Percolating cermet thin film thermistor

Abstract

A cermet thin film resistor having small particles of a refractory metal embedded in a ceramic insulator at compositions near the percolation transition. The cermets are produced by co-deposition in a dual-electron beam evaporator. The refractory metal is typically Mo or Pt. The insulator is typically a Al.sub.2 O.sub.3, although other insulators, for example SiO.sub.2 may be used. Deposition occurs onto a suitable substrate such as a sapphire under an oxygen environment, typically 10.sup.-5 Torr O.sub.2 with the stage heated in the range of typically 400.degree. C. Such is done to increase the size of the metallic regions. The microstructure is 10-50 .ANG. embedded metal in the ceramic. The resulting films are in the range of 1500 .ANG. thick which provides a film having a typical resistivity of 400 m.OMEGA. - cm which may then be patterned using lithography techniques to form two or four terminal resistors.

Dependencies are inferred from the claim text.