The comparative electrical characteristics of Au/n-Si (MS) diodes with and without a 2% graphene cobalt-doped Ca3Co4Ga0.001Ox interfacial layer at room temperature

Microelectronic Engineering, cilt.149, ss.166-171, 2016 (SCI İndekslerine Giren Dergi)

To investigate the effect of 2% graphene cobalt (GC)-doped (Ca3Co4Ga0.001Ox) interfacial layer on the main

electrical parameters, Au/n-Si (MS) Schottky barrier diodes (SBDs) were fabricated with and without

this inter-facial layer. Using forward and reverse bias current–voltage (I–V) measurements, selected electrical

parameters of these diodes were obtained and compared at room temperature. The energy density distribution

profiles of the surface states (Nss) were obtained from the forward-bias I–V data by taking into account the

voltage-dependent effective barrier height (Φe) and ideality factor (n(V)). The value of Nss for the MPS-type

diode is one order of magnitude lower than that of the MS diode. These results indicated that the 2% GC-doped

(Ca3Co4Ga0.001Ox) interfacial layer prevents reaction and inter-diffusion between Au and n-Si as well as

passivating the active dangling bonds at the semiconductor surface. In addition, the voltage-dependent

profile of the resistance (Ri) was also obtained for the two diodes from the I–V data using Ohm's law. In both

the MS- and MPS-type diodes, an apparent exponential increase in Nss was observed from the mid-gap toward

the bottom of the Ec. The experimental results show that the existence of Nss, Rs, and the interfacial layer has a

great effect on the electrical characteristics of these structures. The value of the depletion layerwidthwas obtained

from C–V measurements at 300 kHz for the two diodes. The obtained results show that the GC-doped

(Ca3Co4Ga0.001Ox) interfacial layer considerably enhances the diode performance.