1. Monolithic integration of patterned BaTiO3 thin films on Ge wafers
- Author
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Agham Posadas, Anne-Marie Kelleher, Alexander A. Demkov, Mary Anne White, Dan O'Connell, Ray Duffy, Michael Schmidt, Paul K. Hurley, and Patrick Ponath
- Subjects
Materials science ,Ferroelectricity ,Thin films ,02 engineering and technology ,Epitaxy ,01 natural sciences ,Electron diffraction ,Etching (microfabrication) ,0103 physical sciences ,Materials Chemistry ,Wafer ,Electrical measurements ,Electrical and Electronic Engineering ,Thin film ,Instrumentation ,010302 applied physics ,business.industry ,Process Chemistry and Technology ,Semiconductor device design ,021001 nanoscience & nanotechnology ,X-ray diffraction ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Optoelectronics ,0210 nano-technology ,business ,Molecular beam epitaxy - Abstract
Titanates exhibit electronic properties highly desirable for field effect transistors such as very high permittivity and ferroelectricity. However, the difficulty of chemically etching titanates hinders their commercial use in device manufacturing. Here, the authors report the selective area in finestra growth of highly crystalline BaTiO3 (BTO) within photolithographically defined openings of a sacrificial SiO2 layer on a Ge (001) wafer by molecular beam epitaxy. After the BaTiO3 deposition, the sacrificial SiO2 can be etched away, revealing isolated nanoscale gate stacks circumventing the need to etch the titanate thin film. Reflection high-energy electron diffraction in conjunction with scanning electron microscopy is carried out to confirm the crystallinity of the samples. X-ray diffraction is performed to determine the out-of-plane lattice constant and crystal quality of the BTO film. Electrical measurements are performed on electrically isolated Pt/BaTiO3/SrTiO3/Ge capacitor devices.Titanates exhibit electronic properties highly desirable for field effect transistors such as very high permittivity and ferroelectricity. However, the difficulty of chemically etching titanates hinders their commercial use in device manufacturing. Here, the authors report the selective area in finestra growth of highly crystalline BaTiO3 (BTO) within photolithographically defined openings of a sacrificial SiO2 layer on a Ge (001) wafer by molecular beam epitaxy. After the BaTiO3 deposition, the sacrificial SiO2 can be etched away, revealing isolated nanoscale gate stacks circumventing the need to etch the titanate thin film. Reflection high-energy electron diffraction in conjunction with scanning electron microscopy is carried out to confirm the crystallinity of the samples. X-ray diffraction is performed to determine the out-of-plane lattice constant and crystal quality of the BTO film. Electrical measurements are performed on electrically isolated Pt/BaTiO3/SrTiO3/Ge capacitor devices.
- Published
- 2018
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