| 摘要 |
A PN junction varactor is provided to increase a capacitance value per unit area by forming a P or an N doping region made of a comb type. An N-type well region(305) is formed in a substrate. P-type and N-type doping regions(310,315) are formed as a comb type in the N-type well region. The P-type and N-type doping regions of the comb type are alternately disposed to form a PN junction of a single ended structure. A capacitance value is varied by a potential applied to the PN junction. A potential applied to the PN junction is a potential applied to the P-type doping region and the N-type doping region. A predetermined voltage is applied to the P-type doping region. A voltage higher than a predetermined voltage applied to the P-type doping region is applied to the N-type doping region.
|
