HANDLE SUBSTRATE, COMPOSITE SUBSTRATE FOR SEMICONDUCTOR, AND SEMICONDUCTOR CIRCUIT SUBSTRATE AND METHOD FOR MANUFACTURING SAME

摘要

It is provided a handle substrate of a composite substrate for a semiconductor. The handle substrate is composed of a translucent polycrystalline alumina. A purity of alumina of the translucent polycrystalline alumina is 99.9% or higher, an average of a total forward light transmittance of the translucent polycrystalline alumina is 60% or higher in a wavelength range of 200 to 400 nm, and an average of a linear light transmittance of the translucent polycrystalline alumina is 15% or lower in a wavelength range of 200 to 400 nm.