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

Abstract

We studied the thermal reaction of Pd/In0.52Al0.48As contacts using capacitance–voltage (C–V), current–voltage, Auger electron spectroscopy, and x-ray diffraction analyses and compared the results to those for Pd/Al0.25Ga0.75As and Pd/In0.53Ga0.47As contacts. The thickness of InAlAs consumed by the reaction during annealing was calculated directly from the measured C–V profiles. Pd starts to react with InAlAs at a temperature of 100 °C, lower than it does with AlGaAs. For thermally annealed Pd/InAlAs and Pd/AlGaAs, both compositional and structural changes were found at the Pd/semiconductor interface. However, in heat-treated Pd/InGaAs samples, compositional changes but no structural changes were observed.

Thermally stable In0.7Ga0.3As/In0.52Al0.48As pHEMTs using thermally evaporated palladium gate metallization

“…More importantly, the continuous diffusion of Pt is also a concern as device performance might degrade during successive heat treatment processes or during high-power operation [6]. In contrast, the diffusion of Pd saturates after thermal annealing [11]. Pd buried gate on InGaAs-AlGaAs structure has been extensively studied in the past, while there has only been a limited amount of works conducted on the InGaAs-InAlAs structure until recently [15].…”

“…The Ti-gate device showed B = 0.56 eV and n = 1.59 when compared to the 5 nm and 10 nm Pd-gate devices which have B = 0.58 eV and B = 0.59 eV and n = 1.58 and n = 1.57, respectively. The increased B and n for the Pd-gate devices are attributed to the break-down of native oxides on the InAlAs surface during the heat treatment [11], therefore, leading to the reduction of off-state leakage.…”

Temperature-dependent hydrogen sensing characteristics of a new Pt/InAlAs Schottky diode-type sensor

“…Researches on this ternary compound semiconductor were focused on In 0.52 Al 0.48 As whose lattice constant is matched to InP as well as In 0.53 Ga 0.47 As materials [4,5]. The detailed characteristics of these In 0.52 Al 0.48 As Schottky diodes with different metals were also extensively studied [5][6][7]. However, little has been published regarding the In 0.52 Al 0.48 As material system for microsensor application.…”

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.…”