SiGe Esaki tunnel diodes fabricated by UHV-CVD growth and proximity rapid thermal diffusion

A process for realisation of SiGe Esaki diodes in layers grown by ultra-high vacuum chemical vapour deposition has been developed and the first Esaki diodes are reported for this growth method. Intrinsic SiGe-layers are grown on highly boron-doped p(+)-Si layers, while post-growth proximity rapid thermal diffusion of phosphorous into the SiGe is employed to form an n(+)-layer. Tunnel diodes with a depletion layer width of about 6 nm have been realised in Si0.74Ge0.26, showing a peak current density of 0.18 kA/cm(2) and a current peak-to-valley ratio of 2.6 at room temperature.