JP2008299208A - Method for manufacturing stereoscopic pattern of thick film resist - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a projecting stereoscopic pattern of a thick film resist having a perpendicular side wall while eliminating generation of a "footing" state. <P>SOLUTION: In Fig.(a), a resist 2 is applied on a transparent substrate 1, and a reflector 3 such as a metal film or a dielectric film is disposed on the back face of the transparent substrate 1. When the resist 2 in this state except for a portion to be the convex pattern is exposed by use of a stepper through a mask 4, exposure light partially reaches the transparent substrate 1 and is transmitted through the transparent substrate 1 and reflected by the reflector 3 as shown by arrows in the figure, and the reflected light partially reaches an unexposed portion of the resist to expose this portion. Thereby, the luminous energy of exposure in a portion which is conventionally in a "hemming bottom" state is increased to exceed a development threshold. As a result, by developing the resist 2, the "hemming bottom" portion shown by dashed lines in (b) is eliminated and the projecting stereoscopic pattern of the thick film resist having perpendicular side walls of the resist 2 is formed as shown by a hatching in Fig.(b). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a convex thick film resist three-dimensional pattern having a vertical sidewall. In the present specification and claims, the term “thick film” means that the film thickness is 10 μm or more.

  In recent years, there has been an increasing demand for fine three-dimensional elements in the fields of optical communication, medical, computer, and measurement. Conventionally, in order to manufacture such a fine three-dimensional element, a mother mold is manufactured by machining, an electroformed mold is manufactured by using this mother mold, and further, by injection molding using an electromold, A method of manufacturing a three-dimensional element has been common.

  However, as a more complicated and finer micro three-dimensional shape element is required, it becomes difficult to cope with the method of manufacturing the mother die using such machining, and instead, photolithography technology is used. Thus, a method of forming a three-dimensional shape with a film thickness resist and using this as a matrix has been adopted.

  An example of the method is shown in FIG. As shown in FIG. 2A, the resist 12 coated on the substrate 11 is irradiated with exposure light through a mask 13 of a stepper to expose portions other than the convex pattern (the resist is positive). ). When the resist 12 is developed, a three-dimensional pattern of the convex resist 12 is formed on the substrate 11 as shown in FIG.

  However, in such a method of manufacturing a convex resist three-dimensional pattern, when the resist film is thick, the side surface of the resist three-dimensional pattern is not vertical as shown by the broken line in FIG. As shown by hatching 2 (b), there is a problem that a portion that does not dissolve is generated in the portion opposite to the incident direction of the exposure light, resulting in a so-called “soaking” state.

  This is considered to be because the exposure light attenuates as it travels through the resist 12. At that time, in the portion far from the non-exposed portion, the attenuation is small because the scattered light of the adjacent light beam is incident, but in the portion close to the non-exposed portion, there is no scattered light from the non-exposed portion, so the attenuation becomes large, Eventually, the range in which light exceeding the development threshold reaches is indicated by an arrow in FIG. 2 (a), and as a result, a "slipping" state occurs.

  Conventionally, in order to solve this problem, an attempt has been made to optimize the focus position and exposure amount of a stepper used for exposure, as well as to optimize the developer and the development time. However, the larger the resist film thickness, the more inevitably the “soaking” becomes larger depending on the γ characteristics of the resist, and it is impossible to make the side walls vertical.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method for producing a convex thick film resist three-dimensional pattern that eliminates the occurrence of a “soaking” state and that has a vertical sidewall.

  A first means for solving the above-described problem is a method for producing a convex thick film resist three-dimensional pattern having a vertical sidewall, and the back surface of the transparent substrate is exposed when the resist applied on the transparent substrate is exposed. A method for producing a resist three-dimensional pattern, comprising a step of causing light reflected from (a surface opposite to a surface coated with a resist) to contribute to photosensitivity of the resist.

  The second means for solving the problem is the first means, characterized in that a reflector for reflecting light incident from the front side is provided on the back surface of the transparent substrate. is there.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a "soaking" state can be eliminated and the manufacturing method of the convex thick film resist solid pattern with a perpendicular | vertical side wall can be provided.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining an outline of a manufacturing method of a thick film resist three-dimensional pattern which is an example of an embodiment of the present invention. In FIG. 1A, a resist 2 having a thickness of 10 μm or more is applied on a transparent substrate 1, and a reflector 3 such as a metal film or a dielectric multilayer film is provided on the back surface of the transparent substrate 1.

  In such a state, when the stepper is used and the resist 2 other than the portion that becomes the convex pattern is exposed through the mask 4, a part of the exposure light reaches the transparent substrate 1 and is transmitted through the transparent substrate 1. As indicated by the arrow, the light is reflected by the reflector 3, and a part of the light reaches a part that is not exposed, and this part is exposed.

  Therefore, the exposure amount of the portion that has been in the “slipping” state is increased and exceeds the development threshold value. As a result, when the resist 2 is developed, the “slipping” portion indicated by the broken line in FIG. Thus, as shown by hatching in FIG. 2B, a three-dimensional pattern of a convex resist in which the side wall of the resist 2 is vertical is formed.

  In this embodiment, the reflector 3 is provided on the back side of the transparent substrate 1. However, when the object is achieved by the reflected light from the back side surface of the transparent substrate 1, the reflector 3 is deliberately used. There is no need to provide.

As the metal film constituting the reflector 3, a Cr film, an Al film, or the like can be used, and as the dielectric multilayer film, a reflective film formed by alternately laminating SiO ₂ and TiO ₂ can be used. .

It is a figure for demonstrating the outline | summary of the manufacturing method of the thick film resist solid pattern which is an example of embodiment of this invention. It is a figure for demonstrating the conventional method of forming a three-dimensional shape with a film thickness resist using a photolithographic technique.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2 ... Resist, 3 ... Reflector, 4 ... Mask

Claims (2)

  A method for producing a convex thick film resist three-dimensional pattern with vertical sidewalls, wherein when the resist coated on the transparent substrate is exposed, the back surface of the transparent substrate (the surface opposite to the surface coated with the resist) A method of producing a thick resist pattern having a step of contributing to the photosensitivity of the resist.   2. The method for producing a resist solid pattern according to claim 1, wherein a reflector for reflecting light incident from the front surface side is provided on the back surface of the transparent substrate. .

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