Patent Number: 052987590
Section: abstract

Ultraviolet (UV) light from a lamp (12) or laser (38) is provided for cracking Group V and Group VI species comprising clusters (dimers and tetramers) or metal-organic molecules to form monomers (atoms). The UV radiation interacts with a molecular beam (14) of Group V and Group VI species following their generation in a source cell (16), which may be an effusion source in molecular beam epitaxy (MBE) apparatus, a thermal cracker cell in gas-source MBE apparatus, or a gas injector cell in metal-organic MBE apparatus (MOMBE). As configured, the UV light source and associated elements comprise a unit, termed herein a "photo-cracker cell" (10). The photo-cracker cell includes an elliptical reflective cavity (18), which defines two foci. The source of UV light is located along one focus and the path of the molecular beam is located along the other focus substantially parallel thereto. The photo-cracker cell may be provided on existing MBE or MOMBE apparatus, between the present source cell and the growth chamber (36) in which III-V, IV, and II-VI semiconductor layers on substrates are deposited.