Three-dimensional vertical ZnO transistors with suspended top electrodes fabricated by focused ion beam technology

Abstract

Three-dimensional (3D) vertical architecture transistors represent an important technological pursuit, which have distinct advantages in device integration density, operation speed, and power consumption. However, the fabrication processes of such 3D devices are complex, especially in the interconnection of electrodes. In this paper, we present a novel method which combines suspended electrodes and focused ion beam (FIB) technology to greatly simplify the electrodes interconnection in 3D devices. Based on this method, we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al2O3 gate-oxide both grown by atomic layer deposition. Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires, which avoid cumbersome steps in the traditional 3D structure fabrication technology. Both single pillar and arrays devices show well behaved transfer characteristics with an I on/I off current ratio greater than 106 and a low threshold voltage around 0 V. The ON-current of the 2 × 2 pillars vertical channel transistor was 1.2 μA at the gate voltage of 3 V and drain voltage of 2 V, which can be also improved by increasing the number of pillars. Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.

Reflection Interference Spectroscopy Technology Monitoring the Synthesis of ZnCl2-ZnO Nanosheets on Nanoporous Anodic Alumina Substrate in Real Time

“…With the development of nanotechnology and in-depth research on nanomaterials, effective technologies for preparing composite thin films have been becoming more mature [9]. Therefore, nano-composite films with various unique nanostructures (e.g., nanoparticles, nanorods, nanowires, or nanosheets) and diverse functions play an unprecedented role in practical applications and promote the unconventional development of relevant cutting-edge fields [10,11]. Currently, nanosheet-based composite films are one of the frontier research hotspots in the field of manufacturing and application [12,13].…”