Phase shift mask and method of forming patterns using the same

Patent metadata

Field	Value
Publication number	US-9632438-B2
Application number	US-201514604459-A
Country	US
Kind code	B2
Filing date	Jan 23, 2015
Priority date	Apr 9, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method of forming a pattern includes: preparing a target substrate including a photoresist layer on a base substrate; aligning a phase shift mask to the target substrate, the phase shift mask including a mask substrate comparted into a first region including a first sub region and second sub regions at sides of the first sub region, and second regions at sides of the first region, the phase shift mask including a phase shift layer on the mask substrate corresponding to the first region; fully exposing the photoresist layer at the first sub region and the second regions by utilizing the phase shift mask; and removing the photoresist layer at the first sub region and the second regions to form first and second photoresist patterns corresponding to the second sub regions. Transmittance of the phase shift layer is selected to fully expose the photoresist layer in the first sub region.

First claim

What is claimed is:

1. A method of forming a pattern, the method comprising:
preparing a target substrate comprising a base substrate and a photoresist layer on the base substrate;
aligning a phase shift mask to the target substrate, the phase shift mask comprising a mask substrate comparted into a first region including a first sub region and second sub regions at sides of the first sub region, and second regions at sides of the first region, the phase shift mask comprising a phase shift layer on the mask substrate corresponding to the first region, and a plurality of openings respectively corresponding to the second regions on the mask substrate;
fully exposing the photoresist layer at the first sub region and the second regions by utilizing the phase shift mask; and
removing the photoresist layer at the first sub region and the second regions to form first and second photoresist patterns corresponding to the second sub regions,
wherein transmittance of the phase shift layer is selected to fully expose the photoresist layer in the first sub region.

2. The method according to claim 1 , wherein the first and second sub regions are symmetrical from a center of the first region.

3. The method according to claim 1 , wherein the transmittance of the phase shift layer is higher than 45%.

4. The method according to claim 3 , wherein the phase shift layer is provided as a plurality of phase shift layers with an interval between the phase shift layers,
wherein a width of the interval between the phase shift layers and a width of each of the phase shift layers are determined by 0.2×W 2 <W 1 <0.7×W 2 ,
where W 2 is the width of the interval between the phase shift layers and W 1 is the width of each of the phase shift layers.

5. The method according to claim 4 , wherein the width of the interval between the phase shift layers is from 1 μm to 8 μm.

6. The method according to claim 1 , wherein an amount of exposure light utilized to expose the photoresist layer is lower than 45 mJ.

7. The method according to claim 1 , wherein the phase shift layer is configured to invert a phase of light.

8. The method according to claim 1 , wherein the target substrate further comprises an etch target layer interposed between the base substrate and the photoresist layer, and
the method further comprises: etching the etch target layer with a mask of the first and second photoresist patterns.

Assignees

• Samsung Display Co Ltd

Inventors

• Lee Dongeon
• Kang Min
• Kim Bong Yeon
• Son Yong
• Woo Junhyuk
• Lee Hyunjoo
• Ju Jinho

Classifications

• H10P76/204 Primary

  of organic photoresist masks · CPC title

• G03F7/2008

  characterised by the reflectors, diffusers, light or heat filtering means or anti-reflective means used · CPC title

• G03F7/70191

  Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like · CPC title

• G03F9/7003 Primary

  Alignment type or strategy, e.g. leveling, global alignment · CPC title

• G03F1/26 Primary

  Phase shift masks [PSM]; PSM blanks; Preparation thereof · CPC title