Summary of the invention
For addressing the above problem, the objective of the invention is needs for the photoetching technique development of satisfying digital micro-mirror maskless lithography characteristics, solve large-area graphs and inscribe the splicing problem that exists, a kind of graphic joining method of maskless digital photolithography is provided for this reason.
In order to reach said purpose, the present invention provides the graphic joining method of a kind of maskless digital projection photoetching, and the step of said method comprises:
Step S1: figure to be etched is cut apart, the multiframe spirte after obtaining cutting apart, and every frame spirte is measure-alike;
Step S2: template size is set and every frame spirte is measure-alike;
Step S3: every frame spirte and said template after will cutting apart multiply each other; The gray-scale value of border splicing regions is modulated; Its gray-scale value of the zone that need not splice is kept intact, with this gray-scale value with gray modulation template modulation border splicing regions, the spirte after obtaining to modulate;
Step S4: the spirte after the modulation is shown by exposed frame through digital micro-mirror the spirte after the modulation that the realization digital micro-mirror shows duplicates the splicing of transfer to substrate.
Preferred embodiment: the segmentation procedure of said figure to be etched is following:
Step S11: the size of setting every frame spirte is 1024 * 768 pixels;
Step S12: set the overlapping region width between every frame spirte;
Step S13: to the overlapping region width of setting among the step S12, judge whether figure to be etched can be divided into the integral multiple of 1024 * 768 pixels, if can, then do not carry out the border and fill, then cut apart end; If can not, be the 0 feasible integral multiple that can be divided into 1024 * 768 pixels then with graphic limit patterned grays to be etched, cut apart again then.
Preferred embodiment: the spirte after the said modulation duplicates the splicing of transfer to substrate, has nine kinds of borders splicing situation, needs nine kinds of gray modulation templates of design, each template only around it adjacent superposition boundary zone set the gradual change gray-scale value.
Preferred embodiment: the size of modulation back spirte is 1024 * 768 pixels.
Described graphic joining method; Also comprise through computer control digital micro-mirror display graphics gray modulation state; When the single frames spirte after the modulation makes public; If the gray-scale value of the single frames spirte diverse location point after the modulation is different, then the modulation condition of digital micro-mirror relevant position will change.
Preferred embodiment: the spirte gray-scale value after the different modulation is corresponding to each responsive state of digital micro-mirror; When the spirte after the modulation that every then frame of digital micro mirror shows was inscribed corresponding to the substrate position figure, the photoresist degree that is etched was corresponding with gray-scale value.
Preferred embodiment: said step with gray modulation template modulation border splicing regions gray-scale value comprises: the gray-scale value of the border splicing regions outside by the gray modulation template is reduced to inboard gray scale successively.
Preferred embodiment: the gray-scale value setting for four superposition boundary splicing regions is different from overlapping situation twice, and the outside of gray modulation template reduces to inboard gray scale successively; After the splicing of the spirte of twice demonstration of digital micro-mirror, the gray-scale value of each border splicing regions and overlapping with four times after everywhere gray-scale value equate.
Preferred embodiment: the position of the border splicing regions of the spirte after the modulation that digital micro-mirror shows; Through the lines gray scale of gray modulation template modulation or the degree that is etched is gradual change; There is not tangible transition; Thereby realize the splicing of the spirte that digital micro-mirror shows, make the duplicate transfer of figure integral body to be etched to substrate.
Ultimate principle of the present invention: according to the characteristics of digital micro-mirror, i.e. the spirte size of the each exposure of digital micro-mirror is 1024 * 768 pixels, and need cut apart size for figure to be etched is 1024 * 768 pixel multiframe spirtes.Computer control digital micro-mirror figure gray modulation state, so single frames spirte when exposure, if the gray-scale value of diverse location point is different, then the modulation condition of digital micro-mirror array relevant position will change.Be the different patterns gray-scale value, the digital micro-mirror corresponding state is corresponding one by one with it, when the correspondence position spirte is scribed at substrate then, and the photoresist degree varies appearance that is etched.Based on this principle, plan boundary splicing gray modulation template.
Characteristic and advantage of the present invention:
(1) the present invention made full use of digital micro-mirror flexibly, efficient, cost is low, need not characteristics such as mask, has proposed the effective dividing method of figure to be etched.
(2) the present invention is based on the response of photoresist, designed corresponding border gray modulation template digital micro-mirror figure gray scale.Difference to splicing regions is provided with different gray values.
(3) figure that the present invention will be to be inscribed is cut apart, and multiplies each other with the template that designs then, and the border gray-scale value of every frame spirte is effectively modulated, and realizes the splicing of spirte in the time of by the field exposure.Practice shows, problem graphic joining problems such as the distortion that the present invention exists in the time of solving the large-area graphs exposure preferably, dislocation, parcel are improved the quality of digital projection litho pattern etching.
Embodiment
For making the object of the invention, technical scheme and advantage clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, to further explain of the present invention.
Shown in Fig. 1, a kind of graphic joining method that is applicable to digital micro-mirror maskless digital photolithography provided by the invention, figure to be etched is cut apart, stencil design, spirte receive the corresponding templates modulation, modulation back spirte is by exposed frame.Wherein, before the inscription operation of reality, figure to be etched is divided into the multiframe spirte that the multiframe size is 1024 * 768 pixels, each spirte multiplies each other with the corresponding templates that designs then, realizes the pre-service of spirte.During the exposure of digital micro-mirror maskless digital projection photoetching large-area graphs; Because digital micro-mirror can only show that size is the restriction of 1024 * 768 pixel graphics characteristics; And dimension of picture to be etched usually greater than 1024 * 768 pixels; Can not the direct transfer replication of disposable integral to substrate, need be divided into the multiframe spirte that the displayable size of digital micro-mirror is 1024 * 768 pixels to figure to be etched, gray modulation template reasonable in design is handled the spirte after cutting apart; Be transferred to substrate by exposed frame with the mode of splicing through the multiframe spirte after the modulation of digital micro-mirror demonstration at last, accomplish the duplicate transfer of figure integral body to be etched to substrate.Said method comprises:
Step S1: at first figure to be etched is cut apart, the multiframe spirte after obtaining cutting apart, and every frame spirte is measure-alike, and its size is 1024 * 768 pixels; (figure is cut apart the practical implementation method and seen below said) figure to be etched is not (generally be greater than) 1024 * 768 pixel sizes usually, and digital micro-mirror can only show the spirte of 1024 * 768 pixel sizes, so need cut apart (filling).
Step S2: the spirte corresponding gray modulation template of design after cutting apart, its size with cut apart after the multiframe spirte measure-alike, i.e. 1024 * 768 pixels; (concrete grammar of stencil design sees below said).
Step S3: multiframe spirte and said corresponding templates after will cutting apart multiply each other, and make the grey value profile of the spirte border splicing regions that digital micro-mirror the shows outside of serving as reasons reduce successively to the inboard; The gray-scale value setting of four superposition boundary splicing regions is different from overlapping situation twice, but the size of gray-scale value is reduced to inboard gray scale by the outside successively; After the spirte splicing that twice digital micro-mirror shows, the gray-scale value of each border splicing regions and overlapping with four times after everywhere gray-scale value equate.Accomplish the gray modulation of each spirte with this.
Step S4: spirte after the modulation among the step S3 is shown by exposed frame the splicing of the spirte after realizing simultaneously modulating through digital micro-mirror.After spirte exposure splicing after all modulation is accomplished, then accomplished the duplicate transfer of figure integral body to be etched to substrate.
Fig. 2 a to Fig. 2 d is the large-area graphs splicing several types of common wrong synoptic diagram that modulation does not exist through the gray scale template.
Wherein, the grey lines are represented the single frames spirte of actual needs exposure, are the wrong place of splicing in the black wire frame.When twice spirte of Y direction made public, because stitching error causes that cross-wise lines misplaces, vertically lines ruptured for Fig. 2 a.
Equally, illustrate like Fig. 2 b, when twice spirte exposure of directions X, because the splicing mistake causes vertical lines to misplace, cross-wise lines ruptures.
Shown in Fig. 2 c, though in the splicing of Y direction accurately, cross-wise lines misplaces.But there is error in the directions X splicing, causes cross-wise lines to overlap.Here because over-exposed meeting makes the lines chap; Equally, in the directions X splicing accurately, vertically lines misplace.But there is error in the splicing in the Y direction, causes cross-wise lines to overlap.Here because over-exposed meeting makes the lines chap.
Illustrating like Fig. 2 d is modal phenomenon; At X; All there is error in the spirte splicing that the digital micro-mirror of Y both direction shows; Scheming the lower middle portion figure is that the lines parcel is engulfed structure, and the exposure back is linked to be over-exposed chap " band shape " structure at vertical direction, and this spirte that is digital micro-mirror shows splices unacceptable.
Be depicted as figure to be etched like Fig. 3 and cut apart, wherein, black bold box is the boundary sizes of initial figure to be etched, and dotted line is the boundary line of partition graph.
Because the spirte size is 1024 * 768 pixels after the modulation of the each exposure of digital micro-mirror.Therefore need be divided into size for figure to be etched is 1024 * 768 pixel multiframe spirtes.Dividing method is:
When (1) beginning split image, begin (numbering 1) from the upper left corner, the spirte size of at every turn cutting apart is 1024 * 768 pixels;
(2) the follow-up spirte of cutting apart, some is overlapping with numbering 1 with numbering 1, numbering 3 for numbering 2, and the lap width is edge, and the figure that back face is cut apart is by that analogy.
(3) if figure to be etched can not be divided into the integral multiple of 1024 * 768 pixels, need before cutting apart, will be filled to black through the border, gray-scale value is 0 (for ease of observing, being filled to gridiron pattern among Fig. 3).Wherein the width of lap (edge) can be set as required, and the zone of border filling simultaneously also respective change can take place.
Be depicted as stencil design like Fig. 4, wherein A11~A13, A21~A23 and A31~A33 are the neighbouring relations of nine kinds of templates, represent all situations of actual graphical splicing; Because the responsive state of digital micro-mirror is corresponding one by one with template modulation back spirte gray-scale value, when the every frame spirte after template is modulated was then inscribed, corresponding pixel points gray scale figure was the photoresist degree varies appearance that is etched.Therefore, to the place that the different boundary position need be spliced, need the corresponding single frames spirte pre-service template of design based on the gray scale gradual change.
(numbering is respectively nine kinds of situation that the spirte of A11~A13, A21~A23 and A31~A33) show for digital micro-mirror need splice, corresponding nine templates to 9 thick dashed line frames among Fig. 4.Double-lined arrow is the boundary position of the spirte splicing of adjacent two frame of digital micro mirrors demonstration, needs design gray scale gradual change template.The fine dotted line frame is the overlapping public domain of adjacent four frame spirtes splicing, the lattice that can intersect referring to dotted line among Fig. 3 simultaneously, the i.e. lower right corner of A11; The zone that the upper left corner splicing of the A12 lower left corner, the A21 upper right corner, A22 overlaps is referred to as (A11, A12 here; A21, A22).Therefore, the gray scale setting for each template is different from the spirte splicing overlapping areas that two frame of digital micro mirrors show.
The part of common twice stack, minimum gray value GMinWith maximal value GMaxDetermine by following formula:
Gmin=255×kmin (1)
Gmax=255×kmax
If the width of lap is set to edge, then the gray-scale value in twice template zone, lap splice place (for example, A11 and A12 jointing positions among Fig. 4) is:
mask(1:768,j)
=((255×(kmin+kmax)-255)/(edge-1))×(1024-j)+255×kmin (2)
J=1024-edge+1:1024 wherein, edge is overlapping peak width, j is the row sequence number; kMinBe referred to as gray scale gradual change coefficient minimum value, kMaxBe referred to as gray scale gradual change coefficient maximal value, kMinAnd kMaxSize and the relating to parameters and the 1≤k of photoetching process and DMD deviceMin+ kMax≤1.5, mask representes the gray modulation template.
The part of four splicing stacks is like zone, Fig. 4 fine dotted line frame place.For single frames spirte, for example A11.The gray-scale value of splicing regions (the A11 lower right corner) is expressed as:
mask(768-edge+1,j)
=((255×Kmin+255×(Kmax-Kmin))/(edge-1))×(1024-j) (3)
Wherein: KMin, KMaxSize and the relating to parameters and the 0.5≤K of photoetching process and DMD deviceMin+ KMax≤1, mask representes the gray modulation template.
Therefore after the modulation that shows of digital micro-mirror after the subimage splicing, gray-scale value everywhere and be 255.In spirte splicing after the modulation of digital micro-mirror demonstration, the rest may be inferred for other same cases.As (A12, A13, A22, A23), (A21, A22, A31, A32) or the like.
Shown in Fig. 5, as edge=100 pixel, kMin=0.2, kMax=0.8; KMin=0.1, KMax=0.4 template pattern.The part of twice stack then, minimum gray value is 51 (255 * 0.2), maximal value is 204 (255 * 0.8); The part of four stacks, gray-scale value minimum value 26 (255 * 0.1), gray-scale value maximal value 102 (255 * 0.4).Therefore after the modulation that shows of digital micro-mirror after the subimage splicing, gray-scale value everywhere and be 255.Nine kinds of splicing situation in the difference corresponding diagram 4.Among the figure template gray scale be provided with the rule as shown in Figure 4.A11~A13 shown in Fig. 5, A21~A23 and A31~A33 are respectively spirte splicing situation corresponding grey scale modulation template after the modulation that shows of 9 kinds of different digital micro-mirrors.
Wherein, be that 255, four area grayscale values after overlapping are 255 after the gray-scale value of (1) the twice overlapping region stack; (2) each template gray scale borderline region, gray-scale value increase from outside to inside successively.Therefore, as long as multiframe spirte and corresponding grey scale modulation template that figure to be etched is divided into multiply each other, just can realize the gray modulation on this spirte border.
Shown in Fig. 6 a to Fig. 6 c, wherein Fig. 6 b, Fig. 6 c are Fig. 4 upper left corner first frame spirte, the second frame spirte; Fig. 6 a is to be etched original in its size of partition graph is 2872 * 2804 pixels, sets the edge=100 pixel and just can be divided into the spirte that 9 frame signs are 1024 * 768 pixels.Clearly some is overlapping on the left side of the right of Fig. 6 b and Fig. 6 c.Before the actual exposure, with the first frame spirte and the second frame spirte respectively with Fig. 5 in the template of A11 and A12 multiply each other and realize the gray modulation pre-service.The left side of the second frame spirte will overlap the right of the first frame spirte during exposure, and overlapping width is 100 pixels, thus spirte exposure after the modulation that realization stepping digital micro-mirror shows.
The picture that goes out as shown in Figure 7 is after Fig. 6 a is divided into 9 frame spirtes, modulated by template corresponding, and spliced result is as shown in Figure 7.Can find out among the figure, the gray-scale value of jointing positions greater than around other zones.But during the exposure of single frames spirte, the gray-scale value in splicing boundary zone is less than other zones after the modulation that shows for digital micro-mirror, and the degree that this moment, photoresist was etched not is linear with gray-scale value.After spirte exposure splicing finishes after the modulation that the real figure micro mirror shows; The degree that the photoresist of splicing regions is etched is with other zones are basic identical on every side; Over-exposed problem can not occur, thereby realize level and smooth, the natural transition of spirte splicing after the modulation that adjacent digital micro-mirror shows.
After pursuing the exposure of frame spirte after the modulation that digital micro-mirror shows; Can effectively solve the unmodulated spirte splicing problem that digital micro-mirrors such as dislocation, overlapping, parcel show to a certain extent; Make the lines of jointing positions connect nature, level and smooth; Remedy the inherent shortcoming of work stage positioning error, improve the whole structure of digital micro-mirror maskless digital projection photoetching large-area graphs exposure.
The above; Be merely the embodiment among the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with this technological people in the technical scope that the present invention disclosed; Conversion or the replacement expected can be understood, all of the present invention comprising within the scope should be encompassed in.