Abstract: A multilevel semiconductor device, including: a first level including a first array of first memory cells; a second level including a second array of second memory cells, the first level is overlaid by the second level, where at least one of the first memory cells includes a vertically oriented first transistor, and where at least one of the second memory cells includes a vertically oriented second transistor, and where the first transistor includes a first single crystal channel, and where the second transistor includes a second single crystal channel, and where the first transistor is self-aligned to the second transistor.