Precision thin-film cermet resistors for integrated circuits

The use of thin-film resistors in monolithic integrated circuits is becoming more widespread as the performance requirements imposed upon circuit designers become more stringent. A cermet, consisting of a mixture of Cr and SiO, was selected as a suitable resistor mterial for this purpose because of its compatibility with semiconductor materials and processes, and because of its stability and reproducibility over a wide range of sheet resistance. Cermet films with sheet resistances of 300, 1000, and 2000 Ω/square were flash evaporated on silicon substrates, and resistors were fabricated. The techniques for depositing the cermet films and fabricating the resistors are discussed, and methods for subsequently adjusting the resistors to precise values are described. The properties of the completed resistors are presented in detail.