PURPOSE: To obtain a resistor device having a small temperature coefficient, by connecting polysilicon resistors having a negative temperature coefficient and resistors, which are formed in a semiconductor substrate and have a positive temperature coefficient, and selecting the sizes of both resistors so that the changes in resistance values due to the temperatures are offset.
CONSTITUTION: On an insulating film 3 of SiO2 and the like on a semiconductor substrate 2, first resistors 4 having a negative temperature coefficient are formed by polysilicon. Second resistor 5 having a positive temperature coefficient are formed in the substrate 2 by ion implantation and the like. The resistors 4 and 5 are connected by electrodes 7 in series. At this time, the sizes of the resistors 4 and 5 are selected so that the changes in resistance value due to the respective temperatures are offset. Then, the resistor device having the very small temperature coefficient is obtained.
YOSHII MASURAO
IIZUKA KOJI
TOKYO SANYO ELECTRIC CO