Abstract: Provided is a prepreg including a fiber substrate having a thickness of 40 ?m or more impregnated with a thermosetting resin composition, the prepreg having in the fiber substrate an impregnated region and a non-impregnated region with the thermosetting resin composition, having a surface waviness (Wa) of 5.0 ?m or less. Also provided are a laminate, a metal-clad laminate, a printed wiring board, and a semiconductor package, which are obtained by using the prepreg, a method of producing the prepreg, and a method of producing the metal-clad laminate.

Abstract: Provided is a mask blank substrate being a substrate having two main surfaces, in which one of the two main surfaces of the mask blank substrate on a side on which a transfer pattern is formed has such a surface profile that, when a measurement region of 2.8 mm×2.1 mm of the main surface in a transfer pattern formation region is measured using a white light interferometer under conditions of a pixel number of 640×480, a power spectrum density at a spatial frequency of 1.0×10?2 ?m?1 calculated from a result of the measurement is 6.0×107 nm4 or less.

Abstract: Provided is a mask blank substrate being a substrate having two main surfaces, in which one of the two main surfaces of the mask blank substrate on a side on which a transfer pattern is formed has such a surface profile that, when a measurement region of 2.8 mm×2.1 mm of the main surface in a transfer pattern formation region is measured using a white light interferometer under conditions of a pixel number of 640×480, a power spectrum density at a spatial frequency of 1.0×10?2 ?m?1 calculated from a result of the measurement is 6.0×107 nm4 or less.