Non-volatile storage devices and methods for fabricating non-volatile storage device are described. Sidewalls of the memory cells and their associated word line may be covered with silicon oxide. Silicon nitride covers the silicon oxide adjacent to the word lines, which may provide protection for the word lines during fabrication. However, silicon nitride can trap charges, which can degrade operation if the trapped charges are near a charge trapping region of a memory cell. Thus, the silicon nitride does not cover the silicon oxide adjacent to charge storage regions of the memory cells, which can improve device operation. For example, memory cell current may be increased. Techniques for forming such a device are also disclosed. One aspect includes a method that uses a sacrificial material to control formation of a silicon nitride layer when forming a memory device.