Solid state: Molecular beam epitaxy: Streams of molecules in a vacuum chamber build devices ‘from the atom up’

After years of research, molecular beam epitaxy (MBE), a process for forming thin, single-crystal semiconductor structures in an ultrahigh vacuum, is beginning to pay dividends. Microwave field-effect transistors, semiconductor lasers, millimeter-wave detectors, and a variety of other high-performance devices have been made from the multilayer crystals grown by the process. A greater variety of devices and still higher performance can be expected.