VARACTOR Russian patent published in 1998 - IPC

FIELD: semiconductor devices whose reactance is controlled by voltage variation. SUBSTANCE: varactor has working region with ohmic contact whereon p-n junction or Schottky barrier with other contact is formed; working region is made of plane-parallel semiconductor plate with heterogeneous distribution profile of dope N_i(x)(N_max< N_i(x) < N_min) along its surface in direction of x. Shaped on two side of plate in section containing this profile is p-n junction; plate thickness t meets condition 2R(O,N_min) < t ≤ 2R(Uminbr

), where R(Uminbr) is spatial charge region thickness at minimal breakdown voltage U_br; R(O,N_min) - is spatial charge region thickness at zero bias. Specified mechanism of varactor capacitance variation as function of voltage is provided by choosing functional dependence y(x). and size of p-n junction in direction of y. Working region of varactor may be also made in the form of substrate-shaped semiconductor film of thickness d with p-n junction shaped on one side and film thickness satisfying condition R(O,N_min) < d ≤ R(Uminbr). There have been also developed varactors with predetermined decaying dependence C(U), including linear one, having capacitance coverage factors independent of breakdown voltage. EFFECT: facilitated manufacture. 2 cl, 4 dwg