Rutile-type Ge _x Sn_1−x O₂ alloy layers lattice-matched to TiO₂ substrates for device applications

Abstract

We report the characterization and application of mist-CVD-grown rutile-structured Ge x Sn1−x O2 (x = ∼0.53) films lattice-matched to isostructural TiO2(001) substrates. The grown surface was flat throughout the growth owing to the lattice-matching epitaxy. Additionally, the film was single-crystalline without misoriented domains and TEM-detectable threading dislocations due to the coherent heterointerface. Using the Ge0.49Sn0.51O2 film with a carrier density of 7.8 × 1018 cm−3 and a mobility of 24 cm2V−1s−1, lateral Schottky barrier diodes were fabricated with Pt anodes and Ti/Au cathodes. The diodes exhibited rectifying properties with a rectification ratio of 8.2 × 104 at ±5 V, showing the potential of Ge x Sn1-x O2 as a practical semiconductor.

Carrier density control of Sb-doped rutile-type SnO2 thin films and fabrication of a vertical Schottky barrier diode

“…1) Recently, it was also reported that r-Ge x Sn 1−x O 2 films could be grown coherently on r-TiO 2 substrates without misoriented domains and TEMdetectable threading dislocations in the films. 14) The quality of the coherent films is high enough to fabricate Schottky barrier diodes (SBDs) with high rectification ratios, demonstrating the potential of r-Ge x Sn 1−x O 2 alloys as practical power semiconductors. 14) At present, however, power-electronic applications of r-GeO 2 , r-SnO 2 , and r-Ge x Sn 1−x O 2 alloy have been limited due to the difficulty in doping control.…”

“…14) The quality of the coherent films is high enough to fabricate Schottky barrier diodes (SBDs) with high rectification ratios, demonstrating the potential of r-Ge x Sn 1−x O 2 alloys as practical power semiconductors. 14) At present, however, power-electronic applications of r-GeO 2 , r-SnO 2 , and r-Ge x Sn 1−x O 2 alloy have been limited due to the difficulty in doping control. It is well known that several n-type oxides, i.e.…”