Material for semiconductor substrate, process for producing the same, and semiconductor device with such substrate

摘要

A material for a semiconductor substrate comprising an aluminum-silicon alloy containing from 50% to 80% by weight of silicon and having a thermal conductivity of 0.28 cal/cm.sec. DEG C or higher, a coefficient of thermal expansion of 12 x 10<-><6>/ DEG C or smaller and a density of 2.5 g/cm<3> or lower. This material is produced by molding an Al-Si alloy powder, which has been obtained through rapid solidification by atomization, to form a compact and then consolidating the compact by means of forging, sintering, etc. The substrate material may have an Al or Al alloy covering layer at least one surface thereof and, further, as necessary, an insulating or plating layer on the covering layer. The thus obtained substrate material is lightweight and has a suitable coefficient of thermal expansion for a substrate as well as a high thermal conductivity. Therefore, a semiconductor device with high performance and reliability can be obtained using such substrate material.