| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride substrate which has suitably adjusted warpage and surface roughness, and to provide a method of manufacturing the same, a silicon nitride circuit substrate using the same, and a semiconductor module. SOLUTION: The silicon nitride substrate is manufactured by blending 3 to 4 wt.% of magnesium oxide and 2 to 5 wt.% of oxide of at least one kind of rare earth element with silicon nitride raw material powder, forming a sheet molding thereof, sintering it, and then performing a heat treatment on a plurality of sheet moldings in a stacked state at 1,550 to 1,700°C while applying a load of 0.5 to 6.0 kPa thereon. The silicon nitride substrate contains silicon nitride and has: a degree of orientation of≤0.33 at a surface, the degree of orientation showing an orientation ratio in a plane perpendicular to a thickness direction, which is determined by a ratio of diffracted X-ray intensities of respective predetermined lattice surfaces of a silicon nitride particle; a degree of orientation of 0.16 to 0.33 on a plane obtained by grinding the substrate from its top surface inward by≥20% of the substrate thickness; and a warpage of≤2.0μm/mm. COPYRIGHT: (C)2009,JPO&INPIT |
