Effects of postgate dielectric treatment on germanium-based metal-oxide-semiconductor device by supercritical fluid technology

Abstract

Supercritical fluid ͑SCF͒ technology is employed at low temperature as a postgate dielectric treatment to improve gate SiO 2 /germanium ͑Ge͒ interface in a Ge-based metal-oxide-semiconductor ͑Ge-MOS͒ device. The SCF can transport the oxidant and penetrate the gate oxide layer for the oxidation of SiO 2 / Ge interface at 150°C. A smooth interfacial GeO 2 layer between gate SiO 2 and Ge is thereby formed after SCF treatment, and the frequency dispersion of capacitance-voltage characteristics is also effectively alleviated. Furthermore, the electrical degradation of Ge-MOS after a postgate dielectric annealing at 450°C can be restored to a extent similar to the initial state.

An Ultralow EOT Ge MOS Device With Tetragonal HfO₂ and High Quality Hf_{<italic>x</italic>}Ge_{<italic>y</italic>}O Interfacial Layer

“…The area percentage of Ge 4+ for samples with H 2 O plasma and H 2 O 2 solution treatments are 73% and 58%, respectively. Both of them are higher than those reported in [30]. This is because the oxidation ability of H 2 O plasma and H 2 O 2 solution at high temperature is high.…”

“…Hence, the lower oxidation states Ge x (substoichiometric GeO x or Hf x Ge y O) with unstable phase are fewer for sample with IL formed by H 2 O plasma treatment. The Ge 4+ composition was calculated by comparing the XPS peak areas under the deconvoluted curves [2], [30]. The area percentage of Ge 4+ for samples with H 2 O plasma and H 2 O 2 solution treatments are 73% and 58%, respectively.…”

Performance Enhancement for Tungsten-Doped Indium Oxide Thin Film Transistor by Hydrogen Peroxide as Cosolvent in Room-Temperature Supercritical Fluid Systems

“…27,28 In addition, it is reported that the tiny liquid water can be dissolved as cosolvent in the SCCO 2 fluid and also reach the supercritical phase under a relatively simple condition, which may exhibit an unanticipated oxidation ability. 29 However, most of the SCF applications applied for the oxide TFTs are focusing on the improvement of device reliability, 30,31 and this oxidant and cosolvent effect of highmobility materials has not been discussed yet.…”

“…In general, supercritical-phase fluid (SCF) treatment was used to improve the performance of dielectric properties in resistive random-access memory or passivate defect states in the hydrogenated amorphous silicon TFT without any process damage. − With a special high-pressure system, the supercritical-phase carbon dioxide (SCCO 2 ) can even be achieved around room temperature, which is unique due to the characteristics of high liquid-like solubility and a strong gas-like penetration ability. , In addition, it is reported that the tiny liquid water can be dissolved as cosolvent in the SCCO 2 fluid and also reach the supercritical phase under a relatively simple condition, which may exhibit an unanticipated oxidation ability . However, most of the SCF applications applied for the oxide TFTs are focusing on the improvement of device reliability, , and this oxidant and cosolvent effect of high-mobility materials has not been discussed yet.…”