A method of forming a structure, an array of structures and a memory cell, the method of fabricating a structure, including: (a) forming a trench in a substrate; (b) depositing a first layer of polysilicon on a surface of the substrate, the first layer of polysilicon filling the trench; (c) chemical-mechanical-polishing the first layer of polysilicon at a first temperature to expose the surface of the substrate; (d) removing an upper portion of the first polysilicon from the trench; (e) depositing a second layer of polysilicon on the surface of the substrate, the second layer of polysilicon filling the trench; and (f) chemical-mechanical-polishing the second layer of polysilicon at a second temperature to expose the surface of the substrate, the second temperature different from the first temperature.