Methods of forming an integrated device, and in particular forming one or more sample wells in an integrated device, are described. The methods may involve forming a metal stack over a cladding layer, forming an aperture in the metal stack, forming first spacer material within the aperture, and forming a sample well by removing some of the cladding layer to extend a depth of the aperture into the cladding layer. In the resulting sample well, at least one portion of the first spacer material is in contact with at least one layer of the metal stack.