Laser system, method for processing laser, and method for manufacturing interposer

Abstract

To provide a laser system that suppresses formation of a multiple annular profile in amplified light by an OPA.SOLUTION: The laser system includes: a pump laser apparatus for outputting pump light having a first wavelength; a signal laser apparatus for outputting signal light having a second wavelength longer than the first wavelength; an optical parametric crystal for transmitting the pump light and the signal light and outputting amplified light having the second wavelength; and a photon flux density control mechanism for controlling photon flux densities of the pump light and the signal light such that the sum of the photon flux densities at an input end of the optical parametric crystal of the pump light and the signal light becomes an intensity distribution in which the intensity distribution of the amplified light having the second wavelength monotonically decreases from a center toward an outer side.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a laser system, a laser processing method, and a method for manufacturing an interposer. [Background technology]

[0002] In recent years, semiconductor exposure devices have been required to improve their resolution in response to the miniaturization and high integration of semiconductor integrated circuits. To this end, the wavelength of light emitted from exposure light sources has been shortened. For example, KrF excimer laser devices that output laser light with a wavelength of approximately 248 nm and ArF excimer laser devices that output laser light with a wavelength of approximately 193 nm are used as gas laser devices for exposure.

[0003] The spectral linewidth of the spontaneously oscillating light from KrF excimer laser devices and ArF excimer laser devices is as wide as 350 to 400 pm. Therefore, if a projection lens is constructed using a material that transmits ultraviolet light, such as KrF and ArF laser light, chromatic aberration may occur. As a result, resolution may decrease. Therefore, it is necessary to narrow the spectral linewidth of the laser light output from the gas laser device to a level where chromatic aberration is negligible. Therefore, a line narrowing module (LNM) containing a line narrowing element (e.g., an etalon or grating) may be installed inside the laser resonator of the gas laser device to narrow the spectral linewidth. Hereinafter, a gas laser device with a narrowed spectral linewidth is referred to as a line narrowing gas laser device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3471188 [Patent Document 2] Overview of International Publication No. 2023 / 145524

[0005] A laser system according to one aspect of the present disclosure includes a pump laser device that outputs pump light of a first wavelength, a signal laser device that outputs signal light of a second wavelength longer than the first wavelength, an optical parametric crystal that transmits the pump light and the signal light and outputs amplified light of the second wavelength, and a photon flux density control mechanism that controls the photon flux densities of the pump light and the signal light such that the sum of the photon flux densities of the pump light and the signal light at the input end of the optical parametric crystal results in an intensity distribution in which the intensity distribution of the amplified light of the second wavelength monotonically decreases from the center outward.

[0006] A laser processing method according to another aspect of the present disclosure includes generating laser light of the second wavelength using a laser system including: a pump laser device that outputs pump light of a first wavelength; a signal laser device that outputs signal light of a second wavelength longer than the first wavelength; an optical parametric crystal that transmits the pump light and the signal light and outputs amplified light of the second wavelength; and a photon flux density control mechanism that controls the photon flux densities of the pump light and the signal light so that the sum of the photon flux densities of the pump light and the signal light at the input end of the optical parametric crystal becomes an intensity distribution in which the intensity distribution of the amplified light of the second wavelength monotonically decreases from the center to the periphery; wavelength-converting the laser light of the second wavelength to generate ultraviolet laser light; and irradiating an irradiated object with the ultraviolet laser light to process the irradiated object.

[0007] A method for manufacturing an interposer according to another aspect of the present disclosure includes generating laser light of the second wavelength using a laser system including: a pump laser device that outputs pump light of a first wavelength; a signal laser device that outputs signal light of a second wavelength longer than the first wavelength; an optical parametric crystal that transmits the pump light and the signal light and outputs amplified light of the second wavelength; and a photon flux density control mechanism that controls the photon flux densities of the pump light and the signal light so that the sum of the photon flux densities of the pump light and the signal light at the input end of the optical parametric crystal becomes an intensity distribution in which the intensity distribution of the amplified light of the second wavelength monotonically decreases from the center to the periphery; wavelength-converting the laser light of the second wavelength to generate ultraviolet laser light; and irradiating an object with the ultraviolet laser light to manufacture an interposer. [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 shows a schematic configuration of a laser system according to a comparative example. [Figure 2] FIG. 2 shows a schematic diagram of an optical parametric amplifier (OPA). [Figure 3] FIG. 3 shows a schematic configuration of the beam diameter adjustment optical system of the OPA. [Figure 4] FIG. 4 shows the amplified light in multiple annular profiles. [Figure 5] FIG. 5 shows a schematic configuration of the OPA of the first embodiment. [Figure 6] FIG. 6 shows a schematic configuration of a beam power adjustment system of the OPA of the first embodiment. [Figure 7] FIG. 7 shows amplified light with suppressed multiple ring profiles. [Figure 8] FIG. 8 is a graph showing the conversion efficiency of the amplified light in the form of a heat map. [Figure 9] FIG. 9 is a schematic diagram showing the configuration of a laser processing system and an interposer processing device according to the second embodiment. [Figure 10] FIG. 10 shows a schematic configuration of the electronic device. [Figure 11] FIG. 11 is a flowchart showing a method for manufacturing an electronic device. Embodiment

[0009] -table of contents- 1. Laser system and amplification system according to comparative examples 1.1 Overview of the laser system 1.1.1 Configuration 1.1.2 Operation 1.2 Overview of the amplification system 1.2.1 Configuration 1.2.2 Operation 1.2.3 Actions and Effects 2. Challenges 3. Embodiment 1 3.1 Configuration 3.2 Operation 3.3 Condition Derivation 3.4 Actions and Effects 4. Embodiment 2 4.1 Configuration of the laser processing system 4.2 Operation of the laser processing system 5. Method for manufacturing an electronic device including an interposer 5.1 Example of electronic device configuration 5.2 Manufacturing methods for electronic devices 6.Other

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0011] 1. Laser system and amplification system according to comparative examples 1.1 Overview of the laser system 1.1.1 Configuration 1 shows a schematic configuration of a laser system 20 according to a comparative example. The comparative example in this disclosure refers to a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0012] The laser system 20 includes a signal laser device 210, an amplification system 230, a pump laser device 270, and a wavelength conversion system 280. The laser system 20 outputs pulsed laser light having a wavelength of approximately 193.4 nm.

[0013] The signal laser device 210 includes a semiconductor laser 211 and a solid-state amplifier 213. The semiconductor laser 211 oscillates in a single longitudinal mode as a CW (Continuous Wave) at a wavelength of approximately 1553 nm or approximately 1407 nm.

[0014] The solid-state amplifier 213 includes a semiconductor optical amplifier (SOA) that amplifies the CW oscillated laser light output from the semiconductor laser 211.

[0015] The pump laser device 270 includes a semiconductor laser 271, a solid-state amplifier 273, an LBO crystal 275, which is a nonlinear optical crystal, and a dichroic mirror (DM) 277. "LBO" is represented by the chemical formula LiB3O5.

[0016] The semiconductor laser 271 includes a semiconductor laser that oscillates in a single longitudinal mode CW at a wavelength of about 1030 nm or about 1064 nm. The solid-state amplifier 273 is an amplifier that includes an SOA (not shown), a Yb fiber amplifier, or an Yb:YAG crystal.

[0017] The LBO crystal 275 converts the wavelength of laser light of approximately 1030 nm into second harmonic light (wavelength of approximately 515 nm). Below, a case will be described in which the semiconductor laser 211 outputs laser light of approximately 1553 nm wavelength and the semiconductor laser 271 outputs laser light of approximately 1030 nm wavelength. Note that even when the semiconductor laser 211 outputs laser light of approximately 1407 nm wavelength and the semiconductor laser 271 outputs laser light of approximately 1064 nm wavelength, the laser system 20 still outputs pulsed laser light of approximately 193.4 nm wavelength.

[0018] DM277 is disposed on the optical path behind LBO crystal 275, and has high transmittance for pulsed laser light with a wavelength of approximately 515 nm and high reflectance for pulsed laser light with a wavelength of approximately 1030 nm. The pulsed laser light with a wavelength of approximately 1030 nm that is highly reflected by DM277 enters amplification system 230 as pump laser light.

[0019] The amplification system 230 includes an optical parametric amplifier (OPA) 240. The OPA 240 is an amplifier including, for example, a PPLN (periodically poled lithium niobate) crystal or a PPKTP (periodically poled potassium titanyl phosphate) crystal. The OPA 240 receives pump laser light and signal laser light, and pulse-amplifies the signal laser light.

[0020] The wavelength conversion system 280 includes a DM 283 and CLBO crystals 281, 285, and 287, which are nonlinear optical crystals. "CLBO" has the chemical formula CsLiBO. 10 The CLBO crystals 281, 285, and 287 are each placed on a rotation stage including a piezoelectric element (not shown), and are configured so that the angle of incidence of each crystal can be changed at high speed.

[0021] The CLBO crystal 281 converts the second harmonic light (wavelength: about 515 nm) into the fourth harmonic light (wavelength: about 258 nm).

[0022] The DM 283 is configured to highly reflect the pulsed laser light output from the amplification system 230 and to highly transmit the pulsed laser light output from the CLBO crystal 281, and is positioned so that both pulsed laser lights are incident on the CLBO crystal 285 coaxially.

[0023] The CLBO crystal 285 and the CLBO crystal 287 are arranged in series, and output pulsed laser light with a wavelength of approximately 193.4 nm by two sum frequency generation operations.

[0024] The laser system 20 is controlled by a solid-state laser processor 40 and a laser processor 10. The processor in this disclosure is a processing device including a storage device in which a control program is stored and a CPU (Central Processing Unit) that executes the control program. The processor may also include a GPU (Graphics Processing Unit). The processor is specially configured or programmed to execute various processes included in this disclosure.

[0025] The solid-state laser processor 40 is connected to the signal laser device 210, the pump laser device 270, and the wavelength conversion system 280. The laser processor 10 is connected to the solid-state laser processor 40. Note that the processing function of the solid-state laser processor 40 may be implemented in the laser processor 10.

[0026] 1.1.2 Operation The solid-state laser processor 40 controls the current value of the semiconductor laser 271 of the pump laser device 270 to cause CW oscillation and output CW laser light with a wavelength of approximately 1030 nm. Furthermore, the solid-state laser processor 40 pulses the CW laser light with the SOA of the solid-state amplifier 273, and pulse-amplifies the CW laser light with an amplifier including a Yb fiber amplifier or Yb:YAG crystal of the solid-state amplifier 273.

[0027] The LBO crystal 275 converts the pulsed laser light having a wavelength of approximately 1030 nm into second harmonic light having a wavelength of approximately 515 nm. The second harmonic light having a wavelength of approximately 515 nm passes through the DM 277 with high transmittance and enters the wavelength conversion system 280.

[0028] Here, the DM 277 highly reflects the pulsed laser light with a wavelength of about 1030 nm that has not been wavelength converted by the LBO crystal 275 , and makes it incident on the OPA 240 as pump laser light for the amplification system 230 .

[0029] The solid-state laser processor 40 also controls the current value of the semiconductor laser 211 to output a CW laser beam having a wavelength of approximately 1553 nm. The solid-state laser processor 40 then performs amplification using the solid-state amplifier 213, and outputs the amplified CW laser beam having a wavelength of approximately 1553 nm from the signal laser device 210.

[0030] The OPA 240 of the amplification system 230 receives as input the pulsed laser light having a wavelength of approximately 1030 nm reflected by the DM 277 as pump laser light, and also receives as input the CW laser light having a wavelength of approximately 1553 nm output from the signal laser device 210 as signal laser light, and outputs amplified pulsed laser light having a wavelength of approximately 1553 nm.

[0031] The first pulsed laser beam having a wavelength of approximately 1553 nm output from the amplification system 230 and the second pulsed laser beam having a wavelength of approximately 515 nm output from the pump laser device 270 are input to the wavelength conversion system 280. The second pulsed laser beam is converted into an ultraviolet pulsed laser beam having a wavelength of approximately 258 nm by a CLBO crystal 281. The first pulsed laser beam and the ultraviolet light having a wavelength of approximately 258 nm are then sum-frequency generated by a CLBO crystal 285, and wavelength-converted to a wavelength of approximately 221 nm. After that, a pulsed laser beam having a wavelength of approximately 193.4 nm is output by a CLBO crystal 287 as a sum frequency with the pulsed laser beam having a wavelength of approximately 1553 nm.

[0032] The generated pulsed laser light having a wavelength of about 193.4 nm may be amplified by an excimer amplifier (not shown).

[0033] 1.2 Overview of the amplification system 1.2.1 Configuration 2 shows a schematic configuration of the OPA 240. The OPA 240 includes PPLN crystals 241 and 243, beam diameter adjusting optical systems 245, 247, 249, and 251, DMs 253, 255, 257, and 259, dampers 261 and 263, optical path mirrors 262, 266, and 268 for forming optical paths, and a beam splitter 264.

[0034] 3 schematically shows the configuration of the beam diameter adjustment optical system 245 of the OPA 240. The beam diameter adjustment optical system 245 includes a plurality of lenses 242. The lenses 242 are held by holders 244, respectively, and are arranged opposite each other on a base plate 246. The beam diameter adjustment optical system 245 is configured to adjust the distance between the lenses 242. The other beam diameter adjustment optical systems 247, 249, and 251 may have a similar configuration.

[0035] The beam diameter adjusting optical systems 245 and 247 are configured so that the beam waist diameters of the signal laser beam and the pump laser beam incident on the PPLN crystal 241 are approximately the same within the crystal. The beam diameter adjusting optical system 245 is disposed on the optical path of the signal laser beam, and the beam diameter adjusting optical system 247 is disposed on the optical path of the pump laser beam.

[0036] The beam diameter adjusting optical systems 249 and 251 are configured so that the beam waist diameters of the signal laser beam and the pump laser beam incident on the PPLN crystal 243 are approximately the same within the crystal. The beam diameter adjusting optical system 249 is disposed on the optical path of the signal laser beam between the PPLN crystal 241 and the PPLN crystal 243, and the beam diameter adjusting optical system 251 is disposed on the optical path of the pump laser beam.

[0037] Each of the beam diameter adjusting optical systems 245, 247, 249, and 251 may be configured to maintain the inter-lens distance between a pair of opposing lenses 242 (see FIG. 3). The beam diameter adjusting optical systems 245, 247, 249, and 251 can adjust the beam waist position and beam waist diameter of each of the signal laser beam and the pump laser beam.

[0038] The beam splitter 264 is disposed on the optical path of the pump laser beam so as to split the pump laser beam from the pump laser device 270 and cause the pump laser beam to enter each of the beam diameter adjustment optical systems 247 and 251. The optical path mirror 266 is disposed so as to reflect the pump laser beam reflected by the beam splitter 264 and guide it to the beam diameter adjustment optical system 251.

[0039] DM253 and DM257 are dichroic mirrors for combining the signal laser light and the pump laser light. For example, they highly reflect light with a wavelength of approximately 1553 nm and highly transmit light with a wavelength of approximately 1030 nm.

[0040] DM255, 259 are dichroic mirrors for separating the pump laser light and idler light from the output light of the PPLN crystals 241, 243. DM255, 259 highly reflect light with a wavelength of, for example, approximately 1553 nm, and highly transmit light with wavelengths of approximately 1030 nm and approximately 3070 nm.

[0041] Dampers 261 and 263 absorb the pump laser light and idler light separated by DMs 255 and 259. In addition, a plurality of optical path mirrors 262, 266, and 268 are arranged to configure the optical path of the OPA 240.

[0042] 1.2.2 Operation The signal laser beam and the pump laser beam are incident on the PPLN crystal 241 via beam diameter adjusting optical systems 245 and 247, respectively. At this time, the beam waist positions of the signal laser beam and the pump laser beam incident on the PPLN crystal 241 are set to coincide with each other, and the beam waist diameters of both coaxially incident laser beams inside the PPLN crystal 241 are set to be approximately the same for the pump laser beam and the signal laser beam.

[0043] When the signal laser light and the pump laser light are incident on the PPLN crystal 241, optical parametric amplification occurs in the PPLN crystal 241, generating amplified light with the same wavelength of approximately 1553 nm as the signal laser light and idler light with a wavelength of approximately 3070 nm, which corresponds to the difference frequency between the signal laser light and the pump laser light.

[0044] The pump laser light and idler light output from the PPLN crystal 241 are absorbed by the damper 261 via the DM 255. Light with a wavelength of approximately 1553 nm, including the amplified light and signal laser light output from the PPLN crystal 241, is incident on the PPLN crystal 243 via the DM 255, the beam diameter adjusting optical system 249, and the DM 257. The laser light with a wavelength of approximately 1553 nm output from the PPLN crystal 241 becomes the signal laser light input to the PPLN crystal 243.

[0045] The pump laser beam reflected by the beam splitter 264 enters the PPLN crystal 243 via the optical path mirror 266, the beam diameter adjusting optical system 251, and the DM 257. At this time, the beam waist diameters of the pump laser beam and the signal laser beam are set to be approximately the same inside the PPLN crystal 243. Optical parametric amplification occurs in the PPLN crystal 243, generating amplified light with a wavelength of approximately 1553 nm, the same as the signal laser beam, and idler light with a wavelength of approximately 3070 nm, which corresponds to the difference frequency between the signal laser beam and the pump laser beam.

[0046] The pump laser light and idler light output from the PPLN crystal 243 are absorbed by the damper 263 via the DM 259. The amplified light output from the PPLN crystal 243 is used for sum frequency generation in the CLBO crystal 285 of the wavelength conversion system 280 (see FIG. 1).

[0047] 1.2.3 Actions and Effects The beam waist diameters inside each of the PPLN crystals 241 and 243 are adjusted so that the pump laser beam and the signal laser beam are approximately the same. This is because, in order to widen the region where efficient phase matching can be achieved at the beam waist position where the beams can be regarded as plane waves, beam waists of the same diameter are set near the center of the crystal. As a result, the mode matching of the signal laser beam and the pump laser beam is improved, and strong amplified light is obtained.

[0048] 2. Challenges In an amplification system 230 using an OPA 240, a multi-ring profile may occur depending on the conditions under which the signal light and pump light are incident on the crystal. For example, under certain conditions, the amplified light from the OPA 240 may have a multi-ring profile. Figure 4 shows amplified light with a multi-ring profile.

[0049] Amplified light with a multi-loop profile has poor focusing properties, and in subsequent wavelength conversion and amplification, only about half of the output of the OPA 240 can be used. For this reason, there was a need for a laser system that could prevent the amplified light from being multi-looped.

[0050] 3. Embodiment 1 3.1 Configuration The laser system 20 according to the first embodiment includes an OPA 240A shown in Fig. 5 instead of the OPA 240 shown in Fig. 2. The other configurations may be the same as those in Fig. 1.

[0051] Fig. 5 schematically illustrates the configuration of the OPA 240A of the first embodiment. Differences between the configuration illustrated in Fig. 5 and Fig. 2 will be described below. The OPA 240A includes beam power adjustment systems 265, 267, and 269. Each beam power adjustment system includes, for example, a half-wave plate (HWP) 248, a polarizing beam splitter (PBS) 252, and a power meter 256 or a damper (see Fig. 6).

[0052] 6 shows a schematic configuration of beam power adjustment systems 265, 267, and 269 of the OPA 240A of the first embodiment. The HWP 248 is held by a rotating holder 250 so as to be rotatable about the optical axis. The PBS 252 is held by a holder 254. The PBS 252 may be of a cube type or a flat type. The HWP 248 and the PBS 252 are arranged in this order on the optical path, and a power meter 256 or a damper is arranged on the reflected optical path of the PBS 252.

[0053] The beam power adjusting systems 265 and 267 are respectively arranged in the optical paths of the signal light and the pump light incident on the PPLN crystal 241, and adjust the power of the signal light and the pump light incident on the PPLN crystal 241. The optical intensity distribution of the signal light and the pump light incident on the PPLN crystal 241 is a Gaussian distribution.

[0054] The beam power adjusting system 269 is disposed in the optical path of the pump light incident on the PPLN crystal 243 and adjusts the power of the pump light incident on the PPLN crystal 243 .

[0055] The other configurations may be the same as those in FIG.

[0056] 3.2 Operation The beam power adjusting systems 265, 267, and 269 can adjust the polarization components that are transmitted through the PBS 252 by rotating the HWP 248. At this time, the adjustment may be performed while measuring the power of the polarization components reflected by the PBS 252 with a power meter 256, or the power meter 256 may be temporarily placed in the transmission light path of the PBS 252 to adjust the power of the transmitting laser light.

[0057] The sum of the photon flux densities of the input signal light and input pump light of the PPLN crystals 241 and 243 is adjusted by the beam power adjusting systems 265, 267, and 269 and the beam diameter adjusting optical systems 245, 247, 249, and 251 so as to satisfy the following equation (1) at the beam center.

[0058]

number

[0059] After the adjustment is completed, the rotation angle of the HWP 248 may be fixed and a damper may be placed in place of the power meter 256, or the power meter 256 may be removed from the transmitted light path.

[0060] The wavelength of approximately 1030 nm is an example of a "first wavelength" in the present disclosure, and the wavelength of approximately 1553 nm is an example of a "second wavelength" in the present disclosure. Each of the PPLN crystals 241 and 243 is an example of an "optical parametric crystal" in the present disclosure. The combination of the beam power adjustment systems 265 and 267 and the beam diameter adjustment optical systems 245 and 247 is an example of a "photon flux density control mechanism" in the present disclosure. The beam diameter adjustment optical system 245 is an example of a "first focusing optical system" in the present disclosure, and the beam diameter adjustment optical system 247 is an example of a "second focusing optical system" in the present disclosure. The beam power adjustment system 265 is an example of a "first power manipulator" in the present disclosure, and the beam power adjustment system 267 is an example of a "second power manipulator" in the present disclosure. The lenses 242 and 242 are an example of a "lens pair" in the present disclosure. The HWP 248 is an example of a "λ / 2 plate" in the present disclosure. PBS252 is an example of a "polarizing beam splitter" in this disclosure. Semiconductor laser 271 is an example of a "first semiconductor laser" in this disclosure. Solid-state amplifier 273 is an example of a "first solid-state amplifier" in this disclosure. LBO275 is an example of a "first nonlinear optical crystal" in this disclosure. Semiconductor laser 211 is an example of a "second semiconductor laser" in this disclosure. Solid-state amplifier 213 is an example of a "second solid-state amplifier" in this disclosure. CLBO281 is an example of a "second nonlinear optical crystal" in this disclosure. CLBO285 is an example of a "third nonlinear optical crystal" in this disclosure. CLBO287 is an example of a "fourth nonlinear optical crystal" in this disclosure.

[0061] 3.3 Condition Derivation In the plane wave approximation, the change in the optical electric field due to the nonlinear optical effect is expressed by the following equations (2) to (4) (see, for example, Chapter 8, Section 4 of "Optoelectronics: Developments" by Yariv-Yeh (Maruzen Publishing)).

[0062]

number

[0063] The meaning of each symbol is as follows:

number

[0064] The initial condition of OPA is z=0, and E S =E S,in ,E i =0,E p =E p,in In this case, the solution of this differential equation is expressed as the following equations (5) to (9) using Jacobi's elliptic functions sn, cn, and dn.

[0065]

number

[0066]

number

[0067]

number

[0068]

number

[0069]

Number

[0070] The Jacobi elliptic functions sn, cn, and dn are defined by the following equations (10) to (12).

Number

[0071]

Number

[0072]

Number

[0073]

Number

[0074] The optical intensity I of the signal light s and the complex amplitude E of the electric field of the signal light s are related by the following equation (16).

Number

[0075] The optical intensity I of the pump light p and the complex amplitude E of the electric field of the pump light p are related by the following equation (17).

Number

[0076]

Number

[0077]

Number

Number

[0078] Here, as the input light, a Gaussian beam near the beam waist is considered. It is approximated that the change in the beam diameter of the input light can be ignored over the entire length of the crystal, and the calculation result of the plane wave approximation can be applied. <000039​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Here, K is the complete elliptic integral of the first kind, and is expressed by the following equation (25).

[0085]

number

[0086] The light intensity of a Gaussian beam decreases from the center to the periphery. Therefore, if the condition u≦K(m) can be satisfied at the center of the beam, the output light profile will also decrease from the center to the periphery, which is thought to prevent the occurrence of multiple ring-shaped profiles. Figure 7 shows the light amplified by the OPA240A, which suppresses the occurrence of multiple ring-shaped profiles. As shown in Figure 7, the intensity distribution of the light amplified by the OPA240A decreases monotonically from the center to the periphery.

[0087] Since u≦K(m), it is preferable to satisfy the following equation (26) at the beam center.

[0088]

number

[0089] The photon flux density j is expressed by the following equation (27): s , j p By rearranging equation (26) using the formula, we obtain equation (1).

number

number

[0090] 3.4 Actions and Effects Figure 8 is a graph showing the conversion efficiency of amplified light using a heat map. The horizontal axis of Figure 8 represents the intensity (arbitrary units) of the input signal light, and the vertical axis represents the intensity (arbitrary units) of the input pump light. The right side of Figure 8 shows a legend for the heat map along with the definition of the conversion efficiency. The conversion efficiency is calculated by subtracting the intensity (arbitrary units) of the input signal light (arbitrary units) from the intensity (arbitrary units) of the output signal light (arbitrary units) as the numerator and the intensity (arbitrary units) of the input pump light as the denominator.

[0091] For example, if the light intensity at the center of the beam is selected in the elliptical region at the top right of the graph shown in Figure 8, the input intensity weakens toward the outer periphery of the beam, and the conversion efficiency increases and decreases, resulting in a multiple ring-shaped profile (see Figure 4).

[0092] In contrast, if the light intensity at the center of the beam is selected in the elliptical region at the bottom left of the graph shown in Figure 8, the conversion efficiency does not increase but decreases as one moves toward the outer periphery of the beam. The elliptical region at the bottom left of Figure 8 is the region that satisfies the condition of equation (1).

[0093] In the OPA 240A according to the first embodiment, the sum of the photon flux densities of the input signal light and the input pump light is adjusted to satisfy the condition of formula (1) by the configuration shown in Fig. 5. Thus, according to the first embodiment, it is possible to obtain amplified light in which the formation of a multi-ring profile is suppressed.

[0094] Here, when adjusting the power of the signal light and the pump light, it is possible to consider a configuration in which the output of the semiconductor laser 211 or the solid-state amplifier 213 is adjusted without using the beam power adjusting systems 265 and 267. However, in this case, there is a concern that the heat input condition of the crystal of the solid-state amplifier 213 will change, which may change the thermal lens effect of the crystal.

[0095] A change in the thermal lens effect of the crystal may change the intensity distribution and divergence angle of the light amplified by the solid-state amplifier 213. A change in the intensity distribution of the light amplified by the solid-state amplifier 213 also changes the profile of the light amplified by the OPA 240. A change in the divergence angle of the light amplified by the solid-state amplifier 213 may change the beam waist position of each input light in the OPA 240, resulting in a decrease in amplification efficiency.

[0096] For this reason, there is a need for a configuration that allows power adjustment while maintaining the intensity distribution and divergence angle of the amplified light from the solid-state amplifier 213. The configuration shown in Fig. 5 is one example. Therefore, it is sufficient if power adjustment is possible while maintaining the intensity distribution and divergence angle, and a configuration in which adjustment is performed by replacing an ND filter or the like is also acceptable.

[0097] 4. Embodiment 2 4.1 Configuration of the laser processing system Fig. 9 schematically shows the configuration of a laser processing system 1 according to embodiment 2. The laser processing system 1 shown in Fig. 9 includes a laser processor 10, a laser system 20, a laser processing device 30, a solid-state laser processor 40, and an optical path tube 60. The laser processing system 1 may be used to drill holes in glass for an interposer.

[0098] The laser processing device 30 includes a laser processing processor 31, an irradiation optical system 33, a frame 37, an XYZ stage 39, and a table 41 on which an object 50 to be irradiated is placed.

[0099] The illumination optical system 33 includes high-reflection mirrors (HM) 331 , 333 , and 335 , an attenuator 337 , an illumination optical system 339 , a photomask 341 , a projection optical system 343 , a window 345 , and a housing 347 .

[0100] The HMs 331 , 333 , and 335 are fixed to respective holders (not shown) within a housing 347 , and are arranged so that the laser light output from the laser system 20 enters the illumination optical system 339 .

[0101] The attenuator 337 is disposed on the optical path between the HM 331 and the HM 333. The attenuator 337 includes two partially reflecting mirrors (not shown) and a rotation stage (not shown) that changes the incident angles of the partial reflecting mirrors.

[0102] The illumination optical system 339 is fixed to a holder 348 and is positioned to provide Kohler illumination to the photomask 341 .

[0103] The photomask 341 is, for example, a mask in which a pattern of a metal or dielectric multilayer film is formed on a synthetic quartz substrate that transmits ultraviolet light.

[0104] The projection optical system 343 is fixed to a holder 349 and is arranged so that the beam waist position of the laser light condensed through a window 345 can be condensed at a predetermined depth ΔZsfw from the incident surface within the irradiation object 50. The projection optical system 343 may be a single lens or a combination of lenses with aberration correction.

[0105] The window 345 is located on the optical path between the projection optical system 343 and the irradiation target 50, and is disposed in a hole in the housing 347 via an O-ring or the like (not shown).

[0106] The housing 347 is provided with an inlet 351 and an outlet 353 for N 2 gas, which are sealed with an O-ring or the like (not shown) to prevent outside air from entering the housing 347 .

[0107] An irradiation optical system 33 and an XYZ stage 39 are fixed to a frame 37, and a table 41 is placed on the XYZ stage 39. An object to be irradiated 50 is fixed on the table 41. When manufacturing an interposer, the object to be irradiated 50 may be, for example, a glass substrate such as quartz glass.

[0108] Here, there is air between the window 345 and the object 50 to be irradiated.

[0109] The optical path tube 60 is disposed between the laser system 20 and the irradiation optical system 33, and is sealed with an O-ring or the like (not shown). The inside of the optical path tube 60 is also purged with N2 purge gas.

[0110] 4.2 Operation of the laser processing system The laser processing processor 31 controls the position of the irradiated object 50 using the XYZ stage 39 so that the beam waist of the laser light focused by the irradiation optical system 33 is located at a predetermined depth from the surface within the irradiated object 50 and the focused diameter becomes a predetermined focused diameter.

[0111] Next, the laser processing processor 31 transmits the target pulse energy Et to the laser processor 10 and controls the transmittance T of the attenuator 337 so that the fluence on the irradiation object 50 becomes the target fluence Fm.

[0112] The laser processing processor 31 transmits to the laser processor 10 a light emission trigger Tr signal having a predetermined number of pulses Nm at a predetermined repetition frequency fm.

[0113] Upon receiving the light emission trigger Tr signal, the laser processor 10 controls the laser system 20 so as to achieve the target pulse energy Et.

[0114] The laser processor 10 outputs a laser beam in synchronization with the light emission trigger Tr signal, and the laser beam enters the laser processing device 30.

[0115] The laser light is highly reflected by the HM331, passes through the attenuator 337 with a transmittance T, and enters the HM333.

[0116] The laser light highly reflected by the HM 333 enters the illumination optical system 339 via the HM 335 .

[0117] The laser light transmitted through the illumination optical system 339 passes through a window 345 and is collected at a predetermined depth position from the surface on the incident side within the object 50 to be irradiated.

[0118] As a result, the laser beam is irradiated at a predetermined depth in the irradiation object 50 with a fluence Fm, a repetition frequency fm, and a pulse number Nm, and a hole is drilled by the laser beam.

[0119] The laser processor 10, the laser processing processor 31, and the solid-state laser processor 40 may be provided independently, or any one of the processors may have all three functions. Also, an entity having the functions of the laser processor 10, the laser processing processor 31, and the solid-state laser processor 40 may simply be called a processor.

[0120] 5. Method for manufacturing an electronic device including an interposer 5.1 Example of electronic device configuration Fig. 10 schematically shows the configuration of an electronic device 100. The electronic device 100 shown in Fig. 10 includes an integrated circuit chip 101, an interposer 102, and a circuit board 103. The integrated circuit chip 101 is, for example, a chip-shaped integrated circuit board in which an integrated circuit is formed on a silicon substrate. The integrated circuit chip 101 is provided with a plurality of bumps 101b that are electrically connected to the integrated circuit.

[0121] The interposer 102 comprises an insulating glass substrate with a plurality of through holes formed therein, and a conductor is provided in each through hole to electrically connect the front and back of the glass substrate.

[0122] One surface of the interposer 102 is formed with a plurality of lands connected to the bumps 101b provided on the integrated circuit chip 101, and each land is electrically connected to one of the conductors in the through-holes. The other surface of the interposer 102 is provided with a plurality of bumps 102b, and each bump 102b is electrically connected to one of the conductors in the through-holes.

[0123] Lands corresponding to the number of bumps 102b are formed on one surface of circuit board 103. Circuit board 103 also includes a plurality of terminals electrically connected to these lands.

[0124] 5.2 Manufacturing methods for electronic devices Fig. 11 is a flowchart showing a method for manufacturing the electronic device 100. As shown in Fig. 11, the method for manufacturing the electronic device 100 in this description includes a first bonding step SP1 and a second bonding step SP2.

[0125] In the first bonding process SP1, the integrated circuit chip 101 and the interposer 102 are bonded together. Specifically, the bumps 101b of the integrated circuit chip 101 are placed on the lands of the interposer 102, and the bumps 101b are electrically connected to the lands. In this way, the integrated circuit chip 101 and the interposer 102 are electrically connected together.

[0126] In the second bonding process SP2, the interposer 102 and the circuit board 103 are bonded together. Specifically, the bumps 102b of the interposer 102 are placed on the lands of the circuit board 103, and the bumps 102b and the lands are electrically connected together. In this way, the integrated circuit chip 101 is electrically connected to the circuit board 103 via the interposer 102. Through the above steps, the electronic device 100 is manufactured.

[0127] 6.Other The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0128] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, words such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." Furthermore, it should be construed to include combinations of these with elements other than "A," "B," and "C."

Claims

1. a pump laser device that outputs pump light of a first wavelength; a signal laser device that outputs signal light having a second wavelength longer than the first wavelength; an optical parametric crystal that transmits the pump light and the signal light and outputs amplified light of the second wavelength; a photon flux density control mechanism that controls the photon flux densities of the pump light and the signal light so that the sum of the photon flux densities of the pump light and the signal light at the input end of the optical parametric crystal becomes an intensity distribution in which the intensity distribution of the amplified light of the second wavelength monotonically decreases from the center toward the periphery, Laser system.

2. 10. The laser system of claim 1, The photon flux density control mechanism includes: a first focusing optical system that adjusts the beam diameter of the signal light; a second focusing optical system for adjusting a beam diameter of the pump light; a first power manipulator that adjusts the power of the signal light; a second power manipulator for adjusting the power of the pump light; Laser system.

3. 3. The laser system of claim 2, each of the first and second focusing optical systems includes a pair of lenses configured to adjust a distance between the lenses; each of the first power manipulator and the second power manipulator includes a λ / 2 plate and a polarizing beam splitter, and is configured to adjust a rotation angle of the λ / 2 plate around an optical axis; Laser system.

4. 10. The laser system of claim 1, the light intensity distribution of the pump light and the signal light is a Gaussian distribution; Laser system.

5. 10. The laser system of claim 1, controlling the photon flux densities of the pump light and the signal light includes controlling the photon flux densities of the pump light and the signal light so that a sum of the photon flux densities of the pump light and the signal light satisfies a condition determined by the optical parametric crystal, the pump light, the signal light, and the idler light. Laser system.

6. 6. The laser system of claim 5, The condition is: a crystal length of the optical parametric crystal; an effective nonlinear constant of the optical parametric crystal; a refractive index of the optical parametric crystal at each of the wavelengths of the pump light, the signal light, and the idler light; the angular frequencies of the pump light, the signal light, and the idler light; and the beam intensities of the pump light, the signal light, and the idler light at the beam centers in the optical parametric crystal, respectively. Laser system.

7. 10. The laser system of claim 1, The photon flux densities of the pump light and the signal light satisfy the following formula: [Equation 1] Here, the subscripts s, i, and p represent signal light, idler light, and pump light, respectively. [Equation 2] Laser system.

8. 10. The laser system of claim 1, The pump laser device a first semiconductor laser, a first solid-state amplifier, and a first nonlinear optical crystal; Laser system.

9. 10. The laser system of claim 1, The signal laser device is a second semiconductor laser and a second solid-state amplifier; Laser system.

10. 10. The laser system of claim 1, a wavelength conversion system that converts the wavelength of the amplified light of the second wavelength output from the optical parametric crystal; Laser system.

11. 11. The laser system of claim 10, The wavelength conversion system includes: the amplified light of the second wavelength output from the optical parametric crystal and ultraviolet light are incident thereon to output a sum frequency wave; Laser system.

12. 11. The laser system of claim 10, The wavelength conversion system includes: a second nonlinear optical crystal, a third nonlinear optical crystal, and a fourth nonlinear optical crystal arranged in series; Laser system.

13. A laser processing method, comprising: a pump laser device that outputs pump light of a first wavelength; a signal laser device that outputs signal light having a second wavelength longer than the first wavelength; an optical parametric crystal that transmits the pump light and the signal light and outputs amplified light of the second wavelength; generating the laser light of the second wavelength by a laser system including a photon flux density control mechanism that controls the photon flux densities of the pump light and the signal light so that the sum of the photon flux densities of the pump light and the signal light at the input end of the optical parametric crystal becomes an intensity distribution in which the intensity distribution of the amplified light of the second wavelength monotonically decreases from the center to the periphery, and wavelength-converting the laser light of the second wavelength to generate ultraviolet laser light; The ultraviolet laser beam is irradiated onto an object to process the object. Laser processing method.

14. The laser processing method according to claim 13, The photon flux density control mechanism includes: a first focusing optical system that adjusts the beam diameter of the signal light; a second focusing optical system for adjusting a beam diameter of the pump light; a first power manipulator that adjusts the power of the signal light; a second power manipulator for adjusting the power of the pump light; Laser processing method.

15. The laser processing method according to claim 14, each of the first and second focusing optical systems includes a pair of lenses configured to adjust a distance between the lenses; each of the first power manipulator and the second power manipulator includes a λ / 2 plate and a polarizing beam splitter, and is configured to adjust a rotation angle of the λ / 2 plate around an optical axis; Laser processing method.

16. The laser processing method according to claim 14, controlling the photon flux densities of the pump light and the signal light includes controlling the photon flux densities of the pump light and the signal light so that a sum of the photon flux densities of the pump light and the signal light satisfies a condition determined by the optical parametric crystal, the pump light, the signal light, and the idler light. Laser processing method.

17. The laser processing method according to claim 16, The condition is: a crystal length of the optical parametric crystal; an effective nonlinear constant of the optical parametric crystal; a refractive index of the optical parametric crystal at each of the wavelengths of the pump light, the signal light, and the idler light; the angular frequencies of the pump light, the signal light, and the idler light; and the beam intensities of the pump light, the signal light, and the idler light at the beam centers in the optical parametric crystal, respectively. Laser processing method.

18. The laser processing method according to claim 16, The photon flux densities of the pump light and the signal light are controlled to satisfy the following equation: [Equation 3] Here, the subscripts s, i, and p represent signal light, idler light, and pump light, respectively. [Equation 4] Laser processing method.

19. A method for manufacturing an interposer, comprising: a pump laser device that outputs pump light of a first wavelength; a signal laser device that outputs signal light having a second wavelength longer than the first wavelength; an optical parametric crystal that transmits the pump light and the signal light and outputs amplified light of the second wavelength; a photon flux density control mechanism that controls the photon flux densities of the pump light and the signal light so that a sum of the photon flux densities of the pump light and the signal light at an input end of the optical parametric crystal becomes an intensity distribution in which the intensity distribution of the amplified light of the second wavelength monotonically decreases from the center to the periphery,

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