Method for the measurement of aberration of optical projection system

Claim 2

An aberration measurement method for measuring an amount of an aberration of an optical projection system comprising: the step of locating a mask in an optical path of the optical projection system the mask being formed with a line-and-space pattern containing lines, each line having an equal line width; the step of locating a substrate coated with a photoresist in a projection position of the optical projection system; the step of exposing the line-and-space pattern to the photoresist coated on the substrate by varying an amount of exposure and a position of exposure, while projecting the line-and-space pattern with the optical projection system; the step of developing the substrate exposed; and the step of determining an amount of an aberration on the basis of a ratio of a first amount of exposure to a second amount of exposure, the first amount of exposure being an exposure amount in which an image of a one line of the lines on both pitchwise ends of the line-and-space pattern disappears and the second amount of exposure being an exposure amount in which an image of an other line of the lines on both pitchwise ends of the line-and-space pattern disappears, in the line-and-space pattern images by the photoresist in each position of exposure formed on the substrate by the developing step.

Claim 3

An aberration measurement method for the measurement of an amount of an aberration of an optical projection system, comprising: the step of locating a mask in an optical path of the optical projection system, the mask being formed with plural groups of line-and-space patterns, each line-and-space pattern group containing plural lines with each line having a different line width from each other; the step of locating a substrate coated with a photoresist in a projection position of the optical projection system; the step of exposing the patterns to the photoresist coated on the substrate at a predetermined amount of exposure by projecting with the optical projection system; the step of developing the substrate exposed; and the step of determining an amount of an aberration by measuring a pitchwise width of an image of each line-and-space pattern group by the photoresist formed on the substrate by the developing step.

Claim 4

The aberration measurement method as claimed in claim 3, wherein the plural lines each having a different line width are disposed on both sides in a pitchwise direction of the line-and-space pattern having the lines with equal line widths.

Claim 5

An aberration measurement method for measuring an amount of an aberration of an optical projection system comprising: the step of locating a mask in an optical path, the mask being formed with a line-and-space pattern containing lines each having an equal line width and with a wedge-shaped pattern disposed on each of both pitchwise end sides of the line-and-space pattern, the wedge-shaped pattern being so formed as for its line width to vary gradually in a lengthwise direction of the line; the step of locating a substrate coated with a photoresist in a projection position of the optical projection system; the step of exposing the patterns to the photoresist coated on the substrate at a predetermined amount of exposure while projecting the patterns with the optical projection system; the step of developing the substrate exposed; and the step of determining an amount of an aberration on the basis of information in respect of a shape of the wedge-shaped pattern in the image of the pattern by the photoresist formed on the substrate by the developing step.

Claim 6

The aberration measurement method as claimed in claim 5, wherein said information in respect to the shape of the wedge-shaped pattern is information on a positions in which line widths of the wedge-shaped patterns become equal to each other in a lengthwise direction of the pattern.

Claim 7

The aberration measurement method as claimed in claim 5, wherein said information in respect to the shape of the wedge-shaped pattern is information on a length of the wedge-shaped pattern.

Claim 8

An aberration measurement method for measuring an amount of an aberration of an optical projection system, comprising: the step of locating a mask in an optical path of the optical projection system, the mask being formed with a line-and-space pattern containing lines each having an equal line width and with a wedge-shaped pattern disposed on each of both pitchwise end sides of the line-and-space pattern, the wedge-shaped pattern being so formed as for its line width to vary gradually in a lengthwise direction of the line; the step of locating a substrate formed with a photoresist thereon in a projection position of the optical projection system; the step of exposing the pattern to the photoresist of the substrate by varying an amount and a position of exposure by projecting the pattern with the optical projection system; the step of developing the substrate exposed; and the step of determining an amount of an aberration on the basis of a ratio of a first amount of exposure to a second amount of exposure the first amount of exposure being an exposure amount in which an image of a one pattern of the wedge-shaped pattern disappears and the second amount of exposure being an exposure amount in which an image of an other pattern of the wedge-shaped pattern disappears, in the line-and-space pattern images by the photoresist in the position of exposure formed on the substrate by the developing step.

Claim 9

The aberration measurement method as claimed in any one of claims 5 to 8, wherein said wedge-shaped pattern has a constant line width in a predetermined distance in its lengthwise direction and the line width of the wedge-shaped pattern varies stepwise as a whole.

Claim 10

A mask for an optical projection system having plural groups of line-and-space patterns disposed such that a line having a different line width is located on its both pitchwise sides of a line-and-space pattern containing a line having an equal line width.

Claim 11

A mask for an optical projection system having a line-and-space pattern containing a line having an equal line width and a wedge-shaped pattern disposed on its both pitchwise end sides of the line-and-space pattern and formed so as for its line width to vary gradually in a lengthwise direction of the line.

Claim 12

An aberration measurement method for measuring an amount of an aberration of an optical projection system, comprising: the step of locating a mask in an optical path of the optical projection system, the mask being formed with a pattern containing either of a line-and-space pattern or an isolated line pattern: the step of locating a substrate coated with a photoresist in a projection position of the optical projection system; the step of exposing the pattern to the photoresist of the substrate by projecting with the optical projection system: the step of developing the substrate exposed; and the step of measuring an amount of a deviation of a position of an image of the line-and-space pattern or an image of the isolated line pattern by the photoresist formed on the substrate by the developing step.

Claim 13

An aberration measurement method for measuring an amount of an aberration of an optical projection system, comprising: the step of locating a mask in an optical path of the optical projection system, the mask being formed with a first pattern containing either of a line-and-space pattern or an isolated line pattern, each having a predetermined line width WA, and a second pattern containing either of a line-and-space pattern or an isolated line pattern, each having a predetermined line width WB different from the predetermined line width WA; the step of locating a substrate with a photoresist coated thereon at a projection position of the optical projection system; the step of exposing each of the first pattern and the second pattern formed on the mask to the photoresist of the substrate by projecting with the optical projection system; the step of developing the exposed substrate; and the step of measuring an amount of a deviation between a position of an image of a line of the first pattern and a position of an image of a line of the second pattern by the photoresist formed on the substrate by the developing step.

Claim 14

The aberration measurement method as claimed in claim 13, wherein said mask is formed with said first pattern and said second pattern with each line parallel to each other.

Claim 15

An aberration measurement method for measuring an amount of an aberration of an optical projection system, comprising: the step of locating a mask in an optical path of the optical projection system, the mask being formed with a first pattern containing either of a line-and-space pattern or an isolated line pattern, each line having a predetermined line width WA, a second pattern containing either of a line-and-space pattern or an isolated line pattern, each line having a predetermined line width WB different from the predetermined line width WA, and a third pattern containing either of a line-and-space pattern or an isolated line pattern, each line having the line width WB; the step of locating a substrate with a photoresist coated thereon at a projection position of the optical projection system; the step of exposing each of the first, second and third patterns formed on the mask to the photoresist of the substrate by projection with the optical projection system; the step of developing the exposed substrate; and the step of measuring an amount of a deviation between a position of an image of a line of the first pattern and a position of an image of a line of the second or third pattern by the photoresist formed on the substrate by the developing step, by correcting the amount thereof on the basis of the positions of the line images of the second and third patterns.

Claim 16

The aberration measurement method as claimed in claim 15, wherein said mask is formed with the first, second and third patterns with lines thereof disposed parallel to each other.

Claim 17

An aberration measurement method for measuring an amount of an aberration of an optical projection system, comprising: the step of locating a first mask in an optical path of the optical projection system, the first mask being formed with a first pattern containing either of a line-and-space pattern or an isolated line pattern, each line having a predetermined line width WA and a second pattern containing either of a line-and-space pattern or an isolated line pattern, each line having a predetermined line width; the step of locating a second mask in the optical path of the optical projection system, the second mask being formed with a third pattern containing either of a line-and-space pattern or an isolated line pattern, each line having a predetermined line width WC and a fourth pattern containing either of a line-and-space pattern or an isolated line pattern, each line having the predetermined line width WB; the step of locating a substrate with a photoresist coated thereon at a projection position of the optical projection system; the step of exposing each of the pattern on the first mask and the pattern on the second mask to the photoresist of the substrate by projection with the optical projection system; the step of developing the exposed substrate; and the step of measuring an amount of a deviation between a position of an image of a line of the first pattern and a position of an image of a line of the third pattern by the photoresist formed on the substrate by the developing step, by correcting the amount thereof on the basis of the position of an image of a line of the second pattern and the position of an image of a line of the fourth pattern.

Claim 18

The aberration measurement method as claimed in claim 17, wherein: said mask is formed with the first and second patterns so as for lines thereof to be disposed parallel to each other and with the third and fourth patterns so as for lines thereof to be disposed parallel to each other; and said step of exposing by projection further comprises a step for locating each mask so as to make each line of each pattern of each mask parallel to each other.

Claim 19

An aberration measurement method for measuring an amount of an aberration of an optical projection system, comprising: the step of locating a one mask in an optical path of the optical projection system the one mask being formed with a first line-and-space pattern group having a first line-and-space pattern, a second line-and-space pattern and a third line-and-space pattern formed in a zigzag pattern, the first line-and-space pattern containing lines with each line having a predetermined line width WA disposed parallel to and linearly symmetrically to a first virtual center line intersecting with an optional virtual reference line LA0 at an angel α not larger than 45°, the second line-and-space pattern containing lines with each line having the predetermined line width WA disposed parallel to and linearly symmetrically to a second virtual center line intersecting at an angel -α at an intersection point YA on the virtual reference line LA0 apart in a predetermined distance LN1 from an intersection point XA between the virtual reference line LA0 and the first virtual center line, and the third line-and-space pattern containing lines with each line having the predetermined line width WA disposed parallel to and linearly symmetrically to a third virtual center line intersecting at an angel α at an intersection point ZA on the virtual reference line LA0 apart in the predetermined distance LN1 from the intersection point YA; the step of locating an other mask with with a second line-and-space pattern group in the optical path of the optical projection system, the second line-and-space pattern group having a fourth line-and-space pattern a fifth line-and-space pattern and a sixth line-and-space pattern formed in a zigzag pattern the fourth line-and-space pattern containing lines with each line having the predetermined line width WB disposed parallel to and linearly symmetrically to a fourth virtual center line intersecting with an optional virtual reference line LB0 at an angel -α, the fifth line-and-space pattern containing lines with each line having the predetermined line width WB disposed parallel to and linearly symmetrically to a fifth virtual center line intersecting at an angel α at an intersection point YB on the virtual reference line LB0 apart in a predetermined distance LN2 from an intersection point XB between the virtual reference line LB0 and the fourth virtual center line, and the sixth line-and-space pattern containing lines with each line having the predetermined line width WB disposed parallel to and linearly symmetrically to a sixth virtual center line intersecting at an angel -α at an intersection point ZB on the virtual reference line LB0 apart in the predetermined distance LN2 from the intersection point YB; the step for exposing the first line-and-space pattern group on the one mask and the second line-and-space pattern group on the other mask in a superimposed manner to the photoresist by projection with the optical projection system; the step of developing the substrate exposed; and the step of measuring a deviation between a position of an image of a line of the first line-and-space pattern group and a position of an image of a line of the second line-and-space pattern group by the photoresist formed on the substrate by the developing step by utilizing a Moire mark.

Claim 20

The aberration measurement method as claimed in claim 19, further comprising: the step of locating the one mask in the optical path of the optical projection system, the one mask being further formed with a third line-and-space pattern group in a position different from the position of the first line-and-space pattern group, the third line-and-space pattern group containing lines having a seventh line-and-space pattern, an eighth line-and-space pattern and a ninth line-and-space pattern formed each in a zigzag pattern, the seventh line-and-space pattern group containing lines having each line of the predetermined line width WC disposed parallel to and linearly symmetrically to a seventh virtual center line intersecting at an optional angel β with a virtual reference line LC0 parallel to the virtual reference line LA0 and apart in a predetermined distance LN11, the eighth line-and-space pattern containing lines having each line of the predetermined line width WC disposed parallel to and linearly symmetrically to an eighth virtual center line intersecting at an angel -β at an intersection point YC on the virtual reference line LC0 apart in a predetermined distance LN3 from an intersection point XC between the virtual reference line LC0 and the seventh virtual center line, and the ninth line-and-space pattern containing lines with each line having the predetermined line width WC disposed parallel to and linearly symmetrically to a ninth virtual center line intersecting at an angel β at an intersection point ZC on the virtual reference line LC0 apart in the predetermined distance LN3 from the intersection point YC; and the step of locating the other mask in the optical path of the optical projection system, the other mask being further formed with a fourth line-and-space pattern group in a position different from a position of the second line-and-space pattern, the fourth line-and-space pattern group being disposed parallel to and linearly symmetrically to the third line-and-space pattern group so as for the virtual reference line LC0 to come into agreement with a virtual reference line LD0 disposed parallel to the virtual reference line LB0 and apart in a predetermined distance LN12 therefrom; wherein the step of measuring a deviation between the position of the image of the line of the first line-and-space pattern group and the position of the image of the line of the second line-and-space pattern group by utilizing the Moire mark further comprises the step of measuring the deviation by correction with a Moire mark of an image of the third line-and-space pattern group and an image of the fourth line-and-space pattern group.

Claim 21

The aberration measurement method as claimed in claim 20, wherein the distance LN11 and the distance LN12 are set to be equal to each other.

Claim 22

A mask for an optical projection system having a first line-and-space pattern group formed thereon, the first line-and-space pattern group having a first line-and-space pattern, a second line-and-space pattern and a third line-and-space pattern formed in a zigzag pattern, the first line-and-space pattern containing lines having each line of the predetermined line width WA disposed parallel to and linearly symmetrically to the first virtual center line intersecting with the optional virtual reference line LA0 at the angel α not larger than 45°, the second line-and-space pattern containing lines having each line of the predetermined line width WA disposed parallel to and linearly symmetrically to the second virtual center line intersecting at the angel -α at the intersection point YA on the virtual reference line LA0 apart in the predetermined distance LN1 from the intersection point XA intersecting the virtual reference line LA0 with the first virtual center line, and the third line-and-space pattern containing lines having each line of the predetermined line width WA disposed parallel to and linearly symmetrically to the third virtual center line intersecting at the angel α at the intersection point ZA on the virtual reference line LA0 apart in the predetermined distance LN1 from the intersection point YA.

Claim 23

A mask set for an optical projection system comprising: the mask for the optical projection system as claimed in claim 22; and an other mask being formed with a second line-and-space pattern group having a fourth line-and-space pattern, a fifth line-and-space pattern and a sixth line-and-space pattern formed in a zigzag pattern, the fourth line-and-space pattern containing lines with each line of the predetermined line width WB disposed parallel to and linearly symmetrically to the fourth virtual center line intersecting with the optional virtual reference line LB0 at an angel -α not larger than 45°, the fifth line-and-space pattern containing lines with each line of the predetermined line width WB disposed parallel to and linearly symmetrically to the fifth virtual center line intersecting at the angel α at the intersection point YB on the virtual reference line LB0 apart in the predetermined distance LN2 from the intersection point XB between the virtual reference line LB0 and the fourth virtual center line, and the sixth line-and-space pattern containing lines with each line of the predetermined line width WB disposed parallel to and linearly symmetrically to the sixth virtual center line intersecting at the angel α at the intersection point ZB on the virtual reference line LB0 apart in the predetermined distance LN2 from the intersection point YB.

Claim 24

The mask set for an optical projection system as claimed in claim 22, further comprising: the one mask being further formed with a third line-and-space pattern group in the position different from the position of the first line-and-space pattern group, the third line-and-apace pattern group containing a seventh line-and-space pattern, an eighth line-and-space pattern and a ninth line-and-space pattern formed in a zigzag pattern, the seventh line-and-space pattern group containing lines having each line of the predetermined line width WC disposed parallel to and linearly symmetrically to the seventh virtual center line intersecting at the optional angel β with the optional virtual reference line LC0 parallel to the virtual reference line LA0 and apart in the predetermined distance LN11 therefrom, the eighth line-and-space pattern containing lines having each line of the predetermined line width WC disposed parallel to and linearly symmetrically to the eighth virtual center line intersecting at the angel -β at the intersection point YC on the virtual reference line LC0 apart in the predetermined distance LN3 from the intersection point YC between the virtual reference line LC0 and the seventh virtual center line, and the ninth line-and-space pattern containing lines having each line of the predetermined line width WC disposed parallel to and linearly symmetrically to the ninth virtual center line intersecting at the angel β at the intersection point ZC on the virtual reference line LC0 apart in the predetermined distance LN3 from the intersection point YC.

Claim 25

The mask set for an optical projection system as claimed in claim 24, wherein the other mask is further formed with a fourth line-and-space pattern group in a position different from a position of said second line-and-space pattern group in a manner that the fourth line-and-space pattern group is disposed parallel to and linearly symmetrically to said third line-and-space pattern group and said virtual reference line LC0 and said virtual reference line LC0 comes substantially in agreement with a virtual reference line LD0 parallel to said virtual reference line LB0 and apart in a predetermined distance LN12.

Claim 28

The method for measuring an aberration of an optical projection system as claimed in claim 27, wherein: said plural measuring patterns are line-and-space patterns having lines of equal line widths; and measuring the amount of the aberration on the basis of a variation in shapes of the patterns on both pitchwise end sides of said line-and-space patterns.

Claim 29

The method for measuring an aberration of an optical projection system as claimed in claim 27, wherein: said plural measuring patterns are wedge-shaped patterns so as for each line width to vary gradually in a lengthwise direction of the pattern; and measuring the amount of the aberration on the basis of a variation in shapes of said wedge-shaped patterns.

Claim 30

An exposure apparatus, comprising: an optical projection system in which plural measuring patterns are formed by illumination with fluorescent light; and an operation unit in which an amount of an aberration is determined by comparing the measuring patterns on both end sides of said plural measuring pattern images.

Claim 31

The exposure apparatus as claimed in claim 30, further comprising: a control unit in which transcribing said pattern is transcribed onto said substrate by varying a light quantity of exposing light and a position of exposure; wherein said operation unit determines the amount of the aberration on the basis of a ratio of an exposure amount in which an image of a one line of the patterns locating on the both pitchwise end sides of the patterns in each exposure position disappears to an exposure amount in which an image of an other line of the patterns locating thereon in each exposure position disappears.