A DMD direct writing hybrid wave exposure method

Abstract

The present invention discloses a DMD direct writing mixed-wave exposure method. Along the DMD scanning direction, the DMD is divided into several independent micromirror regions, and there is no intersection between adjacent independent micromirror regions. A plurality of incident lights with different wavelengths are respectively irradiated onto each independent micromirror region on the DMD. The incident lights with different wavelengths reflected by each independent micromirror region are sequentially irradiated onto the same photosensitive region on the photosensitive surface as the DMD scans. The incident lights with different wavelengths reflected by each independent micromirror region are sequentially superimposed with the same exposure pattern in the same photosensitive region on the photosensitive surface. The independent micromirror region passing through the previous photosensitive region on the photosensitive surface enters the next photosensitive region and performs exposure as the DMD scans, and the current photosensitive region obtains an exposure pattern with the same or different shape as that of the previous photosensitive region. The DMD direct writing mixed-wave exposure method of the present invention solves the problem of inconvenient optical path coupling of multiple wavelength incident lights in DMD multi-wave mixed direct writing exposure in the prior art.

Description

Technical Field

[0001] The present invention belongs to the field of DMD direct writing exposure, and more specifically relates to a DMD direct writing mixed-wave exposure method. Background Art

[0002] In the field of laser direct imaging devices, the mainstream light modulation technology is the DMD technology. This technology mainly relies on flipping millions of micro-mirrors on the DMD to achieve the purpose of light modulation. All along, in the field of micro-nano pattern processing such as PCB, the image transfer is carried out in a single-wavelength manner. Then, with the continuous development of direct writing technology and the expansion of application fields, many application scenarios that require the combined action of multiple wavelengths to complete the image transfer have also begun to try using direct imaging technology. Multi-wave mixing poses challenges to the design of the optical path system. Currently, various research and common methods are to first couple the incident light optical paths of multiple wavelengths, and then transmit them through optical fibers into the illumination system of the direct imaging device, and then directly irradiate the DMD for use. The advantage of this method is that as long as the incident light of multiple wavelengths is well coupled, although the illumination system of the direct imaging device does not need to be changed, the imaging part of the direct imaging device needs to be correspondingly changed, and there are also many limitations in the coupling of incident light of multiple wavelengths, such as the need to re-design the coupling as the number of wavelengths changes, etc., which is not flexible enough. Summary of the Invention

[0003] The purpose of the present invention is to provide a DMD direct writing mixed-wave exposure method to solve the problem of inconvenient coupling of incident light optical paths of multiple wavelengths in DMD multi-wave mixed direct writing exposure in the prior art.

[0004] A technical solution of the present invention is a DMD direct writing mixed-wave exposure method. Along the DMD scanning direction, the DMD is divided into several independent micro-mirror areas, and there is no intersection between adjacent independent micro-mirror areas;

[0005] Several incident lights of different wavelengths are respectively irradiated onto each independent micro-mirror area on the DMD; the incident lights of different wavelengths reflected by each independent micro-mirror area, along with the DMD scanning, are successively irradiated onto the same photosensitive area on the photosensitive surface; the incident lights of different wavelengths reflected by each independent micro-mirror area are successively superimposed with the same exposure pattern on the same photosensitive area on the photosensitive surface;

[0006] The independent micro-mirror area passing through the previous photosensitive area on the photosensitive surface, along with the DMD scanning, enters the next photosensitive area and performs exposure, and the current photosensitive area obtains an exposure pattern with the same or different shape as that of the previous photosensitive area.

[0007] Preferably, all independent micro-mirror areas have DMD matrix micro-mirrors with the same number of columns.

[0008] Preferably, there is a spacing between adjacent independent micromirror regions, and the width of the spacing is the product of the exposure delay time of incident light of two different wavelengths and the DMD scanning speed.

[0009] Preferably, the incident light irradiated onto each independent micromirror region on the DMD has at least two incident lights with unequal wavelengths.

[0010] Preferably, the incident light irradiated onto the same independent micromirror region is single-wavelength incident light.

[0011] Preferably, the incident light irradiated onto the same independent micromirror region is mixed incident light of multiple wavelengths.

[0012] Preferably, the incident light includes, but is not limited to, laser, UV, DUV, and EUV.

[0013] Preferably, the DMD performs forward scanning or oblique scanning.

[0014] The beneficial effect of a DMD direct-write mixed-wave exposure method according to the technical solution of the present invention is that when mixing and photosensitizing incident light of multiple wavelengths, there is no need to perform incident light optical path coupling. The incident light of different wavelengths is directly irradiated onto the DMD according to requirements. By controlling the DMD frame flipping, photosensitization of the photosensitive surface with incident light of multiple different wavelengths can be achieved. The DMD direct-write mixed-wave exposure method of this technical solution has good flexibility and strong adaptability, and does not require changing the hardware equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the partition of independent micromirror regions on the DMD in a DMD direct-write mixed-wave exposure method according to the technical solution of the present invention; that is, when the DMD is in the forward scanning state, it is a schematic diagram of the mixing of incident light of multiple wavelengths on the DMD.

[0016] Figure 2 It is a schematic diagram of the partition of independent micromirror regions on the DMD in a DMD direct-write mixed-wave exposure method according to the technical solution of the present invention; that is, when the DMD is in the oblique scanning state, it is a schematic diagram of the mixing of incident light of multiple wavelengths on the DMD.

[0017] Figure 3 It is a schematic diagram of the exposure process of a DMD direct-write mixed-wave exposure method according to the technical solution of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings of the specification.

[0019] A DMD direct-write mixed-wave exposure method according to the technical solution of the present invention divides the DMD into several independent micromirror regions along the DMD scanning direction, and the adjacent independent micromirror regions do not intersect;

[0020] Incident lights of several different wavelengths are respectively irradiated onto each independent micromirror area on the DMD; the incident lights of different wavelengths reflected by each independent micromirror area are sequentially irradiated onto the same photosensitive area on the photosensitive surface as the DMD scans; the incident lights of different wavelengths reflected by each independent micromirror area are sequentially superimposed with the same exposure pattern in the same photosensitive area on the photosensitive surface.

[0021] The independent micromirror area passing through the previous photosensitive area on the photosensitive surface enters the next photosensitive area and is exposed as the DMD scans, and the current photosensitive area obtains an exposure pattern with the same or different shape from the previous photosensitive area.

[0022] In this technical solution, all independent micromirror areas have DMD matrix micromirrors with the same number of columns.

[0023] In this technical solution, there is a spacing between adjacent independent micromirror areas, and the width of the spacing is the product of the exposure delay time of incident lights of two adjacent different wavelengths and the scanning speed of the DMD.

[0024] In this technical solution, the incident lights respectively irradiated onto each independent micromirror area on the DMD have at least two incident lights with unequal wavelengths.

[0025] In this technical solution, the incident light irradiated onto the same independent micromirror area is a single-wavelength incident light.

[0026] In this technical solution, the incident light irradiated onto the same independent micromirror area is a mixed incident light of multiple wavelengths.

[0027] In this technical solution, the incident light includes but is not limited to laser, UV, DUV, and EUV.

[0028] In this technical solution, the DMD performs a forward scan or an oblique scan.

[0029] For a further understanding of a DMD direct-write mixed-wave exposure method according to the technical solution of the present invention, the following further description is made with reference to the accompanying drawings.

[0030] In this technical solution, whether the DMD performs a forward scan or an oblique scan, its mixed-wave exposure method is the same. Along the DMD scanning direction, the DMD is divided into several independent micromirror areas. Here, the "DMD scanning direction" refers to the DMD moving direction, or the DMD moving direction relative to the photosensitive surface, such as Figure 1 and Figure 2 the direction of the dashed arrow shown in, which can be from top to bottom or from bottom to top. Of course, the DMD scanning direction can also be from left to right or from right to left, and the independent micromirror area partitioning is correspondingly changed to sequential partitioning in the left-right direction, ensuring that when the DMD scans and exposes, the incident lights of different wavelengths reflected by each independent micromirror area are sequentially irradiated onto the same photosensitive area on the photosensitive surface.

[0031] The angle change of the illumination system of the direct imaging device is synchronized with that of the DMD, that is, as shown in Figure 1 and Figure 2 , regardless of whether the DMD performs a positive scan or an oblique scan, the method of dividing the "independent micromirror area" on the DMD is the same, and it always occupies several integer matrices in the horizontal and vertical directions on the DMD. As shown in Figure 1 and Figure 2 , both represent a DMD micromirror array of M*N. In general practical applications, the DMD has a micromirror array of 1080*1920. In this M*N DMD micromirror array, there are three independent micromirror areas, which are, from bottom to top: the independent micromirror area Q1 shown by the single solid line shadow area, the independent micromirror area Q2 shown by the grid line shadow area, and the independent micromirror area Q3 shown by the dash-dotted line shadow area.

[0032] In this technical solution, then incident lights of several different wavelengths are sequentially irradiated onto each independent micromirror area on the DMD along the DMD scanning direction according to the exposure sequence of the incident lights of different wavelengths in the same photosensitive area on the photosensitive surface. That is, as shown in Figure 1 and Figure 2 , different wavelengths of incident lights are irradiated in the independent micromirror area Q1 shown by the single solid line shadow area, the independent micromirror area Q2 shown by the grid line shadow area, and the independent micromirror area Q3 shown by the dash-dotted line shadow area.

[0033] In this technical solution, the different wavelengths of incident lights reflected by each independent micromirror area are sequentially superimposed with the same exposure pattern in the same photosensitive area on the photosensitive surface. As shown in (a) and (c) of Figure 3 , assuming that the pattern K1 shown by the thick solid line needs to be obtained in the photosensitive area S1 on the photosensitive surface S, then by controlling the flipping of each micromirror in the independent micromirror area Q1, the independent micromirror area Q2, and the independent micromirror area Q3, the pattern K1 is obtained after being irradiated onto the photosensitive area S1 through the independent micromirror area Q1, the independent micromirror area Q2, and the independent micromirror area Q3 in sequence. That is, in one cycle of the DMD scan, three layers of superimposed pattern K1 are obtained on the photosensitive area S1.

[0034] When the DMD works, by controlling the flipping of the DMD micromirrors, according to the shape of the pattern required in the photosensitive area, the light that does not need to be irradiated into the photosensitive area is reflected to the absorption area, and the light that needs to be irradiated into the photosensitive area is directly irradiated into the photosensitive area after reflection.

[0035] In this technical solution, the independent micromirror area of the previous photosensitive area on the photosensitive surface enters the next photosensitive area and is exposed as the DMD scans, and the current photosensitive area obtains an exposure pattern with the same or different shape as that of the previous photosensitive area. As shown in Figure 3As shown, with the DMD scanning, assume that at time t1, the independent mirror area Q1 scans into the photosensitive area S1 on the photosensitive surface S. At this time, the independent mirror area Q1 reflects light into the photosensitive area S1, obtaining the thick solid line pattern K1 shown in (c). When the scanning at time t1 ends, the DMD scans downward and enters time t2. The independent mirror area Q1 leaves the photosensitive area S1 and enters the photosensitive area S2. At this time, the independent mirror area Q2 enters the photosensitive area S1. At this time, the independent mirror area Q1 and the independent mirror area Q2 reflect light with different graphic shapes, as Figure 3 shown in (b) thereof. That is, at this time, as shown in (d), the light reflected by the independent mirror area Q1 into the photosensitive area S2 will form a pattern K2 shown by the thick solid line in the photosensitive area S2, and the light reflected by the independent mirror area Q2 into the photosensitive area S1 will form a pattern K1 shown by the thick solid line in the photosensitive area S1. At this time, the pattern K1 in the photosensitive area S1 has been exposed to light of two different wavelengths, and the pattern K1 is the superposition of the two exposures. And so on. As the DMD scans downward, at the next moment, the photosensitive area S1 will be superposed and exposed to the pattern K1 again by the independent mirror area Q3, and the photosensitive area S2 will be superposed and exposed to the pattern K2 again by the independent mirror area Q2. As the DMD continues to scan downward, at the next moment, no light will be reflected by the DMD into the photosensitive area S1, and the photosensitive area S2 will be superposed and exposed to the pattern K2 again by the independent mirror area Q3.

[0036] Based on the above technical solution, the photosensitive area S2 is the next photosensitive area of the photosensitive area S1. The graphic shapes obtained by exposure in the photosensitive area S1 and the photosensitive area S2 can be the same or different, which is determined by the required graphic shape on the photosensitive surface. As Figure 3 shown, for the convenience of understanding and observation, it is assumed that the shapes of the pattern K1 and the pattern K2 are different.

[0037] In this technical solution, all independent mirror areas have DMD matrix mirrors with the same number of columns, that is, as Figure 1 or Figure 2 shown, the independent mirror area Q1 shown by the single solid line shadow area, the independent mirror area Q2 shown by the grid line shadow area, and the independent mirror area Q3 shown by the dotted line shadow area have the same number of mirror matrix columns. That is, as Figure 1 or Figure 2 shown, the widths L1 of the independent mirror area Q1 shown by the single solid line shadow area, the independent mirror area Q2 shown by the grid line shadow area, and the independent mirror area Q3 shown by the dotted line shadow area are the same.

[0038] Because during the light exposure, the independent mirror area and the photosensitive area are relatively stationary, which ensures the exposure accuracy.

[0039] In this technical solution, there is a spacing L2 between adjacent independent micromirror regions, and the width of this spacing is the product of the exposure delay time of incident light of two different wavelengths and the DMD scanning speed. When the DMD scans, since the independent micromirror region and the photosensitive region need to be relatively stationary, a certain movement time needs to be given to the DMD. At the same time, during the exposure of the photosensitive region, a certain delay is also required between two exposures. In this way, there should be enough gaps between adjacent independent micromirror regions to provide enough movement time for the DMD. Generally, the DMD scanning speed is uniform, and the width of the spacing between adjacent independent micromirror regions is the product of the exposure delay time of incident light of two different wavelengths and the DMD scanning speed, that is, the product of the time difference Δt between the aforementioned time t1 and time t2 and the DMD scanning speed V, that is, L2 = VΔt.

[0040] In this technical solution, the incident light irradiated onto each independent micromirror region on the DMD has at least two incident lights with unequal wavelengths. The problem solved in this technical solution is the inconvenient optical path coupling of incident lights of multiple wavelengths in the existing DMD multi-wave mixing direct writing exposure. Therefore, the incident light used here must not all have the same wavelength. According to the number of wavelengths of the incident light used, an equal number of independent micromirror regions are set.

[0041] In this technical solution, the incident light irradiated onto the same independent micromirror region is single-wavelength incident light; it can also be mixed incident light of multiple wavelengths. If it is mixed incident light, first, each light source is self-coupled, and finally, the coupled light sources are used as a whole. The light emitted by the overall light source is incident onto the independent micromirror region. Using the coupled multi-wavelength light source as a whole in this way also avoids the coupling problem of each optical path irradiated onto the DMD.

[0042] In this technical solution, the incident light includes but is not limited to laser, UV, DUV, and EUV. In the prior art, UV light is mostly used. The UV light has a short wavelength and can obtain a pattern with higher precision.

[0043] Based on the above technical solution, a DMD direct writing mixed-wave exposure method of the present invention's technical solution directly irradiates incident lights of multiple wavelengths onto specified different regions on the DMD during multi-wavelength light mixing. There is no need for optical path coupling of the incident light, and there is no need to change the hardware structure of the imaging part of the direct imaging device. It only needs to control the DMD image flipping. When the wavelength changes or different wavelengths of incident light are replaced, there is no need to make changes to the hardware device, which has good flexibility and strong adaptability.

[0044] Based on the above technical solution, a DMD direct writing mixed-wave exposure method of the technical solution of the present invention irradiates incident light of different wavelengths to different independent micromirror regions on the DMD when mixing light at multiple wavelengths. In this way, the problem of excessive optical power of the incident light irradiating the same position on the DMD is effectively avoided, and the problem of damage to the DMD caused by excessive light intensity is avoided.

[0045] In the above, the present invention has been described exemplarily in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A DMD direct writing and mixed wave exposure method, characterized in that, Along the DMD scanning direction, the DMD is divided into several independent micromirror regions. There is no intersection and there is a spacing between adjacent independent micromirror regions. The width of the spacing is the product of the exposure delay time of incident light of two different wavelengths and the DMD scanning speed; Several incident lights of different wavelengths are respectively irradiated onto each independent micromirror region on the DMD; the incident lights of different wavelengths reflected by each independent micromirror region are sequentially irradiated onto the same photosensitive region on the photosensitive surface as the DMD scans; the incident lights of different wavelengths reflected by each independent micromirror region are sequentially superimposed with the same exposure pattern in the same photosensitive region on the photosensitive surface; The independent micromirror region passing through the previous photosensitive region on the photosensitive surface enters the next photosensitive region and is exposed as the DMD scans, and the current photosensitive region obtains an exposure pattern with the same or different shape as the previous photosensitive region.

2. The DMD direct writing and mixed-wave exposure method according to claim 1, wherein All independent micromirror regions have DMD matrix micromirrors with the same number of columns.

3. A DMD direct-write hybrid-wave exposure method according to claim 1, characterized in that Among the incident lights respectively irradiated onto each independent micromirror region on the DMD, at least two incident lights have unequal wavelengths.

4. A DMD direct writing hybrid wave exposure method according to claim 1, characterized in that The incident light irradiated onto the same independent micromirror region is single-wavelength incident light.

5. A DMD direct writing hybrid wave exposure method according to claim 1, characterized in that The incident light irradiated onto the same independent micromirror region is mixed incident light of multiple wavelengths.

6. A DMD direct writing and hybrid wave exposure method according to claim 1, characterized in that The incident light includes laser, UV, DUV, and EUV.

7. A DMD direct writing and mixed wave exposure method according to claim 1, characterized in that The DMD performs forward scanning or oblique scanning.

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