Memory cells comprising: a semiconductor substrate having at least two source/drain regions separated by a channel region; a charge-trapping structure disposed above the channel region; and a gate disposed above the charge-trapping structure; wherein the charge-trapping structure comprises a bottom insulating layer, a first charge-trapping layer, and a second charge-trapping layer, wherein an interface between the bottom insulating layer and the substrate has a hydrogen concentration of less than about 3×1011/cm−2, and methods for forming such memory cells.