JP2000356856A - Method for exposing photosensitive resin and photosensitive resin shaped body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily process and edit graphic information by keyboard operations and to obtain a photosensitive resin shaped body in a short time by selectively exposing a photosensitive resin in the basis of computer information and forming exposed and unexposed regions. SOLUTION: A spray head 1 is activated and a carriage 2 is moved in the X and Y directions in accordance with the pattern of computer graphics while spraying a nontranslucent material from the spray head 1 on the resist surface of a substrate 4 to form a pattern of the nontranslucent material on the resist surface of the substrate 4. By irradiation with UV, the resist layer is selectively exposed using the coating of the nontranslucent material as a mask to form a latent image. This latent image is converted to a visible image by development.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of exposing a photosensitive resin to a photosensitive resin, and a molded product of the photosensitive resin formed by using the method.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a printed circuit board manufacturing, or a shadow mask manufacturing used for a TV cathode ray tube, a technique such as so-called photolithography or photoetching has been conventionally used to produce a highly accurate pattern. Established as technology.
As the name (photo…), these technologies use a so-called photoengraving technology, in which a photosensitive photoresist is applied on a substrate, irradiated with ultraviolet light through a photomask, and thereafter, By developing, a photoresist pattern equivalent to the pattern of the photomask is formed (photolithography), or thereafter, etching is performed to form a pattern equivalent to the photoresist on the substrate (photoetching). is there.

FIG. 8 shows a conventional lithography I (resist process) to lithography II in a so-called wafer process (semiconductor manufacturing process).
In the process flow of (etching process), FIG. 9 shows sectional views of a pattern formed by the flow of FIG. 8 in order, and shows a case where a negative resist is used (A) and a case where a positive resist is used. 2B shows both.

[0004] First, a process will be briefly described with reference to FIGS. 8 and 9. Here, an example in which an opening of SiO ₂ is formed on a silicon wafer will be described. (1) Wafer pretreatment A silicon wafer having a thermal oxide film SiO ₂ formed on its surface at about 1 μm is cleaned by cleaning. (2) Resist coating Spin coating (or roll coating)
To apply a photoresist on the wafer (0.
5-1 μm). At this time, in order to improve the adhesion between the wafer and the photoresist, an adhesion improver (such as OAP manufactured by Tokyo Ohka) is applied on the wafer in advance. (3) Prebaking In order to evaporate the solvent component in the applied photoresist, the photoresist is heated in a baking furnace at 80 to 90 ° C for 10 to 20 minutes.

[0005] Mask alignment (4) As shown in FIG.
A photoresist 63 is applied to a surface of a wafer on which a film 62 to be processed is applied, and a photomask 64 is aligned with the photoresist surface. Here, the photomask 64 is made by polishing a glass that is not easily affected by thermal expansion such as quartz glass or low expansion glass with high precision, and a desired pattern made of a chromium deposited film 65 is formed on the surface thereof. Is what it is. The region where the chromium deposited film 65 is formed does not transmit light, and the region where the chromium deposited film is not formed transmits light. (5) Exposure After mask alignment is completed, exposure is performed by UV irradiation. As a result, the photoresist is irradiated or not irradiated with the UV light in the region where the chromium vapor deposition film 65 is formed and in the region where the chromium deposited film 65 is not formed, so that a latent image corresponding to the chromium mask pattern is formed in the 66 photoresist. (Shown in FIG. 9 as an exposed portion in exposure (b)).

(6) Development In order to visualize the latent image 66, as shown in the development (c) of FIG. 9, a portion of the photoresist not irradiated with the UV light is dissolved by a developer (negative resist). in the case of,
Reverse for positive resist). (7) Post-baking In the next step of etching, the photoresist pattern after development is designed to withstand an etching solution.
Heat and cure in a baking oven at ~ 150 ° C for 30-60 minutes. (8) Etching The wafer is immersed in a buffer etching solution of hydrofluoric acid and ammonium fluoride to etch away the SiO ₂ film (the film 62 to be processed) in the region exposed by the photoresist pattern (etching (d in FIG. 9). )). (9) Removal of Resist The unnecessary photoresist is removed (resist removal portion in resist removal (e) of FIG. 9). On the wafer, SiO _{2 of the} same shape as the photoresist pattern
A pattern 69 of the film (the film 62 to be processed) is formed.

[0007]

The above is a photo-etching step generally performed in a wafer process. In the case of using an analog shielding mask as described above, processing, editing and correction of graphic information are performed. For example, when a long time is required, and when the exposure is performed collectively using an analog shielding mask, a light source that can cover a large area is required, and a large light source is required.

The present invention has been made in view of the above circumstances, and selectively exposes a photosensitive resin based on computer information to form a photosensitive region, a non-photosensitive region, or a photosensitive resin. By forming the photosensitive area as a desired final product, unlike the conventional method using an analog shielding mask, graphic information can be easily processed and edited by keyboard operation, and such a photosensitive resin molded article can be obtained in a short time. , And information can be corrected in a short time. In addition, when exposing at once using an analog shielding mask, a light source that can cover a large area is required, but when exposing digitally based on computer information, A large light source is not required because exposure and subsequent movement of the spot are sufficient. In addition, since the molded photosensitive resin obtained by such a method does not require a mold or the like, unlike a general resin structure, it can be obtained in a shorter time and at a lower cost than ordinary resin molding. In addition, since information processing is performed on a computer, complicated shapes can be easily manufactured.

[0009]

The invention according to claim 1 is characterized in that a photosensitive resin is selectively exposed to a photosensitive resin based on computer information to form a photosensitive region and a non-photosensitive region.

According to a second aspect of the present invention, a photosensitive resin is selectively exposed to light based on computer information to form a photosensitive region and a non-photosensitive region, and the photosensitive region of the photosensitive resin is formed as a desired final product. It is characterized by the following.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view for explaining an embodiment of a pattern forming apparatus suitable for use in carrying out a pattern forming method according to the present invention. Here, an apparatus for selectively applying a desired pattern to the resist surface after pre-baking is shown.
1 is an ejection head, 2 is a carriage, 3 is a base holder, 4
Is a substrate coated with a photoresist and prebaked, 5 is a non-translucent material (ink) supply tube, 6 is a signal supply cable, 7 is an ejection head control box, and 8 is an X-direction scan of the carriage 2. A motor, 9 is a Y-direction scan motor of the carriage 2, 10 is a computer, and 11 is a control box.

In the present invention, for example, photolithography is performed on a substrate by the following process using an apparatus as shown in FIG. 1. The substrate is pretreated (washed) and dried. 2. A photoresist layer is formed on a substrate. Here, the substrate is relatively small (for example, 20 cm × 20 cm or less).
In some cases, the liquid resist is coated by spin coating. In the case of a larger substrate, the liquid resist is applied by roller coating or dip coating. When a dry film resist is used, a dedicated laminator is used. 3. Perform pre-baking (for example, at 70 to 90 ° C,
10 to 20 minutes, but only when a liquid resist is used). 4. Design a desired pattern using computer graphics. 5. The prebaked substrate or the substrate 4 on which the dry film resist is laminated is set on the substrate holder 3.

6. While activating the ejection head 1 and injecting the non-translucent material from the ejection head 1 onto the resist surface of the base 4 in accordance with the pattern of the computer graphics,
The carriage 2 is moved in the X and Y directions to form a pattern of a non-translucent material on the resist surface of the base 4. 7. UV light irradiation is performed to selectively expose the resist layer depending on the presence or absence of the coating of the non-translucent material. 8. Perform development. In this case, when a negative type resist is used, the non-photosensitive area, that is, the resist of the area covered with the non-translucent material is dissolved in the developing solution, and the photosensitive area, that is, the area without the non-translucent material is used. Is left as a pattern on the substrate. On the other hand, the opposite is true for a positive type resist. 9. Perform post baking. 10. Perform etching. 11. The resist is removed. The lithography of the pattern designed by computer graphics is completed on the substrate by the process as described above.

The present invention is greatly different from the conventional pattern forming method shown in FIG. 8 in that the present invention does not perform photolithography using a photomask, but uses a non-light-transmitting material to form a resist surface. Is to draw a pattern directly to create a light-transmitting and non-transmitting area. In this way, you can use computer graphics without using expensive photomasks,
Since a desired pattern can be easily formed, the cost is very low. Also, even if the photomask is outsourced or made in-house, it takes a certain number of days, but in the present invention, since such a necessity is not required, the time required for completing the lithography pattern is extremely short. . In particular, when producing a single product or a small number of prototypes, photomask costs are not required, and production is possible in a short time, so that the present invention is effective.

Next, the ejection head used in the present invention will be described. What is known as a so-called inkjet head is suitably used as the ejection head,
For example, an on-demand type configuration as shown in FIG. 2 can be used. FIG. 2 is a view for explaining an example of an ejection head for ejecting a non-translucent material. In a very simple embodiment, the ejection head 1 includes one liquid chamber 12, and the liquid chamber 12 One outflow passage 13 at one end
, The other end of which is limited by one thin circular metal diaphragm 14. The liquid chamber 12 is connected via a tube to a tank 19 containing a non-translucent material, and the liquid chamber 12 is connected to the tube 5 for supplying the non-translucent material. It has an inlet 15 for a non-translucent material inflow channel 16. One piezoelectric crystal 17 is attached to the metal diaphragm 14, and a conducting wire 18 for applying a control impulse to the crystal is connected to the metal diaphragm 14 and the outer surface of the crystal 17. The cross-sectional area of the outflow passage 13 is significantly smaller than the area limited by the metal diaphragm, the ratio of these areas being, for example, 1: 10000.

When an appropriate voltage impulse is applied, the crystal 17 contracts in the radial direction, and since the crystal is attached to the metal diaphragm 14, a bending moment acts on the metal diaphragm 14. As a result, the central portion of the diaphragm curves into the liquid chamber 12. As a result, the volume of the liquid chamber 12 is reduced, the pressure of the liquid in the liquid chamber is increased, and the amount of liquid that can no longer remain in the liquid chamber 12 passes through the outflow passage 13 (and a small portion flows into the liquid chamber 12). (Through passage 16). Since the cross-sectional area of the passages 16 and 13 is significantly smaller than the area of the metal diaphragm 14, the liquid chamber 12
A significant increase in the flow velocity of the liquid compared to the flow velocity of the liquid in particular occurs in the outflow passage 13, in which air is present at the opposite end, not the braking liquid. The speed of the liquid in the outflow passage 13 is about 10 m / s. The reduction of the voltage impulse to zero must be relatively slow. This is because air must not flow into the liquid chamber 12 through the outflow passage 13. The only force opposing this is the weak capillary force. A liquid amount corresponding to the extruded droplet is replenished from the inflow passage 16.

The diameter (nozzle diameter) of the outflow passage 13 depends on the fineness of the pattern to be formed.
Those having a size of about 00 μm are preferably used. The non-translucent material to be used generally contains 2 to 10% of a coloring material such as a dye or pigment, and 10 to 10% of glycerin water or the like.
So-called water-based inks containing 20%, 70 to 80% (arbitrarily determined to be 100% in total) are used. The viscosity is 2-5 cp.

FIG. 3 shows another example of the ejection head.
In the figure, 20 is an ejection head, 21 is an electrostrictive oscillator, 22 is an excitation signal source, 23 is a charged electrode, 24 is a charged signal source, 25 is a deflection electrode, 26 is a deflection power source, 27 is a base, 28 is a gutter, Reference numeral 29 denotes a tank for storing a non-translucent material, and reference numeral 30 denotes a pressure pump, which is known as an ink-jet device called a charge control type or a continuous flow type. It can be suitably used for spraying a translucent material to form a desired pattern of a non-translucent material.

The ejection head shown in FIG. 3 differs from the ejection head shown in FIG. 2 in that the ejection is performed by using a pressure pump, so that the frequency of drop formation is high and a high-speed pattern can be formed. is there. In addition, since the flying speed of the ejection drop is high (15 to 20 m / s), it has a feature that stable drop ejection can be performed. From another viewpoint, the charge control type ejection head shown in FIG. 3 has an advantage that the ejection force is strong and the flight distance can be increased. By utilizing this advantage, lithography according to the method of the present invention can be performed even on a three-dimensional three-dimensional object.
That is, in the above description, the substrate on which the resist layer was formed was a flat body, but a resist layer was provided on the surface of a three-dimensional object (mainly performed by dipping a liquid resist), and Masking with a non-translucent material (ink) by using a jetting head with a strong jetting force, and then performing exposure, development, etching, etc., to form a photolithographic pattern on the surface of the three-dimensional object It is possible to do.

Next, another feature of the present invention will be described. The resin pattern formed on the substrate according to the present invention has a function as an etching-resistant mask for performing lithography by etching thereafter.
Therefore, the part to be covered is etched away to an unnecessary part if it is not completely covered, which causes inconvenience. That is, the pattern of the non-translucent material made of ink or the like that covers the resist layer formed on the base must completely cover the region where light cannot be transmitted.

FIG. 4 is a diagram for explaining the features of the present invention as described above. Here, the description will be made assuming that a positive type resist is used. First, consider a case where a pattern as shown in FIG. 4A is formed on a substrate by lithography. Here, the shaded portion is a region on the substrate to be removed by etching, that is, a region having a slightly lower height by etching than a region not shaded. In this case, before etching, there is a resist in a region that is not shaded and acts as a maskant for etching resistance. In the case of forming an etching resistant maskant using such a resist of a bodi type, a non-translucent material such as ink may be coated in accordance with a pattern of a region not hatched. At this time, if a pattern is formed using a non-translucent material as shown in FIG. 4C, an uncovered area is formed between adjacent dots in an oblique direction, and the uncovered area is exposed to light in a subsequent exposure step. However, at the time of development, the resist in the exposed region dissolves to completely cover the desired pattern (in this case, the longitudinal direction), and it becomes impossible to obtain a resist pattern that can be used as an anti-etching maskant. In order to avoid such inconveniences, when a dot pattern of a non-translucent material is printed, the overlapping ratio of dots in the up, down, left, right, and oblique directions should be set at least as shown in FIG. It is necessary to drive.
In this manner, the desired pattern area is covered with the non-translucent material without gaps, so that an unnecessary portion of the resist is not exposed at the time of exposure, and an etching resistant maskant of a desired pattern is obtained after development. It becomes possible.

FIG. 5 is a view showing an etching step after forming an etching resistant maskant by the system of the present invention. FIG. 5A shows a resist pattern 3 formed by development.
After the formation of No. 3, baking is performed to cure the pattern. Note that a protective layer 32 is provided on the back surface of the substrate 31 so as not to be damaged by etching in a later step. As the protective layer 32, the same resist as that used for pattern formation can be used. FIG. 5B shows a state in which etching is performed in the etching liquid 34. The etching solution varies depending on the material to be removed by etching. For example, a buffer etching solution of hydrofluoric acid and ammonium fluoride is used to remove SiO ₂ . Phosphoric acid is used to remove Al. When the substrate is made of copper, or when a wiring pattern of a printed circuit board is formed (copper pattern), a ferric chloride aqueous solution or the like is used. Here, an example of wet chemical etching is shown as the etching, but plasma dry etching is also effectively used depending on the material to be removed by etching. For example, Ta ₂ N, Ta, or the like formed as a thin film on a Si wafer by sputtering or the like can be removed by plasma dry etching with high precision without undercut and in a short time (several tens of seconds to several minutes). Pattern formation is performed.

FIG. 5C shows a state in which the etching is completed, the unnecessary resist pattern 33 and the protective layer 32 are removed, and the lithography is completed. An uneven pattern 31 ′ corresponding to a pattern created by computer graphics is formed on a substrate 31.
In this example, the method of reducing the amount to be removed by etching and forming an uneven pattern on the surface of the substrate was described. However, when the etching time was increased and the etching was advanced to the bottom of the substrate, the region without the resist pattern was removed. It penetrates down to a method called so-called chemical blanking (chemical blanking). When the present invention is applied to this chemical blanking, a pattern having a desired shape is formed by computer graphics, and the computer graphics pattern is formed on a substrate on which a resist layer is formed by a non-translucent material by an ink jet method. Then, by performing exposure, development, and baking etching, a component having a complicated shape can be easily manufactured without using a photomask. Further, since it is manufactured not by a mechanical method but by a chemical corrosion method, there is no processing distortion or deformation of the part, and a high-precision part can be manufactured at low cost.

FIG. 6 is a diagram for explaining an example in which the present invention is not applied to the above-described chemical blanking. In this example, a resist pattern is formed on the front and back of the substrate so as to have a mirror image relationship with each other. 2 shows a method of simultaneously performing etching from both sides. FIG. 6A shows the substrate 41.
After baking is performed after the resist pattern 42 is formed on the front and back surfaces, the pattern is cured. FIG. 6B shows a state in which etching is performed by spraying an etching solution 44 from both surfaces with a spray nozzle 43. FIG. 6C shows that after the etching is completed, a resist stripper (for example, a resist maker such as Tokyo Ohka Kogyo Co., Ltd. sells a dedicated resist stripper corresponding to each resist) 45. This shows a state in which the unnecessary resist (etching resistant maskant) 42 has been removed and the component fabrication has been completed. In this way, the method of performing chemical blanking by etching from both sides is advantageous in that a high-precision part can be manufactured and a relatively thick substrate can be used as compared with the method of performing etching from one side, so that the strength can be reduced. There is an advantage that strong parts can be manufactured.

FIG. 7 shows an example in which after a resist pattern is formed by the method of the present invention, a metal is deposited on a substrate by plating to form a pattern. FIG.
(A) shows a state in which a resist pattern 52 is formed on a substrate 51 and then baked to cure the pattern. FIG. 7B shows a case where the substrate 51 is used as a cathode and an Ni plate 54 is used as an anode, for example.
This shows a state where the substrate 51 is immersed in a nickel plating solution 53 and Ni plating 55 is applied to a region of the substrate 51 where no resin pattern 52 exists. As the plating solution 55, for example, a nickel sulfamate bath or the like is used. After the Ni plating is deposited, the resist pattern is removed with a dedicated stripping solution, whereby a desired pattern is formed on the substrate by the Ni plating 55. Another example of this method is
As shown in FIG. 7C, after the Ni plating is deposited, the deposited metal (Ni) 55 can be peeled off from the substrate to produce a desired component (electroforming method).

The above example is an example using Ni plating. As another example, a Si wafer is used as a substrate,
After forming and curing the resist pattern, Al is deposited by sputtering or vapor deposition, and thereafter, only the resist pattern is removed, whereby a desired pattern of Al can be formed on the Si wafer. This method uses Al (for example, without etching).
Since a desired pattern of Al) can be formed, other patterns or materials are provided on the substrate, and when they are inconvenient when they are immersed in an etching solution,
By this method, a pattern of Al or the like can be formed.

[0027]

According to the present invention, a photosensitive resin is selectively exposed based on computer information to form a photosensitive area and a non-photosensitive area, or the photosensitive area of the photosensitive resin is formed as a desired final product. Unlike the method using an analog shielding mask as described above, graphic information can be easily processed and edited by keyboard operation, and such a photosensitive resin molded article can be obtained in a short time. In addition, information can be corrected in a short time. In addition, when exposing at once using an analog shielding mask, a light source that can cover a large area is required, but when exposing digitally based on computer information, A large light source is not required because exposure and subsequent movement of the spot are sufficient. In addition, since the molded photosensitive resin obtained by such a method does not require a mold or the like, unlike a general resin structure, it can be obtained in a shorter time and at a lower cost than ordinary resin molding. In addition, since information processing is performed on a computer, complicated shapes can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an example of a pattern forming apparatus suitable for use in carrying out a pattern forming method according to the present invention.

FIG. 2 is a diagram for explaining an example of an ejection head suitable for use in the embodiment of the present invention.

FIG. 3 is a diagram for explaining another configuration example of the ejection head suitable for use in the embodiment of the present invention.

FIG. 4 is a diagram for explaining an example of a pattern forming method according to the present invention.

FIG. 5 is a diagram for explaining an example of an etching step according to the present invention.

FIG. 6 is a view for explaining another example of the etching step according to the present invention.

FIG. 7 is a view for explaining still another example of the etching step according to the present invention.

FIG. 8 is a process flow chart for explaining an example of a conventional pattern forming method.

9 is a diagram showing a cross-sectional view of a pattern formed by the method shown in FIG. 8 according to the process of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Injection head, 2 ... Carriage, 3 ... Substrate holding stand,
4, 27: base, 5: non-translucent material supply tube, 6:
Signal supply cable, 7: injection head control box, 8, 9: carriage skin motor, 10: computer, 11: control box, 12: liquid chamber, 13
... outflow channel, 14 ... metal diaphragm, 15 ... liquid chamber inlet, 16 ... non-translucent material inflow channel, 17 ... piezo electric crystal, 18 ... lead wire, 20 ... ejection head, 21 ... electrostrictive oscillator, 22 ... excitation signal source, 23 ... charging electrode, 24 ... charging signal source, 25 ... deflection electrode, 26 ... deflection power supply, 28 ... gutter, 29 ... tank containing non-translucent material, 30 ... pressure pump, 31 ... Substrate, 32: protective layer, 33: resist pattern, 34: etching solution, 41: substrate, 42: resist pattern, 43: spray nozzle, 44: etching solution, 45: resist removing agent, 51: substrate, 52: resist pattern 53, nickel plating solution, 54, anode electrode, 55, deposited metal, 61, substrate, 62, film to be processed, 63, photoresist, 64, photomask, 6
5: evaporated film (pattern), 66: exposed part, 67: developed part, 68: etched part, 69: resist removal part.

Claims (2)

[Claims] 1. A method for exposing a photosensitive resin, comprising selectively exposing the photosensitive resin based on computer information to form a photosensitive region and a non-photosensitive region. 2. A photosensitive resin is selectively exposed based on computer information to form a photosensitive region and a non-photosensitive region.
A photosensitive resin molded product, wherein a photosensitive region of the photosensitive resin is formed as a desired final product.