| CPC G03F 1/32 (2013.01) | 16 Claims |
|
1. A method of forming a blank mask, comprising:
preparing a transparent substrate; and
forming a phase shift film on the transparent substrate;
wherein the phase shift film comprises a phase difference adjustment layer and a protective layer on the phase difference adjustment layer,
wherein forming the phase shift film on the transparent substrate comprises:
forming a phase difference adjustment layer on the transparent substrate by sputtering using a magnet disposed on a backside of a sputtering target and rotated during sputtering to generate a magnetic field of 30 mT to 50 mT at the surface of the sputtering target; and
forming a protective layer on the phase difference adjustment layer;
wherein the sputtering is performed in an argon-nitrogen-helium atmosphere,
wherein the sputtering is slopped when then Del1 value measured by elipsometry is apprximately zero at a photon energy of 3.8 eV to 4.64 eV, with PE1=3.0 eV and PE2=5.0 eV,
wherein the phase shift film has a XRD maximum peak at 2θ of 15° to 30° when a normal mode X-Ray Diffraction (XRD) analysis is performed on an upper surface of the phase shift film,
where the transparent substrate has a XRD maximum peak at 2θ of 15° to 30° when a normal mode XRD analysis is performed on a lower surface of the transparent substrate, and
wherein the blank mask has AI1 value of 0.9 to 1.1 expressed by:
 where
XM1 is a maximum value of a measured X-ray intensity when the normal mode XRD analysis is performed on the upper surface of the phase shift film, and
XQ1 is a maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the lower surface of the transparent substrate,
wherein the blank mask has the photon energy of the incident light at the point where Del_1 expressed by Equation 7 below is 0 is 3.8 to 4.64 eV, when the PE1 value is 3.0 eV and the PE2 value is 5.0 eV;
 where in the Equation 7,
the DPS value is, after removing the light shielding film from the blank mask, the phase difference between the P wave and the S wave of reflected light if the phase difference between the P wave and S wave of the reflected light is 180° or less, or a value obtained by subtracting the phase difference between the P wave and the S wave of the reflected light from 360° if the phase difference between the P wave and the S wave of the reflected light is more than 180° when the surface of the phase shift film is measured with a spectroscopic ellipsometer by applying an incident angle of 64.5°, and
the PE value is the photon energy of the incident light within the range of PE1 to PE2,
wherein the phase shift film comprises a phase difference adjustment layer and a protective layer disposed on the phase difference adjustment layer, and
wherein the phase shift film comprises a transition metal, silicon, oxygen and nitrogen.
|