Effect of diode size and series resistance on barrier height and ideality factor in nearly ideal Au/n type-GaAs micro Schottky contact diodes

Abstract

Small high-quality Au/n type-GaAs Schottky barrier diodes (SBDs) with low reverse leakage current are produced using lithography. Their effective barrier heights (BHs) and ideality factors from current-voltage (I-V ) characteristics are measured by a Pico ampere meter and home-built I-V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in ideality factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope (AFM) shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100-200 nm. Between barrier height and ideality factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 µm up to 200 µm, the barrier height increases from 0.833 up to 0.933 eV and its ideality factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and ideality factor.

Gaussian distribution of inhomogeneous barrier height in nanocrystalline graphite (NCG)/p-Si Schottky diodes

“…The dissimilarity of ∅ b and η values in the previous work, 33) is due to the difference in the contact area of 7.85 × 10 −5 cm 2 of the NCG/p-Si Schottky contact, which were found to be much smaller compared to this work. This result agreed with the work reported previously, 34) which demonstrated that a wider Schottky contact will lead to an increase of barrier height.…”

Study of Electrical Behavior of Metal‐Semiconductor Contacts on Exfoliated MoS2 Flakes

“…One of the reason of comparatively large ideality factor can be low diode contact area (45 µm 2 ). It has been reported that as the diode size decreases, edge leakage current also plays an important role and Schottky diode parameters varies such as barrier height decreases and ideality factor increases …”

Investigation of de-embedding techniques applied on uni-traveling carrier photodiodes

“…Figure 5(b) calculates the magnitude and phase of G m for UTC-PDs with different sizes at an applied bias voltage of −2 V. It is observed that the negative slope increases for diodes with wider surfaces. This resides on the fact that the values for the real part of the reflection coefficients (Re[G m ]) are higher for smaller devices due to their larger series resistance [64][65][66]. Moreover, the imaginary part of the G m values (Im[G m ]) also show the same trend where the capacitive behavior of the active region is more dominant for wider structures comparing to the parasitics of the TML [67][68][69].…”