AVS 50th International Symposium
    Electronic Materials and Devices Monday Sessions
       Session EM+SC-MoA

Paper EM+SC-MoA3
Contactless Characterization of High Electron Mobility Transistor Structures using Surface Photovoltage Spectroscopy

Monday, November 3, 2003, 2:40 pm, Room 321/322

Session: Defects and Interfaces in Electronic Materials and Devices
Presenter: S. Solodky, Tel Aviv University, Israel
Authors: S. Solodky, Tel Aviv University, Israel
A. Khramtsov, Ben-Gurion University, Israel
T. Baksht, Tel Aviv University, Israel
M. Leibovitch, Gal-El (MMIC), Israel
Hava, Ben-Gurion University, Israel
Y. Shapira, Tel Aviv University, Israel
Correspondent: Click to Email
GaN/AlGaN High Electron Mobility Transistor (HEMT), AlGaAs/InGAs/GaAs pseudomorphic HEMT (PHEMT), and InAlAs/InGaAs metamorphic HEMT (MHEMT) epitaxial structures have been characterized using surface photovoltage spectroscopy (SPS). The interplay between two opposite direction signals coming from the regions with opposite direction of electric fields define the shape of the spectra. The shape of the spectra is interpreted using self-consistent numerical simulations. The effects of the transistor delta-doping levels dtop, dbot and surface charge Qsur on the spectrum features have been studied using numerical simulations. Based on the latter, an empirical model has been developed, which allows extraction and comparison of dtop, dbot and Qsur and is applicable for both double-sided and single sided delta-doped structures. Effect of SiN passivation on GaN/AlGaN HEMT surface is shown. Applying of the model to passivated structure shows reduced Qsur. Prediction of the final device performance by the model is shown for two MHEMT structures. Applying of the model shows sensitivity of the methodology to 7.5% difference of dtop. Devices produced on these structures show relative difference of 8.2% in maximum drain currents, which correlate well with dtop values calculated using the model.