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Title: Oxygen and germanium migration at low temperature influenced by the thermodynamic nature of the materials used in germanium metal-insulator-semiconductor structures

The influence of the reductive character of the metals used for the gate electrode on O migration in gate stacks and following reductive or oxidative reactions at an interface between a high permittivity (high-k) insulating layer and Ge or Si was investigated. The magnitude of the increase or decrease of Ge or Si oxides in the gate stacks caused by the metal layer deposition can be systematically correlated with the oxygen chemical potential (μ{sub O}) of gate metals for both Ge and Si systems. However, the influence of the gate metals on oxidative/reductive reactions of a semiconductor element is more significant for the Ge gate stacks than the Si system. Detailed investigations of Ge oxide as a function of depth were used to determine that the strong μ{sub O} dependence of the increase or decrease in the Ge oxide is because of the high diffusivity of Ge into the high-k oxide. In particular, migration of Ge into the high-k oxide occurs concurrently with O migration towards the reductive metal layer, and the strong reductive character of the metal significantly influences the decrease in the amount of Ge oxide. These results indicate the importance of the selection of gate metals basedmore » on μ{sub O} for controlling high-k/Ge interfacial structures.« less
Authors:
; ; ; ;  [1]
  1. Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)
Publication Date:
OSTI Identifier:
22482034
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DEPOSITION; DEPTH; ELECTRODES; GERMANIUM; INTERFACES; LAYERS; MIGRATION; OXIDATION; OXIDES; OXYGEN; PERMITTIVITY; SEMICONDUCTOR MATERIALS; STACKS