Die by die trimming of drain-side select gate threshold voltage to reduce cumulative read disturb

Abstract

A memory apparatus and method of operation are provided. The apparatus includes drain-side select gate transistors for coupling to a drain-side of each of a plurality of memory holes of memory cells and configured to retain a transistor threshold voltage. The memory apparatus also includes a control means coupled to the drain-side select gate transistor of each of the plurality of memory holes. The control means is configured to select the transistor threshold voltage of the drain-side select gate transistors as a stable transistor threshold voltage for a grouping of the memory cells to minimize shifting of the transistor threshold voltage following a plurality of read operations of the memory cells. The control means is also configured to program the transistor threshold voltage of the drain-side select gate transistor of the plurality of memory holes associated with the grouping of the memory cells to the stable transistor threshold voltage.