Field-effect transistor based on KTaO<sub>3</sub> perovskite

May 01, 2004
FET

Solid state devices based on transition metal oxides, especially with perovskite related structure, are very promising candidates for the next generation electronics due to their rich variety of functions such as superconductivity, ferroelectricity, and colossal magnetoresistance.
K. Ueno et al. from Correlated Electron Research Center (CERC) in Japan report in the last issue of Applied Physics Letters (Vol. 84, No. 19, pp. 3726–3728 ) about fabrication of an n-channel accumulation-type field-effect transistor utilizing a KTaO3 single crystal as an active element and a sputtered amorphous Al2O3 film as a gate insulator.
The device demonstrated an ON/OFF ratio of 104 and a field-effect mobility of 0.4 cm2/V s at room temperature, both of which are much better than those of the SrTiO3 FETs reported previously.

The field-effect transistor (FET) is the most fundamental device among all solid state devices based on transition metal oxides, and thus the fabrication of FETs using perovskite-related oxides for conducting channels is a first step in a large movement towards oxide electronics.
Nevertheless, only a small number of perovskite FETs with relatively low mobilities have been reported so far.

KTaO3, an n-type semiconductor with a band gap of 3.8 eV, which, in single crystalline form, exhibits a relatively higher mobility of 30 cm2/V s at room temperature than other perovskites.

The FET fabricated on the heat-treated surface of a KTaO3 single crystal showed accumulation-type behavior and reproducible n-channel transistor characteristics with a field-effect mobility more than 0.4 cm2/V s and an ON/OFF ratio greater than 104 at room temperature.
The field-effect mobility was almost temperature independent down to 200 K. These results indicate that the Al2O3/KTaO3 interface is worthy of further investigations as an alternative system of future oxide electronics.

Authors have demonstrated that KTaO3 is one of the most promising materials for perovskite FET technology. This strongly inspires future research into oxide electronics.

Explore further: BofA to refund Apple Pay customers charged twice

add to favorites email to friend print save as pdf

Related Stories

Comet Siding Spring whizzes past Mars

2 hours ago

A comet the size of a small mountain whizzed past Mars on Sunday, dazzling space enthusiasts with the once-in-a-million-years encounter.

Major breakthrough could help detoxify pollutants

7 hours ago

Scientists at The University of Manchester hope a major breakthrough could lead to more effective methods for detoxifying dangerous pollutants like PCBs and dioxins. The result is a culmination of 15 years of research and ...

Recommended for you

Nokia turnaround since handset unit sale continues

1 hour ago

Nokia appears to have turned around its fortunes after the sale of its ailing cellphone unit to Microsoft, reporting a third-quarter net profit of 747 million euros ($950 million), from a loss of 91 million euros a year earlier. ...

Yahoo CEO defends strategy in face of criticism

2 hours ago

Signaling her reign has reached a pivotal juncture, Yahoo CEO Marissa Mayer is trying to convince restless shareholders that the long-struggling Internet company is heading in the right direction.

Sk Hynix logs all-time high Q3 earnings

2 hours ago

SK Hynix, the world's second-largest memory chip maker, reported Thursday a record high quarterly net profit for the three months to September on strong sales and currency earnings.

User comments : 0