Multiple byte channel hot electron programming using ramped gate and source bias voltage

Abstract

A memory device having multiple banks, each bank having multiple memory cells and a method of programming multiple memory cells in the device wherein a bias voltage is applied to a common source terminal of the multiple memory cells and a time varying voltage is applied to gates of the memory cells that are to be programmed. In one embodiment, the voltage applied to the gates of the memory cells to be programmed is a ramp voltage. In a second embodiment, the voltage applied to the gates of the memory cells to be programmed is an increasing step voltage. In another embodiment, the bias voltage applied to the common source terminal and the voltage applied to the control gates of the memory cells to be programmed are selected so that the current flowing through cells being programmed is reduced and that the leakage current from memory cells that are not to be programmed is substantially eliminated. In another embodiment, a bias voltage is applied to the common source terminal and a bias voltage is applied to the common well voltage. The combination of the voltages applied to the control gates and to the sources decreases loading on the bitlines to ensure that V,does not fall below a required level necessary for the maintenance of the hot carrier effect during programming. A bias voltage can also be applied to the wells of the memory cells while the common source terminal is held at ground. Feedback control of the programming gate voltages can be used to control the power required for programming.