Fabrication of polarizers, diffraction gratings, and metasurfaces by ion implantation

Abstract

To provide fabrication of a polarizer, a diffraction grating and a meta surface via ion implantation.SOLUTION: The polarizer comprises a plurality of non-conducting areas between conducting wires of a wire grid. The conducting wires may comprise nanowires or nanopillars. The wire grid may be a rectangular or hexagonal grid.SELECTED DRAWING: Figure 1A

Description

【Background Art】 【0001】 Cross - Reference to Related Applications 【0001】This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 471,866, filed on June 8, 2023, entitled "POLARIZER DIFFRACTION GRATING AND META SURFACE FABRICATION VIA ION IMPLANTATION", the disclosure of which is incorporated herein by reference in its entirety. 【0002】 【0002】The limitations and disadvantages of conventional systems and methods for manufacturing will become apparent to those skilled in the art through a comparison of such approaches with some aspects of the methods and systems of the present disclosure described in the remainder of the disclosure with reference to the drawings. 【Summary of the Invention】 【0003】 【0003】A system and method for the manufacture of polarizers, diffraction gratings, and metasurfaces by ion implantation are substantially provided, as illustrated and / or described in connection with at least one of the drawings, as more fully described in the claims. 【Brief Description of the Drawings】 【0004】 [Figure 1A] 【0004】FIG. 1A is a diagram showing an embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 1B] 【0005】 FIG. 1B is a diagram showing the optical polarizer of FIG. 1A after photoresist removal in accordance with various exemplary implementations of the present disclosure. [Figure 2] 【0006】 FIG. 2 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 3] 【0007】Figure 3 shows a wire grid polarizer structure obtained by removing damaged areas and cleaning up the resist after wet etching, according to various exemplary embodiments of this disclosure. [Figure 4] 【0008】 Figure 4 shows a specific example of chemically altering the Al material beneath an exposed resist trench for subsequent lift-off removal, according to various exemplary implementations of this disclosure. [Figure 5] 【0009】 Figure 5 shows a specific example of a metal reflection grating produced via an ion implantation-based removal process according to various exemplary embodiments of this disclosure. [Figure 6A] 【0010】 Figure 6A is a top view of a metasurface designed for a wavelength of 940 nm, according to various exemplary embodiments of this disclosure. [Figure 6B] 【0011】 Figure 6B is a cross-sectional view of the metasurface of Figure 6A, according to various exemplary embodiments of this disclosure. [Figure 7] 【0012】 Figure 7 is a cross-sectional view of another exemplary metasurface according to various exemplary embodiments of the present disclosure. [Figure 8] 【0013】 Figure 8 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. [Figure 9] 【0014】 Figure 9 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. [Figure 10] 【0015】 Figure 10 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. [Figure 11] 【0016】 Figure 11 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. [Figure 12] 【0017】FIG. 12 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 13] 【0018】 FIG. 13 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 14] 【0019】 FIG. 14 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 15] 【0020】 FIG. 15 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 16] 【0021】 FIG. 16 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 17] 【0022】 FIG. 17 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 18] 【0023】 FIG. 18 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. [Figure 19] 【0024】 FIG. 19 is a diagram showing another embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. 【DETAILED DESCRIPTION OF THE INVENTION】 【0005】 【0025】 The present disclosure describes systems and methods for manufacturing diffractive optical elements of various types of diffraction gratings, metasurfaces, and sub-wavelength structures using multiple different ion implantation techniques. 【0006】 【0026】Figure 1A shows an embodiment of an optical polarizer manufactured by ion implantation in accordance with various exemplary implementations of the present disclosure. In Figure 1A, a metal layer 103 of appropriate thickness, such as 500 nm, such as aluminum (Al), is deposited on a substrate 105 of a material that is sufficiently transparent at the target wavelength. When operating the polarizer in a wavelength band from visible (>400 nm wavelength) to near-infrared (<2 μm wavelength), the substrate 105 may be fused silica, although other suitable transparent materials are also possible. A photoresist (PR) 101 is deposited on the Al layer 103 and patterned into a line-space pattern having a period appropriately small compared to the target wavelength range so that diffraction does not occur. 【0007】 【0027】 Thereafter, the structure is ion implanted 107, for example, using Ar or other suitable ions, and the implanted ions propagate into the Al layer 103 through the exposed photoresist trenches and then into the substrate 105 beyond the Al layer 103. This process occurs at room temperature. As the Ar ions 107 propagate through the Al layer 103, damage occurs to the metal and its resistivity increases to a high value or even an infinite value. At the same time, the Al layer 103 that was reflecting until then changes to Al (Al T ) 109 that is transparent in the target wavelength range. Thereby, a wire grid polarizer is generated that includes non-conductive / high-resistivity Al T regions 109 under the exposed resist spaces (damaged) between the periodic line-space patterns of the conductive Al nanowires 111 (undamaged regions). 【0008】 【0028】 Figure 1B shows the optical polarizer of Figure 1A after photoresist removal, in accordance with various exemplary implementations of the present disclosure. 【0029】Figure 2 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of this disclosure. In Figure 2, oxygen 205 (dimer or monatomic oxygen) is implanted into the Al layer 203 of the polarizer. This method can rely on a resist mask for room temperature implantation, but a hard mask (HM) 207 such as SiN or carbon is required for the heating required during implantation or in post-implantation process steps such as annealing after implantation. Either during the implantation process itself or in the subsequent annealing step, the oxygen-implanted portion of the Al layer is converted to Al2O3. The Al / Al2O3 line-spaced structure functions as a polarizer if properly designed.

[0009] 【0030】 By ion-implanting N2 or N into the aluminum layer 203 instead of O2 / O, aluminum nitride can be formed instead of AlxOy, resulting in different embodiments of polarizers.

[0010] 【0031】 Another approach involves implanting specific ions into the aluminum to induce physical damage or chemical modification, which then allows for the complete and selective removal of the damaged or chemically altered portions, for example, by a wet etching process. Figure 3 shows a wire grid polarizer structure obtained after the removal of damaged portions 301 and cleanup of the resist following wet etching, according to various exemplary embodiments of the present disclosure.

[0011] 【0032】Figure 4 shows a specific example of chemically altering the Al material beneath an exposed resist trench for subsequent lift-off removal, according to various exemplary implementations of this disclosure. For example, implantation with Si ions 401 occurs at an angle, chemically altering the Al to form an AlxSiy compound (black region), which can be removed by wet etching using, for example, a fluoride-based or other chemical. The Al surrounded by the transformed region is simply lifted off during the process, forming the structure shown in Figure 3. Note that the implantation angle (indicated by the arrow) can be changed and used to affect the dimensions of the remaining line, for example, by narrowing or widening it. This technique is useful when the desired Al line is thinner than what is determined by the limited range of available resist dimensions.

[0012] 【0033】 Figure 5 shows a specific example of a metallic reflection grating produced via an ion implantation-based removal process according to various exemplary embodiments of the present disclosure. A metallic reflection grating 501 can be designed and manufactured on the condition that a sufficiently thick metallic layer 503 remains beneath the lifted portion of the trench, provided that the implanted layer is Al or another metal and the period of the pattern is large enough to allow diffraction.

[0013] 【0034】 The discussion so far has focused on creating polarizers and diffractometers based on changes resulting from the removal or chemical / physical modification of conductive layers. Similar considerations apply when the layer treated by ion implantation is a dielectric material transparent at the target wavelength. Ion implantation allows for material modification, and subsequent removal can create a transmissive lattice.

[0014] 【0035】Figure 6A shows a top view of a metasurface designed for a wavelength of 940 nm, according to various exemplary embodiments of the present disclosure. Figure 6B shows a cross-sectional view of the metasurface of Figure 6A, according to various exemplary embodiments of the present disclosure. In Figures 6A and 6B, a well-designed two-dimensional resist pattern, e.g., nanopillars 601 on a hexagonal or rectangular grid with sub-wavelength dimensions, is transferred to a dielectric layer by ion implantation. As an example, metasurface materials that enable the design of lenses, dot generators, etc., can be produced.

[0015] 【0036】 In Figures 6A and 6B, the metasurface structure is created by defining subwavelength-scale regions of high and low refractive indices. A unit cell filled with a surrounding medium (air, low refractive index region) containing a high refractive index nanopillar 601 generates an arbitrary phase delay that can be designed into an overall phase surface providing desired functions such as lensing and splitting through lateral functional size (diameter) control. Material removal to create the air-filled portion of the subwavelength-scale unit cell can proceed as described above with reference to Figure 4.

[0016] 【0037】 Alternatively, following a change in material properties (specifically, a change in optical material properties such as refractive index), a metasurface having a high refractive index region 601 (such as the nanopillars in Figure 6) can be generated by appropriate ion implantation, such as Ge, in a suitable host dielectric layer such as silicon dioxide. Figure 7 shows a cross-sectional view of another exemplary metasurface according to various exemplary embodiments of the present disclosure.

[0017] 【0038】 The metasurface in Figure 7 is created by implanting ions into the opening 703 in a (negative) photoresist. The photoresist defines the cross-section of the high refractive index nanofunction 701. Because the refractive index contrast between the nanostructures thus created in the solid host material is usually lower than that of air, the thickness of the host material metasurface layer 705 may need to be carefully adjusted.

[0018] 【0039】Wire grid polarizers can be formed by ion implantation into a film using a patterned periodic lattice mask. In one embodiment, the deposited film is conductive, such as an aluminum film implanted with oxygen or nitrogen ions, and the implanted region is resistive. The resistivity of the implanted region can be controlled by the amount of ions implanted, and the penetration depth into the film can be controlled by the implantation energy.

[0019] 【0040】 Figure 8 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 8, a monolayer 801 of an Al lattice layer is created within an aluminum oxide (AlOx) film on a silicon dioxide (SiO2) substrate 803 using multi-stage implantation with different energies and depths (h).

[0020] 【0041】 Figure 9 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of this disclosure. In Figure 9, the structure of Figure 8 is sealed with a dielectric film 901. The dielectric 901 may be spin-on or deposited using techniques such as chemical vapor deposition (CVD).

[0021] 【0042】 Figure 10 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 10, another layer 801 is added to the structure of Figure 9. Multiple layers 801 may be created by repeating the deposition of an AlOx film and subsequent Al implantation multiple times.

[0022] 【0043】 Figure 11 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 11, a sealing layer 901 is added to the structure of Figure 10. One or more sealing layers 901 may be present.

[0023] 【0044】Figure 12 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 12, the deposition of an AlOx film and subsequent Al implantation are repeated multiple times in succession to create multiple layers 801,1201. Implantation from the uppermost layer 801 may diffuse into the lower layer 1201 during the implantation process.

[0024] 【0045】 Figure 13 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 13, a sealing layer 901 is added to the structure of Figure 12.

[0025] 【0046】 Figure 14 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 14, the sealing layer 901 is located between a plurality of layers 801, 1201.

[0026] 【0047】 Figure 15 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 15, a sealing layer 901 is added to the structure of Figure 14.

[0027] 【0048】 Figure 16 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In the alternative process, a dielectric film is deposited and a lattice is formed by ion implantation of dopants using a patterned periodic lattice mask. Layer 1601 having alternating doped and undoped regions is created using multi-stage implantation.

[0028] 【0049】 Figure 17 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 17, a dielectric film sealing layer 901 is added to the structure of Figure 16.

[0029] 【0050】Figure 18 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 18, the process described with respect to Figure 16 is repeated multiple times in succession to create multiple layers 1601,1801. Implantation from the top layer 1601 may diffuse to the lower layer 1801 during the implantation process.

[0030] 【0051】 Figure 19 shows another embodiment of an optical polarizer manufactured by ion implantation according to various exemplary embodiments of the present disclosure. In Figure 19, a sealing layer 901 is added to the structure of Figure 18. Any embodiment (for example, as shown in Figures 8 to 19) may include an anti-reflective coating during deposition to help reduce transmission loss.

[0031] 【0052】As used herein, the terms “circuit” and “circuit configuration” refer to physical electronic components (i.e., hardware) and any software and / or firmware (”code”) that constitutes the hardware, is executed by the hardware, or may otherwise be associated with the hardware. As used herein, for example, a particular processor and memory may comprise a first “circuit” if it executes one or more lines of the first code, and a second “circuit” if it executes one or more lines of the second code. As used herein, “and / or” means any one or more items in a list joined by “and / or”. For example, “x and / or y” means any element of the set of three elements {(x),(y),(x,y)}. As another example, “x,y and / or z” means any element of the set of seven elements {(x),(y),(z),(x,y),(x,z),(y,z),(x,y,z)}. As used herein, the term “exemplary” means acting as a non-limiting example, case, or example. As used herein, the terms “for example” and “as an example” constitute a list of one or more non-limiting examples, cases, or illustrations. As used herein, a circuit configuration is “operable” to perform its function whenever it has the necessary hardware and code (if any) to perform that function, regardless of whether the performance of that function is disabled or enabled (for example, by a user-configurable setting, factory trim, etc.). As used herein, the term “based on” means “at least partially based on.” For example, “x based on y” means that “x” is at least partially based on “y” (and, as an example, may also be based on z).

[0032] 【0053】Although the Method and / or System has been described with reference to a specific embodiment, it will be understood by those skilled in the art that various modifications may be made and equivalents may be substituted without departing from the scope of the Method and / or System. In addition, many modifications may be made without departing from the scope to adapt a particular situation or material to the teachings of the Disclosure. Thus, the Method and / or System is not limited to the specific embodiment disclosed, and the Method and / or System is intended to include all embodiments that fall within the appended claims.

Claims

[Claim 1] A method for manufacturing a polarizer comprising a plurality of non-conductive regions between grids of a conductive element made of aluminum, The step of generating the non-conductive region by ion implanting the conductive material, which is aluminum, using argon, oxygen, silicon, or nitrogen. A method that includes this. [Claim 2] A method according to claim 1, wherein the conductive element includes a nanowire. [Claim 3] A method according to claim 1, wherein the grid is bonded to a substrate. [Claim 4] A method according to claim 3, wherein the substrate comprises a silica compound. [Claim 5] A method according to claim 3, wherein the substrate is transparent at the wavelength of the object on which the polarizer is operated. [Claim 6] A method according to claim 5, wherein the target wavelength is greater than 400 nm and less than 2 μm. [Claim 7] A method according to claim 1, wherein the nonconductive region comprises aluminum that has been modified to be transparent at the wavelength of the object on which the polarizer is operated. [Claim 8] The method according to claim 1, The method further includes the step of generating the grid by covering a conductive material with a photoresist or mask in a periodic line-space pattern, The step of generating the nonconductive region by ion implantation into a conductive material includes the step of generating the nonconductive region by ion implantation into the conductive material through a portion not covered by the photoresist or mask. method. [Claim 9] A method according to claim 1, wherein the non-conductive region comprises aluminum nitride. [Claim 10] A method according to claim 1, wherein the step of generating the nonconductive region by ion implantation into a conductive material includes the step of generating the nonconductive region by implanting silicon ions into the conductive material at an angle to produce an aluminum-silicon compound. [Claim 11] A method according to claim 10, further comprising the step of removing aluminum surrounded by the region containing the aluminum-silicon compound by a lift-off process. [Claim 12] A method according to claim 10, further comprising the step of removing the aluminum silicon compound by wet etching. [Claim 13] A method according to claim 10, wherein the angle determines the dimensions of the conductive element. [Claim 14] A method according to claim 1, wherein the grid is bonded to a metal layer.

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