System for developing a nitrogen-containing active region
Systems produce flattening layers associated with nitrogen-containing quantum wells and prevent 3-D growth of nitrogen containing layers using high As fluxes. MEE (Migration Enhanced Epitaxy) is used to flatten layers and enhance smoothness of quantum well interfaces and to achieve narrowing of the spectrum of light emitted from nitrogen containing quantum wells. MEE is performed by alternately depositing single atomic layers of group III and V before, and/or after, and/or in-between quantum wells. Where GaAs is used, the process can be accomplished by alternately opening and closing Ga and As shutters in an MBE system, while preventing both from being open at the same time. Where nitrogen is used, the system incorporates a mechanical means of preventing nitrogen from entering the MBE processing chamber, such as a gate valve. The gate valve allows the nitrogen source to be completely cut-off from the chamber during non-nitrogen processing steps.
1 . A system for developing an active region containing nitrogen, comprising:
a semiconductor wafer processing chamber;
at least one material source line coupled to said semiconductor wafer processing chamber, wherein said at least one material source line carries semiconductor processing material into said semiconductor wafer processing chamber, wherein said semiconductor material includes group III and group V constituents;
at least one shutter associated with each of said at least one material source line and located inside said semiconductor wafer processing chamber;
a nitrogen source line coupled to said semiconductor wafer processing chamber, said nitrogen source line for providing nitrogen into said semiconductor wafer processing chamber; and
a gate valve located on said nitrogen source line, said gate valve for blocking nitrogen from entering said semiconductor wafer processing chamber when deployed to a closed position;
wherein at least one nitrogen-free layer can be grown within said semiconductor wafer processing chamber by operating said at least one shutter associated with each of said more than one material source lines to alternately deposit single atomic layers of said group III and group V constituents while said gate valve is deployed.
2 . A system as defined in claim 1 , wherein said material source lines provide Ga, As, In, Sb, P and Al.
3 . A system as defined in claim 1 , further comprising a molecular beam epitaxy processing system.
4 . A system as defined in claim 1 , further comprising a metal-organic chemical vapor disposition processing system.
5 . A system as defined in claim 1 , further comprising a metal-organic vapor phase epitaxy processing system.
6 . A system as defined in claim 1 , further comprising a microprocessor-based system for operating all or part of the MBE system by performing one or more acts selected from the group consisting of: executing programmed processing instructions, collecting measured data from measurement transducers, providing and maintain processing control, report creation, and data/software storage.