Phase shift mask, blank for phase shift mask, and method of manufacturing phase shift mask

Claim 2

A phase shift mask comprising: a first light transmitting region through which exposure light is transmitted; a second light transmitting region through which exposure light having a phase different from that of the exposure light transmitted through said first light transmitting region is transmitted; a light blocking region interposed between said first light transmitting region and said second light transmitting region; a transparent substrate having a major surface; a silicon nitride film formed to cover the major surface of said transparent substrate in said first light transmitting region, thereby exposing the major surface of said transparent substrate in said second light transmitting region, said silicon nitride film having a thickness t n and a refractive index n n ; a silicon oxide film formed on said silicon nitride film, said silicon oxide film having a thickness t 0 and a refractive index n 0 ; and a light blocking film covering the major surface of said transparent substrate in said light blocking region; said phase shift mask satisfying the equation: ##EQU4## wherein m is an arbitrary positive odd number and λ is a wavelength of said exposure light; said silicon nitride film thickness and said silicon oxide film thickness being selected to provide substantially equal transmittance through said first and second light transmitting regions.

Claim 3

The phase shift mask according to claim 1, wherein: said silicon nitride film is formed in direct contact with the major surface of said transparent substrate, and said silicon oxide film is formed in direct contact with said silicon nitride film.

Claim 4

The phase shift mask according to claim 1, wherein said arbitrary positive odd number m is 1.

Claim 5

The phase shift mask according to claim 1, wherein: the film thickness and refractive index of said silicon oxide film are respectively 240±108 Å and 1.47±0.03; and the film thickness and refractive index of said silicon nitride film are respectively 1570±47 Å and 2.09±0.03 when i-line is used as said exposure light.

Claim 6

The phase shift mask according to claim 1, wherein: the film thickness and refractive index of said silicon oxide film are respectively 440±67 Å and 1.51±0.03; and the film thickness and refractive index of said silicon nitride film are respectively 800±26 Å and 2.27±0.04 when KrF eximer light is used as said exposure light.

Claim 7

A phase shift mask comprising: a first light transmitting region through which exposure light is transmitted; a second light transmitting region through which exposure light having a phase different from that of the exposure light transmitted through said first light transmitting region is transmitted; a light blocking region interposed between said first light transmitting region and said second light transmitting region; a transparent substrate having a major surface; a silicon nitride film formed to cover the major surface of said transparent substrate in said first light transmitting region, exposing the major surface of said transparent substrate in said second light transmitting region, said silicon nitride film having a thickness t n and a refractive index n n ; a silicon oxide film formed on said silicon nitride film to cover the major surface of said transparent substrate in said first light transmitting region and to cover the major surface of said transparent substrate in said second light transmitting region, said silicon oxide film having a thickness t 0 and a refractive index n 0 ; and a light blocking film covering the major surface of said transparent substrate in said light blocking region; said phase shift mask satisfying the equation: ##EQU5## wherein m is an arbitrary positive odd number and λ is a wavelength of said exposure light; said silicon nitride film thickness and said silicon oxide film thickness being selected to provide substantially equal transmittances through said first and second light transmitting regions.

Claim 8

A phase shift mask comprising: a first light transmitting region through which exposure light is transmitted; a second light transmitting region through which exposure light having a phase different from that of the exposure light transmitted through said first light transmitting region is transmitted; a light blocking region interposed between said first light transmitting region and said second light transmitting region; a transparent substrate having a major surface; a silicon nitride film formed to cover the major surface of said transparent substrate in said first light transmitting region, exposing the major surface of said transparent substrate in said second light transmitting region, said silicon nitride film having a thickness t n and a refractive index n n ; a silicon oxide film formed on said silicon nitride film to cover the major surface of said transparent substrate in said first light transmitting region and to cover the major surface of said transparent substrate in said second light transmitting region, said silicon oxide film having a thickness t 0 and a refractive index n 0 ; and a light blocking film covering the major surface of said transparent substrate in said light blocking region; said phase shift mask satisfying the equation: ##EQU5## wherein m is an arbitrary positive odd number and λ is a wavelength of said exposure light; said silicon nitride film thickness and said silicon oxide film thickness being selected to provide substantially equal transmittances through said first and second light transmitting regions.

Claim 9

The phase shift mask according to claim 6, wherein: the film thickness and refractive index of said silicon oxide film are respectively 650±150 Å and 1.47+0.03; and the film thickness and refractive index of said silicon nitride film are respectively 1680±47 Å and 2.09±0.03 when i-line is used as said exposure light.

Claim 10

The phase shift mask according to claim 6, wherein: the film thickness and refractive index of said silicon oxide film are respectively 420±100 Å and 1.47±0.03; and the film thickness and refractive index of said silicon nitride film are respectively 980±26 Å and 2.27±0.04 when KrF eximer light is used as said exposure light.

Claim 11

A blank for a phase shift mask comprising: a first light transmitting region through which exposure light is transmitted: a second light transmitting region through which exposure light having a phase different from that of the exposure light transmitted through said first light transmitting region is transmitted; a light blocking region interposed between said first light transmitting region and said second light transmitting region; a transparent substrate having a major surface; a silicon nitride film formed in direct contact with the major surface of said transparent substrate; a silicon oxide film formed in direct contact with said silicon nitride film; and a light blocking film formed in direct contact with said silicon oxide film; said blank satisfying the equation: ##EQU6## wherein m is an arbitrary positive odd number, t n and n n are film thickness and refractive index of said silicon nitride film, respectively, t 0 and n 0 are film thickness and refractive index of said silicon oxide film, respectively, and λ is a wavelength of said exposure light; said silicon nitride film thickness and said silicon oxide film thickness being selected to provide substantially equal transmittance through said first and second light transmitting regions.

Claim 12

A blank for a phase shift mask comprising: a first light transmitting region through which exposure light is transmitted: a second light transmitting region through which exposure light having a phase different from that of the exposure light transmitted through said first light transmitting region is transmitted; a light blocking region interposed between said first light transmitting region and said second light transmitting region; a transparent substrate having a major surface; a silicon nitride film formed in direct contact with the major surface of said transparent substrate; a silicon oxide film formed in direct contact with said silicon nitride film; and a light blocking film formed in direct contact with said silicon oxide film; said blank satisfying the equation: ##EQU6## wherein m is an arbitrary positive odd number, t n and n n are film thickness and refractive index of said silicon nitride film, respectively, t 0 and n 0 are film thickness and refractive index of said silicon oxide film, respectively, and λ is a wavelength of said exposure light; said silicon nitride film thickness and said silicon oxide film thickness being selected to provide substantially equal transmittance through said first and second light transmitting regions.

Claim 13

The blank for a phase shift mask according to claim 9, wherein said arbitrary positive odd number m is 1.

Claim 14

The blank for a phase shift mask according to claim 9, wherein: the film thickness and refractive index of said silicon oxide film are respectively 240±108 Å and 1.47±0.03; and the film thickness and refractive index of said silicon nitride film are respectively 1570±47 Å and 2.09±0.03 where i-line is used as said exposure light.

Claim 15

The blank for a phase shift mask according to claim 9, wherein: the film thickness and refractive index of silicon oxide film are respectively 440±67 Å and 1.51±0.03; and the film thickness and refractive index of said silicon nitride film are respectively 800±26 Å A and 2.27±0.04 when KrF eximer light is used as said exposure light.

Claim 18

The method of manufacturing a phase shift mask according to claim 13, comprising: forming said silicon nitride film by low pressure CVD at a temperature of 600° C. to 800° C.; and forming said silicon oxide film by low pressure CVD at a temperature of 600° C. to 800° C.

Claim 19

The method of manufacturing a phase shift mask according to claim 13, comprising: forming said silicon nitride film by plasma CVD at a temperature of 250° C. to 450° C.; and forming said silicon oxide film by plasma CVD at a temperature of 250° C. to 450° C.

Claim 22

The method of manufacturing a phase shift mask according to claim 16, comprising: forming said silicon nitride film by low pressure CVD at a temperature of 600° C. to 800° C.; and forming said silicon oxide film by low pressure CVD at a temperature of 600° C. to 800° C.

Claim 23

The method of manufacturing a phase shift mask according to claim 16, comprising: forming said silicon nitride film by plasma CVD at a temperature of 250° C. to 450° C.; and forming said silicon oxide film by plasma CVD at a temperature of 250° C. to 450° C.