STATE-OF-THE-ART CONTROL OF GROWTH OF SUPERLATTICES AND QUANTUM-WELLS

In optoelectronics as well as in electronic devices, the application o f low dimensional heterostructures is a core element for obtaining cer tain effects (two-dimensional electro gas; quantum size) or improvemen ts in performance. In this contribution, we will present low pressure metal-organic vapour phase epitaxy (MOVPE) processes and the related r eactor design for medium-, large-, and very-large-scale production of III-V semiconductor structures. The application for low-dimensional st ructure growth will be addressed with examples from industrial and res earch applications. A vital example for multiple application of low di mensional structures is vertical cavity surface emitting lasers (VCSEL s). The design of the Bragg reflectors, the cavity, and accurate and r eproducible growth are crucial for the laser performance. The control of composition in the active part of the laser as well as the film thi ckness of the quantum wells used influence the emission wavelength and threshold current of the lasers. A variety of AlGaInP-based VCSEL str uctures will be discussed with particular emphasis on the effects of t he low dimensions of the structures while extremely high reproducibili ty within the vertical design of the structures is required. The MOVPE process technology has been scaled up successfully from the single 2 in wafer growth chamber to multiple 4 in substrate size reactor. The a pplication of the Planetary Reactor(R) technology in superlattice and quantum well growth has already been industrialized by various laborat ories and production facilities in GaAs/AlGaAs and GaInP/AlGaInP laser technology.