Method for preparing ultra-thin germanium oxide interface repairing layer on Ge substrate

Abstract

The invention discloses a method for preparing an ultra-thin germanium oxide interface repairing layer on a Ge substrate. The method comprises the steps of: selecting a Ge substrate, removing a natural oxide layer on the surface of the Ge substrate, then transferring the Ge substrate in a cavity of an atomic layer deposition system, and depositing a layer of Al2O3 film on the surface of the Ge substrate to serve as an O2 barrier layer in a thermal oxidation process; placing the Ge substrate with the Al2O3 film deposited on the surface thereof into a rapid annealing furnace, and forming an ultra-thin GeOx interface layer at an Al2O3 / Ge interface by utilizing a thermal oxidization way in an O2 atmosphere; placing the Ge substrate with the ultra-thin GeOx interface layer formed at the Al2O3 / Ge interface into the atomic layer deposition reaction cavity, and depositing a high-k gate medium on the Al2O3 film; after grate medium deposition is carried out successively, performing annealing and low-temperature oxygen annealing by utilizing the rapid annealing furnace to further improve the quality of the oxide gate medium and improve the quality of the k-medium / Al2O3 / GeOx / Ge interface. The method is also applicable to a Ge-based MOS (Metal Oxide Semiconductor), an MOSFET (Metal-Oxide -Semiconductor Field Effect Transistor) and other devices including a Ge-based gate laminated layer.

Description

technical field [0001] The invention relates to the field of semiconductor technology, in particular to a method for preparing ultra-thin germanium oxide (GeO) on a Ge substrate. x ) interface repair layer method. Background technique [0002] Germanium (Ge) has been extensively studied as the most promising substrate material for metal-oxide-semiconductor transistors (MOSFETs) in recent years. Compared with silicon, germanium has a high carrier mobility, and its drive current is small, which is suitable for low-temperature processes. In order to realize high-performance small-sized Ge-based MOSFETs, high-k gate stacks must have low interface state density and effectively passivated interface layers. A special interfacial layer is required at the interface of the high-k gate dielectric / Ge as a diffusion barrier layer to prevent the interface reaction between the high-k metal oxide and the Ge substrate under heat treatment conditions. The reported methods of interface pass...

AI Technical Summary

Problems solved by technology

GeO obtained by traditional thermal oxidation x The thickness of the film is usually very large, which is not conducive to achieving a low equivalent oxide thickness (EOT)

Images