JP4355900B2 - Method for planarizing substrate surface, and method for manufacturing planarized substrate, liquid crystal display device, organic EL element, and semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for flattening a substrate surface, a method for manufacturing a flattened substrate, and a flattening in a manufacturing process of a liquid crystal display element, an organic electroluminescent element (organic EL element), a semiconductor device such as a semiconductor, and an optical device such as a microoptics. The present invention relates to a liquid crystal display device, an organic EL element, and a semiconductor device using the manufactured substrate.
[0002]
[Prior art]
Liquid crystal display (LCD) is widely used in direct-view monitors and projection projectors. In many LCDs currently used, liquid crystal is sealed between two glass substrates on which electrodes are formed, and an electric field is applied to the liquid crystal to change the alignment state of the liquid crystal, thereby performing display.
[0003]
In particular, LCDs using TFTs (Thin Film Transistors) are being used because they are excellent in terms of high image quality and high definition. One pixel of a TFT-LCD can be divided into a display portion and a non-display portion where TFTs and wirings are arranged. This non-display portion is generally covered with a light shielding layer and has a structure that does not contribute to display. It has become.
[0004]
By the way, in LCD, the unevenness | corrugation resulting from TFT and wiring arises on the board | substrate surface in the side which touches a liquid crystal. In the LCD, the unevenness of the substrate surface becomes a factor that disturbs the orientation of the liquid crystal, which in turn leads to a decrease in the display quality of the LCD.
[0005]
The cause of the deterioration of the display quality of the LCD in the twisted nematic (TN) mode widely used for the TFT-LCD will be briefly described with reference to FIGS. FIG. 25 is a cross-sectional view of a liquid crystal display element using an ideal planarized substrate having no unevenness, and FIG. 26 is a cross-sectional view of a liquid crystal display element using a substrate having unevenness. The liquid crystal display element has a structure in which a liquid crystal layer 534 is sandwiched between a TFT substrate 532 and a counter substrate 533. The TFT substrate 532 side includes a TFT 523 for controlling a voltage applied to the pixel electrode 524, a wiring 522, a contact hole 526 for electrically contacting the TFT 523 and the pixel electrode 524, a planarization film 525, and the like. On the other hand, the counter substrate 533 side includes a counter electrode 527 and the like. An alignment film exists on the side of the TFT substrate 532 and the counter substrate 533 that is in contact with the liquid crystal layer 534, but is not shown in the drawing.
[0006]
In the TN mode, the alignment of the liquid crystal is controlled by a vertical electric field generated between the pixel electrode 524 and the counter electrode 527. In general, since the contrast ratio (ratio of transmittance during white display and black display) is excellent, a normally white mode of black when a vertical electric field is generated and white when no electric field is used is used. However, when the applied voltages of adjacent pixel electrodes 524 are different, a horizontal electric field is generated between the pixel electrodes 524 as well as the vertical electric field. This lateral electric field generates discontinuous points called point tilts 531 in the alignment vector of the liquid crystal (see, for example, Non-Patent Document 1). The point tilt 531 causes light leakage during black display in the normally white mode. Therefore, in order to conceal disclination in order to obtain a high contrast ratio, it is necessary to enlarge the light-shielding film (BM film), so the value obtained by dividing the area of the pixel opening through which light is transmitted by the total area. A certain pixel aperture ratio decreases. Alternatively, the contrast ratio decreases in order to maintain the pixel aperture ratio and obtain brightness.
[0007]
It is known that it is effective to increase the pretilt angle 530 of the liquid crystal molecules in order to prevent the point tilt 531 due to the lateral electric field from greatly entering the pixel electrode 524 (for example, Non-Patent Document 2). reference.).
[0008]
In an ideal planarized substrate having no unevenness in FIG. 25, by selecting an alignment film that induces a high pretilt angle 530 in the liquid crystal molecules 529, the liquid crystal molecules 529 on the pixel electrode 524 and the wiring 522 have a uniform pretilt angle. 530 is obtained. Therefore, since the point inclination 531 does not enter the pixel electrode 524 greatly, both a high contrast ratio and a high pixel aperture ratio can be achieved.
[0009]
On the other hand, in the substrate on which the convex portion 528 due to the wiring 522 in FIG. 26 exists, the pretilt angle 530 is obtained for the liquid crystal molecules 529 on the pixel electrode 524 by selecting the high pretilt angle alignment film. However, the apparent pretilt angle of the liquid crystal molecules 529a is reduced on the slope of the convex portion 528. In some cases, the pretilt angle is negative. Therefore, if there is a slope due to a convex portion on the wiring, the effect of preventing the point tilt 531 from entering the pixel electrode 524 by increasing the pretilt angle of the liquid crystal molecules is lost, and the brightness or contrast ratio is lowered. To do.
[0010]
In particular, an LCD with a diagonal of about 1 inch for a projector has a pixel pitch of 10 to 30 μm which is very small compared with a direct-view type monitor with a diagonal of 15 inches, etc., and the area occupied by the TFT and wiring is relatively small. Largely, the influence on the display quality due to the unevenness of the substrate surface caused by the TFT and wiring is large.
[0011]
From the above, it is necessary to eliminate the unevenness of the substrate surface and make it flat in order to improve the display quality of the LCD.
[0012]
Next, in the organic EL element, if the anode has irregularities, a leak current is generated and the luminance is lowered. In addition, the anode and the cathode are short-circuited, and current flows only in the shorted portion. The element may not emit light. In order to prevent this, a technique for polishing the anode has been disclosed (see Patent Document 1).
[0013]
FIG. 27 shows a cross-sectional view of the organic EL element. The organic EL element includes a hole transport layer 542, an organic EL layer 543, an upper electrode 544, and a transparent electrode film 545 formed on the TFT substrate 532 and the pixel electrode 524. The insulating layer 541 prevents the pixel electrode 524 and the transparent electrode film 545 from contacting each other. The TFT substrate 532 side includes a TFT 523 for controlling a current between the pixel electrode 524 and the upper electrode 544, a wiring 522, a contact hole 526 for electrically contacting the TFT 523 and the pixel electrode, a planarizing film 525, and the like.
[0014]
The anode corresponds to the pixel electrode 524. However, when the pixel electrode 524 is polished, there is a problem if the TFT substrate 532 is uneven. FIG. 28 is a cross-sectional view of an ideal TFT substrate having no irregularities, and FIG. 29A is a cross-sectional view of a TFT substrate having irregularities.
[0015]
In an ideal TFT substrate having no unevenness as shown in FIG. 28A, the pixel electrode 524 can be polished by chemical mechanical polishing (CMP) using the polishing pad 546 shown in FIG.
On the other hand, in the TFT substrate having unevenness as shown in FIG. 29A, the convex portion 528 becomes an obstacle and the pixel electrode 524 cannot be polished.
[0016]
CMP is a method of polishing a substrate by pressing the substrate against a polishing pad laid on a surface plate and rotating the surface plate while supplying a polishing liquid. The surface can be effectively planarized by a chemical reaction caused by the polishing liquid and mechanical friction between the polishing pad and the substrate.
[0017]
In the field of semiconductor devices, the miniaturization and multilayering of wiring are progressing with higher integration and higher performance, and the miniaturization of wiring can be handled by increasing the resolution at the time of exposure in the photolithography process.
[0018]
However, if the resolution is increased, the depth of focus of the exposure apparatus becomes shallow, so if there are irregularities due to the wiring generated on the substrate surface, the depth of focus of the exposure apparatus can not cope with the irregularities, and the exposure accuracy deteriorates, It becomes difficult to miniaturize the wiring. Therefore, in manufacturing a semiconductor device, it is required to make the substrate surface flat.
[0019]
Further, micro-optics are often used in combination with other optical components and have a laminated structure in order to have a plurality of functions. In order to simplify the assembly with other optical components and the production in a laminated structure, the substrate surface is required to be flat.
[0020]
A microlens array, which is one of microoptics, will be described as an example. In the microlens array, a concavo-convex shape serving as a lens surface is formed on a substrate by thermal sag, etching, machining, or the like of a resist.
[0021]
In this state, for example, since a lens and a prism are combined, even if an attempt is made to produce a prism on a microlens, the production is difficult due to the unevenness of the substrate surface. Therefore, in the micro-optics, it is required to make the substrate surface flat.
[0022]
As a conventional method for planarizing the surface of a substrate in the fields of a liquid crystal display element, an organic EL element, a semiconductor, micro-optics, etc., there are roughly known three methods: a planarization film method, an etch back method, and a polishing method.
[0023]
First, in the planarization film method, a planarization film having excellent flowability when heated is applied to the substrate surface, and the planarization film is heated and reflowed to flatten the substrate surface. The planarization film method will be described with reference to FIG.
[0024]
First, as shown in FIG. 30A, a wiring 611 is formed on a substrate 610, and an insulating film 619 is formed on the surface of the substrate. Here, the insulating film 619 on the surface of the substrate is uneven due to the influence of the wiring 611.
[0025]
Therefore, as shown in FIG. 30B, a planarizing film 616 is applied on the insulating film 619 to flatten the substrate surface. In some cases, the substrate surface is flattened by heating and reflowing the flattening film 616.
[0026]
However, although the planarization film method shown in FIG. 30 can level the unevenness of the substrate surface, the planarization film cannot be sufficiently planarized unless the thickness of the planarization film is made thicker than the unevenness level difference. For this reason, as shown in FIG. 31, the distance between the pixel electrode 624 and the TFT 623 becomes longer, and the contact hole 626 becomes deeper.
[0027]
Next, the etch-back method is a method for flattening by etching a film produced by the planarization film method. The etch back method will be described with reference to FIG.
[0028]
The steps of FIGS. 32A and 32B are the same as the planarizing film method shown in FIG. In the flattening film method, since the flattening film 616 is generally thicker, the flattening film 616 has a problem that the flattening film 616 becomes thicker if high flatness is desired. However, the etch back method does not cause this problem.
[0029]
As shown in FIG. 32C, in the etch-back method, the entire surface of the region to be flattened is etched to reduce the thickness of the flattening film 616. For the etching, dry etching using a reactive gas such as CCl4, CF4, CHF3, or O2 is used.
[0030]
The polishing method is a method of flattening by polishing the substrate surface. In particular, the chemical mechanical polishing (CMP) described above is often used.
[0031]
[Patent Document 1]
JP 09-245965 A
[Non-Patent Document 1]
Japan Society for the Promotion of Science, Organic Materials for Information Science, 142nd Committee, Liquid Crystal Subcommittee “Liquid Crystal Dictionary”, Baifukan Publishing, December 5, 1989, p. 134-136
[Non-Patent Document 2]
Shoichi Matsumoto, “Liquid Crystal Display Technology”, Industrial Book Publishing, November 8, 1996, p193
[0032]
[Problems to be solved by the invention]
In a TFT substrate of a liquid crystal display element or an organic EL element, the contact hole becomes deeper as the planarization film becomes thicker. This increases the contact failure between the pixel electrode and the TFT and decreases the yield.
[0033]
Further, since the planarization by the etch back method is almost determined by the planarization in the planarization film coating process rather than the dry etching process, the planarization by the etch back method cannot be sufficiently performed as in the planarization film method. There is a problem. Further, when the planarizing film is thickened, the etching amount increases and the working time increases.
[0034]
Further, in the polishing method, particularly CMP, planarization can be sufficiently performed, but it is necessary to introduce an expensive CMP apparatus, and there is a problem that the cost of the polishing liquid and the polishing pad which are consumables is increased. . When the planarizing film is an organic material, unlike the polishing of the inorganic film, the film is soft and difficult to polish. Further, scratches may occur during polishing.
[0035]
An object of the present invention is to provide a method for planarizing a substrate surface in a manufacturing process of a liquid crystal display element, an organic EL element, a semiconductor device such as a semiconductor, and an optical device such as a microoptics, a liquid crystal display device using the planarized substrate, an organic It is to provide an EL element.
[0036]
The flattened surface obtained by the present invention is a flat surface that is almost completely flat, or a flattened film layer that is at least thinner than the flattened surface of the conventional flattened film method, and has a flat surface with reduced unevenness. It is a conversion surface.
[0037]
[Means for Solving the Problems]
  The method for planarizing a substrate surface according to the present invention comprises:WetSexualityHigher than convexProcess,Improved wettabilityOnly in the recessSelectively deposit and flatten substrate surfaceA process.
[0038]
Moreover, the manufacturing method of the planarization board | substrate of this invention has the planarization method of the board | substrate surface of the said invention.
[0039]
In order to make the wettability of the concavo-convex parts different from each other by exposure, a wettability changing film whose wettability changes by exposure is applied in advance to the substrate surface, and then only the necessary part is selectively exposed to the above-mentioned film by exposure. A reaction is caused to change the wettability of the film itself, or the above film is decomposed by exposure to expose the film on the lower surface thereof. In order to selectively expose, when an exposure mask having an exposure pattern corresponding to the unevenness of the substrate surface is used, or when the convex portion is formed of a metal that does not affect the back surface of the projection, The exposure is performed from the back surface of the substrate without the convex portion so that only the convex portion is not exposed. In order to promote the exposure effect, a photocatalyst may be included in the wettability changing film, or a photocatalyst film may be provided on the lower surface thereof.
[0040]
A flattening film is applied to the surface of the substrate having different wettability formed in this manner so that the flattening film is not repelled and stacked on the concave portions but the flattening film is stacked on the concave portions. As a result, the planarizing film is not formed on the surface of the convex portion, and it is possible to form the planarizing film only on the concave portion. That is, according to the present invention, the surface of the convex portion of the substrate having a concavo-convex structure and the wettability of the concave portion with respect to the flattening film are different, and the wettability with respect to the flattening film is adjusted according to the concave and convex portions. In this case, a planarizing substrate is obtained with a thin planarizing film thickness.
[0041]
Further, by differentiating the wettability of the convex and concave surface of the concavo-convex structure to the flattening film by discharging, the flattening film is formed on the concave surface without forming the flattening film on the convex surface. You can also As a result, a flattening film is not unnecessarily formed on the convex portion, and a flattened substrate is obtained with a thin flattening film thickness.
[0042]
Furthermore, by differentiating the wettability of the concavo-convex convex surface and concave surface with the planarizing film by using a surface treatment agent, a flattening film is not formed on the convex surface and a flattening film is formed on the concave surface. A membrane can also be formed.
[0043]
After flattening the substrate, the entire surface of the substrate can be made uniform by exposing the protrusions or dissolving the wettability changing film remaining on the protrusions. This makes it possible to form another film on the planarized substrate. If another planarization film is formed as another film, the substrate surface can be further planarized.
[0044]
The present invention can be applied to various apparatuses having a substrate. For example, the liquid crystal display device of the present invention uses a liquid crystal whose surface is planarized by the substrate surface planarization method of the present invention. As a result, it is possible to provide various devices with improved performance or reliability as compared with the prior art.
[0045]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0046]
A method for planarizing a substrate surface according to the present invention is a method for planarizing a substrate surface for forming a surface having irregularities, wherein the wettability of the substrate surface convex portion and the substrate surface concave portion with respect to the planarization film is changed, and the substrate surface is changed. Due to the difference in wettability, a planarizing film is selectively applied to the recesses on the substrate surface to flatten the substrate surface. Here, the concave portion refers to a plane other than the convex portion.
[0047]
As means for changing the wettability of the substrate surface, specifically, a method of pattern exposure corresponding to the uneven shape of the substrate surface, a method of generating a mask on the substrate surface, and performing a surface treatment by discharge, a surface treatment agent There is a way. Hereinafter, embodiments of the present invention according to the respective methods will be described.
[0048]
(Embodiment 1)
FIG. 1 is a cross-sectional view showing the basic concept of a method for planarizing a substrate surface according to Embodiment 1 of the present invention in the order of steps.
[0049]
FIG. 1A shows the state of the substrate surface before flattening. Concave portions 10 a and convex portions 10 b exist on the surface of the substrate 10.
[0050]
First, as shown in FIG. 1B, the substrate surface is subjected to pattern exposure using an exposure mask 14 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 14 has a light transmitting portion 14a and a light shielding portion 14b. The concave portion 10b on the substrate surface corresponds to the light transmitting portion 14a, and the convex portion 10a on the substrate surface corresponds to the light shielding portion 14b. Yes. Further, the substrate surface is water-repellent and has a characteristic that wettability changes to hydrophilicity upon exposure.
[0051]
By exposing the substrate surface, the wettability changing surface 30 in which the wettability with respect to the planarizing film 16 is changed before and after the treatment is formed in the recess 10b. That is, the recess 10b changes from water repellency to hydrophilicity. For example, when the convex portion 10a and the concave portion 10b are a polymer resin having an alkyl group at the terminal group, the pattern-exposed concave portion 10b is wettable from lipophilicity to hydrophilicity by cutting the terminal group by ultraviolet irradiation. Changes.
[0052]
Next, as shown in FIG. 1C, a planarizing film 16 is formed on the substrate surface. Since the convex portion 10a on the substrate surface is water repellent and the concave portion 10b is hydrophilic, the hydrophilic flattening film 16 is laminated only on the hydrophilic concave portion 10b, and on the water repellent convex portion 10a. Do not stack. Thereby, the flattening film 16 is laminated in the concave portion 10a up to the height of the convex portion 10b, and the flattened surface 21 is obtained.
[0053]
If the unevenness of the flattening surface 21 does not become a problem, it is not necessary to form the flattening film 16 until the height of the protrusion 10a is matched. Conversely, the film surface of the planarizing film 16 formed in the recess 10b may be higher than the protrusion 10a.
[0054]
In the above description, the planarizing film 16 is hydrophilic, but may be oleophilic. In this case, the wettability of the pattern-exposed recess 10b changes from oil repellency to oleophilicity.
[0055]
The basic concept of the first embodiment has been described above, and further will be described in detail using a specific example with reference to FIGS. In Embodiments 1-1 to 1-7, embodiments of the present invention in the case where unevenness occurs due to wiring on the substrate will be described. Further, in Embodiments 1-8 to 1-11, the wiring is two-dimensional. Embodiments will be described in the case where they are provided and intersect with each other or when applied to a microlens array or the like.
[0056]
(Embodiment 1-1)
FIG. 2 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-1 of the present invention in the order of steps. FIG. 3 is a top view showing the substrate surface before the planarization process of the substrate surface planarization method shown in FIG.
[0057]
The method for planarizing the substrate surface according to the present embodiment is applicable to a liquid crystal display element, an organic EL element, and a semiconductor substrate surface.
[0058]
As shown in FIG. 2A, the wiring 11 is formed on the substrate 10, and the insulating film 19 is further formed thereon so as to cover the entire substrate. As shown in FIG. 3, a plurality of wirings 11 are arranged in parallel in one direction. A cross section B-B ′ in FIG. 3 corresponds to the cross sectional view in FIG. 2.
[0059]
First, as shown in FIG. 2B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material for the water / oil repellent film 13, fluorocarbon having an alkoxysilyl group is used (hereinafter referred to as FAS1). Examples of FAS1 include compounds represented by the following general formula 1, but are not limited to these examples.
[0060]
Formula 1 (CF_Three-(CF₂)_n-CH₂-CH₂)_m-Si- (OR_Three)_4-m
In the formula, n represents an integer of 0 to 12. m represents an integer of 1 to 3. R represents an alkyl group having 1 to 5 carbon atoms. When FAS1 is irradiated with ultraviolet light, the alkoxysilyl group has hydrophilic SiO 2₂Has a changing nature. Moreover, there is no restriction | limiting in particular in this film thickness. Further, the film forming method of the water / oil repellent layer is not particularly limited, and examples thereof include a spin coat method, a dip method, and a vapor deposition method, but are not limited to these examples.
[0061]
Next, as shown in FIG. 2C, the water / oil repellent film 13 is irradiated with light 15 using an exposure mask 14 having an exposure pattern corresponding to the uneven shape of the substrate surface. Ultraviolet light is used as the light source.
[0062]
The exposure mask 14 includes a light transmitting portion 14a and a light shielding portion 14b. The concave portion on the substrate surface corresponds to the light transmitting portion 14a, and the convex portion on the substrate surface corresponds to the light shielding portion 14b. . Therefore, FAS1 is decomposed in the concave portion irradiated with ultraviolet light, and the water / oil repellent film 13 in the concave portion on the substrate surface changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b serving as a wettability changing surface. . On the other hand, since the convex portion is not exposed, the water / oil repellent film 13 remains as the water / oil repellent portion 13a. That is, the water / oil repellent film 13 is divided into two regions: a hydrophilic / oleophobic portion 13b where FAS1 is decomposed and a water / oil repellent portion 13a where FAS1 remains. Here, the irradiation light may be an electromagnetic wave having energy higher than the water / oil repellent film 13 is decomposed, and the intensity, irradiation angle, irradiation time, and frequency are not limited.
[0063]
After the exposure using the exposure mask 14, the planarizing film 16 is applied to the surface of the water / oil repellent film 13 as shown in FIG. A planarizing film 16 is laminated on the upper surface of the hydrophilic / lipophilic portion 13b. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent part 13a on the wiring 11, the planarizing film 16 is not laminated. By adjusting the coating amount of the planarizing film 16, the surface height of the planarizing film 16 laminated on the hydrophilic / oleophilic portion 13b is matched with the surface height of the water / oil repellent film 13 coated on the wiring 11. As a result, the planarized surface 21 is obtained. Examples of the method for forming the planarizing film 16 include a spin coating method, a dip method, a spray method, a nozzle injection method, a printing method, and a transfer method, but are not limited to these examples.
[0064]
Next, as shown in FIG. 2E, when the substrate 10 is exposed from the wiring 11 side, the water / oil repellent film 13 on the wiring 11 changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b. . This makes it possible to apply another film on the water / oil repellent film 13 on the wiring 11.
[0065]
In order to further apply another film, the substrate 10 may be immersed in perfluorooctane and the water / oil repellent film 13 may be dissolved and removed in addition to the above method. In this case, when the planarizing film 16 is applied, the surface of the planarizing film 16 may be lowered by the amount of the water / oil repellent film 13 to be removed. This step is not necessary when no other film is applied on the water / oil repellent film 13 or when another film can be applied on the water / oil repellent part 13a.
[0066]
As described above, the flattening of the substrate, which is the object of the present invention, is achieved, but the unevenness due to the wiring 11 can be further flattened by performing the following steps. That is, as shown in FIG. 2F, the planarization surface 22 is obtained by further applying the planarization film 17. Since the planarization surface 21 has already been obtained, the planarization film 17 has a high planarization effect even with a small thickness. The flattened surface 22 can further reduce unevenness due to the wiring 11 than the flattened surface 21.
[0067]
By further applying another flattening film (not shown) to the flattened surface 22, it is also possible to obtain a flattened surface (not shown) with even more unevenness. Also at this time, since the other planarization film has already obtained the planarization surface 22, the planarization effect is high even with a small thickness.
[0068]
Next, when the change to the hydrophilic / lipophilic property of the water / oil repellent film 13 by exposure is weak or slow, the change by exposure can be promoted by including a photocatalyst in the water / oil repellent film 13. As the photocatalyst, titanium dioxide, indium oxide, tin oxide, zinc oxide, cadmium sulfide, iron oxide, strontium titanate and the like can be used.
[0069]
Further, the following can be said about the planarizing film 16. First of all, the planarizing film 16 can be arbitrarily laminated as long as it can be laminated on the hydrophilic / lipophilic part 13b of the water / oil repellent film 13 and cannot be laminated on the water / oil repellent part 13a of the water / oil repellent film 13. Can be used.
[0070]
Second, when the planarization film 16 is subjected to heat treatment, the planarization film 16 having good heat melting property can be used to further planarize the substrate surface using the flowability of the planarization film 16. it can.
[0071]
Third, in the present embodiment, the planarizing film 16 is applied after forming the insulating film 19 on the wiring 11. However, the planarizing film 16 is directly applied on the wiring 11, and this planarizing film 16 is applied to the insulating film. You may make it use as.
[0072]
According to the present embodiment, by using the water / oil repellent film 13 that changes from water / oil repellent property to hydrophilic / lipophilic property by exposure, it becomes possible to flatten a substrate having irregularities, and a conventional photolithography apparatus can be used as it is. Therefore, it is not necessary to introduce a new device and the cost can be reduced.
Further, unlike the conventional planarization method, the planarization film 16 is not applied on the wiring 11 due to the effect of the water / oil repellency portion 13a. In addition, the substrate surface can be planarized. Therefore, the film thickness of the planarizing film 16 or the total film thickness of the planarizing film 16 and the planarizing film 17 can be reduced, and the cost can be reduced.
[0073]
(Embodiment 1-2)
FIG. 4 is a cross-sectional view showing another substrate surface planarization method according to Embodiment 1-2 of the present invention in the order of steps.
[0074]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0075]
In this embodiment, in the step of exposing the water / oil repellent film 13, the exposure is performed from the back surface of the substrate without using the exposure mask 14 having the exposure pattern corresponding to the uneven shape of the substrate surface. And different.
[0076]
As shown in FIG. 4A, the wiring 11 is formed on the substrate 10, and the insulating film 19 is further formed thereon. The wiring 11 causing unevenness is made of metal and does not transmit light. On the other hand, the substrate 10 transmits light.
Here, “not transmitting light” means that the substrate 10, a material that does not transmit light, such as metal, and the water- and oil-repellent film 13 are laminated in this order (Condition A), and the substrate 10 and the water- and oil-repellent film 13 are ordered. When exposed from the opposite side of the water / oil repellent film 13, the water / oil repellent film 13 changes from water / oil repellent to hydrophilic / lipophilic in condition B. It is defined that the light having the wavelength necessary for the water / oil repellent film 13 to change from the water / oil repellent property to the hydrophilic / lipophilic property is reflected or absorbed by the substance so that it remains water / oil repellent.
[0077]
In the present embodiment, first, as shown in FIG. 4B, a water / oil repellent film 13 is applied to the surface of the substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0078]
Next, as shown in FIG. 4C, the water / oil repellent film 13 is exposed from the surface opposite to the surface on which the water / oil repellent film 13 is applied. The wiring 11 that causes unevenness is made of metal and does not transmit light 15 and is not exposed to the water / oil repellent film 13, so the water / oil repellent film 13 applied on the wiring 11 remains the water / oil repellent portion 13 a. . On the other hand, where there is no wiring 11 that causes unevenness, the light 15 is transmitted and exposed to the water and oil repellent film 13, so that the water and oil repellent film 13 changes from the water and oil repellent part 13a to the hydrophilic and lipophilic part 13b. To do.
[0079]
Next, as shown in FIG. 4D, a planarizing film 16 is applied. In the hydrophilic / lipophilic portion 13 b, the planarizing film 16 is laminated on the water / oil repellent film 13. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent portion 13 a on the wiring 11, the planarizing film 16 is not laminated on the water / oil repellent film 13. By adjusting the coating amount of the flattening film 16, the flattened surface is obtained by matching the height of the film surface of the flattened film 16 after film formation with the film surface of the water / oil repellent film 13 applied on the wiring 11. 21 is obtained.
[0080]
Next, as shown in FIG. 4E, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the wiring 11 changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b. . This makes it possible to apply another film on the water / oil repellent film 13 on the wiring 11.
[0081]
Also in this embodiment, as shown in FIG. 4F, the planarization surface 22 is obtained by further applying the planarization film 17. The effect is the same as that of Embodiment 1-1.
[0082]
This embodiment is an effective method for planarizing a substrate on which convex portions are formed of a material such as metal that does not transmit light. As a specific effect, the cost of the exposure mask can be reduced.
[0083]
(Embodiment 1-3)
FIG. 5 is a sectional view showing another substrate surface planarization method according to the embodiment 1-3 of the present invention in the order of steps.
[0084]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0085]
This embodiment is different from Embodiments 1-1 and 1-2 in that the photocatalytic film 31 is formed before the water / oil repellent film 13 is applied.
[0086]
As shown in FIG. 5A, the wiring 11 is formed on the substrate 10, and the insulating film 19 is further formed thereon. Note that the top view of the substrate in FIG. 5A before forming the insulating film 19 is the same as FIG. A cross-section B-B ′ in FIG. 3 corresponds to the cross-sectional view in FIG. 5.
[0087]
First, as shown in FIG. 5B, a photocatalytic film 31 is formed on the surface of a substrate having a concavo-convex structure. The material of the photocatalyst film 31 is a substance that generates electrons and holes upon exposure, and examples thereof include indium oxide, tin oxide, zinc oxide, cadmium sulfide, iron oxide, and strontium titanate in addition to titanium dioxide. It is not limited to the example. The film forming method is not particularly limited, and examples thereof include a sputtering method and a sol-gel film forming method. Furthermore, there is no restriction | limiting in particular also about this film thickness.
[0088]
Next, as shown in FIG. 5C, a water / oil repellent film 13 is applied to the surface of the substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0089]
Next, as shown in FIG. 5D, the water / oil repellent film 13 is exposed using an exposure mask 14 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 14 includes a light transmitting portion 14a and a light shielding portion 14b. The concave portion on the substrate surface corresponds to the light transmitting portion 14a, and the convex portion on the substrate surface corresponds to the light shielding portion 14b. . By exposure using the exposure mask 14, the water / oil repellent film 13 in the concave portion of the substrate surface changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b. That is, by forming the water / oil repellent film 13 on the photocatalyst film 31, electrons and holes are generated in the exposed region by the action of the photocatalyst film 31 as a semiconductor photocatalyst, and FAS1 is decomposed. In the decomposed FAS1, the alkoxysilyl group is SiO.₂become. In this way, a change in water and oil repellency is promoted as compared to the case without the photocatalyst film. On the other hand, since the convex portion is not exposed, the water / oil repellent film 13 remains as the water / oil repellent portion 13a. Irradiation light is an electromagnetic wave having energy equal to or greater than the energy corresponding to the band gap of the photocatalyst, and there is no limitation on the intensity, irradiation angle, irradiation time, and frequency. Moreover, you may expose simultaneously these electromagnetic waves and the electromagnetic waves which have energy below the energy equivalent to a band gap.
[0090]
Next, as shown in FIG. 5E, a planarizing film 16 is applied on the water / oil repellent film 13. In the hydrophilic / lipophilic portion 13 b, the planarizing film 16 is laminated on the water / oil repellent film 13. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent portion 13 a on the wiring 11, the planarizing film 16 is not laminated on the water / oil repellent film 13. By adjusting the coating amount of the flattening film 16, the flattened surface is obtained by matching the height of the film surface of the flattened film 16 after film formation with the film surface of the water / oil repellent film 13 applied on the wiring 11. 21 is obtained. The photocatalyst layer 31 can promote the change of the water / oil repellent film 13 from the water / oil repellent property to the hydrophilic / lipophilic property by the exposure.
[0091]
(Embodiment 1-4)
FIG. 6 is a cross-sectional view showing another substrate surface planarization method according to Embodiment 1-4 of the present invention in the order of steps.
[0092]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0093]
This embodiment is different from Embodiments 1-1 to 1-3 in that the water / oil repellent film 13 disappears as a gas decomposition product upon exposure.
[0094]
As shown in FIG. 6A, the wiring 11 is formed on the substrate 10, and the insulating film 19 is further formed thereon. The top view of the substrate of FIG. 6A before the insulating film 19 is formed is the same as FIG. A cross section B-B ′ in FIG. 3 corresponds to the cross sectional view in FIG. 6.
[0095]
First, as shown in FIG. 6B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, fluorocarbon having an alkoxysilyl group is used (hereinafter referred to as FAS2). Examples of FAS2 include compounds represented by the following general formulas 2 to 4, but are not limited to these examples.
[0096]
General formula 2 G-CF₂-(CF₂)_n-CF₂-G
Formula 3 G- (CF₂-CF₂-O)_p-(CF₂-O)_q-G
Formula 4 G- (CF₂-CF₂-O)_p-G
In the formula, n represents an integer of 0 to 12. G is independently F, CH₂-OH or COOH. p and q each independently represent an integer of 0 to 4. FAS2 has the property of decomposing and disappearing as a gas decomposition product when irradiated with ultraviolet light. Moreover, there is no restriction | limiting in particular in this film thickness. Further, the film forming method of the water / oil repellent layer is not particularly limited, and examples thereof include a spin coat method, a dip method, and a vapor deposition method, but are not limited to these examples.
[0097]
Next, as shown in FIG. 6C, the water and oil repellent film 13 is exposed using an exposure mask 14 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 14 includes a light transmitting portion 14a and a light shielding portion 14b. The concave portion on the substrate surface corresponds to the light transmitting portion 14a, and the convex portion on the substrate surface corresponds to the light shielding portion 14b. . By the exposure using the exposure mask 14, the water- and oil-repellent film 13 in the concave portion of the substrate surface disappears from the insulating film 19 as a gas decomposition product. On the other hand, since the convex portion is not exposed, the water / oil repellent film 13 remains as the water / oil repellent portion 13a. Thus, in the recess, the water / oil repellent FAS 2 film, that is, the layer under the water / oil repellent film 13 is exposed. Irradiation light is an electromagnetic wave having energy more than the water- and oil-repellent film 13 is decomposed, and there is no limitation on its intensity, irradiation angle, irradiation time, and frequency.
[0098]
Next, as shown in FIG. 6D, a planarizing film 16 is applied on the water / oil repellent film 13. A planarizing film 16 is laminated on the insulating film 19. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent part 13a on the wiring 11, the planarizing film 16 is not laminated. By adjusting the coating amount of the flattening film 16, the flattened surface is obtained by matching the height of the film surface of the flattened film 16 after film formation with the film surface of the water / oil repellent film 13 applied on the wiring 11. 21 is obtained.
[0099]
Next, as shown in FIG. 6E, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the wiring 11 disappears from the insulating film 19 as a gas decomposition product. As a result, another film can be applied onto the insulating film 19 on the wiring 11. Alternatively, the substrate 10 may be immersed in perfluorooctane, and the water / oil repellent film 13 may be dissolved and removed.
[0100]
Also in this embodiment, as shown in FIG. 6F, the planarization surface 22 is obtained by further applying the planarization film 17. The effect is the same as that of Embodiment 1-1.
[0101]
When the change to the gas decomposition product of the water / oil repellent film 13 by exposure is weak or slow, the change due to exposure can be promoted by including the photocatalyst in the water / oil repellent film 13. At this time, after the FAS 2 is decomposed and disappears, the substance contained in the water / oil repellent film 13 remains. As the photocatalyst, titanium dioxide, indium oxide, tin oxide, zinc oxide, cadmium sulfide, iron oxide, strontium titanate and the like can be used.
[0102]
Embodiment 1-5
FIG. 7 is a cross-sectional view illustrating another substrate surface planarization method according to Embodiment 1-5 of the present invention in the order of steps.
[0103]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0104]
This embodiment is different from the embodiment 1-4 in that the photocatalytic film 31 is formed before the water / oil repellent film 13 is applied.
[0105]
As shown in FIG. 7A, the wiring 11 is formed on the substrate 10, and the insulating film 19 is further formed thereon. The top view of the substrate of FIG. 7A before the insulating film 19 is formed is the same as FIG. A cross section B-B ′ in FIG. 3 corresponds to the cross sectional view in FIG. 7.
[0106]
First, as shown in FIG. 7B, a photocatalytic film 31 is formed on the surface of a substrate having a concavo-convex structure.
[0107]
Next, as shown in FIG. 7C, a water / oil repellent film 13 is applied to the surface of the substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS2 is used.
[0108]
Next, as shown in FIG. 7D, the water and oil repellent film 13 is exposed using an exposure mask 14 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 14 includes a light transmitting portion 14a and a light shielding portion 14b. The concave portion on the substrate surface corresponds to the light transmitting portion 14a, and the convex portion on the substrate surface corresponds to the light shielding portion 14b. . The water / oil repellent film 13 in the concave portion of the substrate surface disappears from the insulating film 19 as a gas decomposition product. On the other hand, since the convex portion is not exposed, the water / oil repellent film 13 remains as the water / oil repellent portion 13a. By forming the water / oil repellent film 13 on the photocatalyst film 31, electrons and holes are generated in the exposed region by the action of the photocatalyst film 31 as a semiconductor photocatalyst, and the FAS 2 is decomposed. The decomposed FAS 2 becomes a gas decomposition product and disappears, and the photocatalytic layer 31 is exposed. Thus, the change in water and oil repellency is promoted as compared with the case where the photocatalyst film 31 is not provided. Irradiation light is an electromagnetic wave having energy equal to or greater than the energy corresponding to the band gap of the photocatalyst, and there is no limitation on the intensity, irradiation angle, irradiation time, and frequency. Moreover, you may expose simultaneously these electromagnetic waves and the electromagnetic waves which have energy below the energy equivalent to a band gap.
[0109]
Next, as shown in FIG. 7E, a planarizing film 16 is applied on the water / oil repellent film 13. A planarizing film 16 is stacked on the photocatalytic film 31. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent part 13a on the wiring 11, the planarizing film 16 is not laminated. By adjusting the coating amount of the flattening film 16, the flattened surface is obtained by matching the height of the film surface of the flattened film 16 after film formation with the film surface of the water / oil repellent film 13 applied on the wiring 11. 21 is obtained.
[0110]
Next, as shown in FIG. 7F, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the wiring 11 disappears from the photocatalyst film 31 as a gas decomposition product. This makes it possible to apply another film on the photocatalytic film 31 on the wiring 11. Alternatively, the substrate 10 may be immersed in perfluorooctane, and the water / oil repellent film 13 may be dissolved and removed.
[0111]
Also in this embodiment, as shown in FIG. 7F, the planarization surface 22 is obtained by further applying the planarization film 17. The effect is the same as that of Embodiment 1-1.
[0112]
In the present embodiment, the photocatalyst layer can promote the change of the water / oil repellent film from the water / oil repellent property to the hydrophilic / lipophilic property by exposure.
[0113]
Embodiment 1-6
FIG. 8 is a cross-sectional view showing another substrate surface planarization method according to Embodiment 1-6 of the present invention in the order of steps.
[0114]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0115]
In this embodiment, after obtaining the flattened surface 21, when the water / oil repellent part 13a of the water / oil repellent film 13 is changed to the hydrophilic / lipophilic part 13b by exposure, the exposure mask 14 is used, The point which exposes only to the water- and oil-repellent part 13a of the oil film 13 differs from Embodiment 1-1 to 1-5.
[0116]
This embodiment is the same as the above-described embodiment, for example, Embodiment 1-1, until the planarized surface 21 is obtained. That is, the steps up to FIG. 2 (d) are the same. FIG. 8 shows only the subsequent steps extracted.
[0117]
In this embodiment, after the flat surface 21 is obtained, as shown in FIG. 8A, the substrate 10 is wired 11 using an exposure mask 14 ′ having an exposure pattern corresponding to the uneven shape of the substrate surface. Exposure from the side. The exposure mask 14 ′ has a light transmitting portion 14 a and a light shielding portion 14 b, where the water repellent and oil repellent portion 13 a is the light transmitting portion 14 a and where the planarizing film 16 is laminated is a light shielding portion. This corresponds to the portion 14b. As a result, the water / oil repellent film 13 on the wiring 11 is changed from the water / oil repellent part 13 a to the hydrophilic / lipophilic part 13 b, and another film can be applied on the water / oil repellent film 13 on the wiring 11. It becomes.
[0118]
Also in this embodiment, as shown in FIG. 8B, the planarization surface 22 is obtained by further applying the planarization film 17. The effect is the same as that of Embodiment 1-1.
[0119]
This embodiment prevents the influence of light on the flattening film when the water / oil repellent film is exposed to light having a wavelength necessary for the water / oil repellent film to change from water / oil repellent to hydrophilic / lipophilic. It is possible. Here, the influence of light means that the molecular weight decreases and the transmittance decreases due to the destruction of the molecular structure of the planarization film due to the wavelength and energy amount of light.
[0120]
(Example 1-7)
FIG. 9 is a cross-sectional view showing another substrate surface planarization method according to Embodiment 1-7 of the present invention in the order of steps.
[0121]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0122]
This embodiment is different from the embodiments 1-1 to 1-6 in that the planarization surface 24 is obtained by cutting the planarization film 17 after obtaining the planarization surface 21.
[0123]
In the present embodiment, any method of Embodiment Examples 1-1 to 1-6 may be used until the planarized surface 21 is obtained. For this reason, the description of the method for obtaining the planarized surface 21 is omitted.
[0124]
As shown in FIG. 9A, there is a substrate in which the unevenness due to the wiring 11 formed on the substrate 10 is flattened by a water / oil repellent film 13 and a planarizing film 16 to obtain a planarized surface 21.
[0125]
In the present embodiment, first, as shown in FIG. 9B, the planarization surface 23 is obtained by further applying the planarization film 17 on the planarization surface 21. The flattened surface 23 is set higher in advance than the finally obtained flattened surface 24.
[0126]
Next, as shown in FIG. 9C, the planarized planarized surface 23 of the planarized film 17 is cut down to the planarized surface 24. At this time, dry etching using a reactive gas such as CCl4, CF2, CHF2, or O2 is used.
[0127]
In general, when a planarized surface has already been obtained, an additional planarizing film for further increasing the flatness may be thin. However, in this embodiment, the additional planarizing film is formed thick and flat. The degree of unevenness can be further reduced because the additional planarization film is shaved after increasing the degree. That is, the planarization surface 24 of the present embodiment can reduce not only the unevenness from the planarization surface 21 but also the planarization surface 22 obtained in Embodiments 1-1 to 1-7.
[0128]
This embodiment can also be applied to Embodiments 2 and 3 described later.
[0129]
Embodiment 1-8
A method for planarizing another substrate surface according to the embodiment 1-8 of the present invention will be described with reference to FIGS. 10A and 10B are a top view and a cross-sectional view showing the substrate surface before the planarization process in the substrate surface planarization method according to the present embodiment. FIG. 11 is a top view showing the water / oil repellency region / hydrophilic / lipophilic region of the substrate surface in the substrate surface planarization method according to the present embodiment. FIG. 12 is a cross-sectional view illustrating the substrate surface planarization method according to the present embodiment in the order of steps.
[0130]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0131]
As shown in FIG. 10A, wiring 11 and wiring 12 are arranged on the substrate 10. 10B is a cross-sectional view taken along a cross-section A-A ′, FIG. 10C is a cross-sectional view taken along a cross-section B-B ′, and FIG. As shown in these drawings, the wiring and the insulating film are formed on the substrate 10 in the order of the wiring 12, the insulating film 19, the wiring 11, and the insulating film 20 from the bottom. The wiring 11 and the wiring 12 intersect with each other at four locations, and the wiring 11 is configured to pass over the wiring 12 at the intersection, but the reverse relationship may be used. In this structure, the difference between the projections and depressions is the largest where the wiring 11 and the wiring 12 intersect. Further, the wirings 11 and 12 are materials such as metal that do not transmit light, and the film thickness thereof is the same.
[0132]
In the following, the planarization step is shown for each of the cross section A-A ′, the cross section B-B ′, and the cross section C-C ′.
[0133]
(About cross section A-A ')
As shown in FIG. 12A, the wiring 12, the insulating film 19, the wiring 11, and the insulating film 20 are formed in this order on the substrate 10 from the bottom. The wiring 11 exists only in a part on the insulating film 19.
[0134]
First, as shown in FIG. 12B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0135]
Next, as shown in FIG. 12C, the water / oil repellent film 13 is exposed from the surface opposite to the surface to which the water / oil repellent film 13 is applied. Since the wirings 11 and 12 that cause unevenness are made of metal, light does not pass through the wirings 11 and 12 and does not reach the water and oil repellent film 13. Therefore, the water / oil repellent film 13 applied on the wirings 11 and 12 remains the water / oil repellent portion 13a. That is, in the cross section A-A ′, the water / oil repellent film 13 remains as the water / oil repellent portion 13 a.
[0136]
Next, as shown in FIG. 12D, a planarizing film 16 is applied. Since the wiring 12 is provided along the cross-section A-A ′, the planarizing film 16 is laminated on the water- and oil-repellent film 13 in the hydrophilic / oleophilic portion 13 b at the front and rear of the cross section. On the other hand, since the upper surfaces of the wirings 11 and 12 on the cross section A-A ′ are water / oil repellent portions 13 a and the planarizing film 16 is repelled, the planarizing film 16 is not laminated. The coating amount of the flattening film 16 is adjusted, and the film surface of the flattened film 16 after film formation and the film surface where the wiring 12, the insulating film 19, the insulating film 20, and the water / oil repellent film 13 are laminated The flattened surface 25 is obtained by matching the heights. The height of the flattened surface 25 is shown in the cross section C-C ′.
[0137]
Next, as shown in FIG. 12E, when the substrate 10 is exposed from the wiring 11 side, the water / oil repellent film 13 on the insulating film 20 changes from the water / oil repellent part 13a to the hydrophilic / lipophilic part 13b. To do. This makes it possible to apply another film on the water / oil repellent film 13 on the insulating film 20.
[0138]
(About cross section B-B ')
As shown in FIG. 12A, the insulating film 19, the wiring 11, and the insulating film 20 are formed in this order on the substrate 10. The wiring 11 exists only in a part on the insulating film 19.
[0139]
First, as shown in FIG. 12B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0140]
Next, as shown in FIG. 12C, the water / oil repellent film 13 is exposed from the surface opposite to the surface to which the water / oil repellent film 13 is applied. Since the wiring 11 that causes the unevenness is made of metal, light is not transmitted and the water and oil repellent film 13 is not exposed, so the water and oil repellent film 13 applied on the wiring 11 remains the water and oil repellent portion 13a. is there.
[0141]
Next, as shown in FIG. 12D, a planarizing film 16 is applied. In the hydrophilic / lipophilic portion 13 b, the planarizing film 16 is laminated on the water / oil repellent film 13. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent portion 13 a on the wiring 11, the planarizing film 16 is not laminated on the water / oil repellent film 13. The coating amount of the planarizing film 16 is adjusted, and the film surface of the planarized film 16 after film formation and the film surface where the insulating film 19, the wiring 11, the insulating film 20, and the water / oil repellent film 13 are laminated. The flattened surface 25 is obtained by matching the heights.
[0142]
Next, as shown in FIG. 12E, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the wiring 11 changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b. . This makes it possible to apply another film on the water / oil repellent film 13 on the wiring 11.
[0143]
(Regarding section C-C ')
As shown in FIG. 12A, the wiring 12, the insulating film 19, the wiring 11, and the insulating film 20 are formed in this order on the substrate 10 from the bottom. The wiring 11 exists only on the wiring 12.
[0144]
First, as shown in FIG. 12B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0145]
Next, as shown in FIG. 12C, the water / oil repellent film 13 is exposed from the surface opposite to the surface to which the water / oil repellent film 13 is applied. Since the wirings 11 and 12 that cause unevenness are made of metal, light does not pass through and the water- and oil-repellent film 13 is not exposed. It remains.
[0146]
Next, as shown in FIG. 12D, a planarizing film 16 is applied. In the hydrophilic / lipophilic part 13 b, a planarizing film is laminated on the water / oil repellent film 13. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent portion 13 a on the wiring 11, the planarizing film 16 is not laminated on the water / oil repellent film 13. The coating amount of the flattening film 16 is adjusted, and the film surface of the flattened film 16 after film formation and the film surface where the wiring 12, the insulating film 19, the insulating film 20, and the water / oil repellent film 13 are laminated are laminated. The flattened surface 25 is obtained by adjusting the height.
[0147]
Next, as shown in FIG. 12E, when the substrate 10 is exposed from the wiring 11 side, the water / oil repellent film 13 on the insulating film 20 changes from the water / oil repellent part 13a to the hydrophilic / lipophilic part 13b. To do. This makes it possible to apply another film on the water / oil repellent film 13 on the wiring 11.
[0148]
Although the unevenness due to the wiring 11 remains on the flattened surface 25, the unevenness difference can be reduced with a thin film thickness of the flattened film at least as compared with the flattened surface of the conventional flattened film method.
[0149]
Further, after obtaining the flattened surface 25, the flattening may be performed by the embodiments 1-1 to 1-7 of the present invention or the conventional flattened film method. When the conventional planarization film method is performed after obtaining the planarization surface 25, the planarization is performed more than when the conventional planarization film method is performed directly on the insulating film 20 without obtaining the planarization surface 25. It is possible to obtain a flattened surface in which the unevenness difference is reduced with a thin film thickness.
[0150]
In the present embodiment, as described above, the water / oil repellent film 13 on the wiring 11 and the wiring 12 is left on the water / oil repellent film 13a, so that Further, the flattening film 16 is not applied. That is, as a result of applying FAS1 to the substrate 10 and performing backside exposure, the water / oil repellent part and the hydrophilic / lipophilic part are as shown in FIG.
[0151]
When the wirings 11 and 12 are not a substance that does not transmit light, such as metal, an exposure mask as described in Embodiment 1-1 can be used, for example.
[0152]
According to this embodiment, by using a water / oil repellent film, it becomes possible to flatten a substrate having convex portions having different heights, and a conventional photolithography apparatus can be used as it is, so that it is necessary to introduce a new apparatus. No cost
In this embodiment, the method of planarizing the concavo-convex substrate using the step of changing the wettability of the substrate surface by pattern exposure is used. However, as a method of changing the wettability, a discharge process using a mask described later is used. A step of changing the wettability of the substrate surface (Embodiment 2) or a step of changing the wettability of the substrate surface by applying a surface treatment agent using a mask (Embodiment 3) may be used.
[0153]
Embodiment 1-9
FIG. 13 is a cross-sectional view of a substrate surface according to Embodiment 1-9 of the present invention.
[0154]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0155]
In this embodiment, the installation situation of the wirings 11 and 12 on the board | substrate 10 is the same as Embodiment 1-9, The detail is as showing in FIG.
[0156]
In the present embodiment, in the step of applying the flattening film 16, the film surface of the flattening film 16 after film formation is matched with the height of the surface of the water / oil repellent film 13 at the intersection of the wirings 11 and 12. The point which obtained the surface 26 differs from Embodiment 1-9.
[0157]
Embodiment 1-10
14 and 15, another method for planarizing the substrate surface according to the embodiment 1-10 of the present invention will be described. FIG. 14 is a top view showing the water / oil repellency region / hydrophilic / lipophilic region of the substrate surface in the planarization step according to the present embodiment. FIG. 15 is a cross-sectional view showing the substrate surface planarization method according to the present embodiment in the order of steps. The state of the substrate surface before planarization is the same as in FIG.
[0158]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0159]
In the present embodiment, the water- and oil-repellent film 13 at the point where the wirings 11 and 12 intersect is obtained by changing the property of the water- and oil-repellent film 13 where the planarizing film 16 is laminated from water- and oil-repellent to hydrophilic and lipophilic. In the step of leaving only the water- and oil-repellent part 13a as the only part 13 and the hydrophilic / lipophilic part 13b in the other parts and applying the planarizing film 16, the film surface of the planarized film 16 after the film formation, It differs from Embodiments 1-9 and 10 in that the level of the surface of the water / oil repellent film 13 at 12 intersections is combined to obtain a flat surface 27 with high flatness. In the present embodiment, the present invention can be applied even if the heights (thicknesses) of the two interconnecting wires 11 and 12 are different.
[0160]
The cross section of the substrate surface before flattening is the same as that shown in FIGS. Hereinafter, the planarization process is shown for each of the cross sections A-A ', B-B', and C-C 'with reference to FIG.
[0161]
(About cross section A-A ')
As shown in FIG. 15A, the wiring 12, the insulating film 19, the wiring 11, and the insulating film 20 are formed in this order on the substrate 10 from the bottom. The wiring 11 exists only in a part on the insulating film 19.
[0162]
First, as shown in FIG. 15B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0163]
Next, as shown in FIG. 15C, by using an exposure mask 14 having an exposure pattern in which light passes only through the intersections of the wirings 11 and 12, and the other parts are blocked. The water / oil repellent film 13 is exposed. That is, the exposure mask 14 has a light transmitting portion 14a and a light shielding portion 14b, and the general portion of the substrate surface other than the intersecting portion of the wirings 11 and 12 intersects the light transmitting portion 14a and the intersecting portions of the wirings 11 and 12. The portions correspond to the light shielding portions 14b, respectively. In FIG. 14, the hatched portion as the water / oil repellent portion corresponds to the light blocking portion 14b.
[0164]
By the exposure using the exposure mask 14, the water / oil repellent film 13 other than the intersection of the wirings 11 and 12 on the substrate surface changes from the water / oil repellent property 13a to the hydrophilic / lipophilic property 13b by the exposure. On the other hand, since the water / oil repellent film 13 at the intersection of the wirings 11 and 12 is not exposed, the water / oil repellent film 13 remains as the water / oil repellent portion 13a.
[0165]
Next, as shown in FIG. 15D, a planarizing film 16 is applied. In the hydrophilic / lipophilic portion 13 b, the planarizing film 16 is laminated on the water / oil repellent film 13. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent part 13 a on the intersection of the wirings 11 and 12, the planarizing film 16 is not laminated on the water / oil repellent film 13. The flattening surface 27 is adjusted by adjusting the coating amount of the flattening film 16 and matching the height of the film surface of the flattening film 16 after film formation with the surface of the water and oil repellent film 13 on the intersection of the wirings 11 and 12. Is obtained.
[0166]
Next, as shown in FIG. 15E, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the intersection of the wirings 11 and 12 becomes hydrophilic and lipophilic from the water / oil repellent part 13a. It changes to part 13b. This makes it possible to apply another film on the water / oil repellent film 13 on the wiring intersection.
[0167]
(About cross section B-B ')
As shown in FIG. 15A, the insulating film 19, the wiring 11, and the insulating film 20 are formed in this order on the substrate 10 from the bottom. The wiring 11 exists only in a part on the insulating film 19.
[0168]
First, as shown in FIG. 15B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0169]
Next, as shown in FIG. 15C, the water / oil repellent film 13 is exposed using an exposure mask 14. In the cross section B-B ′, there is no intersection between the wirings 11 and 12, so that the water / oil repellent film 13 becomes a hydrophilic / oleophilic portion 13 b.
[0170]
Next, as shown in FIG. 15D, a planarizing film 16 is applied. In the hydrophilic / lipophilic portion 13 b, the planarizing film 16 is laminated on the water / oil repellent film 13. By adjusting the coating amount of the flattening film 16 and matching the height of the film surface of the flattened film 16 after film formation with the surface of the water / oil repellent film 13 at the intersection of the wirings 11 and 12, the flattened surface 27 is formed. can get.
[0171]
Next, as shown in FIG. 15E, the substrate 10 is exposed from the wiring 11 side. In the cross section B-B ′, since there is no portion that is the water / oil repellent portion 13 a, the water / oil repellent film 13 does not change, and all remains the hydrophilic / lipophilic portion 13 b.
[0172]
(Regarding section C-C ')
As shown in FIG. 15A, the wiring 12, the insulating film 19, the wiring 11, and the insulating film 20 are formed in this order on the substrate 10 from the bottom. The wiring 11 exists only on the wiring 12.
[0173]
First, as shown in FIG. 15B, a water / oil repellent film 13 is applied to the surface of a substrate having a concavo-convex structure. As the material of the water / oil repellent film 13, FAS1 is used.
[0174]
Next, as shown in FIG. 15C, the water / oil repellent film 13 is exposed using an exposure mask 14. The water / oil repellent film 13 other than the wiring 11 on the substrate surface changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b by exposure. On the other hand, since the wiring 11 is not exposed, the water / oil repellent film 13 remains the water / oil repellent portion 13a.
[0175]
Next, as shown in FIG. 15D, a planarizing film 16 is applied. In the hydrophilic / lipophilic portion 13 b, the planarizing film 16 is laminated on the water / oil repellent film 13. On the other hand, since the planarizing film 16 is repelled in the water / oil repellent portion 13 a on the wiring 11, the planarizing film 16 is not laminated on the water / oil repellent film 13. By adjusting the coating amount of the flattening film 16 and matching the height of the film surface of the flattened film 16 after film formation with the surface of the water / oil repellent film 13 at the intersection of the wirings 11 and 12, the flattened surface 27 is formed. can get.
[0176]
Next, as shown in FIG. 15E, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the wiring 11 changes from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b. . This makes it possible to apply another film on the water / oil repellent film 13 on the wiring 11.
[0177]
As described above, the present embodiment is characterized in that the planarizing film 16 is not applied by leaving the water / oil repellent film 13 on the intersection of the wirings 11 and 12 as the water / oil repellent part 13a. It is said.
[0178]
According to the present embodiment, the use of the water / oil repellent film makes it possible to planarize a substrate having concave portions having different heights, and the conventional photolithography apparatus can be used as it is. Therefore, it is necessary to introduce a new apparatus. Cost can be reduced
In the present embodiment, the method for planarizing the concavo-convex substrate using the step of changing the wettability of the substrate surface by pattern exposure is used. As a method for changing the wettability, the method will be described later as in Embodiment 1-8. A step of changing the wettability of the substrate surface by discharge treatment using a mask (Embodiment 2) and a step of changing the wettability of the substrate surface by applying a surface treatment agent using a mask (Embodiment 3) are used. May be.
[0179]
Embodiment 1-11
FIG. 16 is a cross-sectional view illustrating a method for planarizing a substrate surface according to Embodiment 1-11 of the present invention in the order of steps.
[0180]
The planarization method of the substrate surface according to the present embodiment is applicable when planarizing the substrate surface of a microlens array, which is one of microoptics.
[0181]
As shown in FIG. 16A, a concave hemispherical microlens 18 is formed on the substrate 10. As a manufacturing method of the microlens 18, exposure using a gray level mask, isotropic etching using hydrofluoric acid and a metal mask, mold processing method, and the like are used.
[0182]
Next, as shown in FIG. 16B, a water / oil repellent film 13 is applied in order to flatten the substrate surface having irregularities by the concave hemispherical microlenses 18. As the material of the water / oil repellent film 13, FAS1 is used.
[0183]
Next, as shown in FIG. 16C, the water / oil repellent film 13 is exposed using an exposure mask 14 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 14 has a light transmitting portion 14a and a light shielding portion 14b. The surface of the substrate on which the microlens 18 is installed is on the light transmitting portion 14a, and the surface of the substrate on which the microlens 18 is not installed is light shielding. Each corresponds to the part 14b. By the exposure using the exposure mask 14, the water / oil repellent film 13 on the micro lens 18 is changed from the water / oil repellent portion 13a to the hydrophilic / lipophilic portion 13b by the exposure. On the other hand, since the other portions are not exposed, the water / oil repellent film 13 remains as the water / oil repellent portion 13a.
[0184]
Next, as shown in FIG. 16D, a planarizing film 16 is applied. In the hydrophilic / lipophilic part 13 b where the microlenses 18 are installed, the planarizing film 16 is laminated on the water / oil repellent film 13. On the other hand, the flat portion of the substrate on which the microlenses 18 are not installed is the water / oil repellent portion 13 a and the flattening film 16 is repelled, so that the flattening film 16 is not laminated on the water / oil repellent film 13. By adjusting the coating amount of the flattening film 16, the flattened surface is obtained by matching the height of the film surface of the flattened film 16 after film formation with the film surface of the water / oil repellent film 13 applied to the flat portion of the substrate. 21 is obtained.
[0185]
Next, as shown in FIG. 16E, by exposing the substrate 10 from the wiring 11 side, the water / oil repellent film 13 on the flat portion of the substrate changes from the water / oil repellent portion 13a to the hydrophilic / oleophobic portion 13b. . This makes it possible to apply another film on the water / oil repellent film 13 on the flat portion of the substrate.
[0186]
Also in this embodiment, as shown in FIG. 16F, the planarization surface 22 is obtained by further applying the planarization film 17. The effect is the same as that of Embodiment 1-1, and the unevenness due to the microlens 18 can be reduced from the planarized surface 21.
[0187]
It is also possible to obtain a flattened surface with further reduced irregularities by further applying another flattened film (not shown) to the flattened surface 22.
[0188]
Further, as described in the embodiment 1-1, the planarizing film 16 can be arbitrarily used as long as it can be laminated on the hydrophilic / lipophilic portion 13b and cannot be laminated on the water / oil repellent portion 13a. Further, when the planarization film 16 is subjected to heat treatment, the substrate surface can be further planarized using the flowability of the planarization film 16 by using the planarization film 16 having good heat melting property.
[0189]
In the present embodiment, a microlens array is used as an example of microoptics. However, the object to which the present invention is applied is not limited to the microlens array, and the present invention is not limited to the microlens but can be used on a substrate such as a prism. The present invention can be effectively applied to planarize the optical structure fabricated in (1).
[0190]
In this embodiment, the method of planarizing the concavo-convex substrate using the step of changing the wettability of the substrate surface by pattern exposure is used. However, as a method of changing the wettability, a discharge process using a mask described later is used. A step of changing the wettability of the substrate surface (Embodiment 2) or a step of changing the wettability of the substrate surface by applying a surface treatment agent using a mask (Embodiment 3) may be used.
[0191]
(Embodiment 2)
FIG. 17 is a cross-sectional view showing a method of planarizing a substrate surface according to the second embodiment of the present invention in the order of steps.
[0192]
Before the substrate surface flattening process is performed, a recess 110a and a protrusion 110b as shown in FIG. 17A are formed on the substrate surface.
[0193]
Next, as shown in FIG. 17B, a mask 132 is formed on the convex portion 110b. A photolithography technique is used for mask production.
[0194]
Next, as shown in FIG. 17C, the substrate 110 is exposed to plasma 115. Thereby, the wettability changing surface 130 in which the wettability with respect to the planarizing film 116 is changed before and after the treatment is formed in the recess 110a. On the other hand, since the convex portion 110b protected by the mask 132 is not affected by the plasma irradiation, the wettability does not change in the convex portion 110b on the lower surface of the mask 132. Irradiation is not limited to plasma discharge. For example, in JP-A-6-163143, JP-A-2001-297897, JP-A-2001-237256, etc., wettability may change due to corona discharge, arc discharge, or plasma discharge. Are listed. The reasons for the change in wettability are: 1. the effect of cleaning the substrate surface; 2. the effect of forming fine irregularities on the substrate surface; This is said to be the effect of forming hydroxyl groups on the substrate surface.
[0195]
Next, as shown in FIG. 17D, the mask 132 is peeled off. At this time, the wettability of the wettability changing surface 130 is prevented from returning to the wettability before processing. As described above, a concave portion having a convex portion whose wettability is not changed and a wettability changing surface 130 by the discharge process is formed on the substrate surface.
[0196]
Next, as shown in FIG. 17E, a planarizing film 116 is applied. A planarizing film 116 is laminated on the concave portion 110a having the wettability changing surface 130, and is not laminated on the convex portion 110b. In this way, the planarization film 116 is formed using the difference in wettability of the substrate surface, and the planarization surface 121 is obtained.
[0197]
If the unevenness of the planarization surface 121 does not become a problem, the planarization film 116 does not need to be thick until the height of the projection 110b is matched. On the contrary, the film surface of the planarizing film 116 formed in the concave portion may be higher than the convex portion 110b.
[0198]
The basic concept of the second embodiment has been described above, and further will be described in detail using specific examples with reference to FIGS.
[0199]
(Embodiment 2-1)
FIG. 18 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 2-1 of the present invention in the order of steps. Note that a top view of the substrate surface before planarization is the same as that in FIG. 3, and a cross section B-B ′ in FIG. 3 corresponds to the cross sectional view in FIG.
[0200]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0201]
As shown in FIG. 18A, a wiring 111 is formed on a substrate 110, and an insulating film 119 is further formed thereon.
[0202]
First, as shown in FIG. 18B, a photoresist 132a is applied to the surface of the substrate having a concavo-convex structure. The photoresist 132a has the function of the mask 132 in the second embodiment. A positive resist is used for the photoresist 132a.
[0203]
Next, as shown in FIG. 18C, the photoresist 132a is exposed using an exposure mask 114 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 114 has a light transmitting portion 114a and a light shielding portion 114b. The concave portion on the substrate surface corresponds to the light transmitting portion 114a, and the convex portion on the substrate surface corresponds to the light shielding portion 114b. .
[0204]
Next, as shown in FIG. 18D, the photoresist 132a is developed. By the exposure using the exposure mask 114, the photoresist 132a in the concave portion of the substrate surface is peeled off. On the other hand, since the convex portion is not exposed, the photoresist 132a remains. By this step, a mask is not produced in the concave portion on the substrate surface, and a mask made of the photoresist 132a is produced in the convex portion on the substrate surface.
[0205]
Next, as shown in FIG. 18E, the wettability in which the wettability with respect to the planarizing film 116 is changed into the concave portion where the mask is not formed with the photoresist 132a by surface-treating the substrate 110 with the plasma 133. A change surface 130 is produced.
[0206]
Next, as shown in FIG. 18F, the photoresist 132a is removed. At this time, the wettability of the wettability changing surface 130 is prevented from returning to the wettability before processing. On the surface of the substrate 110 having a concavo-convex structure, a photoresist 132a is peeled off to form a convex portion where the wettability is not changed and a concave portion having a wettability changing surface 130 whose wettability is changed by the discharge treatment.
[0207]
Next, as shown in FIG. 18G, a planarizing film 116 is applied. On the wettability changing surface 130, the planarizing film 116 is stacked on the insulating film 119. On the other hand, since the planarizing film 116 is repelled on the wiring 111, the planarizing film 116 is not stacked. By adjusting the coating amount of the planarizing film 116, the planarized surface 121 is obtained by matching the film surface of the planarized film 116 after film formation with the height of the wiring 111. Examples of the method for forming the planarizing film 116 include a spin coating method, a dip method, a spray method, a nozzle injection method, a printing method, a transfer method, and the like, but are not limited to these examples.
[0208]
In this embodiment, plasma is used when changing the wettability of the substrate surface, but other corona discharge, arc discharge, or the like may be used.
[0209]
Although a positive resist is used as the photoresist 132a, a negative resist can be used in consideration of a change in wettability with respect to the planarizing film 116 due to the positive negative of the exposure mask 114 and the plasma 133.
[0210]
(Example 2-2)
FIG. 19 is a cross-sectional view illustrating another method for planarizing a substrate surface according to the embodiment 2-2 of the present invention.
[0211]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0212]
The present embodiment is different from the embodiment 2-1 in that the exposure is performed from the back surface of the substrate without using an exposure mask having an exposure pattern corresponding to the uneven shape of the substrate surface in the step of exposing the photoresist 132a.
[0213]
This embodiment is the same as Embodiment 2-1 until the photoresist 132a is formed. That is, the same applies up to FIG. In the present embodiment, the wiring 111 that causes unevenness is made of metal.
[0214]
First, the photoresist 132a is exposed from the surface opposite to the surface coated with the photoresist 132a. Since the wiring 111 is made of metal and does not transmit light, the photoresist 132a is not exposed. Thus, the photoresist 132a applied on the wiring 111 is left as a film during development. On the other hand, in a portion where there is no metal that causes unevenness, light is transmitted and exposed to the photoresist 132a, so the photoresist 132a is peeled off during development. Note that a positive resist is used as the photoresist 132a.
[0215]
Next, as shown in FIG. 19B, the photoresist 132a is developed. By this step, a mask is not formed in the concave portion on the substrate surface, and a mask made of the photoresist 132a is formed on the convex portion on the substrate surface.
[0216]
Subsequent steps, that is, steps after FIG. 18E are the same as those in the embodiment 2-1.
[0217]
This embodiment is an effective method for flattening a substrate having irregularities on the substrate surface by convex portions made of a material that does not transmit light, such as metal. Thereby, the cost of the mask for exposure can be reduced.
[0218]
(Embodiment 3)
FIG. 20 is a cross-sectional view showing the basic concept of the method for planarizing a substrate surface according to the third embodiment of the present invention in the order of steps.
[0219]
As shown in FIG. 20A, the substrate 210 has a convex portion 210a and a concave portion 210b.
[0220]
Next, as shown in FIG. 20B, a mask 214 is formed on the convex portion 210a. A photolithography technique is used for mask production.
[0221]
Next, as shown in FIG. 20C, a surface treating agent 212 is applied. As the surface treatment agent 212, a material whose wettability with respect to the planarizing film 216 is changed by the surface treatment is selected. As the surface treatment agent 212, a silane coupling agent, a fluorine-based coating material, or the like is used.
[0222]
Next, as shown in FIG. 20D, the mask 214 is peeled off. At this time, the surface treatment agent 212 applied to the recesses 210b is prevented from peeling off. As a result, the wettability does not change in the convex portion 210a, while the wettability changing surface by the surface treatment agent 212 is formed in the concave portion 210b.
[0223]
Next, as shown in FIG. 20E, a planarizing film 216 is formed on the substrate surface. The planarizing film 216 does not accumulate in the convex portion 210a, and the planarizing film 216 accumulates in the concave portion 210b. That is, utilizing the fact that the wettability of the substrate surface with respect to the planarization film 216 is different, the planarization film 216 is formed and the planarization surface 221 is obtained.
[0224]
If the unevenness of the planarization surface 221 is not a problem, the planarization film 216 does not need to be thickened until the height of the projection 210a is matched. Conversely, the film surface of the planarization film 216 formed in the concave portion 210b may be higher than the convex portion 210a.
[0225]
The above is the basic concept of the third embodiment, and further will be described in detail using a specific example with reference to FIG.
[0226]
(Embodiment 3-1)
FIG. 21 is a cross-sectional view illustrating a method of planarizing a substrate surface according to Embodiment 3-1 of the present invention in the order of steps. The state of the substrate surface before the planarization is the same as in Embodiment 1-1, and details are as shown in FIG. Further, a cross section B-B ′ in FIG. 3 corresponds to the cross sectional view of FIG. 21.
[0227]
The method for planarizing the substrate surface according to the present embodiment is applicable to planarizing the substrate surface of a liquid crystal display element, an organic EL element, or a semiconductor.
[0228]
As shown in FIG. 21A, a wiring 211 is formed on a substrate 210, and an insulating film 219 is further formed thereon.
[0229]
First, as shown in FIG. 21B, a photoresist 232 is applied to the substrate surface having a concavo-convex structure. A positive resist is used as the photoresist 232.
[0230]
Next, as shown in FIG. 21C, the photoresist 232 is exposed using an exposure mask 214 having an exposure pattern corresponding to the uneven shape of the substrate surface. The exposure mask 214 has a light transmitting portion 214a and a light shielding portion 214b. The concave portion on the substrate surface corresponds to the light transmitting portion 214a, and the convex portion on the substrate surface corresponds to the light shielding portion 214b. .
[0231]
Next, as shown in FIG. 21D, the photoresist 232 is developed. By the exposure using the exposure mask 214, the photoresist 232 in the concave portion of the substrate surface is peeled off. On the other hand, since the convex portion is not exposed, the photoresist 232 remains as a film. By this step, a mask is not formed on the concave portion on the substrate surface, and a mask made of the photoresist 232 is formed on the convex portion on the substrate surface.
[0232]
Next, as shown in FIG. 21E, a surface treating agent 235 is applied. As the surface treatment agent 235, a material whose wettability with respect to the planarizing film 216 is changed by the surface treatment is selected. As the surface treatment agent 235, a silane coupling agent, a fluorine-based coating material, or the like is used.
[0233]
Next, as shown in FIG. 21F, the photoresist 232 is peeled off. At this time, the concave portion is prevented from returning to the wettability before the surface treatment agent 235 is applied. As a result, on the surface of the substrate 210 having a concavo-convex structure, the photoresist 232 is peeled off, and the concave portion having the wettability changing surface 230 in which the wettability is changed by the surface treatment agent 235. Can do.
[0234]
Next, as shown in FIG. 21G, a planarizing film 216 is applied. On the wettability changing surface 230, the planarizing film 216 is stacked on the insulating film 219. On the other hand, since the planarization film 216 is repelled on the wiring 211, the planarization film 216 is not stacked. By adjusting the coating amount of the planarizing film 216, the planarized surface 221 can be obtained by matching the film surface of the planarized film 216 after deposition with the height of the insulating film 219 applied over the wiring 211. Examples of the method for forming the planarization film 216 include a spin coating method, a dip method, a spray method, a nozzle injection method, a printing method, and a transfer method, but are not limited to these examples.
[0235]
(Other embodiments)
Next, an application example of the flattening substrate created according to the first to third embodiments (including the detailed description of the embodiment 1-1 and the like) will be described.
[0236]
FIG. 22 is a view showing a liquid crystal display device according to another embodiment of the present invention.
[0237]
FIG. 22A uses a TFT substrate 41 with flattened TFTs and wirings according to the first to third embodiments of the present invention. The TFT substrate 41 and the counter substrate 42 are bonded together with a sealant 43 to sandwich the liquid crystal layer 50. FIG. 22B shows a microlens-mounted liquid crystal display element. Although the microlens mounting counter substrate 49 in which the microlens surface 45 is flattened by the flattening film 46 according to the embodiment 1-11, the TFT substrate in which the TFT and the wiring are flattened according to the first to third embodiments of the present invention is used. 41 may be used. The planarized substrate of the present invention may be used for both substrates.
[0238]
In this embodiment, since the planarized substrate of the present invention is used, a liquid crystal display element with high aperture ratio, high contrast, good yield, and low cost can be obtained.
[0239]
FIG. 23 is a diagram showing an optical system of a liquid crystal projector using a liquid crystal display element according to another embodiment of the present invention.
[0240]
In the present embodiment, a liquid crystal projector can be configured by using the components described below together with the microlens-mounted liquid crystal display element manufactured according to the above embodiment.
[0241]
In this liquid crystal projector, a light source 61, a color separation optical system that separates white light from the light source into three light beams of red, green, and blue by a dichroic mirror 64 and the like, and three sheets for red, green, and blue are used. A color synthesizing optical system comprising a microlens-equipped liquid crystal display elements 66, 67, 68 and a cross dichroic prism 69 for synthesizing images displayed by the three liquid crystal display elements, and a synthesized display image on a screen At least a projection lens 70 for enlarging and projecting the image is used.
[0242]
As shown in FIG. 23, the liquid crystal projector condenses the light emitted from the light source 61 by the reflector 62, and then separates the light beam by the two dichroic mirrors 64 to separate the light beam into three primary colors. . Of the three primary color beams, the red beam is reflected by the mirror 65 and then illuminates the microlens-mounted red liquid crystal display element 66. The green light beam illuminates the microlens-mounted green liquid crystal display element 67, and the blue light beam is sequentially reflected by the mirror 65 and then illuminates the microlens-mounted blue liquid crystal display element 68. As the liquid crystal display elements for red, green, and blue, active matrix type elements are used in which TFTs are arranged for each pixel to drive the liquid crystal. In addition, a microlens for condensing light at the opening of the pixel to improve luminance is formed. The images displayed on the red, green, and blue liquid crystal display elements are synthesized by the cross dichroic prism 69 and then enlarged and projected onto a screen (not shown) by the projection lens 70.
[0243]
In the present embodiment, since the liquid crystal display element is manufactured using the planarized substrate, a liquid crystal projector with improved display quality can be obtained. In addition, bright display is possible by using a microlens-mounted liquid crystal display element.
[0244]
FIG. 24 is a diagram showing an organic EL device according to another embodiment of the present invention.
[0245]
In this embodiment, a TFT substrate 51 in which TFTs and wirings are flattened according to Embodiments 1 to 3 of the present invention is used. An organic EL layer 52 is provided on the TFT substrate 51, and the metal seal 54 and the TFT substrate 51 are bonded together with a sealing agent 53 in order to shield this from moisture. Further, the water absorbing material 55 is also interposed between the metal seal 54 and the TFT substrate 51.
[0246]
In this embodiment, since the planarized substrate of the present invention is used, an organic EL element with improved reliability can be obtained.
[0247]
The present invention is not limited to the liquid crystal display element and organic EL described above. For example, in a semiconductor device having a substrate made of a semiconductor, the present invention can be applied to flatten the surface of the substrate when the surface is uneven.
[0248]
【The invention's effect】
As described above, according to the present invention, the unevenness of the substrate surface is obtained by utilizing the difference in wettability between the surface of the concave portion and the convex portion of the substrate surface having unevenness and the wettability of the surface of the substrate. By selectively forming the wettability changing surface only on the concave portion on the surface, the substrate surface having the unevenness can be satisfactorily at least with a flattening film thickness thinner than the flattening surface of the conventional flattening film method. It can be flattened.
[0249]
Since the process of changing the wettability of only the recesses on the substrate surface is performed by pattern exposure, discharge treatment using a mask, and application of a surface treatment agent using a mask, the substrate surface is flattened only by replacing the photomask used during exposure. Can be implemented. For this reason, the conventional photolithography apparatus can be used as it is, and it is not necessary to introduce a new apparatus, thereby reducing the cost.
[0250]
When the substrate convex portion is formed of metal, an exposure mask can be eliminated by performing pattern exposure from the back surface of the substrate without the convex portion. Further, it can be applied to a large area substrate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1 of the present invention in the order of steps.
FIG. 2 is a cross-sectional view illustrating a method for planarizing a substrate surface according to Embodiment 1-1 of the present invention in the order of steps.
FIG. 3 is a top view showing a substrate surface before planarization in a substrate surface planarization method according to Embodiments 1-1 to 1-7 of the present invention.
FIG. 4 is a cross-sectional view showing a method for planarizing a substrate surface according to Embodiment 1-2 of the present invention in the order of steps.
FIG. 5 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-3 of the present invention in the order of steps.
FIG. 6 is a cross-sectional view illustrating a method of planarizing a substrate surface according to Embodiment 1-4 of the present invention in the order of steps.
FIG. 7 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-5 of the present invention in the order of steps.
FIG. 8 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-6 of the present invention in the order of steps.
FIG. 9 is a cross-sectional view showing a method for planarizing a substrate surface according to Embodiment 1-7 of the present invention in the order of steps.
FIGS. 10A and 10B are a top view and a cross-sectional view showing a substrate surface before planarization in the substrate surface planarization method according to Embodiments 1-8 to 1-10 of the present invention. FIGS.
FIG. 11 is a top view showing a water / oil / oil repellency region / hydrophilic / lipophilic region on a substrate surface in a planarization step in the method for planarizing a substrate surface according to Embodiment 1-8 of the present invention.
FIG. 12 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-8 of the present invention in the order of steps.
FIG. 13 is a cross-sectional view of a substrate in a method for planarizing a substrate surface according to Embodiment 1-9 of the present invention.
FIG. 14 is a top view showing a water / oil repellency region / hydrophilic / lipophilic region on a substrate surface in a planarization step according to Embodiment 1-10 of the present invention.
FIG. 15 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-10 of the present invention in the order of steps.
FIG. 16 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 1-11 of the present invention in the order of steps.
FIG. 17 is a cross-sectional view illustrating a method of planarizing a substrate surface according to a second embodiment of the present invention in the order of steps.
FIG. 18 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 2-1 of the present invention in the order of steps.
FIG. 19 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 2-2 of the present invention in the order of steps.
FIG. 20 is a cross-sectional view showing a method of planarizing a substrate surface according to a third embodiment of the present invention in the order of steps.
FIG. 21 is a cross-sectional view showing a method of planarizing a substrate surface according to Embodiment 3-1 of the present invention in the order of steps.
FIG. 22 is a view showing a liquid crystal display device according to another embodiment of the present invention.
FIG. 23 is a diagram showing an optical system of a liquid crystal projector using a liquid crystal display element according to another embodiment of the present invention.
FIG. 24 is a view showing an organic EL device according to another embodiment of the present invention.
FIG. 25 is a cross-sectional view of a liquid crystal display element using an ideal planarized substrate having no unevenness.
FIG. 26 is a cross-sectional view of a liquid crystal display element using a substrate having projections and depressions in the prior art.
FIG. 27 is a cross-sectional view of an organic EL element in the prior art.
FIG. 28 is a cross-sectional view of an ideal TFT substrate having no irregularities and an external view of a polishing pad.
FIG. 29 is a cross-sectional view of a TFT substrate having unevenness in the prior art and an outline view of a polishing pad.
FIG. 30 is a cross-sectional view showing an example of a method for planarizing a substrate surface in the prior art in the order of steps.
FIG. 31 is a cross-sectional view of a substrate surface in the prior art.
FIG. 32 is a cross-sectional view showing an example of a method for planarizing a substrate surface in the prior art in the order of steps.
[Explanation of symbols]
10, 110, 210 substrate
10a, 110a, 210a recess
10b, 110b, 210b Convex part
11, 12, 111, 211 wiring
13 Water and oil repellent film
13a Water and oil repellent part
13b Hydrophilic / lipophilic part
14, 14 ', 114 Exposure mask
14a, 114a, 214a Light transmission part
14b, 114b, 214b Light shielding part
15, 115, 215 light
16, 17, 116, 216 planarizing film
18 Micro lens
19, 20, 119, 219 Insulating film
21, 22, 23, 24, 25, 26, 121, 221 Flattened surface
31 Photocatalytic membrane
30, 130, 230 Wetting change surface
41 TFT substrate
42 Counter substrate
43 Sealant
44 Microlens substrate
45 Micro lens surface
46 Planarization film
47 Adhesive
48 Cover glass
49 Counter substrate with microlens
50 Liquid crystal layer
51 TFT substrate
52 Organic EL layer
53 Sealant
54 Metal seal
55 Water absorbent
61 Light source
62 Reflector
63 Light Conversion Integrator
64 Dichroic mirror
65 mirror
66 Liquid crystal display element for red with micro lens
67 Liquid crystal display element for green with microlens
68 Liquid crystal display element for blue with microlens
69 Cross Dichroic Prism
70 projection lens
132 Mask
132a photoresist
115 plasma
235 Surface treatment agent
521 substrate
522 Wiring
523 TFT
524 pixel electrode
525 Planarization film
526 contact hole
527 Counter electrode
528 Convex
529, 129a Liquid crystal molecules
530 Pretilt angle
531 point tilt
532 TFT substrate
533 Counter substrate
534 Liquid Crystal Layer
541 Insulation layer
542 Hole transport layer
543 Organic EL layer
544 Upper electrode
545 Transparent electrode film
546 Polishing pad

Claims (15)

And enhanced Ru step than the convex portion get wet Re sex of the recess of the substrate surface having unevenness,
Selectively deposited only in the recess in which the wettability is increased, the steps you planarizing the substrate surface,
A method for planarizing a substrate surface. Get wet Re sex of Ru higher than protrusion step of the recess, on the substrate, forming a wettability changing layer which wettability is changed by the exposure, a step of selectively exposing only the recess, the The method for planarizing a substrate surface according to claim 1. The method for planarizing a substrate surface according to claim 2, wherein the step of selectively exposing only the recess includes selectively exposing only the recess using an exposure mask. The method comprising: forming a film on the concave portion, and then changing the convex portion to the same wettability as the concave portion; and subsequently forming another film on the convex portion changed to the same wettability. 4. The method for planarizing a substrate surface according to any one of 1 to 3 . The method for planarizing a substrate surface according to claim 1, wherein the step of increasing the wettability of the concave portion over the convex portion includes discharging the concave portion . 6. The method for planarizing a substrate surface according to claim 5 , wherein the step of increasing the wettability of the concave portion over the convex portion includes discharging the surface of the substrate after forming a mask only on the upper surface of the convex portion. The step of forming the mask only on the upper surface of the convex portion is to selectively expose only the concave portion using an exposure mask after forming a mask layer made of the same material as the mask on the upper surface of the substrate. The method for planarizing a substrate surface according to claim 6 , further comprising: The method for planarizing a substrate surface according to claim 1 , wherein the step of increasing the wettability of the concave portion over the convex portion includes applying a surface treatment agent to the concave portion . The step of increasing the wettability of the concave portion from the convex portion includes forming the mask only on the upper surface of the convex portion, applying the surface treatment agent on the substrate surface, and laminating the mask and the surface on the upper surface of the convex portion The method for planarizing a substrate surface according to claim 8 , comprising peeling off the treatment agent. The step of forming the mask only on the upper surface of the convex portion is to selectively expose only the concave portion using an exposure mask after forming a mask layer made of the same material as the mask on the upper surface of the substrate. The method for planarizing a substrate surface according to claim 9 , further comprising: Step of increasing the wettability of the recess from the protrusion, the substrate according to the wettability of the recess, the repellent comprises changing the hydrophilic lipophilic side, to any one of claims 1 to 10 Surface flattening method. A step of flattening the surface of the substrate using the method according to any one of claims 1 to 11, a manufacturing method of planarizing the substrate. A liquid crystal layer, a method of manufacturing a liquid crystal display device which have a pair of substrates sandwiching the liquid crystal layer, at least one of the substrate using the method according to any one of claims 1 to 11 A method for manufacturing a liquid crystal display device, comprising a step of planarizing a surface . A substrate, a manufacturing method of an organic electroluminescent device that have a organic electro Rumi Sene Nsu layer provided on the surface thereof, the substrate using the method according to any one of claims 1 to 11 The manufacturing method of an organic electroluminescent element which has the process of planarizing the surface of this . A method of manufacturing a semiconductor device which have a substrate made of a semiconductor, comprising a step of flattening the surface of the substrate using the method according to any one of claims 1 to 11, a method of manufacturing a semiconductor device .

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