Flash memory TFT based on fully solution processed oxide

Abstract

Charge trapping based non-volatile capacitive flash memory has taken a significant share of today's semiconductor electronics[1]-[3]. As of now, there is no alternative to Silicon Nitride (Sis N4) dielectric for memory technology in terms of low-leakage and intrinsic charge storage properties. However the fabrication process of Si3N4 memory device is very complicated and requires sophisticated ultra-high vacuum system, which is incompatible towards building system on panel (SOP), system on glass (SOG) or ‘see through’ display technologies for large area and cost effective electronics applications[4]. Therefore it is necessary to develop fully spin-coated, sol-gel processed, cost effective flash memory TFT. Recently we reported a fully solution processed two terminal capacitive memory device [3]. However such devices are not suitable for large arrays since flash memory technology today relies on three terminal memory TFTs which are more superior in terms of readout and integration. Here we demonstrate all inorganic, completely oxide based, robust, cost-effective, fully solution processed spin-coated Silicon-Oxide-Hafnia-oxide-Semiconductor (SOHOS) flash memory devices. The performance of fully sol-gel processed memory TFT is equivalent or better than similar devices fabricated by other techniques. We also demonstrate the memory operation mechanism of the device using the experimentally determined complete band structure.