Reflective mask blank having a programmed defect and method of producing the same, reflective mask having a programmed defect and method of producing the same, and substrate for use in producing the reflective mask blank or the reflective mask having a programmed defect
AssigneeHoya Corporation
InventorsTsutomo Shoki, Ryo Ohkubo, Takeru Kinoshita
Life of this patent
Estimating the term…
Abstract
A reflective mask blank has a substrate (1) and a reflective multilayer film (3) formed on the substrate to reflect exposure light. The substrate has a base pattern (2) formed by a predetermined irregularity. On a surface of the reflective multilayer film formed on the base pattern, a step portion corresponding to the base pattern is formed as a programmed defect.
Claims17
A reflective mask blank having a programmed defect, comprising a substrate and a reflective multilayer film formed on the substrate to reflect exposure light incident to the reflective multilayer film, the reflective multilayer film having a principal surface provided with a step portion for causing a phase change in reflected light obtained by reflecting the exposure light.
A reflective mask blank having a programmed defect, comprising a base body comprising a substrate and a reflective multilayer film formed on the base body to reflect exposure light incident to the reflective multilayer film, the base body having a principal surface provided with a base pattern comprising a predetermined irregularity, the reflective multilayer film formed on the base pattern having a principal surface provided with a step portion corresponding to the base pattern so that the reflective multilayer film has the programmed defect.
A substrate for use in producing a reflective mask blank having a programmed defect or a reflective mask having a programmed defect, the base body having a principal surface with a patterned thin film formed thereon to provide a predetermined irregularity on the principal surface.
A method of producing a reflective mask blank comprising a base body comprising a substrate and a reflective multilayer film formed on the base body to reflect exposure light, the method comprising the steps of:
- forming a base pattern comprising a predetermined irregularity on a principal surface of the base body;
- and
- forming the reflective multilayer film on the base pattern to thereby form a step portion on a principal surface of the reflective multilayer film corresponding to the base pattern so that a programmed defect is formed on the reflective multilayer film;
- the reflective multilayer being deposited by sputtering in a condition that the base body is faced to a surface of a sputter target for deposition of the multilayer reflective film and the base body is rotated around a rotation axis which is a normal passing through the center of the principal surface of the base body.
Dependencies are inferred from the claim text.