1. University of Alabama Micro-Fabrication Facility (UA-MFF), Tuscaloosa, Alabama 35487, USA
2. Center for Materials for Information Technology (MINT), University of Alabama, Tuscaloosa, Alabama 35487, USA
3. Department of Metallurgical and Materials Engineering, University of Alabama, Tuscaloosa, Alabama 35487, USA
4. Department of Electrical and Computer Engineering, University of Alabama, Tuscaloosa, Alabama 35487, USA