Light source position correction system of laser direct writing equipment and related equipment

Abstract

The embodiment of the invention provides a light source position correction system for laser direct writing equipment and related equipment, which are used for saving the production cost and improving the production efficiency of the laser direct writing equipment. The correction system in the embodiment of the invention comprises an optical calibration plate, wherein the optical calibration plate comprises a phase change layer and an interference enhancement dielectric layer; the phase change layer is made of a chalcogenide phase change film material, and the mounting position of the optical calibration plate is relatively fixed with the working space of the laser direct writing equipment; the optical read-write module can emit a first characteristic pulse and a second characteristic pulse; wherein the first characteristic pulse is used for exciting a laser irradiation area of the phase change layer to generate phase change, and a preset mark in an amorphous state is generated; the second characteristic pulse is reflected in the sensor camera to form an observation image with a preset mark after the interference is weakened by the interference enhancement dielectric layer; the calculation module is used for calculating the position deviation of the light source according to the deviation between the preset mark and the observation image.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser direct writing imaging, and in particular to a laser direct writing equipment light source position correction system and related equipment. BACKGROUND

[0002] Nowadays, after the laser direct writing imaging equipment is subjected to vibration or long-time operation, the position of the laser source may have a slight error (micron level). In order to maintain the imaging accuracy, the light source position of the laser direct writing imaging equipment needs to be recalibrated.

[0003] In related technologies, the light source position of the laser direct writing imaging equipment needs to be recalibrated by measuring the image position after the production sample (a plate coated with photoresist) is exposed and developed, and then calculating the deviation according to the measurement value (for example, the technical solution in the publication CN119668036A).

[0004] In related technologies, the disassembly and reassembly of the sample (in the new measurement system) inevitably introduces a micron-level mechanical measurement error, destroys the original coordinate system reference, and makes it difficult to break through the sub-micron level in terms of calibration accuracy. In addition, the photoresist consumables on the production sample are irreversible and costly, and the development process involves wet chemical treatment, which is complicated and cannot achieve a fast closed loop of the calibration process. SUMMARY

[0005] The present application provides a laser direct writing equipment light source position correction system and related equipment, which can save production costs and improve the production efficiency of the laser direct writing equipment.

[0006] The first aspect of the present application provides a laser direct writing equipment light source position correction system, which can include:

[0007] An optical calibration plate, the optical calibration plate comprising a phase change layer and an interference enhancement medium layer; the phase change layer is composed of a chalcogenide phase change film material, and the installation position of the optical calibration plate is relatively fixed with the working space of the laser direct writing equipment;

[0008] An optical read-write module, the optical read-write module can emit a first characteristic pulse and a second characteristic pulse; wherein the first characteristic pulse is used to excite the phase change of the laser irradiation area of the phase change layer to generate a preset mark in the amorphous state; after the second characteristic pulse is weakened by interference through the interference enhancement medium layer, the observation image of the preset mark is formed in the sensor camera;

[0009] A calculation module, configured to calculate the position deviation of the light source according to the deviation between the preset mark and the observation image.

[0010] Optionally, as a possible implementation, the laser direct writing device light source position correction system in the embodiment of the application can further include an optical path modulation module, which includes a beam expander collimator, a polarizing beam splitter, a 1 / 4 wave plate and a focusing objective arranged in sequence along the main optical axis.

[0011] Optionally, as a possible implementation, in the embodiment of the application, the thickness d of the interference enhancement medium layer satisfies the following condition: 2nd cos(θ)=(m+1 / 2)λ-δ; wherein n is the refractive index of the interference enhancement medium layer, θ is the refraction angle of the optical pulse in the interference enhancement medium layer, m is a non-negative integer constant, λ is the wavelength of the optical pulse in vacuum, and δ is an additional optical path difference constant.

[0012] Optionally, as a possible implementation, in the embodiment of the application, the optical calibration plate is fixedly arranged at the exposure focal plane or the focal plane conjugate position of the laser direct writing device.

[0013] Optionally, as a possible implementation, in the embodiment of the application, the optical read-write module is further configured to emit a third characteristic pulse to excite the phase change layer to change phase, so that the laser irradiation area changes from amorphous state to crystalline state, thereby eliminating the preset mark.

[0014] Optionally, as a possible implementation, in the embodiment of the application, the chalcogenide phase change material is a solid-state thin film containing Ge-Sb-Te combined elements or Ag-In-Sb-Te combined elements and doped alloys thereof.

[0015] Optionally, as a possible implementation, in the embodiment of the application, the optical calibration plate further includes a lower medium layer composed of a ZnS-SiO2 solid-state thin film, and the thickness of the lower medium layer is set to λ / 4k, wherein k is the refractive index of the lower medium layer.

[0016] Optionally, as a possible implementation, in the embodiment of the application, the chalcogenide phase change material is a solid-state thin film composed of Ge2Sb2Te5 and doped alloys thereof.

[0017] Optionally, as a possible implementation, in the embodiment of the application, the thickness of the phase change layer is 20-200 nm.

[0018] The second aspect of the embodiment of the application provides a laser direct writing device, which can include the laser direct writing device light source position correction system as in the first aspect and any one of the possible implementation manners of the first aspect, and the laser direct writing device further includes a laser array movable relative to an exposure surface in horizontal and vertical directions.

[0019] As can be seen from the above technical solutions, the embodiment of the application has the following advantages:

[0020] In this embodiment, a chalcogenide phase change material is used instead of a photosensitive coating for light source position correction. A first characteristic pulse is used to excite a phase transition in the laser-irradiated area of ​​the phase change layer, generating a preset mark in an amorphous state. A second characteristic pulse, after passing through the interference enhancement medium layer to reduce interference, is reflected in the sensor camera to form an observation image of the preset mark. The deviation between the preset mark and the observation image is used to calculate the position deviation of the light source. The chalcogenide phase change material can withstand tens of thousands of write and erase cycles, greatly saving material and time costs and improving the production efficiency of the laser direct-write equipment. In addition, the installation position of the optical calibration plate is relatively fixed with the working space of the laser direct-write equipment, allowing for direct actual position detection in the same coordinate system, reducing mechanical measurement errors introduced by disassembly and improving calibration accuracy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of one embodiment of a laser direct writing device light source position correction system according to the present application.

[0022] Figure 2 This is a schematic diagram of one embodiment of the optical calibration plate in this application.

[0023] Figure 3 This is a schematic diagram of the optical path modulation module in a laser direct writing device light source position correction system according to an embodiment of this application. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] In the description of this application, unless otherwise stated, "a plurality of" means two or more. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components.

[0027] For ease of understanding, the specific processes in the embodiments of this application are described below. Please refer to [link / reference]. Figure 1 In one embodiment of the present invention, the laser direct writing device light source position correction system may include: an optical calibration plate 10, an optical read / write module 20, a computing module 30, and a (semiconductor image) sensor camera 50 (e.g., a CCD camera, a CMOS camera, etc.). Specifically, in this embodiment, the optical calibration plate 10 may include a phase transition layer 101 made of a chalcogenide phase transition material and an interference enhancement medium layer 102. The mounting position of the optical calibration plate 10 is relatively fixed relative to the working space of the laser direct writing device. Preferably, the optical calibration plate 10 is fixedly disposed at the exposure focal plane or the focal plane conjugate position of the laser direct writing device.

[0028] For example, the chalcogenide phase change material can be a solid film containing Ge-Sb-Te or Ag-In-Sb-Te composite elements and their doped alloys, such as a Ge2Sb2Te5 solid film; the specific composition is not limited here. The chalcogenide phase change material in this application is crystalline in its normal state. When irradiated with a specifically modulated laser wave (high power, short pulse), the irradiated area rapidly heats up to an amorphous state within a short time. Afterward, as the laser irradiation stops, the area rapidly cools down, and the atoms are "frozen" in the amorphous state, forming a mark. This marked state can be maintained for a sufficient time by irradiation with other modulated laser waves (medium power, long pulse) to provide thermal energy for atomic rearrangement, causing it to anneal and recover to a highly reflective crystalline state, thus erasing the mark. The chalcogenide phase change material can undergo tens of thousands of write and erase cycles without the need for similar photosensitive coatings (e.g., photoresist) in the prior art, significantly saving material and time costs. Preferably, the thickness of the phase change layer can be 20 to 200 nm.

[0029] Optionally, the interference enhancement dielectric layer 102 is preferably a solid-state thin film with high light transmittance and tunable refractive index. The specific material can be selected according to requirements and is not limited here. For example, a ZnS-SiO2 solid-state thin film can be used to adaptively adjust the refractive index to match different wavelengths of laser light.

[0030] Preferably, the thickness d of the interference enhancement medium layer 102 satisfies the following condition: 2nd cos(θ)=(m+1 / 2)λ-δ; where n is the refractive index of the interference enhancement medium layer, θ is the refraction angle of the light pulse in the interference enhancement medium layer, m is a non-negative integer constant (m represents the interference order, which is set as a constant according to requirements), λ is the wavelength of the light pulse in vacuum, and δ is an additional optical path difference constant (if only one of the two coherent beams experiences half-wave loss δ=λ / 2, if both beams experience or do not experience half-wave loss δ=0, which is set as a constant according to requirements).

[0031] Optionally, to prevent the heat from the laser pulse from dissipating rapidly to the substrate, a lower dielectric layer 103 can be disposed below the phase transition layer. Preferably, the lower dielectric layer 103 is composed of a solid thin film of the same material as the interference enhancement dielectric layer (e.g., a ZnS-SiO2 solid thin film), and its thickness is set to λ / 4k, where k is the refractive index of the lower dielectric layer, used to assist in adjusting the reflection phase.

[0032] In this embodiment, the optical read / write module 20 can be configured to emit a first characteristic pulse and a second characteristic pulse under specific control commands. The first characteristic pulse is used to excite the phase transition layer to undergo a phase transition from an amorphous state to a crystalline state and generate a preset mark. The second characteristic pulse is reflected by the phase transition layer after the phase transition, and then, after the interference is weakened by an interference enhancement medium layer, it forms an observation image with the preset mark in the semiconductor image sensor camera 50.

[0033] For example, as one possible implementation, the optical read / write module in this application embodiment is equipped with an acousto-optic modulator on the light-emitting side of each laser source, which can modulate the emitted light from each laser source into a first characteristic pulse, a second characteristic pulse, or a third characteristic pulse according to control commands. For example, the first characteristic pulse can be a high-power, short pulse (causing the local temperature of the material to rapidly rise to above the melting point Tm, followed by abrupt laser cessation and rapid cooling of the material, e.g., with a temperature >10). 9 (At a rate of K / s), atoms do not have time to arrange themselves in an orderly manner and are "frozen" in an amorphous state. The specific pulse power and pulse width are adaptively set according to the material selection. The second characteristic pulse can be a low-power continuous wave with energy far below the phase transition threshold, used only to detect reflectivity. The third characteristic pulse can be a medium-power, long pulse (heating the material to between the crystallization temperature Tg and the melting point Tm, holding it for a sufficient time to provide thermal energy for atomic rearrangement, so that it anneals and recovers to a highly reflective crystalline state. The specific pulse power and pulse width are adaptively set according to the material selection).

[0034] The calculation module is used to calculate the positional deviation of the light source based on the deviation between the preset marker and the observed image (i.e., the actual position of the preset marker). For the specific calculation process, please refer to relevant technologies.

[0035] As disclosed above, in this embodiment, a chalcogenide phase change material is used instead of a photosensitive coating for light source position correction. A first characteristic pulse is used to excite a phase transition in the laser-irradiated area of ​​the phase change layer, generating a preset mark in an amorphous state. A second characteristic pulse, after passing through an interference enhancement medium layer to reduce interference, is reflected in the sensor camera to form an observation image of the preset mark. The deviation between the preset mark and the observation image is used to calculate the position deviation of the light source. Chalcogenide phase change materials can withstand tens of thousands of write and erase cycles, greatly saving material and time costs and improving the production efficiency of laser direct writing equipment. In addition, the installation position of the optical calibration plate is relatively fixed with the working space of the laser direct writing equipment, allowing for direct actual position detection in the same coordinate system, reducing mechanical measurement errors introduced by disassembly and improving calibration accuracy.

[0036] To prevent damage to the laser array from the strong light echo reflected by the mirror during the writing of the preset mark, and to improve the signal-to-noise ratio of the read signal, it is necessary to optimize the laser optical path in the embodiments of this application. Please refer to... Figure 3 Optionally, as a possible implementation, the laser direct-writing device's light source position correction system can also include an optical path modulation module 40. This module may include a beam expander collimator 401, a polarizing beam splitter 402, a quarter-wave plate 403, and a focusing objective 404 arranged sequentially along the principal optical axis. During the writing process, linearly polarized light is transmitted through the polarizing beam splitter 402, passes through the quarter-wave plate 403 to become circularly polarized light, and is focused onto the optical calibration plate 10 by the focusing objective 404. During the reading process, the light reflected from the optical calibration plate 10 (circular polarization chiral reversal) passes through the quarter-wave plate 403 again, recovering to linearly polarized light, but with a vibration direction perpendicular to the incident light (rotated 90°). This reflected light is totally internally reflected by the polarizing beam splitter 402 and introduced into a lateral semiconductor image sensor camera for imaging, thereby calculating the light source position deviation.

[0037] This application also provides a laser direct writing device, which may include a laser direct writing device light source position correction system as described in any of the above possible embodiments. After the laser source position is corrected by the laser direct writing device light source position correction system, the laser direct writing device can control the laser array to move relative to the exposure surface in the horizontal and / or vertical directions, and expose and image the photosensitive coating on the exposure surface placed in the workspace during the relative movement. The specific imaging process can be referred to in related technologies, which will not be elaborated here.

[0038] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser direct writing apparatus light source position correction system, characterized by, The laser direct writing device light source position correction system comprises: an optical calibration plate comprising a phase change layer and an interference enhancement medium layer; the phase change layer is composed of a chalcogenide phase change thin film material, and the installation position of the optical calibration plate is fixed relative to the working space of the laser direct writing device; an optical read-write module capable of emitting a first characteristic pulse and a second characteristic pulse; wherein the first characteristic pulse is used to excite the phase change of the laser irradiation area of the phase change layer to generate a preset mark in an amorphous state; after the second characteristic pulse passes through the interference enhancement medium layer to weaken the interference, a observation image of the preset mark is formed in the sensor camera by reflection; a calculation module for calculating the position deviation of the light source according to the deviation between the preset mark and the observation image.

2. The system of claim 1, wherein, The optical path modulation module comprises a beam expander, a polarizing beam splitter, a 1 / 4 wave plate and a focusing objective arranged in sequence along the main optical axis.

3. The system of claim 1 or 2, wherein, The thickness d of the interference enhancement medium layer satisfies the following condition: 2nd cos(θ) = (m+1 / 2)λ-δ; wherein n is the refractive index of the interference enhancement medium layer, θ is the refraction angle of the optical pulse in the interference enhancement medium layer, m is a non-negative integer constant, λ is the wavelength of the optical pulse in vacuum, and δ is an additional optical path difference constant.

4. The system of claim 3, wherein, The optical calibration plate is fixedly arranged at the exposure focal plane or the focal plane conjugate position of the laser direct writing device.

5. The system of claim 3, wherein, The optical read-write module is also used to emit a third characteristic pulse to excite the phase change of the phase change layer, so that the laser irradiation area changes from an amorphous state to a crystalline state to eliminate the preset mark.

6. The system of any one of claims 1 to 5, wherein, The chalcogenide phase change material is a solid-state thin film comprising Ge-Sb-Te combined elements or Ag-In-Sb-Te combined elements and their doped alloys.

7. The system of any one of claims 1 to 5, wherein, The optical calibration plate further comprises a lower medium layer composed of a ZnS-SiO2 solid-state thin film, and the thickness of the lower medium layer is set to λ / 4k, wherein k is the refractive index of the lower medium layer.

8. The system of any one of claims 1 to 5, wherein, The chalcogenide phase change material is a solid-state thin film composed of Ge2Sb2Te5 and its doped alloys.

9. The system of any one of claims 1 to 5, wherein, The thickness of the phase change layer is 20 to 200 nm.

10. A laser direct writing apparatus, characterized by, The laser direct writing device further comprises a laser array capable of moving relative to the exposure surface in the horizontal direction and the vertical direction.

Images