Fabrication and electrical characterization of nickel/p-Si Schottky diode at low temperature

• The research manuscript represents the measurement of barrier parameters from I-V and C-V characteristics over a wide range of temperature.
• While the barrier height ϕb decreases, ideality factor η and series resistance Rs increase with a decrease in temperature; the changes being quite significant at very low temperatures.
• The ln(Is/T2) vs 1000/T plot shows deviation from linearity at low temperatures.
• From the activation energy plot the zero-bias barrier height of Ni/p-Si Schottky diodes found to be ∼0.405 V and the Richardson’s constant A** obtained from the intercept of the straight portion at the ordinate found to be 4.42 × 103 Am−2 K−2, much lower than the known value of 3.2 × 105 Am−2 K−2 for p-type silicon.
• The inhomogeneities were found to have Gaussian distribution of barrier heights with mean 0.587 eV and standard deviation 0.06 eV.

In this study the current–voltage and capacitance–voltage characteristics of metal semiconductor Ni/p-Si(100) based Schottky diode on p- type silicon measured over a wide temperature range (60–300 K) have been studied on the basis of thermionic emission diffusion mechanism and the assumption of a Gaussian distribution of barrier heights. The parameters ideality factor, barrier height and series resistance are determined from the forward bias current–voltage characteristics. The barrier height for Ni/p-Si(100) Schottky diode found to vary between 0.513 eV and 0.205 eV, and the ideality factor between 2.34 and 8.88 on decreasing temperature 300–60 K. A plot involving the use of ϕb versus 1/T data is used to gather evidence for the occurrence of a Gaussian distribution of barrier height and obtain the value of standard deviation. The observed temperature dependences of barrier height and ideality factor and non-linear activation energy plot are attributed to the Gaussian distribution of barrier heights at the metal-semiconductor contact. The barrier height of Ni/p-Si(100) Schottky diode was also measured over wide temperature from the capacitance-voltage study.

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