Reflective mask and method for manufacturing a reflective mask

Abstract

The objective is to provide a reflective mask and a method for manufacturing a reflective mask that can improve the detection of foreign matter adhering to the outer periphery. [Solution] A reflective mask comprising a base material, a multilayer reflective layer formed on a first main surface of the base material, a cap layer formed on the multilayer reflective layer, and an absorbent layer formed on the cap layer, wherein the base material has a first main surface, a second main surface opposite to the first main surface, and a base material outer peripheral end surface connecting the first main surface and the second main surface, the absorbent layer has an absorbent layer outer peripheral end surface that is recessed inward from the base material outer peripheral end surface in a plan view, and has an outer peripheral region between the base material outer peripheral end surface and the absorbent layer outer peripheral end surface in a plan view, the outer peripheral region has an inclined surface that is inclined with respect to the second main surface from the absorbent layer outer peripheral end surface toward the base material outer peripheral end surface.

Claims

1. Substrate and A multilayer reflective layer formed on the first main surface of the substrate, A cap layer formed on the multilayer reflective layer, The cap layer comprises an absorbent layer formed on the cap layer, The substrate has a first main surface, a second main surface opposite to the first main surface, and an outer peripheral end surface of the substrate connecting the first main surface and the second main surface. The absorbent layer has an outer peripheral end surface that is recessed inward from the outer peripheral end surface of the substrate in a plan view. In a plan view, the outer peripheral region is located between the outer peripheral end surface of the substrate and the outer peripheral end surface of the absorption layer. The outer peripheral region has an inclined surface that is inclined with respect to the second main surface, extending from the outer peripheral end surface of the absorption layer toward the outer peripheral end surface of the substrate. In a cross-sectional view, the shape of the substrate on the first main surface side and the shape of the substrate on the second main surface side in the outer peripheral region excluding the chamfer are asymmetrical. In a plan view, the outer peripheral region has a cap layer exposed region where the cap layer is exposed. Reflective mask.

2. Substrate and A multilayer reflective layer formed on the first main surface of the substrate, A cap layer formed on the multilayer reflective layer, The cap layer comprises an absorbent layer formed on the cap layer, The substrate has a first main surface, a second main surface opposite to the first main surface, and an outer peripheral end surface of the substrate connecting the first main surface and the second main surface. The absorbent layer has an outer peripheral end surface that is recessed inward from the outer peripheral end surface of the substrate in a plan view. In a plan view, the outer peripheral region is located between the outer peripheral end surface of the substrate and the outer peripheral end surface of the absorption layer. The outer peripheral region has an inclined surface that is inclined with respect to the second main surface, extending from the outer peripheral end surface of the absorption layer toward the outer peripheral end surface of the substrate. In a plan view, the outer peripheral region excluding the chamfer has a substrate exposed region where the substrate is exposed. In a plan view, the outer peripheral region has a cap layer exposed region where the cap layer is exposed. Reflective mask.

3. The substrate comprises a metal film formed on the second main surface, In a plan view, the metal film and the outer peripheral region overlap. A reflective mask according to claim 1 or 2.

4. In a plan view, the outer peripheral region has a substrate exposed region where the substrate is exposed and a cap layer exposed region where the cap layer is exposed. In a plan view, the exposed cap layer region is located between the exposed substrate region and the outer peripheral end surface of the absorption layer. A reflective mask according to claim 1 or 2.

5. The exposed substrate region and the exposed cap layer region constitute an inclined surface that is inclined with respect to the second main surface from the outer peripheral end face side of the absorption layer toward the outer peripheral end face side of the substrate. The reflective mask according to claim 4.

6. In a cross-sectional view, the absolute value ΔC of the inclination of the inclined surface of the cap layer exposed region with respect to the second main surface is smaller than the absolute value ΔS of the inclination of the inclined surface of the substrate exposed region with respect to the second main surface. The reflective mask according to claim 4.

7. The absolute value ΔS of the inclination of the inclined surface of the substrate exposure region with respect to the second main surface is 0.01° or more. The reflective mask according to claim 2.

8. The inclined surface of the outer peripheral region is inclined with respect to the second main surface such that the thickness of the reflective mask decreases toward the outer edge of the reflective mask, In a cross-sectional view, the absolute value ΔG of the inclination of the inclined surface of the outer peripheral region with respect to the second main surface has at least one of the regions where it monotonically increases or remains constant from the outer peripheral end surface of the absorption layer toward the outer peripheral end surface of the substrate. A reflective mask according to claim 1 or 2.

9. In a plan view, the minimum width Wm of the outer peripheral region is 0.5 mm or more and 5.0 mm or less. A reflective mask according to claim 1 or 2.

10. In a plan view, the ratio of the minimum width Ws of the substrate exposure area to the minimum width Wc of the cap layer exposure area (Ws / Wc) is 0.2 or more and 5.0 or less. The reflective mask according to claim 4.

11. The aforementioned substrate is SiO 2 including, A reflective mask according to claim 1 or 2.

12. A method for manufacturing a reflective mask according to claim 1 or 2, A preparation step for preparing a blank substrate comprising a base material, a multilayer reflective layer formed on the first main surface of the base material, a cap layer formed on the multilayer reflective layer, and an absorption layer formed on the cap layer, A resist pattern formation step of forming a resist pattern on the absorption layer of the blank substrate, The process includes a peripheral region formation step, in which a peripheral region is formed by etching through the resist pattern, A method for manufacturing a reflective mask.

13. In the outer peripheral region formation step, the outer peripheral region is formed, which includes a substrate exposed region where the substrate is exposed and a cap layer exposed region where the cap layer is exposed. The manufacturing method according to claim 12.

14. In the outer peripheral region formation step, a mask pattern region is formed by etching through the resist pattern, which includes an absorption region where the absorption layer exists and a reflection region where the absorption layer does not exist. The manufacturing method according to claim 12.

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