GROWTH OF GaAs AND GaAlAs IN MOLECULAR BEAM EPITAXY
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
The optimum growth temperature by molecular beam epitaxy (MBE) of gallium aluminum arsenide (GaAlAs) is 700ŒC, which is not compatible with the growth of gallium arsenide (GaAs) which may be grown at 600ŒC. In heterojunction devices, an abrupt change of materials may be structurally desirable. The substrate temperature cannot be changed abruptly. Interruption of growth is generally not practiced due to accumulation of impurities at the interface in the pause period. A compatible situation is achieved where the substrate temperature is maintained at 600ŒC, but the growth rate is reduced from the normal 1 mm/h to N 0.1 mm/h. At this growth rate, the GaAlAs grows smoothly with the grown material exhibiting very sharp photoluminescence features and an exciton peak with width of N 4 meV.