Abstract
A process is described to obtain NiCr resistors with adjustable temperature coefficient of resistance (TCR) by reactive sputtering in an Ar-atmosphere with a small amount of oxygen in the range of 2% to 6%. As deposited the films show a TCR < −200 ppm/K. By heat treatment in air at a temperature of 350°C the TCR can be raised to values above −20 ppm/K. The time of heat treatment necessary to obtain a given TCR depends on the oxygen/argon ratio during sputtering. The long term stability is not affected by the choice of this ratio in a wide range.Resistor networks with a solderable conductor pattern of TiPdAu have a TCR of 0±7 ppm/K and a long term resistance drift ≤ 2‰ in the first 1,000 hours at 125°C.