1. In a data storage device including a plurality of floating gate storage transistors having respective control gates, sources and drains, an apparatus for hot electron injecting a charge into a floating gate comprising: a voltage source, coupled to the control gate, the source, and the drain of a selected floating gate storage transistor, to supply a gate programming potential to the control gate, a voltage to the source, and a voltage to the drain of the selected floating gate storage transistor to hot electron inject a charge into the floating gate; and a control circuit coupled to the voltage source for varying the gate programming potential during hot electron injection within a single pulse having a first interval and a second interval after the first interval, so that a first potential sufficient to induce hot electron injection is applied during the first interval of the single pulse and a second potential higher than the first potential is applied during the second interval of the single pulse; wherein the single pulse has a duration less than 2 microseconds.