Near-Ohmic Contact of n-GaAs with GaS/GaAs Quasi-Metal-Insulator-Semiconductor Structure

Abstract

We report on the current-voltage (I–V) characteristics of a metal/ultrathin GaS (thickness<100 Å)/n+-GaAs (carrier concentration=2×1018 cm-3) quasi-metal-insulator-semiconductor (QMIS) structure. The GaS was grown by molecular beam epitaxy (MBE) employing the precursor tertiarybutyl-galliumsulfide-cubane ([(t-Bu)GaS]4). The I–V characteristics of the QMIS structure depend on the work function of various metals (Au, Al, Ti). We discovered that a QMIS structure leads to a reduction of Schottky-barrier height itself. Furthermore, we demonstrated near-ohmic contact (contact resistivity=3.7×10-3 Ωcm2) for a Ti/97-Å-thick GaS/n+-GaAs QMIS structure. From the relationship between the semiconductor barrier height and the metal work function, we determined that Fermi level pinning was almost eliminated by GaS passivation.

Spin-glass ordering in the layered III-VI diluted magnetic semiconductor Ga1−xMnxS

“…Work on GaS includes growth of GaS films and multilayers on a GaAs substrate, 8,10 thermal conductivity, 11 and fabrication of Ohmic contacts to n-GaAs using GaS. 9,12 Suhre et al 3 have shown that adding In to GaSe strengthens the material enough to polish optical faces along arbitrary crystalline directions while enhancing the optical characteristics.…”

New value of old knowledge: sulphur-based GaAs surface passivation and potential GaAs application in molecular electronics and spintronics

“…Direct deposition of GaS was successfully performed using a gallium cluster ([(t-Bu) GaS] 4 ) as a singlesource precursor under ultra-high vacuum conditions of the MBE system [102,103,112]. The substrates were cleaned using trisodium ethylaminoarsinic (TDMAAS) and bisdimethylaminochloroarsinic (BDMAASCl) [102].…”

“…The substrates were cleaned using trisodium ethylaminoarsinic (TDMAAS) and bisdimethylaminochloroarsinic (BDMAASCl) [102]. During the deposition of pure GaS, the precursor cell was maintained at 120 °C [102,112]. The substrate temperature was maintained in the 350 °C to 500 °C temperature range.…”

“…The substrate was at a high temperature because it was essential to produce the required surface reconstruction, which played an important role in determining the extent of the improvement in the electrical properties of the GaS/GaAs interface. For instance, As rich (4×4) surface reconstruction produced 5×10 10 eV cm −2 surface states [102] while As rich (2×4) surface reconstruction yielded 1.8×10 11 eV cm −2 density of surface states [112] at GaS/GaAs interface. The deposited GaS film was reported to be amorphous and exhibited excellent surface morphology [102].…”

Transport mechanism analysis of non-equilibrium charge carrier in heterojunctions with GaS–CdTe:Mn thin films

“…By rearrangement of Ga and S atoms in the GaS, the films take the crystalline structure of the substrate [7,8]. This transformation can be used as the buffer layer especially in the GaAs semiconductor structures [11,12].…”