Schottky cell memory technology for nonvolatile memory applications

This Ph.D. dissertation demonstrates a novel concept for nonvolatile memory (NVM). The concept may become a new technology for NVM. We shall call this new technology as Schottky Cell Memory (SCM) technology. SCM is based on the alterable Schottky barrier height arising from the reversible electron movement from an electric-field-controlled charge source near a metal-semiconductor Schottky interface to an adjacent quantum well. Depending on the resultant charge state in the adjacent quantum well, this movement modulates the current flowing over the Schottky barrier, thereby differentiating at least two states which correspond to “1” and “0” of stored data. Once the device is on a particular state, the device retains memory of the state it has been set on, even if it is held at zero bias for long periods of time. The device can be electrically addressed in a high-density device matrix. The state of the device can be repetitively switched by a positive or negative voltage pulse and can be read at a low sense voltage without destroying it. The device requires low power for switching and reading, is nonvolatile, is radiation tolerant, and is compatible with other conventional device processing for integration with microelectronic elements on a same substrate such as silicon (Si), gallium arsenide (GaAs), and indium phosphor (InP).