BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method for forming a pattern by using a photo-nanoimprint technology, an imprint apparatus using therefore, and a curable compound used therefore.

Description of the Related Art

There has been a growing requirement for miniaturization in a semiconductor device, a MEMS, or the like, and hence a photo-nanoimprint technology has been attracting attention as a microfabrication technology. In the photo-nanoimprint technology, a photocurable composition (resist) is cured in a state in which a mold having a fine groove/land pattern formed on its surface is pressed against a substrate (wafer) having applied thereto the photocurable composition. Thus, the groove/land pattern of the mold is transferred onto the cured film of the photocurable composition and hence the pattern is formed on the substrate. According to the photo-nanoimprint technology, a fine structural body of the order of several nanometers can be formed on the substrate.

A method for forming a pattern by a photo-nanoimprint technology disclosed in Japanese Patent No. 4791357 is described with reference to a schematic sectional view ofFIG. 1. First, a liquid resist102is dispensed dropwise discretely onto a pattern forming area on a substrate101by using an inkjet method (laying step (1),FIG. 1(1)). Liquid droplets of the resist102dispensed dropwise spread on the substrate as indicated by an arrow103indicating a direction in which a liquid droplet spreads (FIG. 1(1)). The phenomenon is called prespread. Next, the resist102is molded with a mold104that has a pattern formed thereon and is transparent to irradiation light105to be described later (mold contacting step (2),FIG. 1(2)). In the mold contacting step (2), the liquid droplets of the resist102spread over the entire region of a gap between the substrate101and the mold104(FIG. 1(2)). The phenomenon is called spread. In addition, in the mold contacting step (2), the resist102is filled into a groove portion on the mold104by the capillary phenomenon as indicated by the arrow103indicating a direction in which a liquid droplet spreads (enlarged portion ofFIG. 1(2)). The filling phenomenon is called fill. A time period from contact between the mold104and the resist102to the completion of the spread and the fill is called a filling time. After the completion of the filling of the resist102, the resist102is cured by being irradiated with the irradiation light105(light irradiating step (3),FIG. 1(3)), and then the mold is released from the cured product (releasing step (4),FIG. 1(4)). The performance of those steps results in the formation of a cured film (photocured film)106having a predetermined pattern shape on the substrate101.

A series of step units ranging from the mold contacting step (2) to the releasing step (4) is referred to as “imprinting step (Im)”. In addition, a series of step units ranging from the laying step (1) to the releasing step (4) is referred to as “shot”, and an area where the mold is in contact with the resist, in other words, an area where a pattern is formed on the substrate101is referred to as “shot area”. When the laying step (1) and the imprinting step (Im) are performed on predetermined areas on a substrate201in a predetermined order and a predetermined number of times as illustrated inFIG. 2, the substrate201having, at desired positions, cured films209each having a desired groove/land pattern shape can be obtained.

The photo-nanoimprint technology disclosed in Japanese Patent No. 4791357 has involved a problem in that a time period (filling time) from the initiation of the contact of the mold to the completion of the spread and the fill is long, and hence throughput is low.

As described in the foregoing, the liquid droplets of the resist dispensed dropwise discretely spread on the substrate gradually before the mold is brought into contact with the resist (prespread). Accordingly, in the case where a waiting step is provided in a period from the completion of the laying step (1) to the initiation of the mold contacting step (2) in which the mold is brought into contact with the resist, the prespread advances to a larger extent, and hence a time required for spread after the contact of the mold can be made shorter than that in the case where no waiting step is provided. However, the waiting step is required, and hence the extent to which a required time for one shot is shortened is small and no large improvement in throughput is achieved.

In view of the foregoing, an object of the present invention is to provide a photo-nanoimprint technology having a short filling time and high throughput.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problem, according to one embodiment of the present invention, there is provided a method for forming a pattern by using a photo-nanoimprint process, including performing, on each of a plurality of shot areas on a surface of a substrate, in this order:

a laying step (1) of dispensing liquid droplets of a curable composition (A) containing at least a polymerizable compound (a) dropwise discretely to lay the liquid droplets;

a mold contacting step (2) of bringing the curable composition (A) and a mold into contact with each other;

a light irradiating step (3) of irradiating the curable composition (A) with light from a mold side to cure the composition; and

a releasing step (4) of releasing the mold from a cured product of the curable composition (A),

in which when steps from the mold contacting step (2) to the releasing step (4) are collectively called an imprinting step (Im), before the imprinting step (Im) is performed on one shot area on which the laying step (1) has already been performed out of the plurality of shot areas, the laying step (1) is performed on another shot area selected from the plurality of shot areas.

According to another embodiment of the present invention, there is provided a method for forming a pattern by using a photo-nanoimprint process, including performing, on each of a plurality of shot areas on a surface of a substrate, in this order:

a laying step (1) of dispensing liquid droplets of a curable composition (A) containing at least a component (a) serving as a polymerizable compound dropwise discretely to lay the liquid droplets;

a mold contacting step (2) of bringing the curable composition (A) and a mold into contact with each other;

a light irradiating step (3) of irradiating the curable composition (A) with light from a mold side to cure the composition; and

a releasing step (4) of releasing the mold from a cured product of the curable composition (A),

in which when steps from the mold contacting step (2) to the releasing step (4) are collectively called an imprinting step (Im), the laying step (1) on one shot area selected from the plurality of shot areas and the imprinting step (Im) on another shot area on which the laying step (1) has already been performed out of the plurality of shot areas are simultaneously initiated, and are simultaneously ended.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

