(Invited) Epitaxial Transition Metal Nitrides for III-Nitride Devices - Application for Epitaxial Lift-Off and Transfer
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-09-01 |
| Journal | ECS Meeting Abstracts |
| Authors | Brian P. Downey, David J. Meyer, D. S. Katzer, Neeraj Nepal, Virginia D. Wheeler |
| Institutions | United States Naval Research Laboratory, National Postdoctoral Association |
Abstract
Section titled āAbstractāIntegration of epitaxial metallic layers within a semiconductor device structure has long been desired for a variety of applications; however, the practical realization of this goal has remained elusive. We have recently demonstrated the epitaxial growth of a transition metal nitride, Nb 2 N, on 6H-SiC substrates using plasma-assisted molecular beam epitaxy [1]. The films, ranging from 4 to 100 nm in thickness, exhibited single phase, sub-nm rms roughness, and low resistivity. Furthermore, high quality III-nitride layers can be grown on the Nb 2 N/SiC templates, either in a continuous growth run or after removing and re-loading the Nb 2 N/SiC template [2], without observable reaction between any of the layers. III-nitride material quality has been verified by growing a high-electron-mobility transistor (HEMT) device structure on a Nb 2 N/SiC template, achieving a two-dimensional electron gas (2DEG) mobility of 1400 cm 2 /V-s, a sheet carrier density of 1.2x10 13 cm -2 , and a maximum drain current in excess of 1 A/mm [3]. One unique application of this HEMT/Nb 2 N/SiC structure is utilizing the Nb 2 N layer as a sacrificial release layer for HEMT lift-off and transfer to alternative substrates of interest [4]. We have found that the intact HEMT structure can be released from the substrate without observable degradation of the 2DEG electrical properties by selective etching of the buried Nb 2 N layer using XeF 2 vapor phase etching [3]. This process opens the door for the integration of GaN devices with various other technological platforms (heterogeneous integration) or onto alternative substrates such as plastic or diamond. Additionally, this process could allow for the reuse of SiC substrates after device lift-off. This presentation will focus on the materials development of epitaxial Nb 2 N layers and their use as a sacrificial release layer for III-nitride device transfer from SiC substrates. [1] D.S. Katzer et al., Appl. Phys. Express, vol. 8, no. 8, 085501 (2015). [2] N. Nepal et al., Appl. Phys. Express, vol. 9, no. 2, 021003 (2016). [3] D.J. Meyer et al., CS MANTECH Conference, May 16 - 19, Miami, USA (2016). [4] D.J. Meyer and B.P. Downey, āLift-off of epitaxial layers from silicon carbide or compound semiconductor substrates,ā US patent application no. 14/331,440. PCT application no. PCT/US14/46609.