A highly tunable lateral quantum dot realized in InGaAs/InP by an etching technique

We report on the realization of a quantum dot in a modulation doped InGaAs/InP heterostructure by electron beam lithography and chemical wet etching. Using etched trench defined in-plane gates and a local top gate, the tunneling barriers, electron density, and electrostatic potential of the dot can be tuned. Electrical measurements reveal clear Coulomb blockade behavior of the electron transport through the dot and the behavior of electron tunneling through its excited states. (C) 2008 American Institute of Physics.