Ultrathin Amorphous <i>p</i>-Type Tellurium Oxide Films Enabled by Cryogenic Deposition.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41701519.
- Also identified by DOI 10.1021/acsnano.5c19884.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Amorphous <i>n</i>-type metal oxides, such as In<sub>2</sub>O<sub>3</sub> and Indium Gallium Zinc Oxide (IGZO), have shown promise as back-end-of-line (BEOL) compatible transistors, potentially offering a new paradigm for monolithic 3D stacking. However, a high-performance <i>p</i>-type counterpart remains a critical bottleneck. Tellurium suboxide (TeO<sub><i>x</i></sub>) has recently been shown to be a promising <i>p</i>-type semiconductor for BEOL applications. Yet, it remains to be seen if sub-10 nm TeO<sub><i>x</i></sub> films, needed for practical device applications, can be achieved with acceptable hole mobilities. Here, we report ultrathin TeO<sub><i>x</i></sub> transistors fabricated via cryogenic thermal evaporation at a substrate temperature of -80 °C. This low-temperature process suppresses crystallization and surface diffusion, yielding ultrasmooth films with root-mean-square roughness as low as 4 Å. The back-gated TeO<sub><i>x</i></sub> transistors achieve an on/off current ratio of 10<sup>5</sup> and a field-effect mobility of 2.8 cm<sup>2</sup> V<sup>-1</sup> s<sup>-1</sup> at a channel thickness of 5.5 nm, retaining <i>p</i>-type switching behavior down to 2.4 nm. Selenium alloying further enhances the on/off current ratio by an order of magnitude while enabling bandgap tuning without compromising mobility.