| 摘要 |
FIELD: semiconductor devices. SUBSTANCE: device has semiconductor film with electric contact. Film is located either on substrate which type of conductance differs from that of film or on metal substrate, which provides Schottky-effect barrier and has another contact. Working area of film 0≅ x≅ Xmax,, z1(x)≅ z≅ z2(x) (in direction of x) has either varying shape of dope distribution Ni(x,y), or varying shape of film depth D(x), or varying shape for both dope distribution and film depth. Doping shape distribution and film depth depend on only condition that working film area becomes totally depleted from basic charge carriers before p-n junction or Schottky-effect barrier breaks down when external voltage is applied, where Ui(x) is voltage for breakdown of semiconductor film in section of x-y, y is coordinate which runs starting from border between film and substrate along film depth; q is elementary charge, εε0 is dielectric permeability of semiconductor film, Uk is integral potential. Electric contact to film is generated on free area of its working part and is designed as strips, which are connected to one another or as single strip. Dependency of capacitance on voltage C(U) is kept for given range of closing voltage Umin≅ U≅ Umax due to choice of shape of working film area as F(x) = z2(x)-z1(x) in direction Z or by choice of either D(x) or Ni(x, y), where x and z are curve orthogonal coordinates in plane that coincides with border between substrate and film. Coordinates may be rectangular. Doping shape and film depth shape out of working area conform to condition of total film depletion from basic charge carriers when external voltage at p-n junction is minimal (U=Umin):. EFFECT: increased merit factor for varicaps which coefficient for capacitance overload is not restricted by breakdown voltage. 4 cl, 5 dwg |
