abstract |
The present invention aims at providing a circuit board 125 in which a thermal stress or a thermal strain in a phase of manufacture is reduced, and which has a low thermal resistance and is low in cost, and a semiconductor device using the same. The circuit board 125 includes a ceramics substrate 110 containing therein a nitride, a circuit wiring board 130 joined to one surface of the ceramics substrate 110 through a joining layer 120, and a metallic supporting member 125' joined to the other surface of the ceramics substrate 110 through a joining layer 120. The joining layer 120 is a sintered body containing therein silver or copper, and an oxide layer is formed in a joining interface between the ceramics substrate 110 and the sintered body. The oxide layer is composed of a polycrystalline layer on a side of the ceramics substrate 110, and is composed of an amorphous layer on a side of the sintered body. |