Reflective mask and method for manufacturing reflective mask
A reflective mask comprises a substrate, first and second stacked bodies, and an intermediate portion. The first stacked body is provided on a surface of the substrate. The first stacked body includes a plurality of first layers and a plurality of second layers. A refractive index for a first electromagnetic ray of the first layer is different from a refractive index for the first electromagnetic ray of the second layer. The second stacked body includes a plurality of third layers and a plurality of fourth layers. A refractive index for the first electromagnetic ray of the third layer is different from a refractive index for the first electromagnetic ray of the fourth layer. A reflectance to the first electromagnetic ray of each of the first stacked body and the second stacked body is higher than a reflectance to the first electromagnetic ray of the intermediate portion.
1. A reflective mask, comprising:
a substrate;
a first stacked body provided on a surface of the substrate, the first stacked body including a plurality of first layers and a plurality of second layers arranged alternately in a first direction, the first direction being perpendicular to the surface, a refractive index for a first electromagnetic ray of the first layer being different from a refractive index for the first electromagnetic ray of the second layer;
a second stacked body provided on the surface and arranged with the first stacked body in a second direction, the second direction intersecting the first direction, the second stacked body including a plurality of third layers and a plurality of fourth layers arranged alternately in the first direction, a refractive index for the first electromagnetic ray of the third layer being different from a refractive index for the first electromagnetic ray of the fourth layer; and
an intermediate portion provided in at least one portion between the first stacked body and the second stacked body,
a reflectance to the first electromagnetic ray of the first stacked body being higher than a reflectance to the first electromagnetic ray of the intermediate portion,
a reflectance to the first electromagnetic ray of the second stacked body being higher than the reflectance to the first electromagnetic ray of the intermediate portion.
2. The reflective mask according to claim 1 , wherein a wavelength of the first electromagnetic ray is not less than 1 nanometer and not more than 20 nanometers.
3. The reflective mask according to claim 1 , wherein a transmittance for the first electromagnetic ray of the intermediate portion is higher than a transmittance for the first electromagnetic ray of the first stacked body and a transmittance for the first electromagnetic ray of the second stacked body.
4. The reflective mask according to claim 1 , wherein
the first layer includes molybdenum,
the second layer includes silicon,
the third layer includes molybdenum, and
the fourth layer includes silicon.
5. The reflective mask according to claim 1 , wherein the intermediate portion includes silicon oxide.
6. The reflective mask according to claim 1 , further comprising:
a first metal layer provided on the first stacked body, the first metal layer including ruthenium; and
a second metal layer provided on the second stacked body, the second metal layer including ruthenium.
7. A method for manufacturing a reflective mask, comprising:
forming a resist pattern by removing one portion of a resist film of a mask blank,
the mask blank including
a substrate,
a stacked film including a plurality of first films and a plurality of second films stacked alternately on a surface of the substrate, a refractive index for a first electromagnetic ray of the second films being different from a refractive index for the first electromagnetic ray of the first films,
a metal film provided on the stacked film,
a hard mask provided on the metal film, and
a resist film provided on the hard mask,
the resist pattern including a region where one portion of the hard mask is exposed and a region covered with a remainder of the resist film;
exposing one portion of the metal film by removing the one portion of the hard mask;
exposing the stacked film by removing the one portion of the metal film, and exposing a remainder of the hard mask by removing the remainder of the resist film;
forming a first stacked body and a second stacked body covered with the remainder of the hard mask by removing at least one portion of the exposed stacked film;
cleaning the first stacked body and the second stacked body using a cleaning liquid;
forming an intermediate portion around each of the first stacked body and the second stacked body by supplying a solution to the cleaning liquid and by curing the solution by baking, the solution including a component transmitting the first electromagnetic ray;
performing etch-back to planarize the intermediate portion and expose the remainder of the hard mask; and
exposing a remainder of the metal film by removing the remainder of the hard mask.
8. The method according to claim 7 , wherein a wavelength of the first electromagnetic ray is not less than 1 nanometer and not more than 20 nanometers.
9. The method according to claim 7 , wherein the baking is implemented in a vacuum.
10. The method according to claim 7 , wherein
the first film includes molybdenum; and
the second film includes silicon.
11. The method according to claim 7 , wherein the intermediate portion includes silicon oxide.
12. The method according to claim 7 , wherein the metal film includes ruthenium.
13. A method for manufacturing a reflective mask, comprising:
forming a stacked film including a plurality of first films and a plurality of second films stacked alternately on a surface of a substrate, a refractive index for a first electromagnetic ray of the second films being different from a refractive index for the first electromagnetic ray of the first films;
forming a metal film on the stacked film;
forming a hard mask on the metal film;
forming a resist film on the hard mask;
forming a resist pattern by removing one portion of the resist film, the resist pattern including a region where one portion of the hard mask is exposed and a region covered with a remainder of the resist film;
exposing one portion of the metal film by removing the one portion of the hard mask;
exposing the stacked film by removing the one portion of the metal film, and exposing a remainder of the hard mask by removing the remainder of the resist film;
forming a first stacked body and a second stacked body covered with the remainder of the hard mask by removing at least one portion of the exposed stacked film;
cleaning the first stacked body and the second stacked body using a cleaning liquid;
forming an intermediate portion around each of the first stacked body and the second stacked body by supplying a solution to the cleaning liquid and by curing the solution by baking, the solution including a component transmitting the first electromagnetic ray;
performing etch-back to planarize the intermediate portion and expose the remainder of the hard mask; and
exposing a remainder of the metal film by removing the remainder of the hard mask.
14. The method according to claim 13 , wherein a wavelength of the first electromagnetic ray is not less than 1 nanometer and not more than 20 nanometers.
15. The method according to claim 13 , wherein the baking is implemented in a vacuum.
16. The method according to claim 13 , wherein
the first film includes molybdenum; and
the second film includes silicon.
17. The method according to claim 13 , wherein the intermediate portion includes silicon oxide.
18. The method according to claim 13 , wherein the metal film includes ruthenium.