ATOMIC LAYER EPITAXY OF PLANAR-DOPED STRUCTURES FOR NONALLOYED CONTACTS AND FIELD-EFFECT TRANSISTOR

Atomic layer epitaxy has been used for the low-temperature deposition of planar-doped structures using organometallic sources AsH3 and H 2Se. Carrier concentration in the 1019/cm 3 range was achieved, with a sharp concentration profile comparable to the best reported for equivalent structures by molecular beam epitaxy. A set of planar-doped Se sheets, separated by 50 Å of GaAs, was used for nonalloyed contacting layers to n-GaAs films with contact resistivity in the low 10-6 Ω cm2 range. Finally, a planar-doped field-effect transistor (FET) was fabricated with planar-doped sidewall source and drain contacting layers, giving a performance comparable to that of reported planar-doped structures by other techniques. This is considered to be the first demonstration of a planar-doped FET using organometallic sources.