| 摘要 |
PURPOSE:To obtain a resistance circuit network which has high integration and high accuracy by alternately arranging the first and second polysilicon resistors insulated from each other on an insulating film of an Si substrate and connecting the resistors equally in number. CONSTITUTION:The first polysilicon unit resistors 5 are formed by a photoetching method on an oxidized film 8 on an Si substrate 10, an oxidized film 9 is covered, and the second polysilicon unit resistors 6 are similarly formed. Accordingly, the resistors of approx. double in number can be formed on the same area. Windows 7 are opened, and lead conductors 1-3 and mutually connecting conductors 4 are then formed. Since the unit resistors are equal in number even if the variation in the resistor is independently produced due to different impurity diffusion amounts of the first and second polysilicons, the ratio of the resistance values can be maintained constantly. The time constant of the CR is controlled by the diffusion of the impurity, thereby forming a CR filter having high integration and high accuracy. |
