State-of-the-art control of growth of superlattices and quantum wells

In optoelectronics as well as in electronic devices, the application of low dimensional heterostructures is a core element for obtaining certain effects (two-dimensional electro gas, quantum size) or improvements in performance. In this contribution, we will present low pressure metal-organic vapour phase epitaxy (MOVPE) processes and the related reactor design for medium-, large-, and very-large-scale production of III–V semiconductor structures. The application for low-dimensional structure growth will be addressed with examples from industrial and research applications. A vital example for multiple application of low dimensional structures is vertical cavity surface emitting lasers (VCSELs). The design of the Bragg reflectors, the cavity, and accurate and reproducible growth are crucial for the laser performance. The control of composition in the active part of the laser as well as the film thickness of the quantum wells used influence the emission wavelength and threshold current of the lasers. A variety of AlGalnP-based VCSEL structures will be discussed with particular emphasis on the effects of the low dimensions of the structures while extremely high reproducibility 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 application of the Planetary Reactor® technology in superlattice and quantum well growth has already been industrialized by various laboratories and production facilities in GaAsAlGaAs and GalnPAlGalnP laser technology.