JPH0367265B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a pattern forming method in the manufacture of semiconductor integrated circuits. More specifically, the present invention particularly involves forming a layer of a base material for flattening on a semiconductor substrate having steps, and providing a positive photosensitive resin layer thereon to form a multilayered organic material layer. The present invention relates to an industrially advantageous pattern forming method that can easily form a pattern faithful to a mask pattern in one development process after image forming exposure is performed on the pattern. Conventionally, in the manufacture of semiconductor integrated circuits, in order to form a pattern on a material to be etched, for example, a desired circuit is applied to an actinic ray-sensitive resin (hereinafter referred to as resist) formed on a predetermined semiconductor substrate. Actinic light is irradiated through a mask with a pattern drawn on it, the irradiated resist is then developed, and then the semiconductor substrate is etched using a dry or wet method, and the resist is peeled off to form the desired pattern. Such operations are typically repeated several times to obtain the final integrated circuit device. In recent years, the progress of microlithography technology, which is one of the microfabrication technologies mentioned above, has been remarkable.In particular, lithography technology that uses light has improved overlay accuracy and step-and-repeat exposure equipment with excellent resolution has been developed. development of,
Thanks to improvements in optical systems, lithography in the submicron region using light, which was previously thought to be impossible, is no longer a dream. Various improvements in such equipment have made it possible to create finer patterns, but in order to accurately transfer fine patterns onto a substrate, several technical issues must be resolved. is necessary. By the way, the substrate used for forming a semiconductor integrated circuit element inevitably has various steps and unevenness on its surface, and its flatness is not necessarily high. Such steps and irregularities on the substrate surface have a great effect on the uniformity of the resist coating film thickness, and the film thickness changes locally, and is thicker in concave areas and thinner in convex areas, and as a result, the coated surface is usually It has a wave-like appearance. This immediately causes large variations in exposure characteristics, which is unfavorable in terms of pattern formation. In addition, the unevenness of the substrate surface causes diffused reflection of the irradiated light, leading to a decrease in the accuracy of desired pattern dimensions or a decrease in resolution. Furthermore, in recent years, step-and-repeat projection exposure apparatuses, so-called steppers, which can provide high resolution, have been introduced into semiconductor device manufacturing lines in place of conventional contact-type exposure apparatuses. This stepper achieves higher resolution using a single wavelength of light, such as 436 nm, by improving the light source or optical system. There is a problem in that standing waves are likely to be generated on a flat substrate with no surface. Therefore, in order to perform better high-resolution pattern formation, it is necessary to solve the above problems. To do this, it is necessary to eliminate unevenness on the substrate surface, suppress reflection from the substrate, and It is required to prevent the generation of standing waves. In order to meet these demands, recently a method has been developed to provide a multilayered resist on a substrate. For example, a layered organic film is coated thickly as the bottom layer on a substrate with steps, flattened, and then layered on top. A three-layer resist method has been proposed, in which a thin film made of metal or inorganic material is formed by a CVD method, and a resist film is further formed on top of the thin film. However, although this method can form patterns with high resolution and a large aspect ratio, the process is extremely complicated, the throughput is extremely low, and productivity is poor, and the photosensitive materials used for these methods are dry etched. It has a major drawback of not being resistant to time. A two-layer resist method has also been proposed as a method that reduces process complexity. This method involves forming an organic film on the substrate that has the effect of flattening it and suppressing reflections from the substrate surface, and then forming a resist film on top of it, and aims to obtain a pattern with high transfer accuracy. It is something. however,
In this two-layer resist method, after forming an organic film as the base of the resist film on the substrate, when applying the resist on top of it, dissolution and mixing occurs at the interface between the upper layer and the lower layer, causing the surface of the upper layer to As a result, unevenness occurs, and a coating film with an uneven thickness is formed as a whole. Furthermore, when dissolution and mixing occurs, the solubility of this portion in the developing solution generally differs. With such a method, it is impossible to faithfully reproduce the mask dimensions and obtain a pattern with the required precision, resulting in problems such as a decrease in resolution and poor development. For this reason, after forming the lower layer, some kind of treatment is applied to the surface to prevent dissolution and mixing, but usually materials with completely different solubility characteristics for solvents are selected and used as the upper and lower layers. I am using it. For example, a rubber-based negative resist is used as the lower layer and an alkali-soluble positive resist is used as the upper layer, or polymethyl methacrylate or polymethyl isopropenyl ketone containing a dye is applied as the lower layer, and the upper layer is an alkali-soluble positive resist. (Japanese Unexamined Patent Publication No. 58-51517) has been proposed. However, in these methods, the solubility in the developer is completely different, so although it is easy to form a two-layer film, the development process requires a two-step process and is complicated. be. Problems to be Solved by the Invention The purpose of the present invention is to overcome these drawbacks, to obtain a high-resolution pattern even when using a substrate with steps, and to obtain a pattern that is faithful to the mask pattern in one development process. An object of the present invention is to provide a pattern forming method suitable for industrial implementation, which can obtain a pattern. Means for Solving the Problems As a result of extensive research, the present inventors found that a diphenylamine derivative having a specific hydroxyl group and a formalin or formalin-alcohol modified melamine derivative were condensed in the presence of an acid catalyst. The condensate is insoluble in general organic solvents, but soluble in special organic solvents and alkaline solutions, has excellent storage stability, and can easily form a multilayer resist structure without any surface treatment. In addition, it has excellent dry etching resistance and a wide range of baking temperatures, making it an excellent base material for photosensitive resins. The inventors have discovered that the above object can be achieved by providing a layer made of a mixture of the above substances on a substrate as a base layer for an alkali-soluble positive photosensitive resin layer, and based on this knowledge, the present invention has been completed. It came to this. That is, the present invention provides a substrate with the general formula (R in the formula is a hydrogen atom or a hydroxyl group.) A condensate obtained by condensing at least one kind of diphenylamine derivative represented by the following formula with formalin or a formalin-alcohol-modified melamine derivative in the presence of an acid catalyst, Alternatively, after forming a layer consisting of a mixture of the condensate and a substance that has absorption ability in the photosensitive wavelength range of the photosensitive resin, an alkali-soluble positive photosensitive resin layer is further provided on this layer, and then from the top surface The present invention provides a pattern forming method characterized by performing image forming exposure by irradiating actinic rays and then developing with an alkaline aqueous solution. The diphenylamine derivatives used to produce the condensate in the present invention are those represented by the general formula (), such as p-hydroxydiphenylamine, m-hydroxydiphenylamine, o-hydroxydiphenylamine, 2,4-
These include dihydroxydiphenylamine, 3,5-dihydroxydiphenylamine, and the like. These may be used alone or in combination of two or more. In these diphenylamine derivatives having a hydroxyl group, the solubility of the obtained condensate in a solvent depends on the bonding position of the hydroxyl group. Therefore, it is desirable to appropriately select whether to use only one type or to use two or more types depending on the purpose and use of the condensate. For example, p
Those having a hydroxyl group at the - position have better solubility in alkaline aqueous solutions than those at the m-position. It is preferable to determine the condensate after considering the blending ratio of the compound and the m-position compound in advance. Especially p
When the − position is prepared in the range of 70 to 95% by weight,
Since the solubility in an alkaline aqueous solution can be easily controlled, reliability is increased. Furthermore, formalin-alcohol-modified melamine derivatives are those obtained by modifying melamine with formalin and converting it into methylol by a known method, or by further alkoxylating this using a lower alcohol having 1 to 4 carbon atoms. , usually the following general formula () (At least one of R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ in the formula is a methylol group, and the rest are hydrogen atoms, or at least one is an alkyl group having 1 to 4 carbon atoms.) It is a mixture of monomers and multimers such as dimers and trimers of the compound represented by the following formula: an alkoxymethyl group consisting of an alkoxymethyl group, and the remainder being a methylol group or a hydrogen atom. The amount of this multimer is desirably about several percent or less by appropriately selecting reaction conditions for modification. If the amount of the polymer is too large, the resulting condensate will have low solubility in special solvents, which is undesirable for use. Furthermore, this modified melamine derivative preferably has at least one methylol group added to the molecule as a monomer. Further, such modified melamine derivatives are commercially available as, for example, Nikaratsuku (manufactured by Sanwa Chemical Co., Ltd.) and Nikaresin (manufactured by Nippon Carbide Industries Co., Ltd.), so they can be easily obtained. The condensate used in the method of the present invention can be obtained by condensing the diphenylamine derivative described above with formalin or a formalin-alcohol-modified melamine derivative in the presence of an acid catalyst. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, phosphoric acid, and sulfuric acid, and organic acids such as formic acid and oxalic acid.
Preferred among these catalysts are phosphoric acid, sulfuric acid, or a mixture thereof, since the degree of condensation related to the resulting condensate melt can be easily controlled. Regarding the amount of acid catalyst, since the viscosity of the reaction liquid increases as the reaction progresses, the amount of acid catalyst should be approximately equal to or more than the amount of raw materials to be charged, preferably 2.
It is desirable to use more than twice as much. If the amount of the acid catalyst is too small, the reaction system may become highly viscous, almost solidified, and cannot be stirred, so care must be taken. The reaction temperature is not necessarily constant depending on the type of raw materials and other conditions, but it is usually 15 to 70℃.
be selected as appropriate within the range. This reaction is an exothermic reaction, but if the temperature is lower than necessary at the beginning of the reaction, it will be difficult for the reaction to progress. It is preferable to proceed with the reaction while maintaining a predetermined temperature from the beginning. Furthermore, if the reaction temperature is higher than necessary, the reaction product may gel, which is not preferable. Regarding the charging ratio of the diphenylamine derivative and the modified melamine derivative, if the amount of the modified melamine derivative is large, the reaction system tends to gel more easily as the reaction progresses, and the solubility of the resulting condensate tends to decrease. There is. On the other hand, when the amount of the diphenylamine derivative increases, gelation becomes less likely to occur, but the resulting condensate tends to have significantly increased solubility. Therefore, it is desirable to charge the modified melamine derivative in such a proportion that the amount of the modified melamine derivative is within the range of 1 to 60% by weight, preferably 25 to 55% by weight, based on the total amount of raw materials charged. Furthermore, it seems that the longer the reaction time, the higher the degree of polymerization of the resulting condensate, and the higher the molecular weight. Therefore, a short reaction time gives a highly soluble product, while an increase in viscosity occurs as the reaction time progresses, reaching an almost constant viscosity in 48-72 hours. Further, the solubility of the obtained condensate tends to gradually decrease with the length of the reaction time, but no major change is observed after a certain reaction time has elapsed. The condensate thus obtained exhibits solubility only in certain limited special solvent systems. Such special solvent systems include, for example, N-methyl-2-
Polar solvents such as pyrrolidone, N-acetyl-2-pyrrolidone, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof, or the polar solvent, which is a non-solvent for the condensate but is a non-solvent for the condensate. is a mixed solvent with a compatible solvent. Furthermore, the condensate is characterized by good solubility in inorganic or organic alkaline solutions. The above-mentioned condensate is effective as a base material by itself, but in order to prevent standing waves caused by reflection from the substrate and diffused reflection due to irregularities on the substrate surface,
If necessary, a substance having an absorption ability in the wavelength range sensitive to the photosensitive resin used may be mixed with the condensate. Examples of substances having absorption ability in the photosensitive wavelength range include Coumarink, Coumarin 314, Coumarin 338, Quinoline Yellow, Magneson, Varifast Yellow AUM [manufactured by Orient Chemical Co., Ltd.],
Varifast Yellow 4220 [Orient Chemical Co., Ltd.]
], Oplus Yellow 136 [Orient Chemical Co., Ltd.]
[Manufactured by] Sumiplast Yellow H5G [Sumitomo Chemical Co., Ltd.]
Sumiplast Yellow HLR [Sumitomo Chemical Co., Ltd.]
[manufactured by Bayer], Oleosol Fast Yellow GCN [manufactured by Sumitomo Chemical Co., Ltd.], Macrolex Yellow 3G [manufactured by Bayer], Macrolex Yellow 6G [manufactured by Bayer], Kayaset Orange G [manufactured by Nippon Kayaku Co., Ltd.] , Kayaset Yellow 2G [manufactured by Nippon Kayaku Co., Ltd.], Kayaset Yellow GN [manufactured by Nippon Kayaku Co., Ltd.], Oil Yellow
Examples include dyes such as 18 (manufactured by Shirad Kagaku Co., Ltd.) and p-hydroxy-p'-dimethylaminoazobenzene. These may be used alone or in combination of two or more.
Each of these dyes has a unique solubility, and in order to effectively exhibit the antireflection effect,
1% by weight or more, preferably 5 to 1% by weight based on the condensate
It is desirable to add 40% by weight. If this amount is too small, the antireflection effect will not be sufficiently exhibited, and if it is too large, it may not be completely dissolved, or even if it is dissolved, it may precipitate later, which is not preferable. In the method of the present invention, the above-mentioned condensate or, if desired, a mixture of the condensate with a substance having an absorbing ability in the photosensitive wavelength range of the photosensitive resin is used as the base material, and a layer made of this material is formed on the substrate. Formed as geological strata. This underlayer is effective for flattening a substrate having steps or unevenness. To form the base layer, for example, an organic solvent solution of the base material is spin-coated onto the substrate using a spinner, and then heated at 90 to 200°C, preferably 120°C.
Dry treatment at a temperature of ~170°C. At this time, the appropriate drying time is selected depending on the drying temperature, but in general, when using a hot air dryer, it is 10 minutes or more, preferably about 20 to 60 minutes, and when using a hot plate, it is 1 minute or more, preferably It takes about 2 to 10 minutes. In the present invention, an alkali-soluble positive photosensitive resin layer is further provided on the base layer thus formed. As this photosensitive resin layer, currently commercially available resists can be used, such as the OFPR series (manufactured by Tokyo Ohka Kogyo Co., Ltd.), the AZ series (manufactured by Shippray Co., Ltd.), and the KAR ( (manufactured by Kodatsuku Co., Ltd.), and these are all quinonediazide-based or naphthoquinonediazide-based, but
The resist used in the present invention is not limited to these types. Furthermore, the underlayer has the characteristic that when a resist is applied thereon, it can be applied immediately without the need for surface treatment. This shows that it is particularly effective as a base layer in forming a resist film with a multilayer structure. Furthermore, in the present invention, if necessary, a thin film of metal or inorganic material may be provided on the base layer, and a photosensitive resin layer may be formed thereon. Next, actinic rays are irradiated from the upper surface of the positive photosensitive resin layer thus provided through a mask on which a desired pattern is drawn in accordance with a conventional method to perform image-forming exposure. As the active light, for example, a carbon arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, an ultraviolet fluorescent lamp, a metal halide lamp, sunlight, etc. are used. In the method of the present invention, after performing image forming exposure in this way, using an alkaline aqueous solution,
Development processing is performed according to a commonly used method.
For this development treatment, known alkaline aqueous solutions are used, such as inorganic aqueous alkaline solutions containing alkali metals and organic alkaline aqueous solutions that do not contain alkali metals, but the latter is preferable, and a typical example is tetra Examples include aqueous solutions of quaternary ammonium compounds such as methylammonium hydroxide and choline. Effects of the Invention In the method of the present invention, since the underlying material used exhibits good solubility in an aqueous inorganic or organic alkali solution, it is possible to form an etching mask pattern on a substrate with only one development process. The pattern formation process is simpler than the conventional multilayer resist method. In addition, the base material has excellent storage stability, does not easily undergo deterioration such as gelation during long-term storage, and has good epithelial membrane formation.
It also has features such as excellent adhesion. Furthermore, as a major feature of the present invention, in the conventional two-layer resist method, the base material dissolves in the resist applied on top of it and the contact surface is likely to change in quality. However, in the present invention, the pattern formation process is complicated by applying some kind of surface treatment to the underlying material or by applying a resist with completely different solubility. Direct application of the resist does not cause any adverse effects, and the resist is not particularly limited. As described above, the pattern forming method of the present invention has significantly simpler steps than conventional methods, especially in the multilayer resist method. In addition, in the present invention, the base material used has a flattening ability and can form a film with a particularly high antireflection effect, so it is effective in step-and-repeat exposure that tends to generate standing waves. In addition, in order to flatten the stepped and uneven parts of the substrate and suppress differences in dimension conversion due to diffused reflection, it has features such as high pattern dimensional accuracy and a wider exposure latitude compared to conventional methods. have. EXAMPLES Next, the present invention will be explained in more detail with reference to synthesis examples and examples, but the present invention is not limited to these examples in any way. Synthesis Example 1 Prepare 600g of 85% phosphoric acid in the beaker 1,
Add 200 g of p-hydroxydiphenylamine to a water bath kept at 30°C while stirring.
After confirming that it has completely dissolved, add Nikaratsuku MW22A, a melamine derivative whose main component is pentabutoxymethylmonomethylolmelamine.
Slowly add 100 g of [manufactured by Sanwa Chemical Co., Ltd.] to the above solution and stir. The internal temperature of the reaction system gradually rises due to the exothermic reaction, but in order to avoid a sudden rise in temperature, the total amount of the nickel is added while cooling the reaction system while controlling the addition of the nikarac. After that, continue stirring for about 2 hours, then raise the temperature of the water bath to 40℃ and continue stirring for 24 hours. The viscosity of the reaction product has increased since the initial stage of the reaction, and this product is slowly and continuously dripped into 20 mL of pure water in a 30 stainless steel tank while stirring at high speed. Since the reaction product is highly viscous, it falls like a string. After dropping the entire amount of the reaction product and stirring for another 1 hour, suction filtration is performed using No. 63 filter paper to separate the condensate, and the mixture is stirred and washed again in 10 pure water. This washing and filtration process is repeated, and the washing is completed after confirming that the pH of the washing liquid is neutral. This material is then dried in a hot air dryer at 80°C for a day and a night. The obtained condensate was a brownish black particulate material, but it was easy to crush into powder. The yield was approximately 90% of the theoretical yield, indicating that the synthesis was efficient. Synthesis Examples 2 to 18 As shown in the attached table, condensates were synthesized in the same manner as in Synthesis Example 1 except that the types of diphenylamine derivatives and modified melamine derivatives, their charging ratios, and synthesis conditions were varied. The yield is also shown in the table. All of these were able to be synthesized efficiently with a theoretical yield of 60% or higher.

【table】

【table】

[Table] Example 1 1.5 g each of the condensates obtained in Synthesis Examples 1 to 4
to which about 0.3 g of p-hydroxy-p'-dimethylaminoazobenzene was added was dissolved in 8.5 g of dimethylacetamide as a solvent,
This was filtered through a membrane filter with a pore size of 0.45 μm to obtain a test coating solution. As the base substrate, a 3-inch silicon wafer was used, in which aluminum was vacuum-deposited to a thickness of about 600 to 800 nm on a SiO ₂ pattern having a depth of 1 μm. The above coating solution was dropped onto the cleaned base substrate, and then applied using a Mikasa spinner at an initial speed of 600 rpm for 3 seconds.
The coating was applied by spinning at 4000 rpm for 40 seconds. Using a resist coater model TR4000 (manufactured by Tatsumo), each sample was dried on a hot plate from 130°C to 180°C at 10°C intervals for 5 minutes to form a base layer. As an upper layer resist
Immediately after drying, spin coating was performed using OFPR800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 4000 rpm for 20 seconds, followed by drying on a hot plate at 110° C. for 90 seconds. A two-layer resist could be formed without any dissolution of the underlayer. Next, mask aligner PLA500 [Canon Inc.
A contact method was used to perform 8-step multiple exposure at 0.2-second intervals from 4.6 seconds to 6.0 seconds using a 4.0-second exposure system. Note that the irradiation intensity at a wavelength of 365 nm at this time was approximately 6.2 mW/cm ² . Next, using a tetramethylammonium hydroxide aqueous solution prepared to approximately 2% by weight as a developer, it was developed at 23°C.
After developing by dipping for 75 to 80 seconds, rinsing in pure water for 30 seconds and spin drying was performed. As a result, the two-layer resist was developed in one development process, and a pattern faithful to the mask pattern was formed. In addition, when we measured the pattern dimension width by microscopic observation at the positions corresponding to the peaks and valleys of the resist pattern that intersects the step part on the surface of the base substrate, the difference was found compared to the case of the single-layer resist method. It was clear that it had an antireflection effect. Example 2 A coating solution consisting of 1.5 g of the condensate obtained in Synthesis Example 3, about 0.3 g of Magneson, and 8.5 g of dimethylacetamide was prepared in the same manner as in Example 1. As the base substrate, a wafer having a 1 μm SiO ₂ step and aluminum deposited to a thickness of 600 to 800 nm was used. Apply the above coating liquid to this substrate.
Apply at 4000rpm, resist coater model
After drying at 160℃ for 5 minutes using the hot plate attached to TR4000 to form a base layer,
OFPR800 was applied onto this and dried on a hot plate at 110°C for 90 seconds to form a resist layer.
This was subjected to contact exposure for 5.2 seconds using Mask Aligner PLA500, then developed for 80 seconds using the same developer as in Example 1, washed with pure water, and then spin-dried. The formed pattern was almost faithful to the mask pattern, and the line width measuring device (manufactured by Hitachi Electronics)
As a result of measuring the dimensions above and below the step, it was found that the line dimension difference between the peak and valley tends to be smaller.
The effectiveness of the anti-reflection film was confirmed. Example 3 To the condensate obtained in Synthesis Example 3, the dye Coumarin 7 was added as a characteristic wavelength absorber in varying amounts of 1, 5, 10, and 20% by weight.
A coating solution was prepared by dissolving the condensate in dimethylacetamide to a concentration of about 15% by weight. Using the same silicon wafer as in Example 1 as a base substrate, the coating solution was spin-coated and dried at 160° C. for 5 minutes to form a film with a thickness of about 200 nm. to this
OFPR800 was applied using a resist coater model TR4000 and dried at 110°C for 90 seconds. Next, exposure was performed in the same manner as in Example 1 using Mask Aligner PLA500, and then the product was maintained at 23°C and developed by immersion in the same developer as in Example 1 for 80 seconds, washed with pure water for 30 seconds, and spin-dried. did. When the resulting pattern was observed under a microscope, it was found that some parts remained undeveloped when the exposure time was 5.2 seconds or less, but it was completely developed when the exposure time was longer than that. When the line dimensions of the resist between the peaks and valleys in the stepped portion of the formed pattern were measured in the same manner as in Example 2, it was found that the antireflection effect varied depending on the amount of absorbent added. That is, if the amount added is less than 5%, no great effect can be expected, but if the amount added is more than 5%, the effect can be fully confirmed, and the larger the amount added, the greater the effect. In addition, when the absorption spectrum in the ultraviolet wavelength region of a film formed on a quartz plate by the method described above using the prepared coating solution was measured using an ultraviolet light measuring device model 200-20 manufactured by Hitachi, Ltd., it was found that the addition of the absorbent As expected, it was confirmed that as the amount increased, the absorbance increased. Example 4 The same test as in Example 3 was conducted, except that the absorbent in Example 3 was changed to Coumarin 314, and results with similar trends were obtained. Example 5 The same test as in Example 3 was conducted except that the absorbent in Example 3 was changed to Coumarin 338, and results with similar trends were obtained. Example 6 The condensate obtained in Synthesis Example 5 was dissolved in dimethylacetamide to a concentration of 15% by weight, which contained an amount of p-hydroxy-p'-dimethyl corresponding to about 10% by weight of the condensate. Aminobenzene was added to prepare a coating solution. Using this product, coating film formation and exposure were performed in the same manner as in Example 1, and development was performed for 65 seconds with the same developer as in Example 1. When the exposure amount was less than 5.4 seconds, development defects occurred. . When the time was 5.8 seconds or more, the dissolution of the lower layer film progressed, especially in the fine pattern part of 2 μm or less. Furthermore, through microscopic observation and dimensional measurements, it was possible to confirm the effectiveness of the antireflection film at exposure doses of 5.8 seconds or more. Example 7 Using the condensate obtained in Synthesis Example 6 and quinoline yellow in an amount equivalent to 15% by weight,
A coating solution was prepared in the same manner as in Example 6. Using this product, the steps from film formation to exposure were carried out in the same manner as in Example 1, followed by immersion development for 75 seconds in the same developer as in Example 1 at 23°C, washing with water for 30 seconds, and spin drying. did. As a result, the same results as in Example 6 were obtained. Example 8 Using the condensate obtained in Synthesis Example 7, mounting was carried out in the same manner as in Example 7. As a result, the effect was confirmed by dimensional measurements. Also, compared to Example 7,
Since a condensate with a high reaction temperature during synthesis and not too soluble in alkaline solutions was used, in the case of a two-layer structure, dissolution of the lower layer was suppressed and the pattern did not collapse. Example 9 Using the condensate obtained in Synthesis Example 10, it was dissolved in dimethylacetamide to a concentration of 15% by weight.
A coating solution was prepared by adding 10% by weight of quinoline yellow based on the condensate. Using this material, a film was formed on the same base substrate as in Example 1,
After performing a batch exposure for 5.6 seconds using OFPR800 as the upper layer resist, in the same developer as in Example 1.
It was immersed and developed for 80 seconds, washed with water for 30 seconds, and spin-dried. Since the condensate obtained in Synthesis Example 10 did not have very high solubility in an alkaline solution, it was confirmed by microscopic observation and size measurement that the pattern could be developed without a phenomenon of collapse. Example 10 Magneson was added to 2.0 g of the condensate obtained in Synthesis Example 16.
Add 0.6g of dimethylacetamide 16
A pattern was formed in the same manner as in Example 1, except that the solution obtained by adding and dissolving G was used as the coating liquid for the base material. A pattern with accurate dimension width was obtained. Example 11 Magneson was added to 1.0 g of the condensate obtained in Synthesis Example 17.
Add 0.3g and add 8.5g of dimethylacetamide to this.
When a pattern was formed by adding and dissolving g and using it as a coating liquid for the base material, the other operations were the same as in Example 1, and the same results as in Example 1 were obtained. Example 12 Magneson 0.7 g was added to a mixture of 1.0 g of the condensate obtained in Synthesis Example 14 and 1.0 g of the condensate obtained in Synthesis Example 18.
A pattern was formed in the same manner as in Example 1 except that 16 g of dimethylacetamide was added and dissolved therein as a coating liquid for the base material. As a result, with respect to the resist pattern that intersects with the step portion on the surface of the base substrate, a pattern with extremely high precision was obtained, with little difference in pattern dimension width at positions corresponding to the peaks and valleys. Example 13 Magneson 0.6 was added to a mixture of 1.0 g of the condensate obtained in Synthesis Example 14 and 1.0 g of the condensate obtained in Synthesis Example 15.
A pattern was formed in the same manner as in Example 1, except that 16 g of dimethylacetamide was added and 16 g of dimethylacetamide was added to form a coating solution for the base material.
The difference in dimension conversion of the obtained pattern width was small, and no pattern deformation due to the influence of standing waves was observed, confirming its effectiveness as a base material. Example 14 3.0 g of condensate obtained in Synthesis Example 14 and Magneson
A mixture consisting of 1.0 g of dimethylformamide and 25 g of dimethylformamide was prepared as coating liquid A, and a mixture of 3.0 g of the condensate obtained in Synthesis Example 16, 1.0 g of Magneson, and 25 g of dimethylformamide was prepared as coating liquid B. A pattern was formed in the same manner as in Example 1, except that these coating solutions A and B were mixed at a weight ratio of A:B of 4:5 and used as the base material coating solution. However, a resist pattern faithful to the mask pattern with extremely high pattern dimensional accuracy was obtained, and no pattern deformation due to the influence of standing waves was observed. Example 15 Magneson was added to a mixture of 1.0 g of the condensate obtained in Synthesis Example 14 and 1.0 g of the condensate obtained in Synthesis Example 18.
0.6g and Sumiplast Yellow H5G [Sumitomo Chemical Co., Ltd.]
A pattern was formed in the same manner as in Example 1, except that 16 g of dimethylacetamide was added to the mixture and 16 g of dimethylacetamide was added and dissolved to form a coating solution for the base material. A pattern faithful to the mask pattern with a small difference in dimension conversion was obtained, and no pattern deformation due to the influence of standing waves was observed, confirming its effectiveness as a base material. Example 16 Using the base material used in Example 12, approximately 1 μm
Coated on an aluminum vapor-deposited substrate with steps of 170℃
After drying on a hot plate for 2 minutes at
A film was formed by coating. Next, a filter that transmits light in the range of 400 to 500 nm was installed in the optical path, and exposure was performed for 50 seconds. Next, development was performed at 23° C. for 75 seconds using an aqueous choline solution with a concentration of about 4.2%. As a result, it was possible to obtain an image in which the resist pattern did not become thinner on the step. Example 17 Using the base material used in Example 13, Example 16
When processed in the same manner as above, it was possible to obtain an image with little shift in resist pattern width at step portions. Example 18 Using the base material used in Example 14, NaOH
When an approximately 1.5% aqueous solution was processed as a developer,
It was possible to obtain a pattern with less influence of standing waves and less shift in resist pattern width. Example 19 In Example 18, almost the same results as in Example 18 were obtained when an aqueous solution of monoethanolamine having a concentration of about 28.5% was used as a developer.

Claims (1)

[Claims] 1. On the substrate, as a base layer, a general formula (R in the formula is a hydrogen atom or a hydroxyl group) A condensate obtained by condensing at least one diphenylamine derivative represented by the following and formalin or a formalin-alcohol-modified melamine derivative in the presence of an acid catalyst, Alternatively, after forming a layer consisting of a mixture of the condensate and a substance that has absorption ability in the photosensitive wavelength range of the photosensitive resin, an alkali-soluble positive photosensitive resin layer is further provided on this layer, and then from the top surface A pattern forming method characterized by performing image forming exposure by irradiating actinic rays and then developing with an alkaline aqueous solution.