Variation of the Surface States and Series Resistance Depending on Voltage, and Their Effects on the Electrical Features of a Schottky Structure with CdZnO Interface

• Published in: Journal of electronic materials Vol. 52; no. 4; pp. 2432 - 2440
• Main Authors: Erbilen Tanrıkulu, E., Taşçıoğlu, İ.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2023; Springer Nature B.V
• Subjects: Atom concentration; Capacitance; Characterization and Evaluation of Materials; Chemistry and Materials Science; Density distribution; Depletion; Electronics and Microelectronics; Energy levels; Frequency variation; High voltages; Instrumentation; Interlayers; Materials Science; Optical and Electronic Materials; Original Research Article; Solid State Physics; depending on voltage; the effects of interlayer on the electrical features; and; impedance measurements; frequency-dependent basic electrical parameters; Variation of
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-022-10192-x

In the present study, voltage-dependent variation of the interface traps ( D it ) and series resistance ( R s ) and their effects on the electrical features of a Schottky structure with CdZnO interface were investigated via frequency-dependent impedance measurements ( Z – V ). While two different methods—the high-low frequency capacitance ( C LF – C HF ) and Hill–Coleman methods—were utilized in determining the voltage and frequency dependence of D it , the Nicollian–Brews method was preferred in the calculation of the R s . Experimental results indicate a decrease of both D it and R s values exponentially when frequency increases, and the peak behavior of the D it – V plot occurred at about 1.5 V due to the special density distribution of D it at the interlayer/Si interface. Corrections were carried out on the C / G – V measurements performed at 1 MHz, to examine the effects of R s on the measurements. After these corrections, while the value of capacitance increases more at the intermediate and high voltages corresponding to the depletion and accumulation zones, the G – V plot gives two prominent peaks in these zones, respectively. This correction process reveals that for higher frequencies and intermediate and high voltages, the effect of R s is dominant on the C / G – V graphs. Additionally, to designate some important electrical features of the Schottky structure with CdZnO interface, for instance, the acceptor atom concentration ( N A ), Fermi energy level ( E F ), barrier height (BH, Φ B ), and the width of the depletion layer ( W D ), C −2 – V plots were drawn for the reverse bias zone. Both the Φ B and W D values show an almost linear variation with frequency.