulse.

[0058] The laser processor 24 is an example of a “first processor” in this disclosure. The data acquisition processor 26 is an example of a “second processor” in this disclosure. Each of the laser processor 24 and the data acquisition processor 26 is specially configured or programmed to perform the various processes included in this disclosure.

[0059] Figure 10 shows an example of pulse data received by the data acquisition processor 26 according to Embodiment 1. For each pulse number corresponding to the light emission trigger signal, the data acquisition processor 26 receives the time interval of the light emission trigger signal, the pulse energy, the wavelength, and the spectral linewidth.

[0060] The data acquisition processor 26 compares the interval between light emission trigger signals included in the pulse data with a predetermined set value and determines whether the interval is greater than or equal to the set value. If the interval between light emission trigger signals included in the pulse data is greater than or equal to the set value, the data acquisition processor 26 assigns a reception time to the pulse data. This reception time is assigned by a non-real-time OS.

[0061] Furthermore, if the time interval of the light emission trigger signal included in the received pulse data is not greater than or equal to a set value, the data acquisition processor 26 adds the time interval of the light emission trigger signal to the time of the previous (immediately preceding) pulse data. The set value is greater than the time delay added by the non-real-time OS. The set value is, for example, between 2 seconds and 85 seconds.

[0062] In other words, if the time interval of the light emission trigger signal is less than a set value, the data acquisition processor 26 adds the time obtained by adding the received time interval to the time assigned to the pulse data of the pulsed laser light corresponding to the previous light emission trigger signal to the received pulse data (see Figure 9).

[0063] For example, in the burst oscillation shown in Figure 9, the light emission trigger signal received immediately before the first (leftmost) light emission trigger signal is assumed to be the light emission trigger signal corresponding to the final pulse in the oscillation period immediately preceding a pause period not shown in Figure 9 (for example, a pause period of 2 seconds or more).

[0064] In this case, when the data acquisition processor 26 receives pulse data of pulsed laser light output in response to the first light emission trigger signal from the left in Figure 9, the time interval between this first light emission trigger signal and the previous light emission trigger signal is greater than or equal to a set value. Therefore, the data acquisition processor 26 assigns the reception time of the pulse data to the pulse data of pulsed laser light corresponding to the first light emission trigger signal using a non-real-time OS. In this case, the first light emission trigger signal is an example of the "first light emission trigger signal" in this disclosure, and the previous light emission trigger signal (not shown) is an example of the "second light emission trigger signal" in this disclosure.

[0065] Next, when the data acquisition processor 26 receives pulse data of pulsed laser light output in response to the second light emission trigger signal from the left in Figure 9, the time interval between this second light emission trigger signal and the first light emission trigger signal received immediately before is smaller than the set value. Therefore, the data acquisition processor 26 adds the time interval to the time of the previously received pulse data. In this case, the second light emission trigger signal is an example of the "first light emission trigger signal" in this disclosure, and the first light emission trigger signal is an example of the "second light emission trigger signal" in this disclosure. Thereafter, for each pulse in the oscillation period of the burst oscillation, the time interval of the light emission trigger signal is added to the time of the previous pulse data.

[0066] The setting value may be determined considering the time required to switch the wafer to be exposed. It is preferable to set the wafer setting value in a way that avoids the time being added by a non-real-time OS in the middle of the processing period while the same wafer is being exposed. For example, in a typical semiconductor manufacturing process, the time interval of the light emission trigger signal when exposing the same wafer is less than 2 seconds. Therefore, by setting the setting value to 2 seconds, the reception time can be added to the pulse data by a non-real-time OS at the timing when the wafer to be exposed is changed.

[0067] Figure 11 is a flowchart showing an example of the processing procedure of the data acquisition processor 26 according to Embodiment 1. The differences between Figure 11 and the flowchart in Figure 3 will be explained. The flowchart in Figure 11 includes step S11 instead of step S10 in Figure 3, and includes step S12 between step S11 and step S20. Furthermore, the flowchart in Figure 11 includes step S14, which branches off from the determination process in step S12.

[0068] In step S11, the data acquisition processor 26 receives pulse data from the laser processor 24, which includes data on the interval between light emission trigger signals, in accordance with the timing of the light emission trigger signal.

[0069] Subsequently, in step S12, the data acquisition processor 26 determines whether the light emission trigger signal interval is greater than or equal to a set value.

[0070] If the result of step S12 is a Yes, that is, if the light emission trigger signal interval is greater than or equal to the set value, the data acquisition processor 26 proceeds to step S20.

[0071] If the result of step S12 is a No judgment, that is, if the light emission trigger signal interval is less than the set value, the data acquisition processor 26 proceeds to step S14.

[0072] In step S14, the data acquisition processor 26 adds to the pulse data the time obtained by adding the time interval of the light emission trigger signal to the time of the immediately preceding pulse data. After step S14, the data acquisition processor 26 proceeds to step S30.

[0073] Other operations may be the same as in Figure 1.

[0074] As a result, instead of the "reception time" explained in Figure 5, a time obtained by adding a time interval to the reception time or the time of the previous pulse data is assigned. The time assignment method according to Embodiment 1 explained in Figures 10 and 11 is an example of a "time assignment method" in this disclosure.

[0075] 3.3 Action and Effects Figure 12 shows the oscillation start times for bursts No. 470 to 490 in the laser device according to Embodiment 1. As shown in Figure 12, the lines connecting the oscillation start times for each burst number form a straight line. With such oscillation start times, it is impossible to mistake the order of the bursts.

[0076] Furthermore, in Embodiment 1, the data acquisition processor 26 assigns the reception time to the pulse data received from the laser processor 24 using a non-real-time OS only when the time interval of the light emission trigger signal is greater than or equal to a set value, and when the time interval of the light emission trigger signal is greater than the delay of the time assigned by the non-real-time OS. Therefore, according to the time assignment method of Embodiment 1, the time assigned to multiple pulse data will not be the same, and the order of bursts will not be mistaken.

[0077] According to Embodiment 1, in a non-real-time OS, which is a general-purpose OS, it is possible to assign a time close to the timing of the light emission trigger signal to each pulse data. The data acquisition processor 26 that executes the time assignment method according to Embodiment 1 can assign an appropriate time to each pulse data of the pulsed laser light output in response to the light emission trigger signal, enabling more accurate log collection and storage compared to the configuration of the comparative example. This contributes to enhancing the monitoring function of the external monitoring device 52.

[0078] 4. Embodiment 2 4.1 Configuration Figure 13 schematically shows the configuration of the laser device 10B according to Embodiment 2. The differences between Figure 13 and the configuration shown in Figure 1 will be explained below.

[0079] The laser device 10B according to Embodiment 2 differs from Embodiment 1 in that it transmits a time assignment request to the laser device 10B from a laser irradiation device such as an exposure device 60 or a laser processing device. Figure 13 shows the transmission path of the time assignment request signal transmitted from the exposure device 60 to the data acquisition processor 26 via the laser processor 24. The time assignment request signal is called the time assignment signal. Other configurations may be the same as in Figure 1.

[0080] 4.2 Operation The time assignment signal is a signal sent when it is desired to reset the time based on a non-real-time OS. The data acquisition processor 26 receives the time assignment signal from the exposure apparatus 60 or the laser processor 24 and assigns the time of the non-real-time OS to the pulse data in response to the received time assignment request. If the data acquisition processor 26 does not receive a time assignment signal, it assigns the correct time to each pulse data by adding the time interval of the light emission trigger signal to the time of the pulse data related to the previous reception.

[0081] Figure 14 shows a timing chart of pulse data transmission and reception in the laser device 10B according to Embodiment 2. Figure 14 will now be explained in terms of the differences from Embodiment 1 described in Figure 9. In Embodiment 1, the time interval of the light emission trigger signal is compared with a set value, and if a time equal to or greater than the set value has elapsed, the time of the non-real-time OS is automatically assigned. In contrast, Embodiment 2 differs from Embodiment 1 in that the time of the non-real-time OS is assigned in response to the reception of the time assignment signal.

[0082] Figure 14 shows examples of receiving a time-assignment signal during a burst oscillation period and receiving a time-assignment signal during a pause period. Note that even if a time-assignment signal is received and the reception time is assigned to the data when the time interval of the light-emitting trigger signal is short, such as during burst oscillation, there will be a delay in the assigned time, but the possibility of assigning the same time as the immediately preceding data is small.

[0083] Furthermore, if the time interval of the light-emitting trigger signal is short, such as during burst oscillation, the device may return an error and refuse to accept the time assignment request. A short time interval of the light-emitting trigger signal may be, for example, 2 seconds or less.

[0084] Figure 15 is a flowchart showing an example of the processing procedure of the data acquisition processor 26 according to Embodiment 2. The differences between Figure 15 and the flowchart in Figure 11 will be explained. The flowchart shown in Figure 15 includes step S13 instead of step S12 in Figure 11.

[0085] In step S13, the data acquisition processor 26 determines whether or not it has received a time-assignment signal from the laser irradiation device. The exposure device 60 is an example of a laser irradiation device. The laser irradiation device is not limited to the exposure device 60; it may also be a laser processing device.

[0086] If the result of step S13 is a Yes, that is, if the data acquisition processor 26 receives a time assignment signal, the data acquisition processor 26 proceeds to step S20. In step S20, the data acquisition processor 26 assigns the reception time to the next received pulse data. The data acquisition processor 26 may receive the time assignment signal at the timing of the burst delimiter.

[0087] If the result of step S13 is a No determination, that is, if the data acquisition processor 26 does not receive a time assignment signal, the data acquisition processor 26 proceeds to step S14.

[0088] Other operations are the same as those shown in the flowchart in Figure 11.

[0089] 4.3 Action and Effects According to Embodiment 2, the same effects as in Embodiment 1 can be obtained. Furthermore, according to Embodiment 2, by assigning a non-real-time OS time to the pulse data at the request of a laser irradiation device such as an exposure apparatus 60, it is possible to assign a real-time and accurate time within any range of the emission instruction from the laser irradiation device.

[0090] 5. Others The above description is intended to be illustrative and not restrictive. Therefore, it will be apparent to those skilled in the art that modifications can be made to the embodiments of this disclosure without departing from the claims. It will also be apparent to those skilled in the art that the embodiments of this disclosure can be used in combination.

[0091] Terms used in this specification and throughout the claims should be interpreted as "non-limiting" unless otherwise specified. For example, terms such as "includes," "have," "equip," and "possess" should be interpreted as "not excluding the existence of components other than those described." Also, the modifier "one" should be interpreted as "at least one" or "one or more." Furthermore, the term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." In addition, it should be interpreted as including combinations of these with anything other than "A," "B," and "C."

Claims

1. A method for assigning timestamps to multiple pulse data of a laser device that emits pulsed laser light in bursts, A first processor, including a real-time system, receives a first light emission trigger signal from a laser irradiation device, and measures the time interval between the second light emission trigger signal received immediately before and the first light emission trigger signal using the real-time system. The second processor receives the time interval from the first processor, and if the time interval is less than a set value, it adds the time interval to the time assigned to the pulse data of the pulsed laser light corresponding to the second light-emitting trigger signal to the pulse data of the pulsed laser light corresponding to the first light-emitting trigger signal. Method for assigning time.

2. A method for assigning time according to claim 1, The second processor acquires the pulse data pulse by pulse. Method for assigning time.

3. A method for assigning time according to claim 1, The pulse data includes at least one of pulse energy, wavelength, and spectral linewidth. Method for assigning time.

4. A method for assigning time according to claim 1, The second processor receives the pulse data from the first processor. Method for assigning time.

5. A method for assigning time according to claim 1, The second processor includes a non-real-time OS, The second processor receives pulse data of pulsed laser light corresponding to the first light emission trigger signal from the first processor, and if the time interval is greater than or equal to the set value, the non-real-time OS assigns the time at which the pulse data was received to the pulse data of pulsed laser light corresponding to the first light emission trigger signal. Method for assigning time.

6. A method for assigning time according to claim 1, The aforementioned setting ranges from 2 seconds to 85 seconds. Method for assigning time.

7. A method for assigning time according to claim 1, The laser irradiation device is an exposure device or a laser processing device. Method for assigning time.

8. A method for assigning time according to claim 1, When the second processor detects a burst boundary of the burst oscillation, it creates burst data from the pulse data of the pulse group during the oscillation period of the burst oscillation, including at least one of the following: the start time of the burst oscillation, the end time of the burst oscillation, the average, maximum, and minimum values ​​of the pulse energy, and the average, maximum, and minimum values ​​of the wavelength. Method for assigning time.

9. A method for assigning timestamps to multiple pulse data of a laser device that emits pulsed laser light in bursts, A first processor, including a real-time system, receives a first light emission trigger signal from a laser irradiation device, and measures the time interval between the second light emission trigger signal received immediately before and the first light emission trigger signal using the real-time system. If the second processor receives the time interval from the first processor and does not receive a time assignment signal from the laser irradiation device, the second processor assigns a time to the pulse data of the pulsed laser light corresponding to the first light emission trigger signal, which is the time obtained by adding the time interval to the time of the pulse data of the pulsed laser light corresponding to the second light emission trigger signal. Method for assigning time.

10. A method for assigning time according to claim 9, The second processor acquires the pulse data pulse by pulse. Method for assigning time.

11. A method for assigning time according to claim 9, The pulse data includes at least one of pulse energy, wavelength, and spectral linewidth. Method for assigning time.

12. A method for assigning time according to claim 9, The second processor receives the pulse data from the first processor. Method for assigning time.

13. A method for assigning time according to claim 9, The second processor includes a non-real-time OS, When the second processor receives pulse data of pulsed laser light corresponding to the first light emission trigger signal from the first processor and receives the time assignment signal, the non-real-time OS assigns the time the pulse data was received to the pulse data of pulsed laser light corresponding to the first light emission trigger signal. Method for assigning time.

14. A method for assigning time according to claim 9, The laser irradiation device is an exposure device or a laser processing device. Method for assigning time.

15. A laser device that outputs pulsed laser light in response to a light emission trigger signal received from a laser irradiation device, A first processor including a real-time system that receives a first light emission trigger signal from the laser irradiation device and measures the time interval between the first light emission trigger signal and a second light emission trigger signal received immediately before it using a real-time system, A second processor receives the time interval from the first processor, and if the time interval is less than a set value, assigns a time to the pulse data of the pulsed laser light corresponding to the first light emission trigger signal, which is the time obtained by adding the time interval to the time of the pulse data of the pulsed laser light corresponding to the second light emission trigger signal. A laser device, including a laser device.

16. A laser apparatus according to claim 15, The second processor acquires the pulse data for each pulse. Laser device.

17. A laser apparatus according to claim 15, The pulse data includes at least one of pulse energy, wavelength, and spectral linewidth. Laser device.

18. A laser apparatus according to claim 15, The second processor includes a non-real-time OS, The second processor receives pulse data of pulsed laser light corresponding to the first light emission trigger signal from the first processor, and if the time interval is greater than or equal to the set value, assigns the time at which the non-real-time OS received the pulse data to the pulse data of pulsed laser light corresponding to the first light emission trigger signal. Laser device.

19. A laser apparatus according to claim 15, The aforementioned setting ranges from 2 seconds to 85 seconds. Laser device.

20. A laser apparatus according to claim 15, The laser irradiation device is an exposure device or a laser processing device. Laser device.

Images