Hitachi Metals, Ltd.

Tokyo Electron Limited

Koichi Terao

Takeshi Shimada

Kazuya Toji

Kazuhiro Nishikawa

Kei Matsumoto

Yuichi Takano

A semiconductor porcelain composition is prepared by separately preparing a composition of (BaR)TiO(R is La, Dy, Eu, Gd or Y) and a composition of (BiNa)TiO, and calcining the composition of (BaR)TiOat a temperature of 900&#xb0; C. through 1300&#xb0; C. and calcining the composition of (BiNa)TiOat a temperature of 700&#xb0; C. through 950&#xb0; C., and then mixing, forming and sintering the calcined powders. Similarly, a semiconductor porcelain composition is prepared by separately preparing a composition of (BaM)TiO(M is Nb, Ta or Sb) and a composition of (BiNa)TiO, and calcining the composition of (BaM)TiOat a temperature of 900&#xb0; C. through 1300&#xb0; C. and calcining the composition of (BiNa)TiOat a temperature of 700&#xb0; C. through 950&#xb0; C., and then mixing, forming and sintering the calcined powders.

Semiconductor porcelain composition and method of producing the same

The invention intends to provide, in BaTiOsemiconductor porcelain composition, a semiconductor porcelain composition that, without using Pb, can shift the Curie temperature to a positive direction and can significantly reduce the resistivity at room temperature. According to the invention, when Ba is partially substituted by an A1 element (at least one kind of Na, K and Li) and an A2 element (Bi) and Ba is further substituted by a specific amount of a Q element, or when Ba is partially substituted by an A1 element (at least one kind of Na, K and Li) and an A2 element (Bi) and Ti is partially substituted by a specific amount of an M element, the optimal valence control can be applied and whereby the resistivity at room temperature can be significantly reduced. Accordingly, it is optimal for applications in a PTC thermistor, a PTC heater, a PTC switch, a temperature detector and the like, and particularly preferably in an automobile heater.

Semiconductor porcelain composition

A semiconductor porcelain composition [(BiNa)(BaR)]TiOwith 0&#x3c;x&#x2266;0.2, 0&#x3c;y&#x2266;0.02 and R being selected from the group consisting of La, Dy, Eu, Gd or Y is prepared by separately calcining a composition of (BaR)TiOat a temperature of 900&#xb0; C. through 1300&#xb0; C. and calcining a composition of (BiNa)TiOat a temperature of 700&#xb0; C. through 950&#xb0; C., and then mixing the two calcined powders and forming and sintering the mixed calcined powder. Similarly, a semiconductor porcelain composition [(BiNa)(Ba][TiM]Owith 0&#x3c;x&#x2266;0.2, 0&#x3c;z&#x2266;0.005 and M being selected from the group consisting of Nb, Ta and Sb is prepared by separately calcining a composition of (BaM)TiOat a temperature of 900&#xb0; C. through 1300&#xb0; C. and calcining a composition of (BiNa)TiOat a temperature of 700&#xb0; C. through 950&#xb0; C., and then mixing the two calcined powders, and forming and sintering the mixed calcined powders.

A method of producing a semiconductor disk represented by a composition formula [(BiNa)(BaR)]TiO, in which R is at least one element of La, Dy, Eu, Gd and Y and x and y each satisfy 0&#x2266;x&#x2266;0.14, and 0.002&#x2266;y&#x2266;0.02 includes carrying out a sintering in an inert gas atmosphere with an oxygen concentration of 9 ppm to 1% and wherein a treatment at an elevated temperature in an oxidizing atmosphere after the sintering is not carried out.

Method of producing semiconductor porcelain composition

A glass material for use in a microwave-transparent window of a plasma processing apparatus is provided. The glass material has not only good properties similar to those of quartz glass but a corrosion resistance particularly to fluorine-containing plasma. The glass having the corrosion resistance to the fluorine-containing plasma is composed of a first glass phase consisting of Si and O and a second glass phase consisting of Si, Al and O. The second glass phase has a mass ratio of Al to Si of at least 0.01. The glass member is useful as a component for forming an electromagnetic-wave introducing window of the plasma processing apparatus or the like.

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Osaka, Japan

Koichi Terao