Nonvolatile Poly-silicon Memory Device with Oxide-Nitride-Oxynitride Stack Structure on Glass for Flat Panel Display

Abstract

This paper explains how non-volatile memory (NVM) devices with an oxide/nitride/oxynitride (ONO) structure on a rough poly-silicon (poly-Si) surface were fabricated and studied using poly-Si thin film transistor (TFT) technology on a glass substrate. When a flat panel display (FPD) such as an organic light emitting diode (OLED) or a liquid crystal device (LCD) displays a static image, the brightness of the panel is altered because of degradation of the driving current. In order to prevent degradation of the driving current, an NVM device can be applied to the compensation circuit for the pixels of a FPD. To fabricate an NVM device on glass, a metal/oxide/nitride/oxynitride/poly-Si (MONOS) structure with an ultra-thin silicon oxynitride (SiOxNy) using nitrous oxide (N2O) plasma as the tunneling layer was used instead of the general methods of oxidation and deposition for ultra-thin silicon dioxide (SiO2). The memory window of a fabricated NVM device which has a MONOS structure with a tunneling layer of ultra-thin SiOxNy at a programming voltage of − 16 V and erasing voltage of + 11 V for a pulse time of 1s is 2.8 V. This is because of programming and erasure of charges in the silicon nitride (SiNx) layer. Because of the properties of NVM device on glass, NVM devices can be used in various FPD.