AVS 52nd International Symposium
    Electronic Materials and Processing Monday Sessions
       Session EM+NS-MoM

Paper EM+NS-MoM3
Nm-Resolution Study of Various Quantum-Well Inclusions in 4H-SiC using Ballistic Electron Emission Microscopy: Quantum-Well Energy Depth and Local Transport Behavior

Monday, October 31, 2005, 9:00 am, Room 310

Session: Novel Approaches in Wide Bandgap Semiconductors
Presenter: K.-B. Park, The Ohio State University
Authors: K.-B. Park, The Ohio State University
J.P. Pelz, The Ohio State University
M. Skowronski, Carnegie Mellon University
J. Grim, Carnegie Mellon University
X. Zhang, Carnegie Mellon University
M.A. Capano, Purdue University
Correspondent: Click to Email
Thin planar inclusions with local cubic stacking can form in hexagonal SiC during device operation, processing, or growth. These have been found to behave as electron quantum wells (QWs), and strongly impact material and device property. We have used nm-resolution Ballistic Electron Emission Microscopy (BEEM)@footnote 1@ to study the electronic properties of individual "single stacking-fault (1SF)" cubic inclusions forming during p-i-n diode operation in (1 1 -2 0) oriented 4H-SiC, where the inclusions intersect a Pt Schottky Barrier (SB) interface. BEEM indicates a QW energy depth of ~0.25 eV below the host 4H-SiC for these 1SF inclusions, comparable to a previous calculated energy of ~0.22 eV@footnote 2@ and a reported ~0.282 eV energy measured by luminescence quenching.@footnote 3@ We are also currently studying inclusions of a different structure forming during CVD growth on 8° miscut n-type 4H-SiC substrates. BEEM indicates a QW energy depth of ~0.40 eV for these inclusions, between the measured ~0.25 eV depth of 1SF inclusions and the ~0.53 eV depth we previously measured on "double" SF inclusions forming during high-temperature processing@footnote 1@. We also observe that the local BEEM current amplitude and SB height on the surrounding 4H-SiC material are quite different on either side of these inclusions, possibly due to strong spontaneous polarization in 4H-SiC and/or subsurface scattering from the 8° inclined inclusion. Work supported by ONR and NSF. @FootnoteText@ @footnote 1@ Y. Ding, K. -B. Park, J. P. Pelz, K. C. Palle, M. K. Mikhov, B. J. Skromme, H. Meidia, and S. Mahajan, Phys. Rev. B 69, 041305(R) (2004).@footnote 2@ H. Iwata et al., Mater. Sci. Forum 389-393, 533 (2002).@footnote 3@ S. G. Sridhara et al., Appl. Phys. Lett. 79, 3944 (2001).