SUBSTRATE BIAS GENERATOR

摘要

A substrate bias generator comprises a capacitor (222) including an electrically insulating film (270) sandwiched between two electrodes (226,272) one of which is disposed on one main face of a P<-> semiconductor substrate (210) through another electrically insulating film (224), and first, second and third N<+> semiconductor regions (214-218) disposed in spaced relationship on the same main face. The first and second regions (214, 216) form a grounded source and a drain of a MOSFET (228) connected to both its gate and one of the electrodes (272) of the capacitor (222). The second and third regions (216, 218) form a source and a drain of another MOSFET (234) connected to both its gate and the other main face of the substrate (210). A signal is applied to the other electrode of the capacitor (222).