Asymmetric dense floating gate nonvolatile memory with decoupled capacitor

Abstract

A nonvolatile memory ('NVM') bitcell includes a capacitor, an asymmetrically doped transistor, and a tunneling device. The capacitor, transistor, and tunneling device are each electrically coupled to different active regions and metal contacts. The three devices are coupled by a floating gate that traverses the three active regions. The tunneling device is formed in a native region to allow for greater dynamic range in the voltage used to induce tunneling. The FN tunneling device is used to erase the device, allowing for faster page erasure, and thus allows for rapid testing and verification of functionality. The asymmetric transistor, in conjunction with the capacitor, is used to both program and read the logical state of the floating gate. The capacitor and floating gate are capacitively coupled together, removing the need for a separate selection device to perform read and write operations.