JPH0439917A - Processing method of fine pattern - Google Patents

Abstract

PURPOSE:To process a fine pattern with high accuracy, with high efficiency and at low costs by a method wherein a pattern-shaped ultraviolet-ray hindering electrodeposition layer which has been formed on a support material is transcribed on an object to be processed and a resist film is developed via the layer. CONSTITUTION:An ultraviolet-ray hindering electrodeposition layer 3 is electrodeposited and formed on a conductive support material 1 where an insulating layer 2 of a desired pattern has been formed. The support material on which said electrodeposition layer has been formed is aligned with and brought into close contact with an object 4, to be processed, on which a photoresist 5 and an adhesive layer 6 have been coated and formed sequentially. After that, the support material is stripped off; and the ultraviolet-ray hindering electrodeposition layer is transcribed on the object to be processed. Then, the electrodeposition layer is irradiated with ultraviolet rays 7. After that, a developing treatment of the above-mentioned photoresist is executed; in addition, its etching treatment is executed. As required, the processes up to the etching treatment are repeated a plurality of times. Thereby, a plurality of fine processing operations can be executed to the object to be processed such as a fine processing operation of a TFT or the like.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for processing fine patterns, and in detail,
A processing method suitable for high precision, mass production, and low cost processing of fine patterns performed in the manufacturing process of various semiconductor elements such as gI film transistors, thin film diodes, solar cells, thin film sensors, SAW devices, and TSBs. Regarding.

[Conventional technology and the problem to be solved by the invention]

Color liquid crystal display using thin film transistors (T
In recent years, PT-LCD (PT-LCD) has been incorporated into pocket TVs and portable TVs, and has just entered the stage of practical use. oriented development is already gaining momentum. Due to these trends, 40
The demand for manufacturing large-sized TPTs such as inch, 70-inch, etc. began to rise. For this reason, the pattern of thin film transistors to be formed has been forced to become smaller and the size of the substrate has become larger, and mass production has become necessary. In order to meet these production requirements, the current photolithography method has major problems such as the development of large exposure equipment such as steppers and equipment investment, which requires a huge amount of money, and there is a limit to the applicable size of the photomask. ing.

On the other hand, instead of the steps up to developing the resist film in the photolithography method, a method is also known in which a resist film is directly printed in a desired pattern on the workpiece using a printing method and a fine pattern is formed by etching. There is.

Although the above-mentioned processing method in which the resist film is formed by printing means does not have any major restrictions and can be easily applied to pattern formation due to the increase in the size of products such as TPT of 20 to 70 inches, it has the following problems. There is.

That is, as the above-mentioned printing means, intaglio offset printing method, lithographic offset printing method, color separation method, screen printing method, etc. are typically applied.
Although it is suitable for printing a resist pattern with a relatively large line width (200 μm or more), it is not suitable for printing a fine pattern with a smaller line width. Among them, in the case of intaglio offset printing method, if a harder ink is used,
Although it is possible to print fine line patterns of about 90 μm, the transfer of ink to the workpiece becomes poor, and similarly to other printing methods, when attempting to print thinner line patterns, the coating film thickness becomes thinner. As a result, it was unsuitable for forming resist patterns that required corrosion resistance. Another disadvantage is that the printed resist pattern is deformed due to the influence of the fluidity of the ink, the pressure of the plate, and some of the ink remains on the plate without being transferred, resulting in poor reproducibility of the printed pattern. There was also. Furthermore, the line width and thickness of the printed resist film may vary depending on the surface condition of the workpiece (presence or absence of unevenness, etc.), or there may be problems in printing on concave areas. Depending on the type, etc., there is also the problem that the adhesiveness with the ink is poor and good printing cannot be performed. Moreover, since the resist film is directly printed on the surface of the workpiece, undesirable impurities (such as Na ions) contained in the printing resist ink may remain in the resist film, and other problems may occur on the workpiece. Depending on the type of paper, there is a problem of contamination caused by printing. Generally, the resist ink used in the above-mentioned printing method has a high viscosity, so it has been impossible to purify it to remove the above-mentioned impurities.

As mentioned above, processing methods using photolithography and printing methods both have advantages and disadvantages, and as a result, mass production is becoming more difficult, especially with the trend of miniaturization of processing patterns of workpieces and enlargement of processing substrates as mentioned above. There was a need for a method that could adequately respond to trends.

[Means for Solving the Problem] As a result of repeated research in order to overcome the various problems of the above-mentioned conventional techniques, the present inventor has developed a method of forming a pattern on a separate support material in place of a photomask in the photolithography method. By transferring the ultraviolet-blocking electrodeposited layer onto a workpiece coated with a photoresist, and exposing and developing the resist film using the ultraviolet-blocking electrodeposited layer, it is possible to create particularly fine patterns of the resist film. Compared to conventional methods, it is possible to perform the process extremely cheaply and efficiently without compromising accuracy, and as a result, the desired fine pattern can be processed with high precision, efficiently, and at low cost through etching. They discovered this and completed the present invention.

That is, in the method for processing a fine pattern of the present invention, an ultraviolet-blocking electrodeposited layer is electrodeposited on a conductive support material on which an insulating layer of a desired pattern has been formed, and the support material on which the electrodeposition layer is formed is subjected to photo-coating. After aligning and adhering the resist and adhesive layer to the workpiece formed by sequential coating, the support material is peeled off and the ultraviolet-blocking electrodeposited layer is transferred to the workpiece. After being irradiated with ultraviolet rays from the side, the photoresist is developed and then etched.

Further, in the method of the present invention, the steps of the above-described processing method can be repeated multiple times to perform micromachining on the workpiece multiple times.

Hereinafter, the processing method of the present invention will be explained with reference to the drawings.

FIGS. 1(a) to 1(c) are cross-sectional explanatory views showing process examples of the processing method of the present invention. In the figure, 1 is a conductive support material, 2 is an insulating layer, 3 is an ultraviolet-blocking electrodeposited layer, 4 is a workpiece, 5 is a photoresist film, 6 is an adhesive layer, 7 is an ultraviolet ray irradiated for development, 5a shows a resist film patterned by development.

In the method of the present invention, first, a support material 1 having a patterned ultraviolet-blocking electrodeposited layer 3 to be transferred as shown in FIG.
and a workpiece 4 on which a photoresist film 5 and an adhesive layer 6 are laminated in this order as shown in FIG. 3(C) are prepared separately.

A supporting material 1 having a patterned ultraviolet-blocking electrodeposited layer 3 has an insulating layer 2 consisting of a positive or negative pattern of a fine pattern to be processed into the supporting material 1, as shown in FIG. 1(a).
After that, an ultraviolet-blocking electrodeposition material is electrodeposited using an electrodeposition method.

The supporting material 1 may be made of a material that has electrical conductivity in its entirety or at least in its surface layer, and specifically, it may be a metal material, a material in which a conductive film is formed on an insulating base material, or the like. Further, the surface of the support material 1 may be subjected to a treatment such as a warm water dip to impart good mold release properties from the electrodeposited layer 3, if necessary. The insulating layer 2 is used to mask the surface portion of the support material corresponding to the non-formed portion of the electrodeposited layer 3 in order to pattern the electrodeposited layer 3. This insulating layer 2 can be formed, for example, by coating PVA or casein sensitized with ammonium dichromate and applying an ordinary solvent-based resist and patterning it by photolithography, or by forming an inorganic insulating film on a support material. However, after applying a resist, the inorganic insulating film can be etched. Typical examples of the above-mentioned ultraviolet-blocking electrodeposition materials are electrodeposition liquid materials containing metal substances used in general electrodeposition methods, but there are also organic substances and polymeric substances that become ionic components in the liquid. It is also possible to use materials containing substances that precipitate on the surface of the conductive support material 1 (electrode) due to reactions with electrolytic components near the electrodes or the like. The thickness of the electrodeposited layer 3 is at least the thickness of the insulating layer 2, and preferably about 1 to 3 μm.

In the present invention, since the patterned ultraviolet blocking layer 3 is formed by electrodeposition, there are the following advantages.

That is, when trying to form the ultraviolet blocking layer 3 by printing means, in conventional printing methods, viscous printing ink is inked by rubbing it against the image area of a printing plate, etc. Physical effects such as pressure force, sliding force, and tensile force affect certain inks in a complex manner, and the ink is not accurately filled into the image area, resulting in a pattern printing with uniform thickness and precision for the UV-blocking layer. There is a drawback that it cannot be done.

Based on the viewpoint that the condition for inking faithfully to the printed area is to perform completely static inking by eliminating the various physical forces mentioned above, the present inventor has devised the present invention in order to achieve this objective. The invention employs an electrodeposition method in which ink components are electrically deposited, and this electrodeposition method enables static inking to the image area. It is clear from the fact that photoelectroforming technology is used to process minute parts that the dimensional accuracy of electrodeposited lines is extremely good.
In fact, according to the above technique, it is possible to form an image with a line width of 1 to 5 μm. In addition, the electrodeposited film thickness depends on the amount of electricity,
Its control is easier than physical inking such as conventional printing means. Moreover, when the image area is made of a photoresist or the like, the electrodeposited material is prevented from growing laterally on the resist side walls of the image area, so that electrodeposition is performed faithfully to the image area of the resist pattern. Therefore, if the resist image area is formed with high precision, the electrodeposited image line will also be faithfully copied, and will therefore be formed with high precision. From the above, even if the image on the printing plate (supporting material) is a fine image of 1 to 2 μm, a highly accurate ink image can be formed by selecting the electrodeposited material (ink).

Therefore, in the present invention, by adopting the electrodeposition method for forming the layer 3, the core layer 3 can be formed statically, eliminating all the physical effects of the printing method, and is extremely fine. It is possible to pattern a layer with uniform thickness with high precision,
Moreover, it has the great advantage that the layer thickness can be easily adjusted by electrical operation.

As the workpiece 4, any article can be used as long as it is patterned by etching. In addition, the workpiece 4 to be subjected to repeated processing may be a single item, a plurality of the same single item or different types of items arranged in a fixed frame, etc., or a single item may be mounted on multiple surfaces on the same board. It may be something. A photoresist film 5 is formed by applying photoresist to such a workpiece 4 so as to have a smooth surface. Known photoresists can be appropriately selected and used, and the photoresist is coated to a thickness of 0.2 to 5 μm, preferably 0.5 to 5 μm, by means such as spin coating with a spinner, coating with a blade coater, and coating with spray coating. Coat to a film thickness of approximately 2 μm.

By applying this photoresist, even if the surface of the workpiece has irregularities, it is hidden (embedded) and smoothed. An adhesive or the like is further applied onto the photoresist film 5 using a spinner, blade coater, or spray coater to form an adhesive layer 6.
form. Examples of the above-mentioned adhesive include trade name: PE-
Adhesives such as 118 and KP-1004 (manufactured by Nippon Carbide) can be used. Note that the adhesive layer 6 needs to ensure ultraviolet transmittance.

Next, in the method of the present invention, the support material 1 on which the ultraviolet-blocking electrodeposited layer 3 is formed is placed on the workpiece 4 so that the electrodeposited layer 3 and the adhesive layer 6 face each other, as shown in FIG. overlap and press tightly. At this time, it is important to accurately position (align) the two and then bring them into close contact.Then, by peeling and removing the support material 1 (along with the insulating layer 2), a patterned ultraviolet-blocking electrode is formed. The adhesive layer 3 is adhered onto the adhesive layer 6 and transferred to the workpiece 4 side (FIG. 4(e)).

After the transfer of the electrodeposition layer 3 is completed, as shown in FIG. 1(e), ultraviolet rays 7 are irradiated onto the workpiece 4 from where the electrodeposition layer 3 is located, and a development process is performed to form the resist film 5. Pattern it ((f) in the same figure). Next, the workpiece 4 having the patterned resist film 5a is etched by a known dry etching method or wet etching method (FIG. 6(6)), and finally the resist film 5, etc. is peeled off and removed. Thus, the processing of the fine pattern 8 on the workpiece 4 according to the present invention is completed (FIG. 4(e)).

In the present invention, by repeating the steps up to the etching process multiple times as necessary, it is possible to perform fine processing on the workpiece multiple times, such as pattern processing of TPT or the like. Incidentally, according to the present invention, the workpiece on which all the fine pattern processing has been completed is sent to a post-process and subjected to necessary processing, processing, etc. thereafter.

FIGS. 2(a) to 2(d) are cross-sectional explanations of some steps showing the other side of the present invention. Figure 1(a) shows that the photoresist film 5 and adhesive layer 6 have been formed on the workpiece 4, as shown in Figure 1(b).
A process in which the electrodeposited layer 3 is accurately aligned and transferred onto the workpiece using a support material 1 having a similar electrodeposited layer 3 as shown in the figure, and then irradiated with ultraviolet rays 7 shows the part. Note that the workpiece 4 illustrated in FIG.
It is a composite structure in which the structure is etched. The difference from the processing method illustrated in FIG. 1 is that a positive resist is used as the photoresist (5) in the first illustrated method, whereas a negative resist is used in the method illustrated in FIG. The reason lies in the fact that it is used. Therefore, when a positive photoresist is used, the portion of the resist film 5 where the electrodeposited layer 3 is not formed is removed by the development process as shown in FIG. 1(f), whereas the negative photoresist is When using the resist film 5, a portion of the resist film 5 in the area where the electrodeposited layer 3 is formed is removed by a development process, as shown in FIGS. 2(a) and 2(b).

In the method of the present invention illustrated in FIG. 2, after the above-mentioned development is completed, the above-mentioned process and ching process are performed (FIG. 2(C)), and finally, the resist film 5 and the like are peeled off and removed. A fine pattern 8 can be formed on the workpiece 4 (FIG. 4(d)).

(Example〕 Next, the present invention will be explained in more detail by giving examples.

Example 1 A water-soluble photosensitive solution containing PVA and ammonium dichromate as main components was applied to a 0.2M thick stainless steel support sheet, exposed and developed using a photomask of a predetermined shape, and
An insulating layer consisting of a pattern with a line width of 10 μm and a film thickness of 1.0 μm was formed. Furthermore, a burning process was performed to strengthen the water resistance and electrical insulation of the insulating layer. Next, the Ni plate was used as an anode,
Using the support sheet as a cathode, electrodeposition was performed in a bath with the following composition and under the electrodeposition conditions to form a film with a thickness of 1.2 mm on the exposed stainless steel surface of the support sheet.
A nickel electrodeposition layer of μm thickness was formed.

Zoku” bottom/Nickel sulfate 250g #!・Nickel chloride 45g/j2・Boric acid
30g7N iJL strip i/PH H: 4.5, Temperature = 50°C1 Current density: 5A/di" Meanwhile, photoresist (Tokyo Ohka type) was applied to the entire surface of the workpiece on which polysilicon (p-3i) was formed :0FPR) was applied to a film thickness of 1.5 μm, and then a vinyl acetate adhesive solution was applied to a film thickness of 1° to 2 μm.

Next, the adhesive layer of the workpiece and the surface of the nickel electrodeposition layer on the support sheet were brought into close contact with each other in accurate alignment, and then the support sheet was peeled off. As a result, the patterned nickel electrodeposition layer was peeled off from the support sheet and transferred to the workpiece side (adhesive layer side) as shown in FIG. 1(e). Next, when ultraviolet rays are irradiated from the electrodeposited layer side, the nickel electrodeposited layer blocks the ultraviolet rays, so the positive photoresist film is
) is developed as shown. After the development was completed, dry etching was performed using CF gas containing 5% oxygen, and finally the resist film, adhesive layer, and electrodeposited layer were removed by a conventional method.

As a result, a fine groove pattern as shown in FIG. 1(5) having a line width of 10 .mu.m and a depth of 5 .mu.m could be formed on the workpiece on which polysilicon was formed.

Example 2 After forming a polysilicon (p-3i) film on a glass substrate 11 (manufactured by Asahi Glass Co., Ltd.: AN) with a thickness of <1.1 m as shown in FIG. 2(a) as a workpiece, a polysilicon film was formed. A TPT substrate was used, in which an insulating film 13 of 5 iOz was formed on the entire surface including 12, and a gate polysilicon (p-St) was deposited 14 to a thickness of 0.1 um on the surface by LPCVD. A negative photoresist (Tokyo Ohka type: OMR) is applied to the entire surface of the workpiece using a spinner coating method to a thickness of 1 μm.
m, and then a photopolymerizable adhesive containing an acrylate monomer and a photopolymerization initiator as main components was applied onto the coating film to a thickness of 1 μm.

On the other hand, ITO was deposited on a 2IIIa thick polyimide film.
After applying photoresistos (20MR manufactured by Tokyo Ohka Co., Ltd.) to a support film formed with a thickness of 0.2 μm, exposure and development were performed using a mask to form an insulating layer with a pattern of 5 μm in line width and 1 μm in layer thickness. Then, using a blank pigment, an electrodeposition layer having a thickness of 1.5 μm was formed in a pattern by electrorheological electrodeposition.

Next, the adhesive layer of the workpiece and the surface of the electrodeposited layer on the support film are brought into close contact with each other with accurate alignment, and then the support film is peeled off to form the patterned electrodeposited layer as shown in Figure 2 (a).
It was transferred to the workpiece side (adhesive layer side) as shown in . Next, when ultraviolet rays are irradiated from the electrodeposited layer side, the resist film is developed as shown in FIG. 2b) since it is a negative type photoresist. After the development was completed, dry etching was performed using CF4 gas containing 5% oxygen, and finally the resist film and adhesive layer were removed by a conventional method.

As a result, it was possible to pattern a TPT substrate with a gate length (line width) of 5 μm. Furthermore, the pattern thus formed had characteristics equivalent to those processed by the conventional method of exposing and processing in Step 7.

(Effects of the Invention) As explained above, the processing method of the present invention uses a UV-blocking electrodeposited layer separately formed in a pattern on a support material and coated with a photoresist instead of a photomask in the photolithography method. transferred onto the workpiece,
Development of the resist film through the ultraviolet-blocking electrodeposited layer (
Even if the contents of the fine patterns to be processed and formed become more diverse and wider, the resist film can be patterned efficiently and at low cost without sacrificing accuracy.

In detail, it is possible to pattern a wide variety of resist films easily and efficiently, without the constraints due to photomask size limitations and the risk of reducing productivity, which is the case with conventional methods that simply apply photolithography. can be carried out according to
Moreover, since ordinary means are applied to the formation of the electrodeposited layer, it is possible to flexibly respond to various pattern contents (conditions) of the resist film without the need to develop new equipment.
There is no way that this will lead to an extreme increase in manufacturing costs. Furthermore, there is no need to use a stepper or the like as an exposure device, and the manufacturing device is simple. Furthermore, in the method of the present invention, the surface of the workpiece can be smoothed by applying a photoresist, and no printing means is used to form the UV-blocking layer, so it is possible to accurately form the UV-blocking electrodeposited layer on the workpiece. In addition, it is possible to transfer the resist film reliably, and as a result, unlike the conventional method in which a patterned resist film is directly printed on the workpiece, the above-mentioned resist film can be changed depending on the surface condition of the workpiece, the type of surface layer, etc. There is no vibration that can cause problems such as printing defects, impurities, contamination, etc. Then, a resist film pattern ([J] is achieved reliably and with good reproducibility) that has a predetermined film thickness similar to that of the photolithography method and consists of an extremely fine pattern with a line width of 100 μm or less (minimum of several μm). can do.

Therefore, according to the processing method of the present invention, the final target of processing a fine pattern can be achieved by performing etching treatment after patterning the excellent resist film as described above. It can be applied with high precision, efficiently, and at a very low cost. Further, in the method of the present invention, by repeating the steps up to the etching process multiple times, the alignment exposure process in the conventional photolithography method is not necessary, and processing suitable for large-scale processing can be achieved.

[Brief explanation of the drawing]

FIGS. 1(a) to (c) are cross-sectional explanatory views showing process examples of the processing method of the present invention, and FIGS. 2(a) to (b) are cross-sectional explanatory views showing other process examples of the present invention. 1... Conductive support material 2... Insulating layer 3... One layer with ultraviolet blocking properties 4... Workpiece 5... Photoresist film 6.
... Adhesive layer 7 ... Ultraviolet light 8 ... Processed fine pattern Figure 1 Figure 2 ↓ ↓ ↓ ↓ ↓ Go-7

Claims (2)

[Claims] (1) A UV-blocking electrodeposited layer is electrodeposited on a conductive support material on which an insulating layer of a desired pattern has been formed, and a photoresist and an adhesive layer are sequentially applied to the support material on which the electrodeposition layer is formed. After aligning and adhering to the workpiece,
The supporting material is peeled off and the ultraviolet-blocking electrodeposited layer is transferred to the workpiece side, and then ultraviolet rays are irradiated from the electrodeposited layer side, and then the photoresist is developed and then etched. A method for processing fine patterns. (2) A method for processing a fine pattern, which comprises repeating the steps of the method according to claim 1 a plurality of times to perform micromachining on a workpiece a plurality of times.