Studies of majority-carrier traps in Zn-doped p-InP by thermally stimulated capacitance techniques

High-barrier Yb/p-InP Schottky diodes were used to study majority-carrier traps in the Zn-doped p-InP single-crystal substrates by thermally stimulated capacitance (TSCAP) techniques. The TSCAP studies involved a forward bias VF=0.6 V, cooling to 90 K, bias switching to reverse bias VR=4.0 V, and then heating at a constant heating rate to 450 K. The junction capacitance was recorded as a function of temperature for various heating rates between 0.05 and 0.5 K/s, and corrected for temperature dependence of the diffusion voltage and the dielectric constant. The trapping parameters of the strong hole trap level were determined from the plots of dΔC/dT vs T at different heating rates, and values of Eh1=EV+0.59 eV and σp1 =3×10−21 cm2 were obtained for the activation energy and capture cross section, respectively, of the hole trap. From the TSCAP data at a constant heating rate and using the Eremin, Strokan, and Turebekov [Sov. Phys. Semicond. 15, 1010 (1981)] method, a hole trap with Eh1=EV+0.62 eV and σp1 =2×10−21 cm2 was also detected. From the amplitude of the steady-state positive capacitance step, a value of NTP =2.7×1014 cm−3 for the concentration of the hole trap level was estimated.