VARICAP Russian patent published in 1998 - IPC

FIELD: microelectronics; semiconductor devices. SUBSTANCE: varicap has semiconductor with ohmic contact and p-n junction with other contact formed on its surface. Semiconductor is made in the form of film arranged on substrate under working section of film 0 ≤ X ≤ X_max, Z1(x) ≤ Z ≤ Z2(x), including that uniformly doped along x and having uniform thickness along x; substrate made of semiconductor material of reverse polarity of conductivity is formed with doping profile nonuniform along x; doping profile and film thickness are chosen proceeding from complete leaning of film working section or its part by major charge carriers up to breakdown of p-n junction upon applying external bias to it. Film ohmic contact is made in the form of interconnected strips or single strip; relationship between capacitance and voltage is chosen depending on selection of functional dependence of film working section size F(x) = z2(x) - z1(x) towards z or selection of film thickness D(x), where x, z are coordinates in plane common with film surface substrate, including rectangular coordinates. EFFECT: improved quality factor of varicap for practically any preset dependence between capacitance and voltage, including varicaps whose capacitance overlapping factor is not limited by breakdown voltage. 8 cl, 6 dwg