ALUMINIUMNITRIDSINTER UND HALBLEITERSUBSTRAT, DAS DARAUS HERGESTELLT IST.

摘要

This improved high heat conductive aluminium nitride sinter (1) consists of 95.5-99.8 wt.% (pref. 96.5-98.5 wt.%) of an AlN crystal particle phase and the remainder of a dysprosium (Dy) oxide phase. The average size of the AlN crystal particles is 2-10 (pref. 3-7) microns. The density of this AlN sinter has a value 99% or more (pref. 99.4% or more) of the theoretical density. 30 Wt.% or more (pref. 50 wt.% or more) of the oxide phase should exist at triple points formed by the AlN crystal particles. The heat conductivity at room temp. of (1) is 150 W/mK or more and the curving strength at room temp. is 30 Kg/mm2 or more (pref. 40 kg/mm2 or more). The semiconductor substrate is produced by forming an alumina-type aluminium oxide (2) layer on the surface of the AlN sinter (the thickness of the layer is 0.1-20 microns, pref. 0.5-3 microns). The alumina-type aluminium oxide (2) is composed of two phases, and alpha-Al2O3 phase and a solid soln. oxide of Dy and Al. The alumina-type oxide layer is formed by heating the AlN sinter at 950-1200 deg.C for 30 mins. in an atmos. where partial pressure of oxygen is 21% or less. Another semiconductor substrate is produced by forming a Ni and/or Cu layer (0.1-10 microns thickness) on a thin layer (100-8000 Angstroms) of Ni and/or Cu formed on the surface of the AlN sinter.