本发明是一种磊晶基板，其特征在于具备：硅基板，其以4×1017cm-3以上且6×1017cm-3以下的浓度含有氧原子，且以5×1018cm-3以上且6×1019cm-3以下的浓度含有硼原子；及，半导体层，其配置于硅基板上，且由具有与硅基板不同之热膨胀系数的材料所构成。借此，可提供一种磊晶基板，该磊晶基板可抑制由硅基板与半导体层之间的应力所导致之翘曲的产生。

The present invention is an epitaxial substrate comprising a silicon substrate containing oxygen atoms at a concentration from 4*1017 cm-3 to 6*1017 cm-3 and boron atoms at a concentration from 5*1018 cm-3 to 6*1019 cm-3, and a semiconductor layer arranged on top of the silicon substrate having a coefficient of thermal expansion different from that of the silicon substrate. In this way, an epitaxial substrate can be provided which suppresses warping due to stress between the silicon substrate and the semiconductor layer.