The present invention provides semiconductor structures and methods for forming semiconductor structures which include monocrystalline oxide films exhibiting both high dielectric constants and low leakage current densities. Reader demographics and reader evaluations of works are recorded and used to rank submitted works. The method further comprises elevating a portion of the plurality of bit lines into a second metal layer overlying the first metal layer. We found that ultrasonic stimulation activates cells presynaptic to ganglion cells, which may include photoreceptors and interneurons.