Abstract: Many holes are formed in an interlayer insulating film and the surface of the interlayer insulating film is covered with a metal film, with its surface undulated by openings or recesses formed to scatter reflection light. The size of the recesses is about the size of contact holes of elements. Hence the recesses are not detectable by an image recognition apparatus. The size of the metal film, however, is set so that it can be detected by the image recognition apparatus.

Abstract: Many holes are formed in an interlayer insulating film and the surface of the interlayer insulating film is covered with a metal film, with its surface undulated by openings or recesses formed to scatter reflection light. The size of the recesses is about the size of contact holes of elements. Hence the recesses are not detectable by an image recognition apparatus. The size of the metal film, however, is set so that it can be detected by the image recognition apparatus.

Abstract: AlN-base sintered body with a high thermal caonductivity is produced by:preparing a compact of a material comprising 100 parts by weight of aluminum nitride and 0.1-10 parts by weight, calculated on metal element, of at least one component selected from the group consisting of elements of Groups 4a, 5a and 6a of the Periodic Table, and compounds thereof; andsintering said compact at a temperature ranging from 1500.degree. to 2000.degree. C. under a non-oxidizing atmosphere having a source of boron and/or carbon supply. The compounds include oxides, borides, nitrides and carbides. The elements include W, Mo, Ta and Ti. Oxides are converted to other compounds through sintering. This AlN-base sintered body has good wettability with metal for metallization and enables simultaneous sintering with metallization layer. Multilayer laminated circuit boards or substrates thereof can be produced.

Abstract: AlN-base sintered body with a high thermal conductivity is produced by:preparing a compact of a material comprising 100 parts by weight of aluminum nitride and 0.1-10 parts by weight, calculated on metal element, of at least one component selected from the group consisting of elements of Group 4a, 5a and 6a of the Periodic Table, and compounds thereof; andsintering said compact at a temperature ranging from 1500.degree. to 2000.degree. C. under a non-oxidizing atmosphere having a source of boron and/or carbon supply. The compounds include oxides, borides, nitrides and carbides. The elements include W, Mo, Ta and Ti. Oxides are converted to other compounds through sintering. This AlN-base sintered body has good wettability with metal for metallization and enables simultaneous sintering with metallization layer. Multilayer laminated circuit boards or substrates thereof can be produced.

Abstract: AlN-base sintered body with a high thermal conductivity is produced by:preparing a compact of a material comprising 100 parts by weight of aluminum nitride and 0.1-10 parts by weight, calculated on metal element, of at least one component selected from the group consisting of elements of Groups 4a, 5a and 6a of the Periodic Table, and compounds thereof; andsintering said compact at a temperature ranging from 1500.degree. to 2000.degree. C. under a non-oxidizing atmosphere having a source of boron and/or carbon supply. The compounds include oxides, borides, nitrides and carbides. The elements include W, Mo, Ta and Ti. Oxides are converted to other compounds through sintering. This AlN-base sintered body has good wettability with metal for metallization and enables simultaneous sintering with metallization layer. Multilayer laminated circuit boards or substrates thereof can be produced.

Abstract: A composite layer aluminum nitride-base sintered body has on at least one surface of AlN-base sintered body having a first layer and a second layer. The first layer is 100 parts by weight of at least one component selected from the group consisting of W, Mo, borides thereof and carbides thereof as a first component (s), and 0.1-50 parts by weight of AlN second component. The second layer has at least one component selected from the group consisting of W, Mo, borides thereof and carbides thereof. The thickness of said first layer is 0.5-40 .mu.m, and the sum of thickness of the first and second layers is 1-50 .mu.m. The AlN may also include sintering aids of oxides of rare earth metal and alkaline earth metals. Hydrides and oxides of Ti, Zr, Nb, V and Mn may be included in the first layer composition.

Abstract: A composite layer aluminum nitride-base sintered body has on at least one surface of AlN-base sintered body having a first layer and a second layer. The first layer is 100 parts by weight of at least one component selected from the group consisting of W, Mo, borides thereof and carbides thereof as a first component(s), and 0.1-50 parts by weight of AlN second component. The second layer has at least one component selected from the group consisting of W, Mo, borides thereof and carbides thereof. The thickness of said first layer is 0.5-40 .mu.m, and the sum of thickness of the first and second layers is 1-50 .mu.m. The AlN may also include sintering aids of oxides of rare earth metal and alkaline earth metals. Hydrides and oxides of Ti, Zr, Nb, V and Mn may be included in the first layer composition.