The Effect of Series Resistance on the Relationship Between Barrier Heights and Ideality Factors of Inhomogeneous Schottky Barrier Diodes

Abstract

We have studied Cd/n-Si (33 dots) Schottky barrier diodes (SBDs). Si surfaces have been prepared by the usual chemical etching, and the evaporation of metal has been carried out in a conventional vacuum system. The effective Schottky barrier heights (SBHs) and ideality factors obtained from the current–voltage (I–V) characteristics differ from diode to diode although the samples were identically prepared. The SBH for the Cd/n-Si diodes ranged from 0.605 eV to 0.701 eV, and ideality factor n from 1.213 to 1.913. The reason for that the experimental data differ from diode to diode has been analyzed by applying thermionic emission theory (TET) of inhomogeneous Schottky contacts together with standard TET and thus the effect of series resistance on the relationship between barrier heights and ideality factors of the inhomogeneous SBDs has clearly been shown. A laterally homogeneous SBH value of approximately 0.770 eV for Cd/n-Si SDs has been obtained by the barrier inhomogeneity model.

Effects of chemical treatment on barrier height and ideality factors of Au/GaN Schottky diodes

“…A study of the importance of series resistance in calculating the characteristic parameters of Si Schottky contacts was done by Aydin et al [1], obtaining their estimations from determination of interface states density distribution from the analysis of the current-voltage measurements. Kampen physical MIGS and the electronegativity concept [10].…”

Analysis of inhomogeneous device parameters using current–voltage characteristics of identically prepared lateral Schottky structures

“…Gaussian function is used to fit the calculated n and U B values. The high values of n obtained by many researchers are attributed to barrier inhomogeneities, the existence of the native oxide layer between metal and semiconductor and the particular distribution of interface states localized at semiconductor [18][19][20][21][22][23]. Figure 4 depicts a plot of the barrier heights as a function of the ideality factors for 50 dots of Au/n-Si/Al Schottky diodes.…”

“…These deviations have been represented by assuming the existence of the barrier height inhomogeneities [13][14][15][16][17][18][19][20][21][22][23]. Sullivan et al [13] and Tung [14] have modeled imperfect metal-semiconductor structures by supposing lateral variation of barrier heights.…”

“…The barrier height inhomogeneity causes big ideality factors, which need to be improved by good uniformity of interface structure [24,25]. The experimental effective barrier heights and ideality factors determined from the I-V measurements vary from diode to diode, even if Schottky structures are identically fabricated [18][19][20][21][22][23]. Chawanda et al [18] have experimentally investigated the relationship between the ideality factors and effective barrier heights of Pd/n-Ge Schottky contact.…”

Determination of the laterally homogeneous barrier height of thermally annealed and unannealed Au/p-InP/Zn-Au Schottky barrier diodes

“…They found larger ideality factors and smaller effective barrier heights when they increased the inhomogeneity of barriers. Thus, it has been pointed out that the BH inhomogeneity model may be also explained by the linear relationship between effective BHs and ideality factors that is often observed on sets of the identically prepared diodes [21][22][23][24][25][26][33][34][35][36][37].…”