University of Twente Student Theses

Login

New physical effects induced by the PZT layer integrated in AlGaN/GaN HEMTs

Zhao, Wei (2018) New physical effects induced by the PZT layer integrated in AlGaN/GaN HEMTs.

[img] PDF
4MB
Abstract:The successful high quality epitaxial growth of a lead zirconate titanate (PZT) thin film on GaN offered available experimental samples for this research, where the physical effects of the PZT layer integrated in AlGaN/GaN HEMTs were investigated. Device simulation results indi-cate that the two-dimensional electron gas (2DEG) density at the AlGaN/GaN interface scales linearly with the polarization of PZT. It has been found how the permittivity of PZT influences the breakdown voltage depends on whether PZT is regarded as an insulator or semiconductor. PZT has been confirmed to be conducting by measurements. A deviation was observed between the two curves within a dual sweep, which can be related the difference of PZT polarization in the two opposite sweep directions. Devices with 0.52 Zr composition exhibited the largest reduction of on-resistance ( ) when the gate voltage was increased from -1.5 V to 0 V. This can be explained by the largest difference between remnant polarization ( ) and satu-ration polarization ( s) of PZT with 0.52 Zr composition. Devices with 0.52 Zr composition also showed the highest gate leakage, which can be explained by the hole induced gate leakage pro-posed in this thesis. Breakdown measurements appeared to show some improvement in our HEMTs compared to conventional counterparts reported in the literature, though more dedicated test structures are needed to analyze these more carefully.
Item Type:Essay (Master)
Faculty:EEMCS: Electrical Engineering, Mathematics and Computer Science
Subject:53 electrotechnology
Programme:Electrical Engineering MSc (60353)
Link to this item:http://purl.utwente.nl/essays/75744
Export this item as:BibTeX
EndNote
HTML Citation
Reference Manager

 

Repository Staff Only: item control page