VARIABLE REACTOR Russian patent published in 1997 - IPC

FIELD: semiconductor instruments, in particular, devices which reactance is controlled by voltage. SUBSTANCE: device has working region which is designed as semiconductor of electronic or hole conductivity with resistance contact. On its surface p-n junction or Schottky barrier with other contact is generated. Working region is designed as semiconductor film which is located on insulating or semi-insulating substrate. Working region provides either non-uniform distribution of doping Ni(x, y), or non-uniform distribution of film depth D(x) or non- uniform distribution of doping and film depth. P-n junction or Schottky barrier is generated on region which has this distribution. Film depth and doping distribution conform to condition of total depletion of working region of film with respect to charge carrier until barrier is broken under external bias voltage: , where Ui(x) is semiconductor film breaking voltage in section of x- y, y is coordinate which runs from film surface towards its depth; ε_s is dielectric permeability of semiconductor film. In addition resistance contact to film is made along perimeter of its working region with space which size is greater than distance for breaking p- n junction for maximal locking voltage at junction. This voltage is equal to minimal locking voltage for which working region of film is totally depleted from charge carriers. Function of capacitance on voltage C(U) in domain of external locking voltage U_min≅ U ≅ U_max is kept due to selection of function of size of p-n junction or Schottky barrier F(x) in direction Z, or by selection of D(x) or Ni(x, y), where x, z are curvilinear orthogonal coordinates in plane of film surface (in particular, rectangular coordinates). F(x) is continuous or piecewise continuous function of x coordinate. EFFECT: increased functional capabilities. 3 cl, 9 dwg