Designer atomic layer etching

A method of etching a material on a substrate, the method comprising:

• identifying process conditions for an atomic layer etching process of the material using a modification gas and a removal gas;
• and
• performing the atomic layer etching process on the material on the substrate by:
• exposing the substrate to the modification gas to modify a surface of the material, the modification gas having a modification energy and a desorption energy with respect to the material to be etched, and
• exposing the modified surface to the removal gas and igniting a plasma to remove the modified surface,
• wherein the modification energy is less than the desorption energy, and the desorption energy is less than a surface binding energy of the material;
• wherein the identifying the process conditions comprises selecting a substrate temperature for performing the exposing the substrate to the modification gas, wherein an ion energy provided by the substrate temperature is between the modification energy and the desorption energy;
• wherein the material has a surface binding energy greater than about 6 eV;
• and
• further comprising setting the substrate at a temperature to provide an ion energy between the modification energy and the desorption energy prior to performing the atomic layer etching process.