GaN & AlN

Research Topics

Our focus is on the development of the HVPE (hydride vapor phase epitaxy) process to grow GaN bulk crystals with 3” and 4” diameter. Furthermore, we engineer the bulk growth of AlN crystals with up to 2” diameter by use of the PVT (physical vapor transport) technique. We put special emphasis on improving the quality of the GaN & AlN crystals e.g. with respect to the reduction of structural defects.

We develop the technology to process the GaN & AlN crystals further to epi-ready wafers. Their quality is controlled in our high temperature MOCVD epi reactor. The GaN & AlN wafers are further processed to special test devices to demonstrate the superior performance and reliability of homoepitaxially grown nitride devices compared to heteroepitaxially produced ones. Therefore, we investigate the electrical performance of nitride devices and correlate their functionality and reliability with the structural and electrical properties of the epitaxial layers grown on foreign and native substrates.

In close collaboration with the University Erlangen-Nuremberg, we explore the ammonothermal growth technique for synthesis of novel nitride compounds. Here the focus is on thermodynamics and kinetics, including the development of models describing the flow, heat and species transport.

 

Services

 

Our services range from the production of GaN and AlN wafers in small quantities to providing nitride epitaxy at temperatures up to 1400°C on different substrates as well as the processing of complete nitride prototype devices.

We analyze nitride crystals and epilayers, beginning at the macroscopic scale down to the atomic level (e.g. characterization of defects on full wafer scale by x-ray topography, examination of defect-etched samples using optical microscopy, cathodoluminescence measurements within a transmission electron microscope, photoluminescence measurements, and atomic force microscopy, to name a few examples).

 

 

© Fraunhofer THM

Employee of Technology Center for Semiconductor THM Freiberg examines gallium nitride substrate.

© Fraunhofer IISB

Fraunhofer IISB is equipped with a wafering laboratory for cutting GaN & AlN crystals into wafers.

© Fraunhofer IISB

The epi ready quality of GaN & AlN wafers after grinding, polishing and cleaning is controlled in house by AlGaN epitaxy up to 1450°C.

Innovative Reliable Nitride based Power Devices and Applications

European Union funded project "InRel-Power"