| abstract |
A silicon nitride substrate made of a silicon nitride sintered body having a high strength and a high thermal conductivity, a method for manufacturing the silicon nitride substrate, and a silicon nitride circuit substrate and a semiconductor module using the same. In the silicon nitride substrate composed of the intergranular phase containing the? -type silicon nitride crystal grains 11 and at least one rare earth element RE, magnesium (Mg) and silicon (Si), the intergranular phases are amorphous phases 12 ) And the MgSiN 2 crystal phase (13), and the X-ray diffraction line peak intensity of any crystal plane of the crystal phase containing the rare-earth element (RE) is the same as that of the crystal grains of (110) (121) of the MgSiN 2 crystal phase (13) is less than 0.0005 times the sum of the peak intensities of the diffraction peaks of (101), (210), (201), (310) Ray diffraction peak intensity of (110), (200), (101), (210), (201), (310), (320) and (002) of the crystal grains of the? The sum of the silicon nitride sintered bodies being 0.0005 to 0.003 times. |