Abstract: A semiconductor device with favorable reliability is provided. The semiconductor device includes a first oxide, a second oxide over the first oxide, a first insulator over the second oxide, a first conductor over the first insulator, and a second conductor and a third conductor over the second oxide. The second conductor includes a first region and a second region, the third conductor includes a third region and a fourth region, the second region is positioned above the first region, the fourth region is positioned above the third region, and each of the second conductor and the third conductor contains tantalum and nitrogen. The atomic ratio of nitrogen to tantalum in the first region is higher than the atomic ratio of nitrogen to tantalum in the second region, and the atomic ratio of nitrogen to tantalum in the third region is higher than the atomic ratio of nitrogen to tantalum in the fourth region.

Abstract: A method for producing a ceramic honeycomb filter having predetermined plugs comprising immersing the end portions of a ceramic honeycomb structure having large numbers of flow paths, with its end surface covered with a mask provided with holes only at positions corresponding to the predetermined flow paths, in a plugging material slurry, so that the plugging material slurry is introduced into the end portions of the predetermined flow paths, and removing plugging material protrusions formed in the flow paths that should not be plugged.

Abstract: A method for producing a ceramic honeycomb filter by immersing an end surface of a ceramic honeycomb structure having a lot of flow paths partitioned by cell walls in a plugging material slurry in a container to introduce the plugging material slurry into the predetermined flow paths to form plugs, and taking the ceramic honeycomb structure provided with the plugs out of the container horizontally.

Abstract: A method for producing a ceramic honeycomb structure comprising applying a coating material to an outer peripheral surface of the ceramic honeycomb body to form an outer peripheral wall, the thickness of the coating material applied being determined from the outer diameter of the ceramic honeycomb body and the drying shrinkage ratio of the coating material, such that the outer diameter of the dried ceramic honeycomb structure is within a target outer size±1.4 mm.

Abstract: A method for producing a honeycomb filter from a honeycomb structure having large numbers of flow paths partitioned by cell walls, comprising inserting a tubular member into each of the flow paths, and injecting a plugging material into each of the flow paths from the tubular member to form a plug in each of the flow paths at a position separate from the end surface of the honeycomb structure, the tubular member having an outer diameter that is 40-90% of the opening size of the flow path, the plugging material comprising at least a ceramic material having a maximum particle size that is 85% or less of the inner diameter of the tubular member, and an average particle size of 1 ?m or more.

Abstract: A method for producing a ceramic honeycomb filter having predetermined plugs comprising immersing the end portions of a ceramic honeycomb structure having large numbers of flow paths, with its end surface covered with a mask provided with holes only at positions corresponding to the predetermined flow paths, in a plugging material slurry, so that the plugging material slurry is introduced into the end portions of the predetermined flow paths, and removing plugging material protrusions formed in the flow paths that should not be plugged.

Abstract: A method for producing a ceramic honeycomb structure comprising applying a coating material to an outer peripheral surface of the ceramic honeycomb body to form an outer peripheral wall, the thickness of the coating material applied being determined from the outer diameter of the ceramic honeycomb body and the drying shrinkage ratio of the coating material, such that the outer diameter of the dried ceramic honeycomb structure is within a target outer size ±1.4 mm.

Abstract: A ceramic honeycomb filter comprising a sintered ceramic honeycomb body having porous partition walls defining flow paths, and plugs formed in predetermined flow paths for removing particulate matter from an exhaust gas passing through the porous partition walls, the sintered ceramic honeycomb body being formed by a cordierite-based ceramic material, at least part of the plugs comprising ceramic particles and an amorphous oxide matrix formed from colloidal oxide.

Abstract: A method for producing a ceramic honeycomb filter by immersing an end surface of a ceramic honeycomb structure having a lot of flow paths partitioned by cell walls in a plugging material slurry in a container to introduce the plugging material slurry into the predetermined flow paths to form plugs, and taking the ceramic honeycomb structure provided with the plugs out of the container horizontally.

Abstract: A method for producing a honeycomb filter from a honeycomb structure having large numbers of flow paths partitioned by cell walls, comprising inserting a tubular member into each of the flow paths, and injecting a plugging material into each of the flow paths from the tubular member to form a plug in each of the flow paths at a position separate from the end surface of the honeycomb structure, the tubular member having an outer diameter that is 40-90% of the opening size of the flow path, the plugging material comprising at least a ceramic material having a maximum particle size that is 85% or less of the inner diameter of the tubular member, and an average particle size of 1 ?m or more.

Abstract: A method for producing a ceramic honeycomb filter having predetermined plugs comprising immersing the end portions of a ceramic honeycomb structure having large numbers of flow paths, with its end surface covered with a mask provided with holes only at positions corresponding to the predetermined flow paths, in a plugging material slurry, so that the plugging material slurry is introduced into the end portions of the predetermined flow paths, and removing plugging material protrusions formed in the flow paths that should not be plugged.

Abstract: A ceramic honeycomb filter comprising a sintered ceramic honeycomb body having porous partition walls defining flow paths, and plugs formed in predetermined flow paths for removing particulate matter from an exhaust gas passing through the porous partition walls, the sintered ceramic honeycomb body being formed by a cordierite-based ceramic material, at least part of the plugs comprising ceramic particles and an amorphous oxide matrix formed from colloidal oxide.

Abstract: A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through the porous partition walls to remove particulates from the exhaust gas, the predetermined flow paths among the flow paths being sealed at their ends, a catalyst being carried by the porous partition walls, the porous partition walls having a porosity of 60-75% and an average pore diameter of 15-25 &mgr;m when measured according to a mercury penetration method, and the maximum of a slope Sn of a cumulative pore volume curve of the porous partition walls relative to a pore diameter obtained at an n-th measurement point being 0.

Abstract: A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through the porous partition walls to remove particulates from the exhaust gas, the predetermined flow paths among the flow paths being sealed at their ends, a catalyst being carried by the porous partition walls, the porous partition walls having a porosity of 60-75% and an average pore diameter of 15-25 &mgr;m when measured according to a mercury penetration method, and the maximum of a slope Sn of a cumulative pore volume curve of the porous partition walls relative to a pore diameter obtained at an n-th measurement point being 0.