Patent ID: 6922458

Claim:
An x-ray exposure method comprising directing x-rays generated by an x-ray source to illuminate, through a mask, a resist on a substrate with a lower layer film interposed between the resist and the substrate, wherein the lower layer film contains C, and, of elements contained within the lower layer, the element absorbing a largest amount of x-rays is C, when thickness of the lower layer film is t (nm), density of the lower layer film is ρ (g/cm 3 ), absorption edge of an element absorbing a largest amount of x-rays of elements contained in the substrate is As (angstrom), K-shell absorption edge of C is Ac (angstrom), and absorption edge of an element absorbing a largest amount of x-rays of elements contained in the resist is Ar (angstrom), then: 0.5×Ar<12.4/((t×ρ/46) (1/1.75) +12.4/Ac)<Ar, and 12.4/((t×ρ/46) (1/1.75) +12.4/As)≦λ≦Ar is satisfied by an average wavelength λ (angstrom) of x-rays absorbed in the resist.