Silicon nitride substrate, silicon nitride circuit substrate, and evaluation method, evaluation device, and evaluation system for silicon nitride substrate and silicon nitride circuit substrate
A silicon nitride substrate including a first surface, and a second surface disposed opposite the first surface. One of the first surface or the second surface is a measurement surface. On the measurement surface, a value of an average full-width-at-half-maximum (FWHM) C ave is broader than 0 cm −1 and narrower than 5.32 cm −1 as measured by using a following measurement method. The measurement method of the average full-width-at-half-maximum (FWHM) C ave : one central point and four edge portions on the measurement surface are determined as measurement points; a Raman spectrum is measured at each of the measurement points; a full-width-at-half-maximum (FWHM) C of a spectral peak having the maximum strength within a range from 850 cm −1 or greater to 875 cm −1 or less is calculated in each Raman spectrum; and an average value of thus calculated full-width-at-half-maximum (FWHM)s C is the average full-width-at-half-maximum (FWHM) C ave .
1 . A sintered silicon nitride substrate comprising:
a plane having a shape that is rectangular;
a plurality of sides, each side having a length equal to or longer than 100 mm;
a sintered substrate material manufactured by nitriding a sheet-shaped molded body that contains silicon;
a first surface; and
a second surface disposed opposite the first surface,
one of the first surface or the second surface being a measurement surface,
on the measurement surface, a value of an average full width at half maximum (FWHM) C ave being broader than 0 cm −1 and narrower than 5.32 cm −1 as measured by using a measurement method below:
a central portion and first, second, third and fourth edge portions on the measurement surface are determined as measurement points;
the first, second, third and fourth measurement points are each located on the sintered silicon nitride substrate at a distance of 10 mm to an adjacent long side of the sintered silicon nitride substrate and 15 mm to an adjacent short side of the sintered silicon nitride substrate;
a Raman spectrum is measured at each of the measurement points;
a full width at half maximum (FWHM) C of a spectral peak having the maximum strength within a range from 850 cm −1 or greater to 875 cm −1 or less is calculated in each Raman spectrum; and
an average value of thus calculated FWHMs C is determined as the average FWHM C ave .
2 . The sintered silicon nitride substrate according to claim 1 ,
wherein thermal conductivity of the sintered silicon nitride substrate is equal to or greater than 110 W/(m·K).
3 . The sintered silicon nitride substrate according to claim 1 ,
wherein an amount of warpage in accordance with a SORI standard is within a range from 0.1 mm to 1 mm.
4 . The sintered silicon nitride substrate according to claim 1 , wherein a thickness of the sintered silicon nitride substrate is 0.15 mm or greater and 0.8 mm or less.
5 . The sintered silicon nitride substrate according to claim 1 , further comprising:
a rare earth element oxide and a magnesium compound as sintering aids, and
wherein, when a number of moles of the rare earth element oxide converted into a trivalent oxide is M 1 , a number of moles of silicon converted into a silicon nitride is M 2 , and a number of moles of the magnesium compound converted into MgO is M 3 , a molar ratio of the M 1 to a total number of moles of the M 1 , the M 2 , and the M 3 is 0.5 mol % or greater and less than 2 mol %.
6 . A silicon nitride circuit substrate comprising:
a sintered silicon nitride substrate comprising:
a plane having a shape that is rectangular;
a plurality of sides, each side having a length equal to or longer than 100 mm;
a sintered substrate material manufactured by nitriding a sheet-shaped molded body that contains silicon;
a first surface; and
a second surface disposed opposite the first surface,
one of the first surface or the second surface being a measurement surface,
on the measurement surface, a value of an average full width at half maximum (FWHM) C ave being broader than 0 cm −1 and narrower than 5.32 cm −1 as measured by using a measurement method below:
a central portion and first, second, third and fourth edge portions on the measurement surface are determined as measurement points;
the first, second, third and fourth measurement points are each located on the sintered silicon nitride substrate at a distance of 10 mm to an adjacent long side of the sintered silicon nitride substrate and 15 mm to an adjacent short side of the sintered silicon nitride substrate;
a Raman spectrum is measured at each of the measurement points;
a full width at half maximum (FWHM) C of a spectral peak having the maximum strength within a range from 850 cm −1 or greater to 875 cm −1 or less is calculated in each Raman spectrum; and
an average value of thus calculated FWHMs C is determined as the average FWHM C ave ;
a metallic circuit disposed on the first surface of the sintered silicon nitride substrate; and
a metallic radiator plate disposed on the second surface of the sintered silicon nitride substrate.
7 . The silicon nitride circuit substrate according to claim 6 ,
wherein the metallic circuit and the metallic radiator plate are each formed of a copper plate.