Abstract: Provided are a method of cleaning a group III nitride single crystal substrate which enables the roughness of a nitrogen-polar face of the group III nitride single crystal substrate to be suppressed to remove foreign substances, and a method of producing a group III nitride single crystal substrate. The method of cleaning a group III nitride single crystal substrate having a group III element-polar face, and the nitrogen-polar face opposite the group III element-polar face includes: cleaning the nitrogen-polar face with a detergent including a fluoroorganic compound.

Abstract: Provided are a method of cleaning a group III nitride single crystal substrate which enables the roughness of a nitrogen-polar face of the group III nitride single crystal substrate to be suppressed to remove foreign substances, and a method of producing a group III nitride single crystal substrate. The method of cleaning a group III nitride single crystal substrate having a group III element-polar face, and the nitrogen-polar face opposite the group III element-polar face includes: cleaning the nitrogen-polar face with a detergent including a fluoroorganic compound.

Abstract: To provide an ultraviolet sterilizing apparatus that is capable of efficiently performing ultraviolet sterilization on a large volume of gas or pressurized liquid in a short time, can be made compact, and can be stably and safely used for a long time.

Abstract: A substrate for device bonding includes a substrate having an electrode layer and a solder layer formed on the electrode layer, wherein the solder layer is a Pb-free solder layer which comprises (1) a base metal composed of (i) Sn, (ii) Sn and Au, or (iii) In, (2) at least one metal selected from the group consisting of Bi, In (only in the case where the base metal is Sn, or Sn and Au), Zn, Au (only in the case where the base metal is In) and Sb, and (3) at least one metal selected from the group consisting of Ag, Ni, Fe, Al, Cu and Pt, and the solder layer has a thickness of 1 to 15 ?m and a surface roughness (Ra) of not more than 0.11 ?m.

Abstract: A substrate for device bonding includes a substrate having an electrode layer and a solder layer formed on the electrode layer, wherein the solder layer is a Pb-free solder layer which comprises (1) a base metal composed of (i) Sn, (ii) Sn and Au, or (iii) In, (2) at least one metal selected from the group consisting of Bi, In (only in the case where the base metal is Sn, or Sn and Au), Zn, Au (only in the case where the base metal is In) and Sb, and (3) at least one metal selected from the group consisting of Ag, Ni, Fe, Al, Cu and Pt, and the solder layer has a thickness of 1 to 15 ?m and a surface roughness (Ra) of not more than 0.11 ?m.

Abstract: A sintered aluminum nitride substrate which has a via hole and an internal electrically conductive layer, having high thermal conductivity and high adhesion strength between the sintered aluminum nitride substrate and the internal electrically conductive layer or the via hole and having other excellent properties. The substrate comprising an internal electrically conductive layer, at least one electrically conductive via hole formed between the internal electrically conductive layer and at least one surface of the substrate, wherein the thermal conductivity of the aluminum nitride sintering product at 25° C. is 190 W/mK or more, and the adhesion strength between the aluminum nitride sintering product and the internal electrically conductive layer is 5.0 kg/mm2 or more.

Abstract: A sintered aluminum nitride having satisfactorily densified via holes, which is free from cracking and has an excellent appearance, is produced through firing an aluminum nitride molding having at least one highly isolated through-hole for via hole formation. At least one through-hole for formation of dummy via holes not used for electrical connection is formed around the highly isolated through-hole for via hole formation, and the through-hole for dummy via hole formation is also filled with a conductive paste. Thereafter, the aluminum nitride molding is fired into the sintered aluminum nitride.

Abstract: It is an object to provide a method of efficiently manufacturing a double-sided circuit board having a metallic via hole which can suitably be used as a submount for mounting a semiconductor device, that is, a substrate in which the electrical contact of a metallic via hole and a circuit pattern is excellent and an element can easily be bonded and positioned. In a ceramic substrate having a via hole filled with a conductive material, a ceramic portion of at least one of faces of the ceramic substrate has a surface roughness of Ra≦0.8 &mgr;m, a substrate in which the conductive material filled in the via hole present on at least one of the faces is protruded from a surface of the face with a height of 0.3 to 5.

Abstract: The object of the present invention is to provide a sintered aluminum nitride substrate which has a via hole and an internal electrically conductive layer, having high thermal conductivity and high adhesion strength between the sintered aluminum nitride substrate and the internal electrically conductive layer or the via hole and having other excellent properties. The substrate according to the invention comprising an internal electrically conductive layer, at least one electrically conductive via hole formed between the internal electrically conductive layer and at least one surface of the substrate, wherein the thermal conductivity of the aluminum nitride sintering product at 25° C. is 190 W/mK or more, and the adhesion strength between the aluminum nitride sintering product and the internal electrically conductive layer is 5.0 kg/mm2 or more.

Abstract: The present invention produces the following substrate and the following process for producing the substrate. A substrate obtained by filling through holes in a sintered product of aluminum nitride with an electrically conducting layer, wherein said sintered product of aluminum nitride has a thermal conductivity of not smaller than 190 W/mK, and the adhesion strength between said sintered product of aluminum nitride and said electrically conducting layer is not smaller than 5.0 kg/mm2.

Abstract: A sintered aluminum nitride having satisfactorily densified via holes, which is free from cracking and has excellent appearance, is produced through firing an aluminum nitride molding having at least one highly isolated through-hole for via hole formation. At least one through-hole for formation of dummy via holes not used for electrical connection is formed around the highly isolated through-hole for via hole formation, and the through-hole for dummy via hole formation is also filled with a conductive paste. Thereafter, the aluminum nitride molding is fired into the sintered aluminum nitride.

Abstract: The present invention prodices the following substrate and the following process for producing the substrate. A substrate obtained by filling through holes in a sintered product of aluminum nitride with an electrically conducting layer, wherein said sintered product of aluminum nitride has a thermal conductivity of not smaller than 190 W/mK, and the adhesion strength between said sintered product of aluminum nitride and said electrically conducting layer is not smaller than 5.0 kg/mm2.

Abstract: A submount including:an insulating substrate having therein a throughhole filled with a sintered metal powder, andan electroconductive layer formed on each of the two opposing surfaces of the insulating substrate, wherein the sintered metal powder filled in the throughhole of the insulating substrate is formed, for example, by filling, in the throughhole, a metal paste composed mainly of copper, tungsten, molybdenum or the like and then conducting firing and wherein the two electroconductive layers are electrically connected with each other at least partially by the sintered metal powder. The submount according to the present invention has a low electric resistance and high reliability and can be made in a small size. Therefore, it can be suitably used as a novel submount for semiconductor laser element, which promises electrical conduction between a semiconductor laser element and a heat sink.