Method of making multi-megohm thin film resistors

摘要

A geometry and method of fabricating thin film resistors which are tolerant of faults in the film and therefore permit attainment of high resistances. The resistor includes a series of connected closed loops (15) each with a member (17) providing a short circuit path. Such members are successively cut and the change in resistance is determined after each cut. This change is compared to certain threshold values to determine the presence or absence of an open circuit fault in each loop. The resistor is then trimmed to its desired value by cutting only the loops where no opens have been discovered.