In: Physics
Your supervisor asked you to design a diode that has a total junction capacitance at 0V of 1pF. You are asked to start with an n-type GaAs wafer with a doping of 1x1017 cm-3, then create the p-type layer by doping the substrate with accepters. The substrate manufacturer told you that the GaAs substrate has trap centers equal to 2x1014 cm-3 and capture cross-sections for electrons and holes was of 1.0x10-12 cm2. After designing the diode, you are asked to calculate the following: (a) the saturation current density, (b) the forward current density at 0.9V, (c) the diffusion capacitance/cm2 at 0.9V, and (d) the junction capacitance/cm2 at V=-2V.
Your design must be practical that can be fabricated and used in
circuits.