Patent ID: 6908777

Claim:
A method for controlling characteristics of a compound semiconductor device comprising: providing a first resistor defining a first resistivity region in a semi-insulating substrate, the first resistor having a first pair of electrodes extending over the first resistivity region, a second resistor defining a second resistivity region in the semi-insulating substrate, the second resistor having a second pair of electrodes extending over the second resistivity region, wherein a ratio of a difference between a surface area of the first resistivity region and a combined surface area of the first pair of electrodes to the combined surface area of the first pair of electrodes, is the same as a ratio of a difference between a surface area of the second resistivity region and a combined surface area of the second pair of electrodes to the combined surface area of the second pair of electrodes; measuring a resistivity of the second resistor; and controlling a resistivity of the first resistor based on the measured resistivity, wherein said controlling a resistivity comprises etching the first and second resistivity regions.