WO2020001467A1

WO2020001467A1 - Multi-wavelength optical system and laser annealing device

Info

Publication number: WO2020001467A1
Application number: PCT/CN2019/092965
Authority: WO
Inventors: 徐建旭; 兰艳平
Original assignee: 上海微电子装备（集团）股份有限公司
Priority date: 2018-06-26
Filing date: 2019-06-26
Publication date: 2020-01-02
Also published as: JP2021529437A; TW202001347A; KR20210027397A; CN110007473A

Abstract

Disclosed by the present application are a multi-wavelength optical system and a laser annealing device. The multi-wavelength optical system comprises: a reference optical path unit, at least one optical path unit to be adjusted, a focal plane compensation unit, and a focusing unit; wherein one focal plane compensation unit is disposed in each optical path of the optical path unit to be adjusted; the light wavelengths of the reference optical path unit and the optical path unit to be adjusted are not equal; each focal plane compensation unit is configured to change an optical path of the corresponding optical path unit to be adjusted, so that light beams of the optical path unit to be adjusted are focused on a second focal plane after passing through the focusing unit; and light beams of the reference optical path unit are focused on the first focal plane after passing through the focusing unit, and the second focal plane and the first focal plane are of a confocal plane.

Description

Multi-wavelength optical system and laser annealing device

This application claims priority from a Chinese patent application filed with the Chinese Patent Office on June 26, 2018 with application number 201810666925.8, the entire contents of which are incorporated herein by reference.

Technical field

The embodiments of the present application relate to the technical field of integrated circuit equipment manufacturing, for example, a multi-wavelength optical system and a laser annealing device.

Background technique

Multi-wavelength combining technology combines multiple light beams with different wavelengths output by multiple light sources into a single beam. In order to ensure the spot performance of the focal plane, the focusing system needs to be compatible with multiple wavelengths to make achromatic differences. design.

In the related art optical system, in order to realize that the focusing unit is compatible with multiple wavelengths, a variety of materials with different refractive indices are generally used to form the focusing unit. Specifically, FIG. 1 is a schematic structural diagram of a multi-wavelength optical system in the related art. Referring to FIG. 1, the multi-wavelength optical system includes two wavelength light sources, which may be referred to as a first light source 011 and a second light source 021. The light emitted by the first light source 011 passes through the first optical front lens group 012 and the first bending reflection The mirror 013, the combining lens 023, and the focusing unit 03 illuminate the surface of the workpiece table 040; the light emitted by the second light source 021 passes through the second optical front lens group 022, the combining lens 023, and the focusing unit 03 to illuminate the surface of the workpiece table 040 . Among them, in order to make the light emitted by the first light source 011 and the light emitted by the second light source 021 pass through the above-mentioned optical elements, and finally focus on the confocal surface of the surface of the workpiece table 040, it is usually necessary to design the focusing unit 03 to use a combination of materials with different refractive indices. Therefore, the design of the focusing unit 03 is difficult and the cost is high.

Summary of the invention

The following is an overview of the topics detailed in this article. This summary is not intended to limit the scope of protection of the claims.

The present application provides a multi-wavelength optical system and a laser annealing device, which can reduce the design difficulty of the focusing unit, thereby reducing the manufacturing cost of the focusing unit.

In a first aspect, an embodiment of the present application provides a multi-wavelength optical system including a reference optical path unit, at least one optical path unit to be adjusted, a focal plane compensation unit, and a focusing unit;

The optical path of each of the optical path units to be adjusted is provided with one of the focal plane compensation units; the optical wavelengths of the reference optical path unit and the optical path unit to be adjusted are not equal; the light beam of the reference optical path unit passes through the The focusing unit is focused on the first focal plane; each of the focal plane compensation units is configured to change an optical path corresponding to the optical path unit to be adjusted so that the light beam of the optical path unit to be adjusted passes the focusing unit and is focused on all Mentioned first focal plane.

In a second aspect, an embodiment of the present application provides a laser annealing apparatus, including the multi-wavelength optical system provided in the first aspect; wherein the reference optical path unit and the optical path unit to be adjusted in the multi-wavelength optical system are used for Emits two lasers with different wavelength ranges; the focal plane compensation unit is configured to change the optical path of the optical path unit to be adjusted so that the light beam of the optical path unit to be adjusted and the light beam of the reference optical path unit respectively pass through the A confocal plane behind the focusing unit; further comprising a workpiece stage, the workpiece stage being located at a confocal plane position of the reference optical path unit and the optical path unit to be adjusted.

After reading and understanding the drawings and detailed description, other aspects can be understood.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the technical solutions in the embodiments of the present application or related technologies more clearly, the drawings used in the description of the embodiments or related technologies are briefly introduced below. The drawings in the following description are some of the applications of the present application. For those of ordinary skill in the art, other embodiments may be obtained based on these drawings without paying creative effort.

1 is a schematic structural diagram of a multi-wavelength optical system in the related art;

2 is a schematic structural diagram of a multi-wavelength optical system according to an embodiment of the present application;

3 is a schematic diagram of a refractive index-wavelength relationship of fused silica;

4 is a schematic diagram of a focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is not provided;

5 is a schematic diagram of a focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is provided;

FIG. 6 is a schematic diagram of a diffuse spot distribution of the optical path unit to be adjusted in the first focal plane in FIG. 4; FIG.

FIG. 7 is a schematic diagram of a diffuse spot distribution of the optical path unit to be adjusted in FIG. 5 on a first focal plane; FIG.

8 is a schematic structural diagram of another multi-wavelength optical system according to an embodiment of the present application;

9 is a schematic structural diagram of still another multi-wavelength optical system according to an embodiment of the present application;

FIG. 10 is a schematic diagram of another focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is not provided; FIG.

11 is a schematic diagram of another focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is provided;

FIG. 12 is the distribution of the diffuse spots on the first focal plane of the optical path unit to be adjusted in FIG. 11; FIG.

FIG. 13 is the distribution of diffuse spots on the first focal plane of the reference optical path unit in FIG. 9; FIG.

FIG. 14 is a schematic structural diagram of a laser annealing apparatus according to an embodiment of the present application.

detailed description

The following describes the present application in detail with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application. It should also be noted that, for convenience of description, the drawings only show a part of the structure related to the present application, but not the entire structure.

FIG. 2 is a schematic structural diagram of a multi-wavelength optical system according to an embodiment of the present application. Referring to FIG. 2, the multi-wavelength optical system includes: a reference optical path unit 11, at least one optical path unit 12 to be adjusted, a focal plane compensation unit 141, and a focusing unit 13; a focal plane is set in an optical path of each optical path unit 12 to be adjusted. Compensation unit 141; the light wavelengths of the reference optical path unit 11 and the optical path unit 12 to be adjusted are not equal; the beam of the reference optical path unit 11 is focused on the first focal plane F11 after passing through the focusing unit 13; each focal plane compensation unit 141 is set to change the corresponding The optical path of the optical path unit 12 to be adjusted causes the light beams of the optical path unit 12 to be adjusted to focus on the first focal plane F11 after passing through the focusing unit 13.

Among them, because the wavelengths of the reference optical path unit 11 and the to-be-adjusted optical path unit 12 are not equal, the refractive index of the focusing unit 13 on the light beam incident from the reference optical path unit 11 under the same material and curvature radius is used. Different from the refractive index of the light beam incident into the optical path unit 12 to be adjusted, the optical focal length of the light beam of the reference optical path unit 11 emitted by the focusing unit 13 and the optical focal length of the optical path unit 12 to be adjusted emitted by the focusing unit 13 are different. That is, the two beams are focused at different focal planes. The light beam of the reference optical path unit 11 is focused on the first focal plane F11 after passing through the focusing unit 13 and correspondingly forms a standard optical focal length. The light beam of the optical path unit 12 to be adjusted passes the focusing unit 13 and focused on the focal surface to be adjusted, correspondingly forming the optical focal length to be adjusted. The focal plane compensation unit 141 is configured to adjust the beam of the optical path unit 12 to be adjusted so that the beam passes through the focusing unit 13 and the position of the focal plane is moved from the position of the focal plane to be adjusted (exemplarily, in the direction Z1) to the first The position of the focal plane F11, that is, the focal plane compensation unit 141 is set to compensate the difference in focal distance between the standard optical focal length and the optical focal length to be adjusted, so that the light beam of the reference optical path unit 11 and the light beam of the optical path unit 12 to be adjusted pass the focusing unit 13 Confocal plane.

Exemplarily, FIG. 3 is a schematic diagram of a refractive index-wavelength relationship of fused silica. The horizontal axis represents the wavelength λ in nanometers (nm), and the vertical axis represents the refractive index n of the fused silica. Referring to FIG. 3, according to the material dispersion relationship, the refractive index of fused silica decreases as the wavelength of a light beam incident on the fused silica increases. Therefore, for the same focusing unit, that is, under the same radius of curvature, The larger the wavelength of the light beam of the focusing unit, the smaller the refractive index of the focusing unit with respect to the light beam incident therein, and the longer the optical focal length of the corresponding light beam. Based on this, for a multi-wavelength optical system, a focal plane compensation unit is provided in the short-wavelength optical path unit, so that the position of the focusing surface (or "focus") is moved backward, and the short-wavelength optical path unit and the long-wavelength optical path unit can be confocal Or, a focal plane compensation unit is provided in the long-wavelength optical path unit, so that the position of the focal plane is moved forward, so that the long-wavelength optical path unit and the short-wavelength optical path unit can be confocal.

It should be noted that the “backward” and “forward” are relative concepts here, and they are for the relative positions of the focusing surface and the focusing unit, not for the limitation of the spatial position. Among them, "backward" represents the direction from the focusing surface to the focusing unit, and "forward" represents the direction from the focusing unit to the focusing surface.

It should be noted that FIG. 2 only exemplarily shows that the number of the optical path units to be adjusted is 1, but it is not a limitation on the multi-wavelength optical system provided in the embodiment of the present application. In other embodiments, the number of the optical path units to be adjusted may be set according to the actual requirements of the multi-wavelength optical system.

For example, FIG. 4 is a schematic diagram of a focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is not provided. Referring to FIG. 4, when no focal plane compensation unit is provided, the light beam of the optical path unit to be adjusted is focused on the focal plane F10 position by the focusing unit 13. At this time, the position of the focal plane F10 to be adjusted and the first focal plane of the reference optical path unit The F11 position is not in the same position, so there is a color difference.

For example, FIG. 5 is a schematic diagram of a focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is provided. Referring to FIG. 5, when the focal plane compensation unit 141 is set, the light beam of the optical path unit to be adjusted first passes through the focal plane compensation unit 141 and then passes through the focusing unit 13 and is then focused on the position of the first focal plane F11. The position of the focal plane F10 is moved backward, that is, the focal plane F10 to be adjusted is moved in a direction Z1 away from the focusing unit 13. Therefore, by setting the focal plane compensation unit 141, the position of the focusing surface of the optical path unit to be adjusted and the position of the focusing surface of the reference optical path unit are both at the first focal plane F11 position, that is, the two optical path units are focused at the same position, thereby eliminating Chromatic aberration. In this way, it is avoided that the design of the focusing unit 13 including materials with different refractive indices is difficult and expensive.

An embodiment of the present application provides a multi-wavelength optical system, including a reference optical path unit, at least one optical path unit to be adjusted, a focal plane compensation unit, and a focusing unit; wherein the reference optical path unit and the optical path unit to be adjusted have different optical wavelengths. The beam of the optical path unit is focused on the first focal plane after passing through the focusing unit; by setting a focal plane compensation unit in the optical path of each optical path unit to be adjusted, the focal plane compensation unit is set to change the optical path of the corresponding optical path unit to be adjusted, so that After passing through the focusing unit, the light beams of the adjusting optical path unit are focused on the first focal plane. Therefore, by setting a focal plane compensation unit, the light beam of the optical path unit to be adjusted and the light beam of the reference optical path unit respectively pass through the focusing unit after being confocal. It avoids the difficulty of designing the focusing unit caused by designing the focusing unit in the optical system by using materials with different refractive indices to achieve confocal planes of beams with different wavelengths, and the cost is higher, which reduces the design difficulty of the focusing unit. , Thereby reducing the manufacturing cost of the focusing unit.

By way of example, FIG. 6 is a schematic diagram of the diffusion spot distribution of the optical path unit to be adjusted on the first focal plane in FIG. 4, that is, the diffuse spot of the light beam of the optical path unit to be adjusted on the focal plane of the standard beam when the focal plane compensation unit 141 is not provided. Distribution diagram. Referring to FIG. 6, P210 represents a diffuse spot at an optical axis position, P212 represents a diffuse spot at an edge position, and P211 represents a diffuse spot at a position halfway between the optical axis and the edge. By way of example, FIG. 7 is a schematic diagram of the diffusion spot distribution of the optical path unit to be adjusted on the first focal plane in FIG. 5, that is, when the focal plane compensation unit 141 is set, the diffusion spot of the light beam of the optical path unit to be adjusted on the focusing plane of the standard beam Distribution diagram. Referring to FIG. 7, P220 represents a diffuse spot representing an optical axis position, P222 represents a diffuse spot at an edge position, and P221 represents a diffuse spot at a position halfway between the optical axis and the edge. Comparing FIG. 6 and FIG. 7, after the focal plane compensation unit 141 is provided, the convergence degree of the diffuse spots at all three positions is enhanced. The more the diffuse spots are converged, the smaller the distance between this plane and the focusing surface of the optical path unit to be adjusted is. That is, the focusing surface of the reference optical path unit and the focusing surface of the to-be-adjusted optical path unit tend to be confocal. Therefore, by setting a focal plane compensation unit, chromatic aberration is eliminated without a difficult design of the focusing unit.

In an embodiment, there may be multiple optical paths to be adjusted. For example, FIG. 8 is a schematic structural diagram of another multi-wavelength optical system provided by an embodiment of the present application. Referring to FIG. 8, the multi-wavelength optical system includes a reference optical path unit 11 and two optical path units 12 to be adjusted. Each optical path unit 12 is provided with a focal plane compensation unit 141 in the optical path, so that two optical paths to be adjusted can be adjusted. After passing through the focusing unit 13, the light beam of the unit 12 and the light beam of the reference optical path unit 11 are focused on the confocal plane of the first focal plane F11.

It should be noted that if the multi-wavelength optical system includes a plurality of optical path units to be adjusted, the wavelengths of the light beams of the plurality of optical path units to be adjusted may be the same or different, which is not limited in the embodiment of the present application.

It should be noted that FIG. 8 only exemplarily shows that the number of the optical path units to be adjusted is two, but it is not a limitation on the multi-wavelength optical system provided in the embodiment of the present application. In other embodiments, the number of optical path units to be adjusted may be set according to the actual requirements of the multi-wavelength optical system, which is not limited in the embodiments of the present application. In addition, the reference optical path unit is relative to the optical path unit to be adjusted, that is, in a multi-wavelength system, the focal plane of one of the optical path units can be selected as the first focal plane, that is, the optical path unit is used as the reference optical path unit; A focal plane compensation element is provided in the optical path of other optical path units to adjust the focal plane of other optical path units, so that the focal planes of other optical path units are adjusted to the position of the first focal plane, thereby achieving a confocal plane of multiple optical path units , That is, to achieve a confocal plane of a multi-wavelength system.

In an embodiment, referring to FIG. 3 or FIG. 8 continuously, the reference optical path unit 11 includes a standard light source 111, a standard optical front lens group 112, and a standard bending reflector 113; the standard optical front lens group 112, which are sequentially arranged along the beam propagation direction. It is set to adjust the energy, angle and spot size of the light beam emitted by the standard light source 111; the standard bending mirror 113 is set to change the propagation direction of the light beam adjusted by the standard optical front lens group 112, so that the light beam is incident on the focusing unit 13.

The standard optical front lens group 112 may include optical elements such as a collimator lens, a beam expander, and a homogenizing unit.

It should be noted that FIG. 3 or FIG. 8 only exemplarily shows that a reference optical path unit 11 includes a standard optical front lens group 112 and a standard bending reflector 113, but it is not provided for the embodiment of the present application. The definition of a multi-wavelength optical system. In other embodiments, the number of the optical front mirror group 112 and the standard bending reflector 113 may be set according to the actual optical path setting requirements of the multi-wavelength optical system.

In an embodiment, referring to FIG. 3 or FIG. 8 continuously, the to-be-adjusted optical path unit 12 includes a to-be-adjusted light source 121, an to-be-adjusted optical front lens group 122, and a combining lens 123, which are sequentially arranged along the beam propagation direction; the to-be-adjusted optical front lens group 122 is set to adjust the energy, angle, and spot size of the light beam emitted by the light source 121 to be adjusted; the combining lens 123 is set to combine the light beam of the reference optical path unit 11 and the light beam of the optical path unit 12 to be adjusted into one; passing through the combining lens 123 The light beam is incident on the focusing unit 13.

The to-be-adjusted optical front lens group 122 may include optical elements such as a collimator lens, a beam expander, and a light homogenizing unit.

It should be noted that FIG. 3 or FIG. 8 only exemplarily shows one optical front lens group 122 to be adjusted, but it is not a limitation on the multi-wavelength optical system provided in the embodiment of the present application. In other embodiments, the number of the optical front lens groups 122 to be adjusted may be set according to the actual optical path setting requirements of the multi-wavelength optical system.

In an embodiment, referring to FIG. 3 or FIG. 8 continuously, the focal plane compensation unit 141 is located in the optical path between the optical front lens group 122 and the combining lens 123 to be adjusted.

In this way, the beam angle, energy and spot size adjusted by the optical front lens group 122 to be adjusted can meet the requirements of the multi-wavelength optical system into the focal plane compensation unit 141, and the focal plane compensation unit 141 performs the optical focal length. Compensation without affecting other optical parameters, thereby simplifying the optical path and simplifying the adjustment process of the focusing surface of the optical path unit to be adjusted.

It should be noted that, in other embodiments, the focal plane compensation unit 141 may be further located between the light source 121 to be adjusted and the combining lens 123 according to the actual requirements of the multi-wavelength optical system.

In an embodiment, the focal plane compensation unit 141 includes a single focal plane compensation lens or a focal plane compensation lens group.

In one embodiment, the standard light source 111 is configured to emit a light beam with a first wavelength, the light source 121 to be adjusted is configured to emit a light beam with a second wavelength, and the focal plane compensation unit 141 includes a single focal plane compensation lens.

The first wavelength is not equal to the second wavelength.

Exemplarily, the first wavelength is 808 nm, and the second wavelength is 527 nm. The focal plane compensation lens is set to adjust the optical path of 527 nm so that it passes through the focusing unit 13 and is confocal with the beam of 808 nm. This is only an exemplary description, not a limitation.

In one embodiment, the standard light source is configured to emit a light beam with a wavelength of a first threshold wavelength range; the light source to be adjusted is configured to emit a light beam with a wavelength of a second threshold wavelength range; the focal plane compensation unit includes a focal plane composed of a plurality of lenses Compensation lens group.

The first threshold wavelength range is not equal to the second threshold wavelength range.

Exemplarily, the first threshold wavelength range is 300 nm-500 nm, and the second threshold wavelength range is 500 nm-800 nm. The focal plane compensation lens group is set to adjust the optical path in the wavelength range of 500nm-800nm so that it passes through the focusing unit 13 and is confocal with the beam in the wavelength range of 300nm-500nm. This is only an exemplary description, not a limitation.

In an embodiment, referring to FIG. 4 or FIG. 5 continuously, the focusing unit 13 includes a focusing lens group; the focusing lens group is configured to focus the light beam of the reference optical path unit and the light beam of the optical path unit to be adjusted separately. Realize the confocal plane of the reference optical path unit and the optical path unit to be adjusted.

In one embodiment, the focusing lens group includes a plurality of lenses of the same material.

Exemplarily, the focusing lens group may include a first focusing lens 151, a second focusing lens 152, a third focusing lens 153, a fourth focusing lens 154, and a fifth focusing lens 155, which are sequentially arranged along a light path propagation direction. In this way, the light beams of the reference optical path unit and the light beams of the optical path unit to be adjusted are respectively focused on a confocal plane.

The use of lenses of the same material can avoid the increase in design difficulty due to the difference in refractive index of the lens materials, so the design difficulty of the focusing unit can be simplified, and the manufacturing process thereof can be simplified.

In one embodiment, the lens material of the focusing lens group is fused silica.

The lenses using fused silica to form the focusing lens group are mature in technology and low in cost.

In an embodiment, the light emitting end of the focusing lens group includes an optical flat plate.

Exemplarily, the fifth focusing lens 155 is an optical flat plate, which can protect the lens of the focusing unit 13 from pollution on the one hand; on the other hand, if the fifth focusing lens 155 is contaminated or damaged, it is convenient for maintenance or replacement, and Compared to lenses with a concave and convex design, the cost is lower.

In an embodiment, when the light beams of the optical path unit to be adjusted and the reference light path unit are light beams of a single wavelength, when the light beam wavelength of the optical path unit to be adjusted is smaller than the light beam wavelength of the reference optical path unit, the focal plane compensation unit is a convex-concave lens; When the beam wavelength of the optical path unit to be adjusted is greater than the beam wavelength of the reference optical path unit, the focal plane compensation unit is a meniscus lens.

The convex-concave lens is configured to move the position of the focusing surface of the optical path unit to be adjusted backward so that the focusing surface of the optical path unit (short wavelength) to be adjusted is at the same position as the focusing surface of the reference optical path unit (long wavelength).

Exemplarily, referring to FIG. 3, the position of the focusing surface of the optical path unit 12 to be adjusted moves in a direction Z1 away from the focusing unit 13, thereby achieving a confocal plane with the reference optical path unit 11.

Exemplarily, Table 1 is a lens parameter table of the convex-concave lens and the focusing unit in FIG. 5.

Among them, the front surface represents the surface where the light is incident, and the rear surface represents the surface where the light is emitted.

The Stop surface is the diaphragm surface, and the image surface is the image surface (or the best focal plane). The radius refers to the curvature radius of the surface, and the refractive index refers to the refractive index of the medium behind the surface (from the direction of light propagation, the incident side of the light is front, and the outgoing side is rear). For example, the refractive index of air Is 1, the refractive index of the lens material of the focusing unit and the convex-concave lens is 1.56. The thickness refers to the thickness of the medium between this surface and the next surface (in the direction of light propagation, after the light exits from this surface, the immediately adjacent surface), where the lens thickness refers to the central mechanical thickness of the lens, The thickness refers to the air gap. The effective caliber refers to the diameter of this surface.

Exemplarily, corresponding to the lens parameters shown in Table 1, the distribution of the diffuse spots of the optical path unit to be adjusted at the position of the first focal plane is shown in FIG. 7. Correspondingly, no focal plane compensation unit is provided. The distribution of diffuse spots is shown in Figure 6. The degree of focus of the diffuse spot can be expressed by the root-mean-square value RMS. The smaller the root-mean-square value RMS, the more the diffuse spot converges, and the smaller the chromatic aberration of the multi-wavelength optical system.

Table 1 Lens parameter table of convex-concave lens and focusing unit in Figure 5

Exemplarily, Table 2 is a distribution parameter table of diffuse spots in FIG. 6 and FIG. 7.

Table 2 Distribution parameters of diffuse spots in Figure 6 and Figure 7

位置position	RMS值RMS value
P210P210	0.4580000.458000
P211P211	0.4649300.464930
P212P212	0.4878340.487834
P220P220	0.0027770.002777
P221P221	0.0023030.002303
P222P222	0.0033470.003347

Wherein, each value represents the root mean square value RMS corresponding to each position.

From the comparison of the root mean square value RMS in Table 2, it can be seen that after the focal plane compensation unit is set, three different positions (including the optical axis positions P210 and P220; the edge positions P211 and P221; the optical axis and the middle half of the position P212) (P222, P222) The root mean square value RMS of the diffuse spot is reduced, that is, the convergence degree of the diffuse spot is increased, that is, the position of the optical path unit to be adjusted is focused on the position of the first focal plane, so the optical path unit to be adjusted and the reference optical path unit are adjusted. Confocal surface eliminates chromatic aberration in multi-wavelength optical systems.

The concave-convex lens is configured to move the position of the focusing surface of the optical path unit to be adjusted forward so that the focusing surface of the optical path unit (long wavelength) to be adjusted is at the same position as the focusing surface of the reference optical path unit (short wavelength).

Exemplarily, FIG. 9 is a schematic structural diagram of still another multi-wavelength optical system according to an embodiment of the present application. Referring to FIG. 9, the position of the focusing surface of the to-be-adjusted optical path unit 12 moves in a direction Z2 close to the focusing unit 13, thereby achieving a confocal plane with the reference optical path unit 11 (the position of the confocal plane is shown by F11).

Exemplarily, FIG. 10 is a schematic diagram of another focusing principle of an optical path unit to be adjusted when a focal plane compensation unit is not provided. Referring to FIG. 10, when the focal plane compensation unit is not provided, the light beam of the optical path unit to be adjusted is focused on the focal plane F10 position by the focusing unit 13. At this time, the position of the focal plane F10 to be adjusted and the first focal plane of the reference optical path unit Position F11 is not in the same position, so there is a color difference.

By way of example, FIG. 11 is a schematic diagram of the focusing principle of another optical path unit to be adjusted when a focal plane compensation unit is provided. Referring to FIG. 11, when a focal plane compensation unit (concave-convex lens 142) is provided, the light beam of the optical path unit to be adjusted first passes through the focal plane compensation unit 142, and then passes through the focusing unit 13 and is then focused on the first focal plane F11 and the first focal plane F11. The position moves backward with respect to the position of the focal plane F20 to be adjusted, that is, moves in a direction Z2 close to the focusing unit 13. At this time, by setting the focal plane compensation unit 142, both the focusing plane of the optical path unit to be adjusted and the focusing plane of the reference optical path unit are at the first focal plane F21 position, that is, the two optical path units are focused at the same position, thereby eliminating chromatic aberration. In this way, it is avoided that the design of the focusing unit 13 including materials with different refractive indices is difficult and expensive.

Exemplarily, Table 3 is a lens parameter table of the meniscus lens and the focusing unit in FIG. 11.

Table 3.Table of lens parameters for the meniscus lens and focusing unit in Figure 11.

The physical meaning of each parameter in Table 3 can be understood by referring to the description of Table 1, and is not repeated here.

Exemplarily, corresponding to the lens parameters shown in Table 3, FIG. 12 is the distribution of the diffuse spots on the first focal plane of the optical path unit to be adjusted in FIG. 11. Referring to FIG. 12, P320 represents a diffuse spot at an optical axis position, P322 represents a diffuse spot at an edge position, and P321 represents a diffuse spot at a position halfway between the optical axis and the edge. Exemplarily, FIG. 13 is the distribution of the diffuse spots on the first focal plane of the reference optical path unit in FIG. 9. Referring to FIG. 13, P410 represents a diffuse spot at an optical axis position, P412 represents a diffuse spot at an edge position, and P411 represents a diffuse spot at a position halfway between the optical axis and the edge.

Exemplarily, Table 4 is a distribution parameter table of diffuse spots in FIG. 12 and FIG. 13.

Table 4 Distribution parameters of diffuse spots in Figure 12 and Figure 13

位置position	RMS值RMS value
P320P320	0.0232500.023250
P321P321	0.0241780.024178
P322P322	0.0281100.028110
P410P410	0.0026870.002687
P411P411	0.0031250.003125
P412P412	0.0047120.004712

It can be seen from the root mean square value RMS of each position in Table 4 that the root mean square value RMS of the diffuse spots at different positions is smaller (the range of the root mean square value RMS in Table 1 can be taken as 0.458-0.488 as The reference value of the root mean square value RMS in the optical system in the related art), that is, the convergence degree of the diffuse spots is relatively large, that is, the confocal plane of the beam of the optical path unit to be adjusted and the beam of the reference optical path unit are focused, eliminating multi-wavelength optics System color difference.

It should be noted that each parameter value in Table 1, Table 2, Table 3, and Table 4 is only an exemplary description of lens parameters, and is not limited.

In an embodiment, when the light beams of the light path unit to be adjusted and the reference light path unit are both light beams with a threshold wavelength, when the light beam wavelength of the light path unit to be adjusted is smaller than the light beam wavelength of the reference light path unit, the focal plane compensation unit is a convex-concave lens group. ; When the beam wavelength of the optical path unit to be adjusted is greater than the beam wavelength of the reference optical path unit, the focal plane compensation unit is a meniscus lens group.

The lens group adjusts the light beams of each wavelength in the threshold wavelength range of the optical path unit to be adjusted by the lens group, so that the light beams of each wavelength are focused to the position of the confocal plane with the first focal plane, thereby realizing a wide-wavelength confocal plane optical system. .

An embodiment of the present application further provides a laser annealing apparatus. For example, FIG. 14 is a schematic structural diagram of a laser annealing apparatus provided by an embodiment of the present application. Referring to FIG. 14, the laser annealing apparatus includes the multi-wavelength optical system provided in the foregoing embodiment, in which the reference optical path unit 11 and the to-be-adjusted optical path unit 12 in the multi-wavelength optical system are set to emit two laser beams with different wavelength ranges; The surface compensation unit 141 is configured to change the optical path of the optical path unit 12 to be adjusted so that the light beam of the optical path unit 12 to be adjusted and the light beam of the reference optical path unit 11 respectively pass through the focusing unit after being confocal; the workpiece stage 040 is also located at the reference Confocal plane position of the optical path unit and the optical path unit to be adjusted. In this way, the multi-wavelength optical system can be used to achieve confocal laser beams of different wavelengths, thereby increasing the energy density of the laser beam on the surface of the workpiece table and improving the annealing efficiency.

The laser annealing device provided in the embodiment of the present application also has the technical effects of the above-mentioned multi-wavelength optical system, and details are not described herein again.

Claims

A multi-wavelength optical system includes a reference optical path unit, at least one optical path unit to be adjusted, a focal plane compensation unit, and a focusing unit;

One focal plane compensation unit is provided in the optical path of each of the optical path units to be adjusted;

The light wavelengths of the reference optical path unit and the optical path unit to be adjusted are not equal;

A beam of the reference optical path unit is focused on a first focal plane after passing through the focusing unit;

Each of the focal plane compensation units is configured to change an optical path corresponding to the optical path unit to be adjusted, so that the light beams of the optical path unit to be adjusted are focused on the first focal plane after passing through the focusing unit.
The multi-wavelength optical system according to claim 1, wherein the focal plane compensation unit includes a single focal plane compensation lens or a focal plane compensation lens group.
The multi-wavelength optical system according to claim 2, wherein the focal plane compensation is in a case where a beam wavelength of the reference optical path unit is a first wavelength and a beam wavelength of the optical path unit to be adjusted is a second wavelength. The unit includes a single focal plane compensation lens.
The multi-wavelength optical system according to claim 2, wherein, when a beam wavelength of the reference optical path unit is a first threshold wavelength range, and a beam wavelength of the optical path unit to be adjusted is a second threshold wavelength range, all The focal plane compensation unit includes a focal plane compensation lens group.
The multi-wavelength optical system according to claim 3, wherein, in a case where the second wavelength is smaller than the first wavelength, the single focal plane compensation lens is a convex-concave lens; In the case of the first wavelength, the single focal plane compensation lens is a meniscus lens.
The multi-wavelength optical system according to claim 4, wherein, in a case where the second threshold wavelength range is smaller than the first threshold wavelength range, the focal plane compensation lens group is a convex-concave lens group; When the two threshold wavelength ranges are larger than the first threshold wavelength range, the focal plane compensation lens group is a meniscus lens group.
The multi-wavelength optical system according to claim 1, wherein the reference optical path unit includes a standard light source, a standard optical front lens group, and a standard bending reflector arranged in order along a beam propagation direction;

The standard optical front lens group is configured to adjust the energy, angle, and spot size of a light beam emitted by the standard light source;

The standard bending mirror is configured to change a propagation direction of a light beam adjusted by the standard optical front lens group, so that the light beam is incident on the focusing unit.
The multi-wavelength optical system according to claim 7, wherein the to-be-adjusted optical path unit comprises a to-be-adjusted light source, an to-be-adjusted optical front lens group, and a combiner lens arranged in order along a beam propagation direction;

The optical front lens group to be adjusted is set to adjust the energy, angle, and spot size of a light beam emitted by the light source to be adjusted;

The combiner is configured to combine the light beam of the reference optical path unit and the light beam of the optical path unit to be adjusted into a single beam;

The light beam passing through the combining lens is incident on the focusing unit.
The multi-wavelength optical system according to claim 8, wherein the focal plane compensation unit is located in an optical path between the to-be-adjusted optical front lens group and the combining lens.
The multi-wavelength optical system according to claim 1, wherein the focusing unit includes a focusing lens group;

The focusing lens group is configured to focus the light beam of the reference optical path unit and the light beam of the optical path unit to be adjusted separately.
The multi-wavelength optical system according to claim 10, wherein the focusing lens group includes a plurality of lenses of the same material.
The multi-wavelength optical system according to claim 11, wherein a lens material of the focusing lens group is fused silica.
The multi-wavelength optical system according to claim 11, wherein the light beam exit end of the focusing lens group comprises an optical flat plate.
A laser annealing device, comprising the multi-wavelength optical system according to any one of claims 1-13;

Wherein, the reference optical path unit and the to-be-adjusted optical path unit in the multi-wavelength optical system are set to emit two lasers with different wavelength ranges; the focal plane compensation unit is set to change the to-be-adjusted optical path unit. An optical path of the confocal plane after the light beam of the optical path unit to be adjusted and the light beam of the reference optical path unit pass through the focusing unit, respectively;

A workpiece stage is further included, and the workpiece stage is located at a confocal plane position of the reference optical path unit and the optical path unit to be adjusted.