Electrical characteristics of selenium-treated GaAs MIS Schottky diodes

Abstract

We have investigated the effect of selenium treatment of GaAs on the metal-insulator-semiconductor (MIS) Schottky diode characteristics. The resuits show that the surface-state density and trap density at the interface decrease. This resu!'; in decrease in the harrier height and retierse cwe.!. The treated diodes showed little aging effect. These observations can be explained using t h e formation of arsenic-selenium and selenium-selenium bonds at the surface and in the thin layer next to the surface within the GaAs.

Neutron irradiation effect on radio-frequency magnetron-sputtered GaN thin films and Au/GaN Schottky diodes

“…42 Sheu et al in their x-ray diffraction measurements on Ni/Au/GaN Schottky devices also identified that the formation of Ga-Au compounds at the Au/GaN interface due to high temperature thermal annealing could reduce the Schottky barrier height, yielding a larger reverse leakage current and a smaller breakdown voltage. In the forward-biased situation, the poorer crystallinity of GaN due to the high neutron irradiation fluence (Ͼ1ϫ10 13 n/cm 2 ) apparently creates dramatic numbers of E t1 and E t2 traps which not only increase the occurrence of scattering with free conduction carriers, but also yield reduced carrier mobility.…”

Characterization of trap sites in thin oxide on selenium-passivated GaAs

“…Aluminium and tantalum contacts were sputtered separately on the anodized surfaces through a metal mask. The contact area was 7 x Since it has been observed that electrical properties of these contacts were improved after rapid thermal annealing [8], therefore this study was done on the annealed contacts (500 "C, 30 s). Proximity method was used during annealing to prevent the possible decomposition of GaAs [lo].…”

“…For passivation, the GaAs surface is exposed to inorganic chemicals such as (NH,),S, Na2S. 9 H 2 0 , and H2S for sulfur passivation [l, 4,5,71 and Na,Se and K,Se for selenium passivations [2, 31. Recently we reported the improvements in the electrical characteristics of metal-insulator-semiconductor (MIS) GaAs Schottky diodes [8] due to passivation of GaAs. The passivation was accomplished by depositing a thin layer (1 nm) of pure selenium on the GaAs surface before growing the insulator.…”

On the characteristics of an electroless plated (EP)-based pseudomorphic high electron mobility transistor (PHEMT)

“…This phenomenon is called the Fermi level pinning effect at metal-semiconductor interfaces (M-S) [5]. Many approaches have been reported to overcome this drawback, e.g., a thin interfacial oxide at M-S interfaces [6,7], sulfur or selenium surface treatments [8,9], and the modification of the surface properties by plasma treatments [10,11]. However, these Schottky barriers suffer from instability and poor reproducibility due to complex interfacial reactions.…”