System and method for forming partial microholes using a variable bessel beam

Abstract

An embodiment of the present disclosure includes an optical assembly including an axicon lens having spherical aberration and configured to generate a laser beam focal line, a set of optical elements spaced apart from the optical lens, and a focusing optical element spaced apart from the set of optical elements, wherein the axicon lens and the set of optical elements are translatable relative to one another along a direction of propagation of the laser beam, and the focusing optical element is at a fixed position along the direction of propagation of the laser beam.

Description

Cross - reference to related applications

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 63 / 107,824, filed on October 30, 2020, the content of which is relied upon and incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure relates to a system and method for forming partial micro - holes, and more particularly, to a system and method for forming partial micro - holes in a glass wafer of a semiconductor substrate using a variable vessel beam.

Background Art

[0003] <00​​​​​​​​Once the device layer is fabricated or transferred to the glass, the Si is completely removed by grinding or chemical etching. During this process, the glass substrate acts as a mechanical support. Before being assembled into individual dies, the glass is then mechanically thinned to 100 μm to 150 μm by grinding.

[0006] For each die measuring 0.5 mm x 0.5 mm, dicing with a typical diamond blade results in a kerf loss of 80 μm to 100 μm, which represents a face loss of up to 30%. [Overview of the project] [Problems that the invention aims to solve]

[0007] Alternatively, if there is a method that minimizes kerf loss to near zero, this valuable resource can be saved and used to deliver significant value to wafer customers. [Means for solving the problem]

[0008] Therefore, the inventors have developed an improved system and method for forming partial microholes in glass wafers for semiconductor substrates using a variable Bessel beam.

[0009] Further features and advantages are described in the following detailed description, which will be partially apparent to those skilled in the art from that description or will be evident by carrying out the embodiments described in the following detailed description, claims, and accompanying drawings. It should be understood that both the summary description so far and the following detailed description are illustrative and intended to provide an overview or framework for understanding the essence and features of the claims.

[0010] A first embodiment of the present disclosure includes a method comprising the step of focusing a pulsed laser beam through an optical assembly positioned in the optical path of the laser beam, on the beam-emitting side of the optical assembly, toward a laser beam focal line oriented toward the propagation direction of the laser beam, wherein the optical assembly includes an axicon lens having spherical aberration and configured to generate a laser beam focal line, a set of optical elements spaced apart from the axicon lens, and a focusing optical element spaced apart from the set of optical elements, wherein the axicon lens and the set of optical elements are movable parallel to each other along the laser beam propagation direction, and the focusing optical element is a laser The method is fixed in place along the beam propagation direction and further includes the steps of: directing a laser beam focal line into a glass material having a thickness of less than 5 mm so that the laser beam focal line causes absorption in the glass material, and the resulting absorption forms a hole along the laser beam focal line in the material; adjusting the distance between an axicon lens and a set of optical elements to adjust the depth of the laser beam focal line in the material; and moving the glass material and the laser beam in parallel with each other so that the laser drills a plurality of holes in the material, with a depth of less than half the thickness of the material, along a first plane.

[0011] A second embodiment of the present disclosure includes the first embodiment and may further include the steps of thinning a glass material to expose the first ends of a plurality of holes on at least one surface, and enlarging the plurality of holes to penetrate through the thickness.

[0012] A third embodiment of the present disclosure includes the first embodiment, wherein the distance between the axicon lens and the set of optical elements may be about 85 to about 110 mm.

[0013] A fourth embodiment of the present disclosure includes the first embodiment, wherein the distance between the set of optical elements and the focusing optical element may be about 30 to about 90 mm.

[0014] A fifth embodiment of the present disclosure comprises any one of embodiments 1 to 4, wherein the depth of the laser beam focal line in the glass material may be about 0.32 mm to about 0.98 mm.

[0015] A sixth embodiment of the present disclosure comprises any one of embodiments 1 to 5, wherein the set of optical elements may include two lenses spaced at a second distance apart.

[0016] A seventh embodiment of the present disclosure includes the sixth embodiment, wherein the second distance can range from about 1 mm to about 50 mm.

[0017] An eighth embodiment of this disclosure includes the first embodiment, which involves a step of forming a semiconductor device on the surface of a material after drilling a plurality of holes in a glass material along a first plane, It could also include...

[0018] A ninth embodiment of the present disclosure includes the eighth embodiment and may further include the step of forming a semiconductor device on the surface of a glass material, and then thinning the material to expose the openings of the holes.

[0019] A tenth embodiment of the present disclosure includes a method comprising the step of focusing a pulsed laser beam onto a laser beam focal line oriented along the propagation direction of the laser beam at the beam exit side of the optical assembly via an optical assembly positioned in the optical path of the laser beam, wherein the optical assembly includes an axicon lens, a collimating lens, and a focusing lens, the axicon lens, collimating lens, and focusing lens comprising a first set of fixed optical elements and three aspherical lenses, the first and second aspherical lenses being movable parallel to each other along the laser beam propagation direction, and the third aspherical lens being The method further includes a set of second optical elements fixed in place along the beam propagation direction, and further includes the steps of: directing a laser beam focal line into a glass material having a thickness of less than 5 mm so that the laser beam focal line causes absorption in the glass material, and the resulting absorption forms holes along the laser beam focal line in the material; adjusting the depth of the laser beam focal line in the material by adjusting the distance between a first aspherical lens and a second aspherical lens; and moving the glass material and the laser beam in parallel with each other so that the laser drills a plurality of holes in the material, with a depth of less than half the thickness of the material, along a first plane.

[0020] An eleventh embodiment of the present disclosure includes the tenth embodiment and may further include the steps of thinning a glass material to expose the first ends of a plurality of holes on at least one surface, and enlarging the plurality of holes to penetrate through the thickness.

[0021] A twelfth embodiment of the present disclosure includes the tenth embodiment, wherein the distance between the first aspherical lens and the second aspherical lens may be about 50 to about 71 mm.

[0022] A thirteenth embodiment of the present disclosure includes a tenth embodiment, wherein the distance between the second aspherical lens and the third aspherical lens may be about 31 to about 48 mm.

[0023] The 14th embodiment of the present disclosure includes the 10th embodiment, and the depth in the material of the laser beam focal line can be from about 0.43 to about 0.66 mm.

[0024] The 15th embodiment of the present disclosure includes the 10th embodiment, and may further include the step of forming a semiconductor device on the surface of the material after drilling a plurality of holes in the glass material along a first plane.

[0025] The 16th embodiment of the present disclosure includes the 10th embodiment, and may further include the step of thinning the material to expose the opening of the hole after forming a semiconductor device on the surface of the glass material.

[0026] The 17th embodiment of the present disclosure is an optical assembly including an axicon lens configured to generate a laser beam focal line from a laser beam having spherical aberration, a set of optical elements spaced apart from the axicon lens, and a focusing optical element spaced apart from the set of optical elements, wherein the axicon lens and the set of optical elements are movable relative to each other in parallel along the propagation direction of the laser beam, and the focusing optical element is in a fixed position along the propagation direction of the laser beam.

[0027] The 18th embodiment of the present disclosure includes the 17th embodiment, and the distance between the axicon lens and the set of optical elements can be from about 85 to about 110 mm.

[0028] The 19th embodiment of the present disclosure includes the 17th embodiment, and the distance between the set of optical elements and the focusing optical element can be from about 30 to about 90 mm.

[0029] The 20th embodiment of the present disclosure includes the 17th embodiment, and the set of optical elements can include two lenses spaced apart by a second distance.

[0030] The 21st embodiment of the present disclosure includes the 17th embodiment, and the second distance can be from about 1 mm to about 50 mm.

[0031] A 22nd embodiment of the present disclosure is an optical assembly comprising an axicon lens, a collimating lens, and a focusing lens, wherein the axicon lens, collimating lens, and focusing lens comprise a first set of fixed optical elements and three aspherical lenses, the first and second aspherical lenses being movable parallel to each other along the laser beam propagation direction, and the third aspherical lens comprising a second set of fixed optical elements along the laser beam propagation direction.

[0032] A 23rd embodiment of the present disclosure includes the 22nd embodiment, wherein the distance between the first aspherical lens and the second aspherical lens may be about 50 to about 71 mm.

[0033] A 24th embodiment of the present disclosure includes the 22nd embodiment, wherein the distance between the second aspherical lens and the third aspherical lens may be about 31 to about 48 mm.

[0034] The accompanying drawings are included for further understanding, are incorporated into this specification, and constitute part thereof. The drawings illustrate one or more embodiments and, together with the detailed description, serve to illustrate the principles and operation of various embodiments. Thus, this disclosure will be fully understood by reading the following detailed description together with the accompanying drawings. [Brief explanation of the drawing]

[0035] [Figure 1] This is a flowchart illustrating exemplary methods for forming microholes in a glass material according to some embodiments of the present disclosure. [Figure 2A] This is a schematic diagram illustrating the arrangement of laser beam focal lines according to some embodiments of the present disclosure, i.e., laser processing by absorption occurring along the focal lines of a material transparent to the laser wavelength. [Figure 2B] This is a schematic diagram illustrating the arrangement of laser beam focal lines according to some embodiments of the present disclosure, i.e., laser processing by absorption occurring along the focal lines of a material transparent to the laser wavelength. [Figure 3A-1]This disclosure describes various possible methods by some embodiments for processing a substrate by forming laser beam focal lines at different locations within a transparent material relative to the substrate. [Figure 3A-2] This disclosure describes various possible methods by some embodiments for processing a substrate by forming laser beam focal lines at different locations within a transparent material relative to the substrate. [Figure 3A-3] This disclosure describes various possible methods by some embodiments for processing a substrate by forming laser beam focal lines at different locations within a transparent material relative to the substrate. [Figure 3A-4] This disclosure describes various possible methods by some embodiments for processing a substrate by forming laser beam focal lines at different locations within a transparent material relative to the substrate. [Figure 4] This is a schematic diagram showing an optical assembly for laser processing according to some embodiments of the present disclosure. [Figure 5] This is a schematic diagram showing an optical assembly for laser processing according to some embodiments of the present disclosure. [Figure 6] The following are exemplary glass blanks according to several embodiments of the present disclosure. [Modes for carrying out the invention]

[0036] Herein, various embodiments of the present disclosure are described in detail, examples of which are shown in the accompanying drawings. Throughout the drawings, the same or similar reference numerals and symbols are used to refer to the same or similar parts, wherever possible. The drawings are not necessarily to scale, and those skilled in the art will notice that the drawings are simplified in order to illustrate the main embodiments of the present disclosure.

[0037] The attached claims are incorporated into and constitute part of this detailed description.

[0038] In this specification, relative terms such as first and second, top and bottom are used simply to distinguish one thing or action from another, and do not necessarily imply or require that such a relationship actually exists between such things or actions.

[0039] Those skilled in the art will see that the configurations and other components of the disclosed herein are not limited to any particular material. Unless otherwise stated herein, other exemplary embodiments of this disclosure may be formed from a wide range of materials.

[0040] Figure 1 shows a flowchart of Method 300. Method 300 includes steps 302 to 312. In step 302, a pulsed laser beam 2, as shown in Figures 2A and 2B, is focused on a laser beam focal line 2b oriented along the laser beam propagation direction at the beam output side of the optical assembly, via an optical assembly located in the laser beam path. The laser beam focal line 2b is a high-energy-density region.

[0041] As shown in Figure 2A, the laser 3 (not shown) emits a laser beam 2 having a portion 2a that is incident on the optical assembly 6. The optical assembly 6 converts the incident laser beam into a laser beam focal line 2b that extends over an expanded range (focal line length l) defined along the beam direction on the emission side.

[0042] Embodiments of this disclosure use a non-diffractive beam ("NDB") to form a laser beam focal line 2b. Typically, the laser processing uses a Gaussian laser beam. When a laser beam with a Gaussian intensity profile is precisely focused, the Rayleigh range Z is given by the following equation. R It will have:

[0043]

number

[0044] The Rayleigh range represents the distance over which the spot size w0 of a beam increases by a factor of √2 at wavelength λ0 in a material with refractive index n0. This range is limited by diffraction. Equation (1) shows that the Rayleigh range is directly related to the spot size, leading to the conclusion that a precisely focused beam (i.e., one with a small spot size) cannot have a long Rayleigh range. Such a beam will maintain this small spot size for only a very short distance. Furthermore, this means that when drilling through a material by varying the depth of the focused region using such a beam, a large area without optical distortion that can limit the beam's focusing characteristics is required to rapidly expand the spot on both sides of the focal point. Moreover, such a short Rayleigh range also requires a large number of pulses to cut through a thick sample.

[0045] However, embodiments of this disclosure use non-diffractive beams (NDBs) instead of the optical Gaussian beams described above. Non-diffractive beams can propagate over considerable distances before diffraction effects inevitably limit the beam focus state. Infinite NDBs are unaffected by diffraction effects, while physically feasible NDBs are limited in their physical range. The central lobe of a beam has a very small radius and can therefore produce a high-intensity beam. There are several types of NDBs, including, but are not limited to, Bessel beams, Airy beams, Weber beams, and Matthew beams, whose field profiles are typically given by special functions that decay more slowly than the Gaussian function in the transverse direction.

[0046] The NDB described herein refers to the case of a bessel beam, but this embodiment should be understood to be not limited thereto. The center spot size of a bessel beam is given by the following equation:

[0047]

number

[0048] However, NA is the numerical aperture given by a plane wave cone making an angle β with respect to the optical axis. The main difference between a Bessel beam and a Gaussian beam is that the Rayleigh range is given by the following equation:

[0049]

number

[0050] However, D is a finite range of the beam given by several apertures or optical elements. Therefore, it is shown that the Rayleigh range can be increased beyond the limit imposed by the central spot size using aperture size D. The actual Bessel beam generation method involves passing a Gaussian beam through an axicon or an optical element having radial linear phase elements.

[0051] Generally, the optical methods for forming a linear focus (i.e., the laser beam focal line) can take many forms, though not limited to, such as a donut-shaped laser beam with spherical lenses, axicon lenses, diffracting elements, or other methods for forming a high-intensity linear region. The type of laser (picosecond, femtosecond, etc.) and wavelength (IR, visible, UV, etc.) can also vary, as long as they reach sufficient optical intensity to create a fractured area in the substrate material.

[0052] In step 304, referring again to Figures 2A and 2B, the laser beam focal line is directed into layer 1, which is a layer of glass substrate on which internal modification and two-photon absorption occur by laser processing. Layer 1 is a component of a larger fabrication, which typically includes a substrate or carrier on which a multilayer laminate is formed. Layer 1 is a layer in a multilayer laminate on which holes, notches, or other features are formed by two-photon absorption-assisted ablation or modification, as described herein. Layer 1 is positioned in the beam path so as to at least partially overlap with the laser beam focal line 2b of the laser beam 2. Reference numeral 1a refers to the surface of layer 1 facing the optical assembly 6 or the laser (the closest or nearby surface), and reference numeral 1b refers to the opposite surface of layer 1 (farther from the optical assembly 6 or the laser, or even further away). The thickness of layer 1 (measured perpendicular to the planes 1a, 1b, i.e., the substrate plane) is denoted by d. In some embodiments, the thickness of the layer is less than 5 mm.

[0053] As shown in Figure 2A, layer 1 is aligned perpendicular to the beam longitudinal axis and therefore behind the same focal line 2b generated by the optical assembly 6 (the substrate is perpendicular to the plane of the drawing). When viewed along the beam direction, layer 1 is positioned such that the focal line 2b (viewed in the beam direction) begins ahead of the surface 1a of layer 1 and ends ahead of the surface 1b of layer 1; that is, the focal line 2b ends within layer 1 and does not extend beyond the surface 1b. In the region where the laser beam focal line 2b overlaps with layer 1, i.e., in the portion of layer 1 that overlaps with the focal line 2b, the extending laser beam focal line 2b causes nonlinear absorption in layer 1. (By properly focusing the laser beam 2 to a portion of length l (i.e., a linear focal point of length l), an appropriate laser intensity is reliably generated along the laser beam focal line 2b, defining an extended portion 2c (aligned along the longitudinal direction of the beam), and causing nonlinear absorption in layer 1 along this portion.) This nonlinear absorption causes a defect line or crack to form in layer 1 along portion 2c. The formation of the defect or crack may extend not only locally but also along the entire length of the extended portion 2c where the absorption occurred. The length of portion 2c (corresponding to the length over which the laser beam focal line 2b overlaps with layer 1) is denoted by the reference designation L. The average diameter or range of the absorbed portion 2c (or the portion of the layer 1 material where the defect line or crack was formed) is denoted by the reference designation D. This average range D may correspond to the average diameter δ of the laser beam focal line 2b, i.e., the average spot diameter in the range between approximately 0.1 μm and approximately 5 μm.

[0054] As shown in Figure 2A, layer 1 (which is transparent to the wavelength λ of laser beam 2) is locally heated by absorption along the focal line 2b. This absorption is caused by a nonlinear effect associated with the high intensity (energy density) of the laser beam within the focal line 2b. Figure 2B shows that the heated layer 1 eventually expands, and the resulting tension leads to the formation of microcracks, with the highest tension occurring at surface 1a.

[0055] Next, we describe typical optical assemblies 6 that can be used to generate focal lines 2b, and typical optical configurations that can use these optical assemblies. All assemblies or configurations are based on the above description, and the same reference numerals are used to refer to identical components or features, or those with equivalent functions. Therefore, only the differences are described below.

[0056] To ensure that the separated surface is of high quality (in terms of fracture strength, geometric accuracy, roughness, and reworkability) after a crack has formed along a contour defined by a series of holes, the individual focal lines used to form the holes defining the crack contour should be generated using the optical assembly described below (hereinafter, the optical assembly will also be referred to as the laser optical system). The roughness of the separated surface is mainly determined by the spot size or spot diameter of the focal lines. Surface roughness can be characterized, for example, by the Ra surface roughness statistic (roughness which is the arithmetic mean of the absolute values ​​of the heights of the sampled surface). When the laser 3 is of a given wavelength λ, in order to achieve a small spot size, for example, from 0.5 μm to 2 μm (in interaction with the material of layer 1), some requirements must usually be imposed on the numerical aperture of the laser assembly 6.

[0057] To achieve the required numerical aperture, the optical system must, on the one hand, have the necessary aperture for a given focal length according to the known Abbe formula (NA = nsin(θ), where n is the refractive index of the material being processed, θ is half the aperture angle, and θ = arctan(D / 2f), where D is the aperture and f is the focal length). On the other hand, the laser beam must illuminate the optical system to the required aperture, which is typically achieved by expanding the beam using a magnifying optical system between the laser and the focusing optical system.

[0058] The spot size should not vary too much for uniform interaction along the focal line. This can be ensured, for example, by illuminating the focusing optical system with only a small circular area, so that the beam aperture, and therefore the percentage of the numerical aperture, changes only slightly (see embodiments described later).

[0059] Figures 3A-1 to 3A-4 show that the position of the laser beam focal line 2b can be controlled by appropriately positioning and / or aligning the optical assembly 6 with respect to layer 1, and further by appropriately selecting the parameters of the optical assembly 6. For example, as shown in Figure 3A-1, the length l of the focal line 2b can be adjusted to exceed the layer thickness d (in this case, twice). When layer 1 is positioned centered (viewed in the beam longitudinal direction) with respect to the focal line 2b, an extended portion 2c where absorption occurs is generated over the entire substrate thickness.

[0060] As shown in Figure 3A-2, a stoichiometric line 2b with a length l approximately corresponding to the layer thickness d is generated. Since layer 1 is positioned such that the stoichiometric line 2b starts outside the material being processed (extending from the substrate surface to a defined substrate depth, but not to the opposite surface 1b), the length L of the absorbed extended portion 2c is shorter than the length l of the stoichiometric line 2b. Figure 3A-3 shows the case where layer 1 is positioned above the starting point of the stoichiometric line 2b (viewed along the beam direction), so that the length l of the stoichiometric line 2b is longer than the length L of the absorbed portion 2c in layer 1, as shown in Figure 3A-2. Therefore, the stoichiometric line starts within layer 1 and extends beyond the opposite surface 1b. Figure 3A-4 shows the case where the length l of the focal line is shorter than the layer thickness d, and when the substrate is centered relative to the focal line as viewed in the incident direction, the focal line starts near surface 1a in layer 1 and ends near surface 1b in layer 1 (e.g., l = 0.75·d). The laser beam focal line 2b may have a length l in the range of, for example, about 0.1 mm to about 100 mm, or in the range of about 0.1 mm to about 10 mm. For example, various embodiments may be configured to have a length l of, for example, about 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.7 mm, 1 mm, 2 mm, 3 mm, or 5 mm.

[0061] In some embodiments, it is particularly advantageous to position the stoichiometric line 2b such that at least one of the surfaces 1a, 1b is covered by the stoichiometric line, and the resulting nonlinear absorption portion 2c begins on at least one of the surfaces of the layer or material being processed. In this way, a substantially ideal cut can be achieved while preventing surface ablation, burrs, and the generation of fine particles.

[0062] Figure 4 shows an optical assembly 6 having a first configuration 121, a second configuration 122, or a third configuration 123. The optical assembly includes a first optical element 101 (viewed along the beam direction), which has an aspherical free surface and is positioned in the beam path of the laser 11 to form an extending laser beam focal line 2b. In some embodiments, the first optical element 101 is an axicon with a cone angle of 5° and is positioned perpendicular to the beam direction at the center of the laser beam 11. The apex of the axicon is oriented in the beam direction. The set of optical elements includes a convex lens 102a and a concave lens 102b, spaced apart from the axicon lens 101. The convex lens 102a is positioned at a distance d2 from the concave lens 102b. The set of optical elements 102a, 102b is positioned at a distance d1 from the axicon lens 101. The focusing lens 103 is separated by a distance d3 from the pair of optical elements 102a and 102b.

[0063] In step 306, as shown in Figure 4, the axicon lens 101 and the set of optical elements 102a and 102b are movable parallel to each other along the laser beam propagation direction, adjusting the depth of the laser beam focal line in the glass material (e.g., layer 1). For example, the distance between the convex lens and the concave lens 102b is increased from the first configuration 121 to the second configuration 122, and further increased from the second configuration 122 to the third configuration. The focusing lens 103 is in a fixed position along the laser beam propagation direction. Each lens is mounted on a parallel movement stage that operates independently along the optical axis. The parallel movement stage can be controlled by a PC using a motor, or manually controlled using a conventional mechanical stage or a cylindrical moving lens barrel. By changing the relative positions of the lenses, it is possible to continuously change the focal depth of the beam in the glass material. In some embodiments, the depth of the laser beam focal line in the glass material is about 0.32 mm to about 0.98 mm, preferably about 0.5 mm to about 0.98 mm, and more preferably about 0.75 mm to about 0.98 mm.

[0064] In some embodiments, the distance d1 between the axicon lens and the optical element set is about 85 to about 110 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 95 to about 110 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 100 to about 110 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 105 to about 110 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 85 to about 105 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 85 to about 100 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 85 to about 95 mm. In some embodiments, the distance d1 between the axicon lens and the optical element set is about 85 to about 90 mm.

[0065] In some embodiments, the distance d3 between the set of optical elements and the focused optical element is about 30 to about 90 mm. In some embodiments, the distance d3 between the set of optical elements and the focused optical element is about 50 to about 90 mm. In some embodiments, the distance d3 between the set of optical elements and the focused optical element is about 70 to about 90 mm. In some embodiments, the distance d3 between the set of optical elements and the focused optical element is about 30 to about 70 mm. In some embodiments, the distance d3 between the set of optical elements and the focused optical element is about 30 to about 50 mm.

[0066] In some embodiments, the distance d2 between the convex lens 102a and the concave lens 102b is about 1 mm to about 50 mm. In some embodiments, the distance d2 between the convex lens 102a and the concave lens 102b is about 15 mm to about 50 mm. In some embodiments, the distance d2 between the convex lens 102a and the concave lens 102b is about 30 mm to about 50 mm. In some embodiments, the distance d2 between the convex lens 102a and the concave lens 102b is about 45 mm to about 50 mm. In some embodiments, the distance d2 between the convex lens 102a and the concave lens 102b is about 1 mm to about 35 mm. In some embodiments, the distance d2 between the convex lens 102a and the concave lens 102b is about 1 mm to about 20 mm.

[0067] Figure 5 shows an optical assembly 6 having a first configuration 231, a second configuration 232, a third configuration 233, or a fourth configuration 234. The optical assembly includes a first set of optical elements, which includes an axicon lens 101, a collimating lens 102, and a focusing lens 103. The axicon lens 101, collimating lens 102, and focusing lens 103 are in fixed positions. Furthermore, the optical assembly includes a second set of optical elements, which includes three aspherical lenses. The first aspherical lens 111 and the second aspherical lens 112 are movable parallel to each other along the laser beam propagation direction. The third aspherical lens 113 is in a fixed position along the laser beam propagation direction. By changing the relative positions of the first aspherical lens 111 and the second aspherical lens 112, it is possible to continuously change the beam focusing depth in the glass material. In some embodiments, the depth of the laser beam focal line in the glass material is approximately 0.43 to approximately 0.66 mm.

[0068] In some embodiments, the distance d1 between the first aspherical lens and the second aspherical lens is about 50 to about 71 mm. In some embodiments, the distance d2 between the second aspherical lens and the third aspherical lens is about 31 to about 48 mm.

[0069] In step 308, the glass material (e.g., layer 1) and the optical assembly are movable parallel to each other, so that the laser drills a plurality of holes in the material along a first plane. Figure 6, 301 shows the system and method of the present disclosure, with a thickness t g The diagram shows a number of holes 254 formed in a layer 1 having a depth t, and a semiconductor device 310 disposed on a second surface of layer 1. The semiconductor device may be formed by a series of manufacturing processes, including thin film deposition, oxidation or nitration, etching, polishing, and thermal and lithographic treatments. Layer 1 has a first surface 305 (also referred to as the non-contact surface) and a second surface 306 on which the semiconductor device is formed. In some embodiments, the depth t of the holes 254 l The thickness of layer 1 is t gIt is less than half of that. In some embodiments, the depth t of the hole 254 l The thickness of layer 1 is t g It is less than 1 / 3 of the total. The upper tip of the hole 254 is located at a distance t1 from the non-contact surface 305. The lower tip of the hole 254 is located at a distance t2 from the second surface 306. In some embodiments, the holes 254 are positioned such that t1 is greater than t2. In step 310, further, referring to 302 in Figure 6, the glass material of layer 1 is thinned to expose the first ends 304 (i.e., upper tips) of the multiple holes 254. The thinning of the glass substrate can be carried out by conventional mechanical and chemical etching processes, or a combination of both. In the case of mechanical processing, the support is physically ground using an abrasive material such as diamond or SiC or a similar material until the holes are exposed. In the case of chemical processing, the support is immersed in a liquid containing HF until the holes are exposed. In the case of hybrid processing, the support is first mechanically ground, and then the support is immersed in an etching solution to complete the final step.

[0070] In step 312, further referring to 303 in Figure 6, after the thinning process, multiple holes 254 are enlarged through the thickness of the glass material of layer 1 to the second surface 306 by mechanical, thermal, or chemical enlargement. In the case of mechanical enlargement, the holes are enlarged using mechanical stress such as bending, twisting, or both. In the case of thermal enlargement, a thermal gradient is created by rapidly heating the glass material using an IR source such as a laser beam, IR radiation, or a hot plate. In the case of chemical enlargement, an etching solution is used to penetrate into the holes and create them.

[0071] Those skilled in the art will see that various modifications can be made to preferred embodiments of the disclosure described herein without departing from the spirit and scope of the disclosure set forth in the appended claims. Accordingly, the disclosure covers modifications and variations as long as they remain within the scope of the appended claims and their equivalents.

[0072] Preferred embodiments of the present invention are described below in separate sections.

[0073] Embodiment 1 In the method, The process of focusing a pulsed laser beam onto a laser beam focal line oriented along the propagation direction of the laser beam at the beam output side of the optical assembly, via an optical assembly positioned in the optical path of the laser beam, Including, the optical assembly is an axicon lens having spherical aberration and configured to generate the laser beam focal line, A set of optical elements spaced apart from the axicon lens, A focusing optical element separated from the aforementioned set of optical elements and Includes, The axicon lens and the optical element set are freely movable parallel to each other along the laser beam propagation direction. The focusing optical element is fixed in a position along the laser beam propagation direction, The aforementioned method further, The process involves directing the laser beam focal line into a glass material having a thickness of less than 5 mm, causing the laser beam focal line to absorb within the glass material, and the resulting absorption forming a hole along the laser beam focal line within the material. A step of adjusting the distance between the axicon lens and the set of optical elements to adjust the depth of the laser beam focal line in the material, The process involves moving the glass material and the laser beam in parallel with each other, thereby causing the laser to drill a plurality of holes in the material, each hole having a depth of less than half the thickness of the material, along a first plane. A method that includes this.

[0074] Embodiment 2 A step of thinning the glass material to expose the first ends of the plurality of holes on at least one surface, The process of enlarging the plurality of holes to penetrate the thickness The method according to Embodiment 1, further comprising:

[0075] Embodiment 3 The method according to Embodiment 1, wherein the distance between the axicon lens and the set of optical elements is about 85 to about 110 mm.

[0076] Embodiment 4 The method according to Embodiment 1, wherein the distance between the set of optical elements and the focusing optical element is about 30 to about 90 mm.

[0077] Embodiment 5 The method according to any one of Embodiments 1 to 4, wherein the depth of the laser beam focal line in the glass material is approximately 0.32 mm to approximately 0.98 mm.

[0078] Embodiment 6 The method according to any one of embodiments 1 to 5, wherein the set of optical elements includes two lenses separated by a second distance.

[0079] Embodiment 7 The method according to Embodiment 6, wherein the second distance is approximately 1 mm to approximately 50 mm.

[0080] Embodiment 8 The process of forming a semiconductor device on the surface of the material after drilling the plurality of holes in the glass material along the first plane is as follows: The method according to Embodiment 1 further includes.

[0081] Embodiment 9 After forming the semiconductor device on the surface of the glass material, the process of thinning the material to expose the opening of the hole is performed. The method according to Embodiment 8 further includes.

[0082] Embodiment 10 In the method, The process of focusing a pulsed laser beam onto a laser beam focal line oriented along the propagation direction of the laser beam at the beam output side of the optical assembly, via an optical assembly positioned in the optical path of the laser beam, Including, the optical assembly is The axicon lens, collimating lens, and focusing lens are a set of first optical elements that are in a fixed position. The system includes three aspherical lenses, the first and second aspherical lenses being movable parallel to each other along the laser beam propagation direction, and the third aspherical lens being a set of second optical elements fixed in the laser beam propagation direction. It includes, The aforementioned method further, The process involves directing the laser beam focal line into a glass material having a thickness of less than 5 mm, causing the laser beam focal line to absorb within the glass material, and the resulting absorption forming a hole along the laser beam focal line within the material. A step of adjusting the depth of the laser beam focal line in the material by adjusting the distance between the first aspherical lens and the second aspherical lens, The process involves moving the glass material and the laser beam in parallel with each other, thereby causing the laser to drill a plurality of holes in the material, each hole having a depth of less than half the thickness of the material, along a first plane. A method that includes this.

[0083] Embodiment 11 A step of thinning the glass material to expose the first ends of the plurality of holes on at least one surface, The process of enlarging the plurality of holes to penetrate the thickness The method according to Embodiment 10, further comprising the following:

[0084] Embodiment 12 The method according to Embodiment 10, wherein the distance between the first aspherical lens and the second aspherical lens is about 50 to about 71 mm.

[0085] Embodiment 13 The method according to Embodiment 10, wherein the distance between the second aspherical lens and the third aspherical lens is about 31 to about 48 mm.

[0086] Embodiment 14 The method according to Embodiment 10, wherein the depth of the laser beam focal line in the material is approximately 0.43 to approximately 0.66 mm.

[0087] Embodiment 15 The process of forming a semiconductor device on the surface of the material after drilling the plurality of holes in the glass material along the first plane is as follows: The method according to Embodiment 10 further includes.

[0088] Embodiment 16 After forming the semiconductor device on the surface of the glass material, the process of thinning the material to expose the opening of the hole is performed. The method according to Embodiment 10 further includes.

[0089] Embodiment 17 In optical assemblies, an axicon lens having spherical aberration and configured to generate a laser beam focal line from a laser beam, A set of optical elements spaced apart from the axicon lens, A focusing optical element separated from the aforementioned set of optical elements and Includes, The axicon lens and the optical element set are freely movable parallel to each other along the propagation direction of the laser beam. The optical assembly wherein the focusing optical element is fixed in position along the propagation direction of the laser beam.

[0090] Embodiment 18 The optical assembly according to Embodiment 17, wherein the distance between the axicon lens and the set of optical elements is approximately 85 to approximately 110 mm.

[0091] Embodiment 19 The optical assembly according to Embodiment 17, wherein the distance between the set of optical elements and the focusing optical element is about 30 to about 90 mm.

[0092] Embodiment 20 The optical assembly according to embodiment 17, wherein the set of optical elements includes two lenses spaced apart by a second distance.

[0093] Embodiment 21 The optical assembly according to Embodiment 20, wherein the second distance is approximately 1 mm to approximately 50 mm.

[0094] Embodiment 22 In optical assemblies, The axicon lens, collimating lens, and focusing lens are a set of first optical elements that are in a fixed position. It includes three aspherical lenses, the first and second aspherical lenses being freely movable parallel to each other along the laser beam propagation direction, and the third aspherical lens being a set of second optical elements fixed in the laser beam propagation direction. Optical assembly including.

[0095] Embodiment 23 The optical assembly according to Embodiment 22, wherein the distance between the first aspherical lens and the second aspherical lens is about 50 to about 71 mm.

[0096] Embodiment 24 The optical assembly according to Embodiment 22, wherein the distance between the second aspherical lens and the third aspherical lens is about 31 to about 48 mm. [Explanation of Symbols]

[0097] 1 layer 2 laser beams 2b Caustic line 6. Optical Assembly 101 Axicon Lens 102 Collimating Lens 103 Focusing Lens

Claims

1. In the method, The process of focusing a pulsed laser beam onto a laser beam focal line oriented along the propagation direction of the laser beam at the beam output side of the optical assembly, via an optical assembly placed in the optical path of the pulsed laser beam, Including, the optical assembly is an axicon lens having spherical aberration and configured to generate the laser beam focal line, A set of optical elements spaced apart from the axicon lens, A focusing optical element separated from the aforementioned set of optical elements and Includes, The axicon lens and the optical element set are freely movable parallel to each other along the laser beam propagation direction. The focusing optical element is fixed in a position along the laser beam propagation direction, The aforementioned method further, The process involves directing the laser beam focal line into a glass material having a thickness of less than 5 mm, causing the laser beam focal line to absorb within the glass material, and the resulting absorption forming a hole along the laser beam focal line within the glass material. A step of adjusting the depth of the laser beam focal line in the glass material by adjusting a first distance between the axicon lens and the set of optical elements, A step of moving the glass material and the pulsed laser beam in parallel to each other, thereby causing the laser to drill a plurality of holes in the glass material along a first plane, wherein the depth of the plurality of holes is less than half the thickness of the glass material. A step of thinning the glass material so that the first ends of the plurality of holes are exposed on at least one surface of the glass material. A method that includes this.

2. The method according to claim 1, wherein the first distance between the axicon lens and the set of optical elements is about 85 to about 110 mm.

3. The method according to claim 1, wherein the second distance between the set of optical elements and the focusing optical element is about 30 to about 90 mm.

4. The method according to any one of claims 1 to 3, wherein the depth of the laser beam focal line in the glass material is about 0.32 mm to about 0.98 mm.

5. In the method, The process of focusing a pulsed laser beam onto a laser beam focal line oriented along the propagation direction of the laser beam at the beam output side of the optical assembly, via an optical assembly placed in the optical path of the pulsed laser beam, Including, the optical assembly is The axicon lens, collimating lens, and focusing lens are a set of first optical elements that are in a fixed position. The system includes three aspherical lenses, the first and second aspherical lenses being freely movable parallel to each other along the laser beam propagation direction, and the third aspherical lens comprising a set of second optical elements fixed in the laser beam propagation direction. It includes, The aforementioned method further, The process involves directing the laser beam focal line into a glass material having a thickness of less than 5 mm, causing the laser beam focal line to absorb within the glass material, and the resulting absorption forming a hole along the laser beam focal line within the glass material. A step of adjusting the depth of the laser beam focal line in the glass material by adjusting the first distance between the first aspherical lens and the second aspherical lens, A step of moving the glass material and the pulsed laser beam in parallel to each other, thereby causing the laser to drill a plurality of holes in the glass material along a first plane, wherein the depth of the plurality of holes is less than half the thickness of the glass material. A step of thinning the glass material so that the first ends of the plurality of holes are exposed on at least one surface of the glass material. A method that includes this.

6. The method according to claim 5, wherein the first distance between the first aspherical lens and the second aspherical lens is about 50 to about 71 mm.

7. The method according to claim 5, wherein the second distance between the second aspherical lens and the third aspherical lens is about 31 to about 48 mm.

8. The method according to claim 5, wherein the depth of the laser beam focal line in the glass material is about 0.43 to about 0.66 mm.

9. The glass material has a first surface, and is configured such that a semiconductor device is formed on the first surface before the step of thinning the glass material. The method according to any one of claims 1 to 8, wherein at least one surface of the thinned glass material is opposite to the first surface.

10. The method according to claim 9, further comprising the step of expanding the plurality of holes toward the first surface in the thickness direction of the glass material.

11. Before the step of thinning the glass material, The glass material has a second surface on the opposite side of the first surface, The first ends of the plurality of holes are located at a first depth from the first surface of the glass material. The second ends of the plurality of holes are located at a second depth from the second surface of the glass material. The second depth from the second surface of the glass material is greater than the first depth from the first surface of the glass material. The method according to claim 9.

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