Barrier Layer Optimization of DIBS-grown MgZnO/CdZnO Heterojunction for High Mobility

Abstract

This work explores the effect of Mg composition and growth environment of the MgZnO barrier layer in dual ion beam sputtering (DIBS) grown MgZnO/CdZnO heterostructure. Results suggest that a lower Mg composition of 5% provides higher mobility by reducing lattice mismatch and to form a well-defined heterojunction. Further, the presence of O2 during the growth environment reduces the carrier mobility (μ) of the two-dimensional electron gas, while increasing the carrier charge density (ns). The optimized heterojunction exhibited an increase in μ from 6.9 cm2/Vs to 28 cm2/Vs while the ns reduces from 3.22 × 1015 cm-2 to 4.22× 1013 cm-2. These findings are crucial for developing DIBS grown MgZnO/CdZnO high electron mobility transistors. © 2026 IEEE.