Etching of m-plane Zn(Mg)O epitaxial films and its impact on surface leakage currents
Open Access
- 18 January 2021
- journal article
- research article
- Published by IOP Publishing in Semiconductor Science and Technology
- Vol. 36 (3), 035023
- https://doi.org/10.1088/1361-6641/abdd07
Abstract
Zinc Oxide is a novel material system for mid-infrared and THz optoelectronics. Especially its non-polar m-plane orientation is a promising candidate for the design of devices like quantum cascade lasers (QCLs) and detectors (QCDs). But for their realization novel fabrication schemes are needed. We present a new inductively coupled plasma reactive ion etching (ICP-RIE) process for etching of m-Zn(Mg)O heterostructures in a CH4-based chemistry. The process has been optimized for smooth vertical sidewalls together with high selectivity towards a SiN etch mask. This was achieved by combining the RIE etching with wet chemical etching in strongly diluted HCl. Similar to various types of semiconductor-based optoelectronic materials and devices [1,2], including other wide-gap semiconductors like (In)GaN [3], we observe surface leakage currents in etched m-plane Zn(Mg)O structures. We show that they depend on the applied etching process and surface treatment techniques as well as the barrier composition in the Zn(Mg)O heterostructures. In addition, a treatment in hydrogen peroxide (H2O2) yields a significant surface leakage current suppression up to several orders of magnitude.Keywords
Funding Information
- European Commission (665107 ("ZOTERAC"))
This publication has 83 references indexed in Scilit:
- Differential Etching of ZnO Native Planes under Basic ConditionsLangmuir, 2012
- The Role of Carbon Doping in ZnOJournal of the Korean Physical Society, 2010
- In Situ Study of the Polar ZnO(0001)−Zn Surface in Alkaline ElectrolytesThe Journal of Physical Chemistry C, 2010
- Optimized configuration for transmissive and reflective bistable chiral-splay nematic liquid crystal deviceApplied Physics Letters, 2006
- Etching characteristics of ZnO thin films in chlorine-containing inductively coupled plasmasMicroelectronic Engineering, 2006
- Hole–LO phonon interaction inquantum dotsPhysical Review B, 2005
- Recent progress in processing and properties of ZnOSuperlattices and Microstructures, 2003
- Transparent conducting V-co-doped AZO thin films prepared by magnetron sputteringThin Solid Films, 2003
- Terahertz semiconductor-heterostructure laserNature, 2002
- The temperature dependence of the band-edge effective masses of InSb, InAs and GaAs as deduced from magnetophonon magnetoresistance measurementsJournal of Physics C: Solid State Physics, 1970