A resistance circuit included in a semiconductor apparatus, which is formed of a plurality of thin film metal resistors connected in series, capable of achieving a precise resistance adjustment over a wide range by disconnecting or changing the resistors by laser beam irradiation. With three thin film metal resistors R1, R2, and R3 connected in series, for example, each having resistance adjustable ranges .DELTA.R1, .DELTA.R2, and .DELTA.R3, resistance adjustment accuracies R1_step, R2_step, and R3_step, and the total resistance adjustable range .DELTA.R0 specified by the relation .DELTA.R0=.DELTA.R1+.DELTA.R2+.DELTA.R3, the resistance circuit is formed to satisfy relational expressions, R1_step.ltoreq..DELTA.R2, R2_step.ltoreq..DELTA.R3, and R3_step.ltoreq.0.001.times..DELTA.R0<R2_step.ltoreq.0.01.times..DELTA.- R0<R1_step.ltoreq.0.1.times..DELTA.R0. This resistance circuit is suitably incorporated into high precision constant voltage generating, and voltage detecting circuits.

A resistor formed on a material layer of a semiconductor integrated circuit and a method for forming the resistor. The resistor comprises a region of resistive material with a plurality of conductive contacts or plugs in electrical contact with and extending away from the resistive material. A first and a second interconnect line are formed overlying the plugs and in conductive contact with one or more of the plurality of plugs, such that a portion of the resistive material between the first and the second interconnect lines provides a desired resistance. According to a method of the present invention, the plurality of conductive contacts are formed using a first photolithographic mask and the first and the second interconnect lines are formed using a second photolithographic mask. The desired resistance is changed by modifying the first or the second mask such that one or more dimensions of a region of the resistive material between the first and the second interconnect lines is altered.