Effects of Mechanical Stress on Electrical Characteristics of IGZO-Based Integrated 1T1M on Flexible Substrate

Abstract

In this study, indium-gallium-zinc oxide (InGaZnO, IGZO) thin-film transistors (TFTs) and memristors are integrated as one transistor-one memristor (1T1M) structure on flexible substrate, and its electrical characteristics are analyzed. The fabrication process includes the formation of IGZO TFTs on flexible substrates and the deposition of memristors on top of TFTs. For the integrated structure, mechanical stress testing with various bending radius (10 and 15 mm) and bending cycles (0, 10, 100, and 200 times) were applied, considering the flexibility of the substrate. Experimental results show that as the bending radius decreased and the bending cycles increased, the conductivity of the 1T1M structure was negatively affected. In particular, with a bending radius of 10 mm, the electrical characteristics of the transistor significantly were degraded, exhibiting reduced conductivity. Degradations in conductivity led to noticeable performance loss in the accuracy of Modified National Institute of Standards and Technology (MNIST) database pattern-recognition simulations, indicating significant impact on the reliability of flexible electronic devices. This study provides valuable insights into material and structural design for enhancing the overall characteristics of flexible neuromorphic computing applications.