| 摘要 |
PURPOSE:To vary and adjust a resistance value easily by forming at least two diffusion resistance regions in a semiconductor region and shaping a gate elec- trode for a field-effect transistor between one parts of each of said diffusion resistance regions. CONSTITUTION:The P type diffusion resistors 1, 2 are formed to an N type epitaxial layer 51 shaped on a p type semiconductor substrate 53. The surfaces of each diffusion resistor 1, 2 are coated with an oxide film 52, the oxide film 52 functions as a gate insulating film for an MOS field-effect transistor, and a wiring 6 is formed on the oxide film 52. Electrodes 3, 4, 5, 7 are each shaped at both ends of several diffusion resistor 1, 2, but the electrodes 4, 7 are short- circuited and used when a resistance value is intended to be adjusted between the electrodes 3, 5. The resistance value can be regulated at the position of the wiring 6 at that time, and the conductivity of a channel formed while connecting a section between the resistors 1, 2 under the wiring 6 is controlled and adjusted by voltage applied to the wiring 6. |
