IN-PLANE-GATE (IPG) TRANSISTORS can be excavated using nanomachining techniques. IPG transistors, in which the source, drain, and gate all lie in a plane rather than in a sandwich, might be especially useful for high-frequency applications. Scientists at the University of Hannover (Hans Werner Schumacher, 011-49-511-762-2523, schumach@nano.uni-hannover.de) have carved out an IPG structure in a semiconductor surface using the probe from an atomic force microscope (see figure at Physics News Graphics). The probe makes an incision into the material extending down about halfway toward a buried interface where, lodged between GaAs and AlGaAs layers, a reservoir of electrons is confined to a plane. The incisions from above do not penetrate into this two-dimensional electron gas (2DEG) but they do shape (and can even pinch off) the conduction of the electrons. The Hannover researchers have also used their inscribing approach to make single-electron transistors (SETs), devices that register the coming and going of single electrons. (Schumacher et al., Applied Physics Letters, 23 August 1999.)