Direct observation of V-pit induced vertical ...
Type de document :
Communication dans un congrès avec actes
Titre :
Direct observation of V-pit induced vertical n-type columns disrupting vertical breakdown of AlGaN/GaN-HEMT heterostructures on Si
Auteur(s) :
Besendörfer, S [Auteur]
Fraunhofer Institute for Integrated Systems and Device Technology [Fraunhofer IISB]
Meissner, E [Auteur]
Fraunhofer Institute for Integrated Systems and Device Technology [Fraunhofer IISB]
Medjdoub, Farid [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Fraunhofer Institute for Integrated Systems and Device Technology [Fraunhofer IISB]
Meissner, E [Auteur]
Fraunhofer Institute for Integrated Systems and Device Technology [Fraunhofer IISB]
Medjdoub, Farid [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Titre de la manifestation scientifique :
13th International Conference on Nitride Semiconductors 2019 (ICNS-13)
Ville :
Seattle
Pays :
Etats-Unis d'Amérique
Date de début de la manifestation scientifique :
2019-07-07
Titre de la revue :
ICNS-13
Discipline(s) HAL :
Sciences de l'ingénieur [physics]
Résumé en anglais : [en]
High electron mobility transistors (HEMTs) based on AlGaN/GaN heterostructures on silicon are stateof-the-art commercial power devices on the basis of nitrides. Performance and reliability of suchdevices are hampered by ...
Lire la suite >High electron mobility transistors (HEMTs) based on AlGaN/GaN heterostructures on silicon are stateof-the-art commercial power devices on the basis of nitrides. Performance and reliability of suchdevices are hampered by the presence of various defects. However, the relation between the natureof those defects and device characteristics is often not understood from a microstructural and physicalpoint of view. In this work we compare two nominally identical HEMT layer stacks that were grownunder different nucleation conditions, but differ significantly in vertical breakdown voltage. By defectselective etching it is shown that this phenomenon is not due to a different dislocation density. Insteada Conductive Atomic Force Microscopy study reveals locally strong electrical conductivity within thebuffer, which results in the formation of discrete vertical leakage paths that were identified tocorrespond to V-shaped defects at interfaces of the layer stack, also called V-pits. A detailed analysisby Cathodoluminescence (CL) mappings and CL-spectroscopy allows an identification of V-pits actingas centers of strongly reduced carbon and increased donor incorporation. Depending on growthconditions of the nucleation layer V-pits within the buffer occure in different sizes and densities acrossthe structure. The V-pits are closed by overgrowth sooner or later and are filled by the material of thefollowing layer. If such pits reach the upper buffer region, column-like areas of locally higher n-typebehavior are formed and disrupt the vertical device breakdown strength. The breakdown voltage isshown to be strongly dependent on the density of those V-pit induced n-type columns underneath theactive device region. An optimized nucleation layer growth was able to enhance the breakdownvoltage by nearly 600V.Lire moins >
Lire la suite >High electron mobility transistors (HEMTs) based on AlGaN/GaN heterostructures on silicon are stateof-the-art commercial power devices on the basis of nitrides. Performance and reliability of suchdevices are hampered by the presence of various defects. However, the relation between the natureof those defects and device characteristics is often not understood from a microstructural and physicalpoint of view. In this work we compare two nominally identical HEMT layer stacks that were grownunder different nucleation conditions, but differ significantly in vertical breakdown voltage. By defectselective etching it is shown that this phenomenon is not due to a different dislocation density. Insteada Conductive Atomic Force Microscopy study reveals locally strong electrical conductivity within thebuffer, which results in the formation of discrete vertical leakage paths that were identified tocorrespond to V-shaped defects at interfaces of the layer stack, also called V-pits. A detailed analysisby Cathodoluminescence (CL) mappings and CL-spectroscopy allows an identification of V-pits actingas centers of strongly reduced carbon and increased donor incorporation. Depending on growthconditions of the nucleation layer V-pits within the buffer occure in different sizes and densities acrossthe structure. The V-pits are closed by overgrowth sooner or later and are filled by the material of thefollowing layer. If such pits reach the upper buffer region, column-like areas of locally higher n-typebehavior are formed and disrupt the vertical device breakdown strength. The breakdown voltage isshown to be strongly dependent on the density of those V-pit induced n-type columns underneath theactive device region. An optimized nucleation layer growth was able to enhance the breakdownvoltage by nearly 600V.Lire moins >
Langue :
Anglais
Comité de lecture :
Oui
Audience :
Internationale
Vulgarisation :
Non
Source :