Investigation on the passivation, band alignment, gate charge, and mobility degradation of the Ge MOSFET with a GeO _x /Al₂O₃ gate stack by ozone oxidation

Abstract

Ge has been an alternative channel material for the performance enhancement of complementary metal–oxide–semiconductor (CMOS) technology applications because of its high carrier mobility and superior compatibility with Si CMOS technology. The gate structure plays a key role on the electrical property. In this paper, the property of Ge MOSFET with Al2O3/GeO x /Ge stack by ozone oxidation is reviewed. The GeO x passivation mechanism by ozone oxidation and band alignment of Al2O3/GeO x /Ge stack is described. In addition, the charge distribution in the gate stack and remote Coulomb scattering on carrier mobility is also presented. The surface passivation is mainly attributed to the high oxidation state of Ge. The energy band alignment is well explained by the gap state theory. The charge distribution is quantitatively characterized and it is found that the gate charges make a great degradation on carrier mobility. These investigations help to provide an impressive understanding and a possible instructive method to improve the performance of Ge devices.

In situ Synthesis of S‐scheme Polymer Heterojunction Poly(phenyl‐1,3,5‐yl)‐benzene)/g‐C3N4 Composites for Efficient Removal of Rhodamine B

“…[7][8][9] At present, the common removal organic pollutants methods include adsorption, biodegradation and advanced oxidation processes (AOPs). AOPs are widely used in the removal of pollutants because of their high degree of oxidation and good degradation effect, AOPs can be divided into ozone oxidation, [10,11] photocatalytic oxidation (UV, visible light), [12][13][14] Fenton oxidation (homogeneous, heterogeneous) [15,16] and any combination of them. [15,17] In recent years, the photo Fenton process, which combines photocatalysis and Fenton process, has become a research hotspot of AOPs because of its strong oxidation ability and high utilization efficiency of oxidants.…”

Oxygen vacancy related hole fast trapping in high mobility cubic-Ge/ZrO2 interface

“…It offers nearly four times higher hole mobility than Si (1900-500 cm 2 Vs −1 ), so Ge FETs are of great interest for high-carrier innovative devices [3]. However, unlike SiO 2 , GeO 2 cannot be the highquality and insulating natural interface layer [4][5][6]. Recent studies have shown that the dielectric constant (k) of cubic zirconia with space group Fm 3m (c-ZrO 2 ) can be as high as 37 compared with amorphous and monoclinic ZrO 2 , due to the higher symmetry and smaller molar volume [7][8][9][10][11].…”