Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
748581 | Solid-State Electronics | 2012 | 5 Pages |
Germanium is an attractive channel material for MOSFETs because of its higher mobility than silicon. In this paper, GeO2 has been investigated as an interfacial layer for high-κ gate stacks on germanium. Thermally grown GeO2 layers have been prepared at 550 °C to minimise GeO volatilisation. GeO2 growth has been performed in both pure O2 ambient and O2 diluted with N2. GeO2 thickness has been scaled down to approximately 3 nm. MOS capacitors have been fabricated using different GeO2 thicknesses with a standard high-κ dielectric on top. Electrical properties and thermal stability have been tested up to at least 350 °C. The κ value of GeO2 was experimentally determined to be 4.5. Interface state densities (Dit) of less than 1012 cm−2 eV−1 have been extracted for all devices using the conductance method.
► Scaling of thermal GeO2 thickness at 550 °C using N2 dilution. ► Physical characterisation of scaled GeO2 layers. ► Fabrication and testing of high-κ gate stacks on germanium using scaled interfacial GeO2.