In the highly efficient fabrication processes for HNOR arrays provided herein, the channel regions of the storage transistors in the HNOR arrays are protected by a protective layer after deposition until the subsequent deposition of a charge-trapping material before forming local word lines. Both the silicon for the channel regions and the protective material may be deposited in amorphous form and are subsequently crystallized in an anneal step. The protective material may be silicon boron, silicon carbon or silicon germanium. The protective material induces greater grain boundaries in the crystallized silicon in the channel regions, thereby providing greater charge carrier mobility, greater conductivity and greater current densities.