Submicrometer Process and RF Operation of InAs Quantum Hot-Electron Transistors

Abstract

The fabrication process of a hot-electron unipolar transistor with vertical transport based on InAs material is reported. Devices with an emitter width of 0.3 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$</tex></formula> are fabricated and characterized. This submicrometer geometry allowed suppressing parasitic resistances and achieving high-current densities required for high-frequency operation. For the first time, for a hot-electron transistor, RF performances were achieved at room temperature. Cutoff frequencies of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$f_{t} = \hbox{75}\ \hbox{GHz}$</tex></formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$f_{\max} = \hbox{88}\ \hbox{GHz}$</tex></formula> were obtained on devices transferred on an insulating substrate.