Capacitance-voltage measurements on p-n-p InP structures

The electrical properties of p-type layers of indium phosphide (InP) formed by the diffusion of zinc into n-type material were studied by capacitance-voltage measurements. A non-correspondence of atom and carrier concentrations was indicated, confirming previous four-point resistivity and Hall Effect studies. Using several specimens, a typical value of 25 was found from C−2-V and C-V curves for the atom/carrier ratio. The dielectric constant of InP was taken to be 11. The width of the depletion region at an intermediate voltage (0.5 V) was typically 0.03 μm. It was concluded that further work on contacting procedures to produce a good Schöttky Barrier at the contact-semiconductor interface should make this technique particularly useful for determining carrier profiles.