We present an investigation of vertical leakage in GaN-on-Si epitaxial stack through electrical characterization and device simulations. Different structures of increasing complexity have been fabricated and analyzed in order to achieve a complete understanding of the main transport mechanisms. We have clarified the role of the Si substrate through comparison of identical structures built on p-type and n-type Si substrates. We show that in the case of p-Si substrates the leakage current is sustained by carrier generation in the Si depletion region. We also find that experiments on structures grown on n-doped silicon are consistent with considering electron injection from the substrate through the AlN/Si barrier as the main current limiting mechanism. Our insights are supported by device simulations that consistently reproduce the experimental capacitance-voltage and current-voltage characteristics as a function of temperature for all the considered structures.

The Role of Silicon Substrate on the Leakage Current Through GaN-on-Si Epitaxial Layers

SAYADI, LUCA;G. Iannaccone;G. Fiori;CURATOLA, GILBERTO
2018-01-01

Abstract

We present an investigation of vertical leakage in GaN-on-Si epitaxial stack through electrical characterization and device simulations. Different structures of increasing complexity have been fabricated and analyzed in order to achieve a complete understanding of the main transport mechanisms. We have clarified the role of the Si substrate through comparison of identical structures built on p-type and n-type Si substrates. We show that in the case of p-Si substrates the leakage current is sustained by carrier generation in the Si depletion region. We also find that experiments on structures grown on n-doped silicon are consistent with considering electron injection from the substrate through the AlN/Si barrier as the main current limiting mechanism. Our insights are supported by device simulations that consistently reproduce the experimental capacitance-voltage and current-voltage characteristics as a function of temperature for all the considered structures.
2018
Sayadi, Luca; Iannaccone, G.; Häberlen, O.; Fiori, G.; Tomberger, M.; Knuuttila, L. O.; Curatola, Gilberto
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/909403
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 22
  • ???jsp.display-item.citation.isi??? 21
social impact