Methods for forming a string of memory cells and apparatuses having a vertical string of memory cells are disclosed. One such string of memory cells can be formed at least partially in a stack of materials comprising a plurality of alternating levels of control gate material and insulator material. A memory cell of the string can include floating gate material adjacent to a level of control gate material of the levels of control gate material. The memory cell can also include tunnel dielectric material adjacent to the floating gate material. The level of control gate material and the tunnel dielectric material are adjacent opposing surfaces of the floating gate material. The memory cell can include metal along an interface between the tunnel dielectric material and the floating gate material. The memory cell can further include a semiconductor material adjacent to the tunnel dielectric material.