Patent ID: 7476471

Claim:
A method for correcting an image corresponding to a mask pattern, said image resulting from obliquely illuminating a front surface of a reflective exposure mask with extreme ultraviolet light (EUV), said method comprising: a step of obtaining a light energy E 0 reflected from the exposure mask when the EUV is substantially normal to the front surface of the exposure mask; a step of obtaining a light energy E 1 reflected from the exposure mask when the EUV is obliquely incident to the front surface of the exposure mask; and a step of correcting the image corresponding to the mask pattern in accordance with a compared result of the light energies E 0 and E 1 , wherein: the front surface of the exposure mask comprises a mask blank film for reflecting the EUV and an absorber film patterned on the mask blank film for absorbing the EUV; and an exposure mask feature is corrected whereby the energy E 1 approximately equals the energy E 0 .