Fluidic devices with slots

Abstract

A method of forming a fluidic device includes providing a substrate including a first layer, a second layer, and a third layer. The first layer includes a target region. The method includes forming a pattern on the third layer such that the pattern is offset from the target region along a first axis, performing, using a laser, a first etching on the second layer to remove a portion of the second layer, and performing a second etching on a portion removed by the first etching to form a slot. The slot includes a first sidewall disposed at a first angle with respect to the first layer and a second sidewall facing the first sidewall and disposed at a second angle with respect to the first layer, the second angle asymmetric to the first angle with respect to a second axis perpendicular to the first axis.

Description

FLUIDIC DEVICES WITH SLOTSBACKGROUND

[0001] Microfabrication and micromachining processes can refer to processes in which micrometer scale or smaller structures and devices can be formed. For example, microfluidic systems correspond to various microstructures which can be implemented in microfluidic devices. As another example, microfluidic devices, such as fluid ejection devices, can correspond to devices of a micrometer or smaller scale that convey, dispense, and / or process small amounts (e.g., microliters, picoliters, etc.) of fluid substances.BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Non-limiting examples of the present disclosure are described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. Unless indicated as representing the background art, the figures represent aspects of the disclosure. For purposes of clarity, not every component can be labeled in every drawing. In the drawings:

[0003] FIG. 1 shows a cross-sectional view of an example structure.

[0004] FIG. 2 shows a flowchart of an example process.

[0005] FIG. 3 shows a flow diagram of an example process.

[0006] FIGS. 4 A, 4B, 4C, and 5 show cross-sectional views of example structures associated with the process of FIG. 3.

[0007] FIG. 6 and FIG. 7 show cross-sectional views of example structures.DETAILED DESCRIPTION

[0008] A fluidic device (e.g., a fluid ejection device, a fluid processing device such as a fluid sensor, etc.) can include a slot (e.g., a fluid handling slot) fluidically connected with a fluid channel, a fluid hole, etc. The slot can be designed to facilitate the control of fluid in the fluidic device. For example, the slot in a fluidic device can be designed to regulate fluid (e.g., ink, analytes, etc.) in the fluidic device (e.g., distribution, pressure, flow, etc. of thefluid), thereby enabling an improved (e.g., uniform, consistent, etc.) ejection and / or processing of the fluid and thus improving the performance.

[0009] The present disclosure provides techniques for forming the slots having various features. According to this disclosure, a mask pattern and / or an etching pattern can be intentionally misaligned with a target region (e.g., a fluid feed hole), and a hybrid process (e.g., a laser etching and a wet etching) can be performed to create different slot features. By misaligning the mask pattern and / or etching pattern in various ways, and selecting different etchants, the shape, dimensions, and other characteristics of the slots can be customized. For example, tilted and / or angled microfluidic paths can be formed within the slot. While such a tilted and / or angled path could be formed by tilting a substrate for the fluidic device, the techniques disclosed herein enable these features without relying on tilting, thereby reducing manufacturing complexity and costs. In addition, the techniques disclosed herein can be used to achieve a tapered design and a fanout array between tightly pitched MEMS and fluidic architectures for a larger manifold system on the supply side.

[0010] Reference is now made to the figures. Although the figures and aspects of the disclosure can show or describe structures herein as having a particular shape, it should be understood that such shapes are merely illustrative and should not be considered limiting to the scope of the techniques described herein. For example, the techniques described herein can be implemented in any shape or geometry for any material or layer to achieve desired results.

[0011] FIG. 1 shows a cross-sectional view of an example structure 100. In some examples, the structure 100 can be a microfluidic structure of a microfluidic device. The structure 100 can include a first layer 110 and a second layer 120. The first layer 110 can include a fluid feed hole 112. The second layer 120 can include a slot 122. Shown in FIG. l is a nonlimiting example of the structure 100. In some examples, the structure 100 can include more, fewer, or different components than shown in or described with respect to FIG. 1.

[0012] In some examples, the slot 122 can be a fluid handling slot of a fluidic device (e.g., a fluid ejection device, a fluid processing device, etc.). The slot 122 can receive and / or contain fluid (e.g., ink). The slot 122 can be fluidically connected with the fluid feed hole 112 and provide the fluid through the fluid feed hole 112 for a downstream process (e.g.,ejection of the fluid). For example, the fluid feed hole 112 can be fluidically connected with a nozzle to eject the fluid.

[0013] In some examples, the slot 122 can include a first sidewall 124 and a second sidewall 126. The second sidewall 126 can face the first sidewall 124. The line mO defines the middle points between the first sidewall 124 and the second sidewall 126, and of the fluid feed hole 112. In some examples, as shown, the first sidewall 124 and the second sidewall 126 can be formed such that the line mO is continuous from a top of the first layer 110 to a bottom of the second layer 120.

[0014] In some examples, the first sidewall 124 can include a plurality of sidewall portions al-a4. In some examples, each of the plurality of sidewall portions al-a4 can be disposed at a different angle with respect to the first layer 110. For example, the sidewall portion al can be disposed at an angle hl, the sidewall portion a2 can be disposed at an angle h2, the sidewall portion a3 can be disposed at an angle h3, and the sidewall portion a4 can be disposed at an angle h4. In some examples, two or more of the sidewall portions al-a4 can be disposed at a same angle (not shown). Although depicted as including four sidewall portions, the first sidewall 124 can include more, fewer, or different sidewall portions.

[0015] In some examples, the second sidewall 126 can include a plurality of sidewall portions bl -b3. In some examples, each of the plurality of sidewall portions bl-b3 can be disposed at a different angle with respect to the first layer 110. For example, the sidewall portion bl can be disposed at an angle j 1, the sidewall portion b2 can be disposed at an angle j2, and the sidewall portion b3 can be disposed at an angle j3. In some examples, two or more of the sidewall portions bl-b3 can be disposed at a same angle (not shown).Although depicted as including three sidewall portions, the second sidewall 126 can include more, fewer, or different sidewall portions.

[0016] As discussed herein, the angles (e.g., the angles hl-h4, j l-j3, etc.) can be associated with a crystalline plane of material for the second layer 120 and / or an etchant used for etching the second layer 120. In some examples, when silicon is used for the second layer 120, the angles can be formed based on the crystal orientation (e.g., (100), (110), (111) planes) and the etching process. For example, when the second layer 120 (e.g., silicon) is etched along the (100) plane with a wet etching process (e.g., potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH), etc.), one of the angles can be associated withthe (100) plane (e.g., approximately 54.7 degrees for silicon). When the second layer 120 (e.g., silicon) is etched along the (110) plane, one of the angles can be associated with the (110) plane (e.g., vertical sidewalls with 90 degrees for silicon). When the second layer 120 (e.g., silicon) is etched along the (111) plane, the etching process can be slower compared with the other planes, which can be utilized to manipulate the shapes, angles, etc. of the slot 122. Accordingly, various designs of the slot 122 can be achieved based on the material selection and etching processes. Non limiting examples of such designs and / or features of the slot 122 are discussed below.

[0017] In some examples, the second sidewall 126 (and / or the first sidewall 124) can include a bottom portion (e.g., the sidewall portion b3) disposed at a predetermined angle associated with the crystalline plane and / or the etchant (e.g., 45 degrees or less). In some examples, the second sidewall 126 (and / or the first sidewall 124) can include a top portion (e.g., the sidewall portion bl) disposed at a predetermined angle associated with the crystalline plane and / or the etchant (e.g., 45 degrees or less). In some examples, the slot 122 can include any angled features (e.g., the sidewalls 124, 126, etc.) that can be formed based on the etching chemistry as discussed herein and / or alignment with the crystalline orientation (e.g., of the second layer 120) thereof. For example, any changes between the angles (e.g., the angles hl-h4, the angles j 1-j 3, etc.) can be implemented based on the alignment with different crystalline planes, without departing from the scope of the present disclosure.

[0018] In some examples, the first sidewall 124 can include a sidewall portion that can have a same angle (e.g., a same magnitude but opposite direction) with a sidewall portion of the second sidewall 126. For example, the sidewall portion a3 can be disposed at the angle h3, which can be the same as the angle j2 at which the sidewall portion b2 is disposed.

[0019] In some examples, the first sidewall 124 and the second sidewall 126 can be formed such that the slot 122 has an asymmetric shape. The slot 122 can be asymmetric such that at least one of a plurality of portions of the first sidewall 124 differs in a shape, a length, or an angle compared to at least one of a plurality of portions of the second sidewall 126. For example, the sidewall portions al-a4 can be asymmetric to the sidewall portions bl-b3, in a length, an angle, a shape, etc., with respect to the y-axis.

[0020] In some examples, a sidewall portion of the first sidewall 124 can be disposed at an angle different from an angle at which a corresponding sidewall portion of the second sidewall 126 is disposed. For example, the sidewall portion al of the first sidewall 124 can be disposed at the angle hl different from the angle j l at which the sidewall portion bl (which the sidewall portion al faces in part) of the second sidewall 126 is disposed.

[0021] In some examples, a sidewall portion of the first sidewall 124 can have a length different from a length of a corresponding sidewall portion of the second sidewall 126. For example, the sidewall portion al of the first sidewall 124 can have a vertical length (e.g., along the y-axis) different from a vertical length of the sidewall portion bl (which the sidewall portion al faces in part) of the second sidewall 126. As shown, the sidewall portion bl can be longer in the y-axis than the sidewall portion al, and thus can face a portion of the sidewall portion a2 as well as the sidewall portion al. In some examples, a sidewall portion of the second sidewall 126 can face any number of sidewall portions of the first sidewall 124 having different angles (e.g., the angles hl, h2, etc.). In some examples, a width (e.g., along the x-axis and / or the z-axis) of the slot 122 can vary along the y-axis. For example, a width at a top portion of the slot 122 can be smaller or larger than a width at a bottom portion of the slot 122.

[0022] In some examples, a portion of the slot 122 can be offset from the fluid feed hole 112. As indicated by the line mO, the slot 122 can have a shape shifted and / or offset (e.g., along the x-axis) from the fluid feed hole 112, through the bottom portion of the slot 122. For example, a bottom opening, a middle point (e.g., in the y-axis), a top opening, etc. of the slot 122 can be shifted and / or offset from the fluid feed hole 112.

[0023] The slot 122 shown in FIG. 1 is a non-limiting example. It should be understood that the slot 122 can include any various details (e.g., shapes, dimensions, angles, etc.) that can result from the processes described with respect to FIG. 2 to FIG. 5 and / or that can be or include the structures described with respect to FIG. 6 and FIG. 7. For example, the slot 122 can include any asymmetric features that can result from the processes described with respect to FIG. 2 to FIG. 5 without departing from the spirit and scope of this disclosure.

[0024] FIG. 2 shows a flowchart of an example process 200. FIG. 3 shows a flow diagram300 of an example process (e.g., the process 200). The process 200 can be associated with an example structure at various fabrication stages shown in FIG. 3. The process 200 and theflow diagram 300 can be associated with the structure 100. For example, the process 200 and the flow diagram 300 illustrate the process for fabricating the structure 100. It is noted that the process 200 and the flow diagram 300 are non-limiting examples. Accordingly, it should be understood that additional operations and / or flows can be provided before, during, or after any of the process 200 and / or any of the flow diagram 300, that any of the process 200 and / or any of the flow diagram 300 can be omitted, and that some other operations or flow diagrams can be briefly described herein.

[0025] While each of these process blocks will be described in greater detail hereinafter, in a brief overview, the process 200 can start with operation 210 of providing a substrate including a first layer, a second layer, and a third layer, wherein the first layer includes a target region. The process can continue to operation 220 of forming a pattern on the third layer such that the pattern is offset from the target region along a first axis. The process 200 can continue to operation 230 of performing, using a laser, a first etching on the second layer to remove a portion of the second layer. The process 200 can continue to operation 240 of performing a second etching on a portion removed by the first etching to form a slot, the slot including asymmetric sidewalls.

[0026] At operation 210 of FIG. 2, a structure 31 of FIG. 3 can be provided. The structure 31 can be a substrate including a first layer 310, a second layer 320, and a third layer 330. The first layer 310 can be associated with the first layer 110. In some examples, the first layer 310 can include a target region 312. In some examples, as shown, the target region 312 can be a fluid feed hole (e.g., the fluid feed hole 112). For example, the substrate can be provided with the fluid feed hole formed therein, or the fluid feed hole can be formed prior to, for example, forming a pattern 321. In some examples, the target region 312 can be a region that is to be formed for a fluid feed hole (e.g., the fluid feed hole 112) in a downstream process. For example, although the target region 312 is depicted as having a hole (e.g., a fluid feed hole), the target region 312 can be processed (e.g., etched, etc.) to form the fluid feed hole in a downstream process (e.g., at operation 210 or later). In some examples, the first layer 310 can be or include SU8. As shown, the line ml defines the middle points of the target region 312. In some examples, the target region 312 can have a width (e.g., in the x-axis) of 50 to 150 pm. The second layer 320 can be associated with the second layer 120. For example, the second layer 120 is where a slot (e.g., the slot 122 is to be formed). In some examples, the second layer 320 can be or include silicon, etc. The thirdlayer 330 can be a mask layer to protect the second layer 320. In some examples, the third layer 330 can be a hard mask layer, including but not limited to, silicon nitride, silicon carbide, hafnium oxide, etc.

[0027] At operation 220 of FIG. 2, a structure 32 of FIG. 3 can be formed, in which a pattern 321 on the third layer 330 can be formed. In some examples, the pattern 321 can be formed by removing a portion of the third layer 330. For example, the portion of the third layer 330 corresponding to the pattern 321 can be etched. Various etching techniques can be used to form the pattern 321, including but not limited to, photolithography, dry etching, etc. In some examples, a portion of the second layer 320 corresponding to the pattern 321 can be removed along with the formation of the pattern 321, as shown in FIG. 3. For example, the portion of the second layer 320 corresponding to the pattern 321 can be etched along with the formation of the pattern 321. In some examples, the pattern 321 can have a width (e.g., in the x-axis) of 250 to 350 pm. In some examples, the pattern 321 can be referred to as a “hard mask cut.” As shown, the line m3 defines the middle points of the pattern 321 (and / or of the hard mask cut).

[0028] The pattern 321 can be formed such that the pattern 321 is offset from the target region 312 along a first axis (e.g., the x-axis). In some examples, the pattern 321 can be formed such that the line m3 is offset from the line ml along the x-axis. That is, the pattern 321 and the target region 312 can be misaligned by an offset si along the x-axis. In some examples, the offset si can range from 30 pm to 300 pm. For example, the offset si can be 45 pm, 60 pm, 110 pm, 150 pm, 230 pm, etc.

[0029] At operation 230 of FIG. 2, a structure 33 of FIG. 3 can be formed, in which a first etching is performed on the second layer 320 to remove a portion 331 of the second layer 320. In some examples, the first etching can be or include a laser etching, and a laser can be applied to the second layer 320 to remove the portion 331 of the second layer 320. In some examples, the laser can be applied to the second layer 320 at normal incidence. In some examples, the portion 331 removed by the first etching can be referred to as a “laser trench.” As shown, the line m2 defines the middle points of the portion 331 (and / or of the laser trench). In some examples, the laser can be applied to the second layer 320 with the third layer 330 serving as a mask. For example, when a width of the laser is smaller than the pattern 321, the laser can be applied to the second layer 320 through the pattern 321. In some examples, the structure 33 can be formed by etching the portion 331 using differentprocesses than lasers. For example, the portion 331 can be directionally etched using photo lithography patterning and dry etching processes.

[0030] In some examples, as shown, the first etching can be performed such that the target region 312 is aligned with the portion 331. For example, the first etching can be performed such that the line ml is aligned with the line m2. Since the portion 331 is aligned with the target region 312, the portion 331 can be offset from the pattern 321 (e.g., the line m2 can be offset from the line m3) by an offset si', which can be the same as the offset si.

[0031] In some examples, the first etching can be performed until a thin portion 335 is left. For example, a duration of the laser application can be controlled such that a predetermined depth of the portion 331 can be removed. In some examples, the first etching can be performed to remove the thin portion 335. In some examples, the first etching can be performed such that the portion 331 can be formed with a predetermined shape, dimension, etc. In some examples, the portion 331 can include a plurality of portions. One of the plurality of portions can be aligned with the target region 312, while another one of the plurality of portions can have a different shape, dimension, etc. In some examples, the portion 331 can be formed by applying the laser multiple times, and each of the laser can be different in a width, a duration, a power, etc.

[0032] At operation 240 of FIG. 2, a structure 34 of FIG. 3 can be formed, in which a second etching is performed on the portion 331 and / or the pattern 321 to form a slot 322. In some examples, the second etching can be performed on the second layer 320 (e.g., the portion 331, the pattern 321, etc.) with the third layer 330 serving as a mask to etch a portion of the second layer 320. As shown in FIG. 3, in forming the structure 34, an additional portion of the second layer 320 is removed from the structure 33. In some examples, the second etching can be or include a wet etching (e.g., KOH, TMAH, etc. for silicon). For example, the additional portion of the second layer 320 can be selectively etched without affecting the first layer 310 or the third layer 330.

[0033] In some examples, at operation 240, the angles (e.g., the angles hl-h4, j 1 -j 3 , etc. shown in FIG. 1) formed in the slot 322 can be associated with a crystalline plane of material for the second layer 320 and / or an etchant used for etching the second layer 320. In some examples, when silicon is used for the second layer 320, the etching process can be performed based on the crystal orientation (e.g., (100), (110), (111) planes) and the etchants.For example, at operation 240, the second layer 320 (e.g., silicon) can be etched along the (100) plane with etchants (e.g., KOH, TMAH, etc.) to form a first corresponding angle associated with the crystal orientation. Likewise, the second layer 320 (e.g., silicon) can be etched along the (110) plane with etchants (e.g., KOH, TMAH, etc.) to form a second corresponding angle associated with the crystal orientation. The second layer 320 (e.g., silicon) can be etched along the (111) plane to form a third corresponding angle associated with the crystal orientation.

[0034] The set of etching, including the first etching (e.g., laser) and the second etching (e.g., wet), can form the slot 322. As discussed with respect to FIG. 1, the slot 322 can include various shapes, dimension, etc. In some examples, the slot 322 can have an asymmetric shape with respect to an axis (e.g., the y-axis or the lines ml, m2). In some examples, the slot 322 can include a first sidewall disposed at a first angle with respect to the first layer 310 and a second sidewall facing the first sidewall and disposed at a second angle with respect to the first layer 310. In some examples, the second angle can be asymmetric to the first angle with respect to an axis (e.g., the y-axis or the lines ml, m2).

[0035] As shown, in some examples, the application of the laser at normal incidence can form the slot 322 with an angled and / or asymmetric shape. For example, the laser applied at normal incidence and the second etching on the portion removed by the laser etching can form a surface angled with respect to the first layer 310. That is, the slot 322 having an angled and / or asymmetric shape can be formed without tilting the laser relative to a substrate (e.g., the structure 33). Since the angled and / or asymmetric shape can be achieved without manipulating the substrate and / or the laser (e.g., the incidence angle, etc.), this can provide a cost-efficient solution in device manufacturing with reduced complexity.

[0036] In some examples, referring to the structure 34, the slot 322 can be formed such that the slot 322 is offset from the target region 312 (e.g., the line m2 is shifted from the line ml), after the second etching. Since the third layer 330 is misaligned from the second layer 320, and / or the portion 331 can be asymmetric, the second etching can etch the second layer 320 asymmetrically. For example, although depicted as aligned with the line ml, the line m2 can be shifted or offset from the line ml after the second etching.

[0037] As discussed below, in addition to the misalignment between the third layer 330 and the second layer 320, the second layer 320 can be misaligned with the first layer 310. Insome other examples, at operation 230, a structure 35 of FIG. 3 can be formed similar to the structure 33. As opposed to the structure 33, in the structure 35, the first etching (e.g., laser etching as discussed above) can be performed on the second layer 320 such that a removed portion 351 (and / or a laser trench) is offset from the target region 312 along the x-axis. As shown, the line m2' defines the middle points of the portion 351 (and / or of the laser trench). In some examples, as shown in the structure 35, the first etching can be performed such that the line ml is misaligned with (e.g., offset from) the line m2' along the x-axis. For example, the laser can be applied along the line m2' to remove the portion 351. Since the portion 351 is offset from the target region 312 by an offset s2, and the portion 351 is offset from the pattern 321 by an offset si', the target region 312 can be offset from the pattern 321 by an offset sl'+s2. In some examples, the offset s2 can range from 10 pm to 50 pm. For example, the offset s2 can be 20 pm, 40 pm, etc.

[0038] At operation 240 of FIG. 2, a structure 36 of FIG. 3 can be formed, in which the second etching is performed on the portion 351 and / or the pattern 321 to form the slot 342. In some examples, the second etching can be performed on the second layer 320 (e.g., the portion 351, the pattern 321, etc.) with the third layer 330 serving as a mask to etch a portion of the second layer 320. As shown in FIG. 3, in forming the structure 36, an additional portion of the second layer 320 is removed from the structure 35. In some examples, the second etching can be or include a wet etching. For example, the additional portion of the second layer 320 can be selectively etched without affecting the first layer 310 or the third layer 330.

[0039] The set of etching, including the first etching (e.g., laser) and the second etching (e.g., wet), can form the slot 342. As discussed with respect to FIG. 1, the slot 342 can include various shapes, dimension, etc. In some examples, the slot 342 can have an asymmetric shape with respect to an axis (e.g., the y-axis or the lines ml, m2'). In some examples, the slot 342 can include a first sidewall disposed at a first angle with respect to the first layer 310 and a second sidewall facing the first sidewall and disposed at a second angle with respect to the first layer 310. In some examples, the second angle can be asymmetric to the first angle with respect to an axis (e.g., the y-axis or the lines ml, m2').

[0040] As shown, in some examples, the application of the laser at normal incidence can form the slot 342 with an angled and / or asymmetric shape. For example, the laser applied at normal incidence and the second etching on the portion removed by the laser etching canform a surface angled with respect to the first layer 310. That is, the slot 342 having an angled and / or asymmetric shape can be formed without tilting the laser relative to a substrate (e.g., the structure 35). Since the angled and / or asymmetric shape can be achieved without manipulating the substrate and / or the laser (e.g., the incidence angle, etc.), this can provide a cost-efficient solution in device manufacturing with reduced complexity.

[0041] In addition to the description with respect to FIG. 3, the first etching (e.g., to form the structure 33 of FIG. 3) can include various etching processes (e.g., multiple laser etching processes), for example, as discussed below.

[0042] FIG. 4 A to FIG. 4C show cross-sectional views of example structures 41, 42, and 43 associated with the process 200 of FIG. 2 and / or the flow diagram 300 of FIG. 3. More specifically, the structures 41, 42, and 43 can be examples of the structure 33 formed by operation 230 (e.g., the first etching discussed with respect to FIG. 3). As shown, each of the structures 41, 42, and 43 can include a target region 412, a hard mask cut 421, and a laser trench 441 (collectively 441, separately, the laser trenches 441 A, 441B, and 441C), which can be substantially similar to or incorporate features of the target region 412, the pattern 321, and the portion 331, respectively.

[0043] Referring to FIG. 4 A, the structure 41 can include the laser trench 441 A. The laser trench 441 A can include a first trench T1 and a second trench T2. In some examples, at operation 230, the laser trench 441 A can be formed by applying the laser multiple times. For example, a first laser can be applied to form the first trench Tl, and a second laser can be applied to form the second trench T2. In some examples, each of the lasers can be different in a width, a duration, a power, etc. For example, the first laser can be applied to form the first trench Tl, while the second laser with a larger width can be applied to form the second trench T2. In some examples, each of the trench Tl and the trench T2 can be aligned with the target region 412. As shown, the line m2 (e.g., the middle points of the trench Tl and the T2) can be aligned with the line ml (e.g., the middle points of the target region 412).

[0044] Referring to FIG. 4B, the structure 42 can include the laser trench 441B. The laser trench 441B can include a first trench Tl and a second trench T2. In some examples, at operation 230, the laser trench 441B can be formed by applying the laser multiple times. For example, a first laser can be applied to form the first trench Tl, and a second laser can beapplied to form the second trench T2. In some examples, each of the laser can be different in a width, a duration, a power, etc. For example, the first laser can be applied to form the first trench Tl, while the second laser with a larger width can be applied to form the second trench T2.

[0045] In some examples, one of the trenches (e.g., the first trench Tl) can be aligned with the target region 412, while another one of the trenches (e.g., the second trench T2) is offset from the target region 412. In some examples, as shown, the second trench T2 can be offset from the first trench Tl along the x-axis. That is, the line m2 (the middle point of the first trench Tl) can be aligned with the line ml, whereas the middle point line (not shown) of the trench T2 is offset from the line ml (and the m2) along the x-axis. In some examples, the second trench T2 can be formed such that the laser trench 44 IB has an asymmetric shape (e.g., asymmetric with respect to the line m2). As shown in FIG. 4B, in some examples, while the second trench T2 is offset from the target region 412, the second trench T2 can have a symmetric shape (e.g., with respect to its own middle point line). In some examples, while the second trench T2 is offset from the target region 412, the second trench T2 can have an asymmetric shape (e.g., with respect to its own middle point line).

[0046] Referring to FIG. 4C, the structure 43 can include the laser trench 441C. The laser trench 441C can include a first trench Tl, a second trench T2, and a third trench T3. In some examples, at operation 230, the laser trench 441C can be formed by applying the laser multiple times. For example, a first laser can be applied to form the first trench Tl, a second laser can be applied to form the second trench T2, and a third laser can be applied to form the second trench T3. In some examples, each of the laser can be different in a width, a duration, a power, etc. For example, the first laser can be applied to form the first trench Tl, while the second laser with a larger width can be applied to form the second trench T2, and the third laser with a reduced duration and / or a reduced power can be applied to form the third trench T3 (e.g., shorter in length compared to the second trench T2).

[0047] In some examples, the second trench T2 and the third trench T3 can be formed such that the laser trench 441C has an asymmetric shape (e.g., asymmetric with respect to the line m2 (the middle point line of the first trench Tl)). In some examples, the first trench Tl can be aligned with the target region 412, while the second trench T2 and the third trench T3 are offset from the target region 412 along the x-axis.

[0048] Shown in FIG. 4A to FIG. 4C are non-limiting examples, and any variation thereof can be implemented to form the laser trenches 441 A, 441B, and 441C. In some examples, any number of laser trenches can be formed, with different powers, widths, duration, etc. of the laser. As with FIG. 4A to FIG. 4C, which describe several non-limiting examples of the structure 33, FIG. 5 discusses non-limiting examples of the structure 35 . The first etching (e.g., to form the structure 35 of FIG. 3) can include various etching processes (e.g., multiple laser etching processes), for example, as discussed below.

[0049] FIG. 5 shows a cross-sectional view of an example structure 51 associated with the process 200 of FIG. 2 and / or the flow diagram 300 of FIG. 3. More specifically, the structure 51 can be an example of the structure 35 formed by operation 230. As shown, the structure 51 can include a target region 512, a hard mask cut 521, and a laser trench 541, which can be substantially similar to or incorporate features of the target region 312, the pattern 321, and the portion 351, respectively.

[0050] Referring to FIG. 5, the structure 51 can include the laser trench 541. The laser trench 541 can include a first trench T1 and a second trench T2. In some examples, at operation 230, the laser trench 541 can be formed by applying the laser multiple times such that the laser trench 541 is offset from the target region 512. A first laser can be applied to form the first trench T1 such that the first trench T1 is offset from the target region 512 by a first offset, and a second laser can be applied to form the second trench T2 such that the second trench T2 is offset from the target region 512 by a second offset. In some examples, the first offset can be the same as the second offset (e.g., as shown in FIG. 5) such that the middle point lines (e.g., the line m2) of the first trench T1 and of the second trench T2 are aligned to each other. In some examples, although not shown, the first offset can be different from the second offset such that the middle point line (e.g., the line m2) of the first trench T1 is offset from the middle point line of the second trench T2 are aligned to each other. In some examples, each of the laser can be different in a width, a duration, a power, etc. For example, the first trench T1 and the second trench T2 can be formed such that the laser trench 541 has an asymmetric shape with respect to the line m2 (e.g., the middle point line of the first trench Tl), as discussed with respect to FIG. 4B and FIG. 4C.

[0051] As discussed above, the slots (e.g., the slots 122, 322, 342, etc.) can be formed by various processes (e.g., the process 200). The description and figures below provide variousnon-limiting examples of the slots, and any variation thereof can be implemented without departing from the spirit and scope.

[0052] FIG. 6 shows cross-sectional views of example structures. In some examples, shown in FIG. 6 are the structures that can be formed by the process 200 of FIG. 2. As shown in FIG. 6, each of the structures can include a slot (e.g., 60A-60N).

[0053] In some examples, the first column of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, without the offset s2; the second column of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset s2 of xl (e.g., 20 pm); and the third column of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset s2 of x2 (e.g., 40 pm). In some examples, the first row of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset si of yl (e.g., 45 pm); the second row of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset si of y2 (e.g., 61 pm); the third row of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset si of y3 (e.g., 112 pm); the fourth row of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset si of y4 (e.g., 152 pm); the fifth row of FIG. 6 corresponds to the structures formed by the process 200 of FIG. 2, with the offset si of y5 (e.g., 228 pm).

[0054] The structures shown in FIG. 6 can have slots including various features, for example those discussed with respect to FIG. 1. The slots can be formed and / or designed based on the processes discussed herein (e.g., the process 200) to have certain features to enable manipulation of fluid. In some examples, as shown, shapes (e.g., the x-axis shape, the y-axis shape), dimensions, etc. of the slot can be controlled based on the offset si and the offset s2. In some examples, the structures (e.g., 60C, 60F, 601, etc.) can have the slots with a shelf structure 610. For example, the shelf structure 610 can be formed when a portion of the shelf structure 610 has a non-etchable surface of a crystalline plane that allows for slower etching of the surface (e.g., the (111) plane). In some examples, the structures (e.g., 60M, 60N, etc.) can have the slots with a step-like structure 620. The steplike structure 620 can have a sidewall portion disposed at a first angle (e.g., 45 degrees or less) with respect to the x-axis. The step-like structure 620 can have an end portion disposed at a second angle (e.g., 60 degrees or greater). The step-like structure 620 can be utilized to manipulate fluid in the slot and / or improve the fluid flow. For example, when air is injected into the slot through the step-like structure 620, the step-like structure 620 can provide anextended area of continuous, positive growth to assist the air bubble to move out of the slot. This improves the fluid flow, because if the bubble remains in the slot, additional bubbles can be accumulated more easily, and thus can stop the fluid flow, which makes the slot and / or the fluid path no longer usable or recoverable.

[0055] FIG. 7 shows cross-sectional views of example structures. In some examples, shown in FIG. 7 are the structures that can be formed by the process 200 of FIG. 2. For example, the structure 71 A, 72A, and 73A can be formed by the process 200 (e.g., at operation 230) and / or can be examples of the structures 33, 35. The structures 71 A, 72A, and 73A can include portions (e.g., removed portions 731, 732, and 733, respectively) removed by the first etching (e.g., laser etching, directional dry etching, etc.). The structure 71B, 72B, and 73B can be formed by the process 200 (e.g., at operation 240) and / or can be examples of the structures 34, 36. The structures 71B, 72B, and 73B can include slots 71S, 72S, and 73S, respectively, formed by the second etching (e.g., wet etching using etchants such as KOH, TMAH, etc.). In some examples, the structures 7 IB, 72B, and 73B can be part of the structure 100 (e.g., the sidewall portions a3, b2, etc.). In some examples, as opposed to the structures shown in FIG. 6, the structures 7 IB, 72B, and 73B can be formed with different etch chemistry (e.g., different crystalline plane, different etchants, etc.). As shown, the slots 71S, 72S, and 73S can be vertical such that sidewalls 712, 722, and 732 of the slots 71S, 72S, and 73S can be disposed at 90 degrees with respect to first layers 710, 720, and 730, respectively. In some examples, the slots (e.g., the slot 73 S) can include a step-like structure (e.g., a step-like structure 740). In some examples, when the slots are formed by etching silicon along the (110) plane (e.g., using KOH), the vertical slots can be formed as shown.

[0056] It should be noted that the structures in FIG. 7 are shown to illustrate and describe examples in which the slots 71s, 72S, and 73 S can be vertical (e.g., as discussed above, when the etching is performed along the (110) plane of silicon using KOH), and thus the misalignment is not specifically depicted or drawn to scale. As discussed above, the structures 71 A, 72A, and 73A can be examples of the structure 33 formed based on the misalignment between the line m2 and ml or the misalignment between the line m3, m2', and ml. The structures 7 IB, 72B, and 73B can be examples of the structure 35 formed based on the misalignment between the line m2 and ml or the misalignment between the line m3, m2', and ml.

[0057] It should be understood that examples described herein should be considered in a descriptive sense and not for purposes of limitation. Descriptions of features or aspects within each example should be considered as available for other similar features or aspects in other examples. While examples have been described with reference to the figures, it should be understood that various changes in form and details can be made therein without departing from the spirit and scope as defined by the following claims.

[0058] The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the description. Therefore, the foregoing examples provided in the figures and described herein should not be construed as limiting of the scope of the disclosure, which is defined in the Claims.

[0059] The disclosure has been described above with reference to the various examples. However, it is to be understood by those of ordinary skill in the art that various modifications can be made in form and detail without departing from the scope of the disclosure as defined by the appended claims and their equivalents.

[0060] Conditional language used herein, such as, among others, "can," "could," "might," "may," “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain examples include, while other examples do not include, certain features, elements, etc. Thus, such conditional language is not generally intended to imply that an example include logic for deciding, with or without other input or prompting, whether these features, elements, etc. are included or are to be performed in any particular example. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

[0061] While the above detailed description has shown, described, and pointed out novel features as applied to various examples, it can be understood that various omissions, substitutions, and changes in the form and details of the structures or processes illustratedcan be made without departing from the spirit of the disclosure. As can be recognized, certain examples described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others.

[0062] The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components.

[0063] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations can be expressly set forth herein for sake of clarity.

[0064] It should be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "includes" should be interpreted as "includes but is not limited to," etc.). It should be understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent should be explicitly recited in the claim, and in the absence of such recitation no such intent is present. In those instances where a convention analogous to "one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances, where a convention analogous to "one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having one of A, B, or C" would include but not be limited to systems that have A alone, B alone,C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It should be understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" should be understood to include the possibilities of "A" or "B" or "A and B." Unless otherwise noted, the use of the words “approximate,” “about,” “around,” “substantially,” etc., mean plus or minus ten percent.

Claims

WHAT IS CLAIMED:

1. A method of forming a fluidic device, the method comprising: providing a substrate including a first layer, a second layer, and a third layer, wherein the first layer includes a target region; forming a pattern on the third layer such that the pattern is offset from the target region along a first axis; performing, using a laser, a first etching on the second layer to remove a portion of the second layer; and performing a second etching on a portion removed by the first etching to form a slot, wherein the slot includes a first sidewall disposed at a first angle with respect to the first layer and a second sidewall facing the first sidewall and disposed at a second angle with respect to the first layer, the second angle asymmetric to the first angle with respect to a second axis perpendicular to the first axis.

2. The method of claim 1, comprising: forming a fluid feed hole in the target region, prior to forming the pattern.

3. The method of claim 1, wherein the portion removed by the first etching is offset from the target region along the first axis.

4. The method of claim 1, wherein when performing the first etching, the laser is applied to the second layer at normal incidence.

5. The method of claim 4, wherein the laser applied at normal incidence and the second etching form a surface angled with respect to the first layer.

6. The method of claim 1, wherein the second etching is a wet etching of the second layer with the third layer serving as a mask.

7. The method of claim 1, wherein the portion removed by the first etching has an asymmetric shape.

8. A method of forming a fluidic device, the method comprising: providing a substrate including a first layer, a second layer, and a third layer, wherein the first layer includes a fluid feed hole, and the third layer includes a pattern and is offset from the first layer along a first axis; applying a laser to the second layer with the third layer serving as a mask to remove a first portion of the second layer; and performing an etching on the second layer with the third layer serving as the mask, to remove a second portion of the second layer, wherein the first portion and the second portion removed from the applying of the laser and the performing of the etching define a slot, the slot having an asymmetric shape with respect to a second axis perpendicular to the first axis.

9. The method of claim 8, wherein the first portion is removed such that a removed portion is offset from the fluid feed hole along the first axis.

10. The method of claim 8, wherein the first portion is removed such that a removed portion has an asymmetric shape.

11. The method of claim 8, wherein the laser is applied to the second layer at normal incidence, and wherein the applying of the laser and the performing of the etching form a surface disposed at an angle with respect to the first layer, the angle associated with a crystalline plane of material for the second layer.

12. The method of claim 8, comprising applying a second laser to the second layer, wherein the second laser is different from the laser in one of a width, a duration, or a power.

13. The method of claim 12, wherein a removed portion removed by the laser is offset from a second removed portion removed by the second laser, along the first axis.

14. A fluidic device, comprising: a first layer including a fluid feed hole; and a second layer including a slot fluidically connected with the fluid feed hole, the slot including: a first sidewall including a plurality of portions, each of which is disposed at a different angle with respect to the first layer, the different angle associated with a crystalline plane of material for the second layer; and a second sidewall facing the first sidewall and including a plurality of portions, each of which is disposed at a different angle with respect to the first layer, wherein the slot is asymmetric such that at least one of the plurality of portions of the first sidewall differs in a shape, a length, or an angle compared to at least one of the plurality of portions of the second sidewall.

15. The fluidic device of claim 14, wherein the first sidewall includes a bottom portion disposed at 45 degrees or less with respect to the first layer and a top portion disposed at 45 degrees or greater.

Images