US 2003/0194620 A1 · Mask blank and method of fabricating phase shift mask from the same

Abstract

A mask blank and a method of fabricating a phase shift mask from the same. The mask blank includes a transparent substrate, a light shield layer formed on the entire upper surface of the transparent substrate, and a multifunctional protective layer formed on the entire surface of the light shield layer. To make the phase shift mask from the blank, the protective layer is patterned, and the exposed portions of the light shield layer are etched using the protective layer pattern as an etch mask to in turn expose first and second regions of the substrate. The phase shift region is formed by etching a groove in the second region of the substrate while the protective layer pattern protects the light shield layer from the etchant. Therefore, undesirable residue is prevented from forming as a result of a reaction between the etchant and the light shield layer and hence, from accumulating at the bottom of a groove constituting the phase shift region. The method also entails forming a photosensitive layer over the protective layer, patterning the photosensitive layer, and patterning the protective layer by using the photosensitive layer pattern as a mask. In this case, the patterned photosensitive layer is removed, and then the resultant structure is cleaned so that no residue remains on the exposed portions of the light shield layer.

Drawings

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Drawings

Claims22

Dependent claims

A mask blank for use in fabricating a phase shift mask of exposure equipment of semiconductor fabricating apparatus, the mask blank comprising:

a transparent substrate;
a light shield layer covering the entire upper surface of the transparent substrate, said light shield layer being substantially opaque to exposure light of a given wavelength and said substrate being transparent to the light;
and
a protective layer covering the entire upper surface of the light shield layer, said protective layer being of a material which produces no residue when exposed to an etch gas capable of etching said substrate.

1 more element

A method of fabricating a phase shift mask comprising the steps of:

forming a light shield layer on the entire surface of a substrate which is transparent to the exposure light, the light shield layer being substantially opaque to exposure light of a given wavelength and the substrate being transparent to the light;
forming a protective layer pattern on the light shield layer;
etching portions of the light shield layer using the protective layer pattern as an etch mask to expose first and second regions of the substrate;
and
while the protective layer pattern remains on a portion of the light shield layer forming the boundary of the second region, forming a phase shift region by etching the second region of the substrate with an etchant to form a groove in the substrate at the second region thereof, wherein the protective layer prevents an interaction between the etchant and the light shield layer at the boundary of the second region.

2 more elements

A method of fabricating a phase shift mask comprising the steps of:

sequentially forming a light shield layer and a protective layer over the entire upper surface of a substrate, the light shield layer being substantially opaque to exposure light of a given wavelength and the substrate being transparent to the light;
coating the entire upper surface of the protective layer with a layer of photosensitive material;
patterning the photosensitive layer to expose portions of the protective layer;
etching the protective layer using the patterned photosensitive layer as an etch mask to expose portions of the light shield layer;
removing the patterned photosensitive layer;
cleaning the resultant structure to remove any residue of the patterned photosensitive layer and underlying protective layer remaining on the exposed portions of the light shield layer;
etching away the exposed portions of the light shield layer using the patterned protective layer as an etch mask to expose first and second regions of the substrate;
and
forming a phase shift region at the second region of the substrate.

6 more elements

Dependencies are inferred from the claim text.

Description4,567 words

Summary1,912 words

#1. Field of the Invention

#The present invention relates to a phase shift mask used to fabricate semiconductor devices, and to a method of fabricating a phase shift mask from a mask blank. More particularly, the present invention relates to a mask blank and to a method of fabricating an alternating phase shift mask from the mask blank.

#2. Description of the Related Art

Brief description of the drawings5 figures

#The above and other objects, features and advantage of the present invention will become more apparent from the following detailed description of preferred embodiments thereof made with reference to the attached drawings, of which:

#FIGS. 1 through 5 are cross-sectional views illustrating a conventional method of fabricating an alternating phase shift mask;

#FIGS. 6 and 7 are cross-sectional views illustrating defects in an alternating phase shift mask fabricated by the conventional method;

Detailed description2,508 words

#The present invention will now be described in more detail below with reference to the accompanying drawings. In the drawings, the thicknesses of layer or regions are exaggerated for the sake of clarity. Furthermore, like reference numerals denote like elements throughout the drawings.

#Hereinafter, a first embodiment of a mask blank according to the present invention will be described. The mask blank is useful in forming optical masks such as a Levenson-type phase shift mask.

#<First Embodiment>

Facts

Application

10/422,956Filed 25 Apr 2003

Priority

KR 99-265512 Jul 1999

Published

16 Oct 2003

Term ends

Not estimatedThe source records don’t support an estimate.

Classification3 codes

G03F 1/30
Phase shift masks [PSM]; PSM blanks; Preparation thereof: alternating PSM, e.g. Levenson-Shibuya PSM; Preparation thereof
G03F 7/09
Photosensitive materials: characterised by structural details, e.g. supports, auxiliary layers
G03F
Photomechanical production of textured or patterned surfaces

Mask blank and method of fabricating phase shift mask from the same

Life of this patent

Mask blank and method of fabricating phase shift mask from the same

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims22

Description4,567 words

Drawings

Classification3 codes

Life of this patent

Description4,567 words