JPH086235A - Photomask and pattern forming method using the same - Google Patents

Abstract

PURPOSE:To make it possible to smoothly peel a photomask at the time of peeling this photomask from the front surface of a photoresist layer after bringing the photomask into proximity to the front surface of this photoresist layer and exposing the photoresist layer. CONSTITUTION:The photomask 1 is constructed by providing the rear surface of a transparent substrate 2 with mask patterns 4 in its prescribed region 3 and providing the rear surface of the transparent substrate 2 around the mask patterns 4 with a release layer 5. In such a case, this release, layer 5 is formed thicker than the thickness of the mask patterns 4. Consequently, only the release layer 5 is eventually brought into tight contact with the front surface of the photoresist layer 13 when the photomask 1 is brought into proximity to the front surface of the photoresist layer 13. Then, the photomask 1 is smoothly peeled from the front surface of the photoresist layer 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask and a pattern forming method using the same.

[0002]

2. Description of the Related Art For example, there is a liquid crystal display panel in which a transparent electrode made of ITO is provided on the upper surface of a transparent film substrate. There is a photolithography method as a method of forming a transparent electrode made of ITO on the upper surface of a film substrate in such a liquid crystal display panel. In this photolithography method, first, an ITO thin film is provided on the upper surface of the film substrate, a photoresist layer is provided on the upper surface of the ITO thin film, then the photoresist layer is exposed using a photomask, and then the photoresist layer is developed. An unnecessary portion is removed to form a resist pattern, and then the ITO thin film is etched by using this resist pattern as a mask, whereby a transparent electrode made of ITO is patterned.

[0003]

By the way, a photomask generally has a structure in which a light shielding pattern made of chromium is provided on the lower surface of a glass substrate. When such a photomask is arranged close to the upper surface of the photoresist layer to improve the resolution, the light shielding pattern may stick to the photoresist layer. In such a case, when the photomask is separated from the photoresist layer, the photoresist layer may be partially transferred to the photomask, which may lead to disconnection of the transparent electrode. It was Further, in an extreme case, there is a problem that the photomask may not be separated from the photoresist layer, which may interfere with the subsequent steps. An object of the present invention is to provide a photomask which can be smoothly separated from the photoresist layer and a pattern forming method using the photomask.

[0004]

According to a first aspect of the present invention, there is provided a photomask in which a transparent substrate, a light-shielding pattern provided on a lower surface of the transparent substrate in a predetermined region, and the transparent portion around the light-shielding pattern. A peeling layer having a thicker film than the light shielding pattern provided on the lower surface of the substrate. A pattern forming method according to the invention of claim 3, wherein a pattern forming layer is provided on the upper surface of the substrate, and a photoresist layer is provided on the upper surface of the pattern forming layer, and the release layer of the photomask according to claim 1 or 2. Is adhered to the upper surface of the photoresist layer, the photoresist layer is exposed using the light-shielding pattern of the photomask as a mask, and then developed to pattern the photoresist layer to form a resist pattern. The pattern forming layer is patterned by using the pattern as a mask to form a pattern.

[0005]

According to the present invention, since the peeling layer which is thicker than the light shielding pattern is provided on the lower surface of the transparent substrate around the light shielding pattern, the peeling layer is formed when the photomask is brought close to the upper surface of the photoresist layer. The light-shielding pattern can be prevented from adhering to the upper surface of the photoresist layer, and thus the photomask can be smoothly separated from the photoresist layer.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows the lower surface of a photomask according to an embodiment of the present invention. Photo mask 1
Is provided with a transparent substrate 2 made of glass or the like. A light-shielding pattern 4 (see FIG. 1B) made of chrome or the like is provided in a light-shielding pattern forming region 3 in a substantially central portion of the lower surface of the transparent substrate 2, and the transparent substrate 2 around the light-shielding pattern 4 is provided.
The peeling layer 5 having a thicker film than the light shielding pattern 4 (see FIG.
(See (B)). The release layer 5 is obtained by adhering a fluororesin film made of polytetrafluoroethylene or the like to the lower surface of the transparent substrate 2, or a fluororesin material made of polytetrafluoroethylene or the like in the transparent substrate 2.
The bottom surface of the is applied by printing or the like. As an example of a specific thickness dimension, the light shielding pattern 4 has 50
The peeling layer 5 has a thickness of about 0 to 1000 Å and a thickness of about 30 to 200 μm.

Next, a pattern forming method using this photomask 1 will be described with reference to FIG. In this pattern forming method, first, the film substrate 1
1. An ITO thin film (pattern forming layer) 12 is provided on the upper surface of 1, and a photoresist layer 13 is provided on the upper surface of the ITO thin film 12.
To provide. Next, the photomask 1 is brought close to the upper surface of the photoresist layer 13. In this case, since the peeling layer 5 is thicker than the light shielding pattern 4, the peeling layer 5 is in close contact with the upper surface of the photoresist layer 13, but the light shielding pattern 4 is in close contact with the upper surface of the photoresist layer 13. You can choose not to.

Next, the photoresist layer 13 is exposed using the light shielding pattern 4 of the photomask 1 as a mask. next,
The photomask 1 is separated from the upper surface of the photoresist layer 13. In this case, only the peeling layer 5 of the photomask 1 is adhered to the upper surface of the photoresist layer 13, and the fluororesin forming the peeling layer 5 has a good peeling property with respect to the photoresist. The photomask 1 can be smoothly separated from the. As a result,
The photoresist layer 13 will not be partially transferred to the photomask 1, and the photomask 1 will not be separated from the photoresist layer 13.

Next, after development, unnecessary portions are removed from the photoresist layer 13 to form a resist pattern. Next, using this resist pattern as a mask, ITO
When the thin film 12 is etched and patterned, IT
A transparent electrode made of O is patterned.

[0010]

As described above, according to the present invention, since the peeling layer which is thicker than the light shielding pattern is provided on the lower surface of the transparent substrate around the light shielding pattern, the photomask is used as the upper surface of the photoresist layer. The peeling layer can be brought into close contact with the upper surface of the photoresist layer and the light shielding pattern can be prevented from being brought into close contact with the film, so that the photomask can be smoothly separated from the photoresist layer.

[Brief description of drawings]

FIG. 1A is a bottom view of a photomask according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view shown for explaining a pattern forming method using the photomask.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photomask 2 Transparent substrate 4 Light-shielding pattern 5 Release layer 11 Film substrate 12 ITO thin film (pattern formation layer) 13 Photoresist layer

Claims (3)

[Claims] 1. A transparent substrate, a light-shielding pattern provided in a predetermined region on the lower surface of the transparent substrate, and a thick film peeling around the light-shielding pattern, which is thicker than the light-shielding pattern provided on the lower surface of the transparent substrate. A photomask having a layer. 2. The photomask according to claim 1, wherein the peeling layer is made of a fluororesin. 3. A pattern forming layer is provided on the upper surface of the substrate,
A photoresist layer is provided on the upper surface of the pattern forming layer, and the release layer of the photomask according to claim 1 is brought into close contact with the upper surface of the photoresist layer, and the light shielding pattern of the photomask is used as a mask to form the photoresist layer. Is exposed to light and then developed to form a resist pattern by patterning the photoresist layer,
A pattern forming method comprising patterning the pattern forming layer using the resist pattern as a mask to form a pattern.