1.09-eV Schottky barrier height of nearly ideal Pt/Au contacts directly deposited on n- and p+n-Al0.48In0.52As layers

Abstract

Pt/Au Schottky contacts on AlInAs lattice-matched to InP have been fabricated using effective cleaning of the semiconductor surface with low-energy (30 eV) Ar+ ions prior to the metal deposition. A short-time annealing of the contacts at moderate elevated temperatures in the range of 230 to 430 °C was employed in order to eliminate eventual postbombardment defects. Subsequently, an increase of the effective Schottky barrier height from 0.85 to 1.09 eV was observed. This improvement is probably due to the heteroalignment between PtAs2 and AlAs phases which easily appears if intimate contacts are considered. Conventionally prepared wafers (without ion-beam treatment) exhibit a barrier height of 0.82 eV which remains unchanged during annealing. The initial breakdown voltage in ion-etched samples rises from −18 to −28 V and the reverse current density at −10 V diminishes by more than two orders to less than 8×10−7 A cm−2. An ideality factor n very close to unity was obtained from the slope of forward current-voltage characteristics of contacts to homogeneously and shallow Zn-doped substrates.

Thermal annealing of Pd/InAlAs Schottky contacts for transistor buried-gate technologies

“…[4][5][6][7] These studies, however, were mainly concerned with the stability of the Schottky barriers and characterizing their electrical property changes due to annealing. In order to use buriedgate technology for the InAlAs/InGaAs/InP system, a thorough understanding of the reaction of the metal/InAlAs interface and its evolution during annealing is needed.…”

Investigation of impact ionization and flicker noise properties in indium aluminum arsenide/indium gallinum arsenide metamorphic high electron mobility transistors with various work function-gate metals

“…The metals that have previously been studied as gate metals include Ti [11][12][13][14], Pt [15][16][17] Pd [11,12,18], and Ir [19][20][21]. Pt exhibits the highest SBH (Schottky barrier height) Z0.8 eV on InAlAs, and has been widely used for the enhanced mode HEMT process.…”

0.3-μm gate-length enhancement mode InAlAs/InGaAs/InP high-electron mobility transistor

“…However, development of E-HEMT technology on InP has been hampered by the inability to achieve sufficiently large gate-Schottky barrier heights on InAlAs. Platinum contacts have shown promise for the Schottky metal with reported barrier heights of 1.09 eV [3]. To date, attempts to realize E-HEMT's on lattice-matched InPbased heterostructures using Pt gates have achieved modest success [4], [5].…”