Thermal atomic layer etch with rapid temperature cycling

A method of processing a substrate, the method comprising:

• supporting and thermally floating a substrate in a processing chamber using one or more substrate supports configured to minimize contact with the substrate;
• modifying one or more surface layers of material on the substrate by chemical adsorption, without using a plasma, while the substrate is maintained at a first temperature;
• and
• removing the one or more modified surface layers on the substrate by desorption, without using a plasma, while the substrate is maintained at a second temperature, wherein the first temperature is different from the second temperature;
• repeating, while the substrate remains in the processing chamber, the modifying of one or more surface layers of material on the substrate by chemical adsorption and the removing the one or more modified surface layers on the substrate by desorption;
• heating, after the modifying, the substrate from the first temperature to the second temperature;
• and
• actively cooling, after the removing, the substrate from the second temperature to the first temperature;
• wherein:
• the heating further comprises one of:
• heating the substrate from a top direction, heating the substrate from a bottom direction, and heating the substrate from both the top and the bottom directions, and
• the cooling further comprises one of:
• cooling the substrate from the top direction, cooling the substrate from the bottom direction, and cooling the substrate from both the top and the bottom directions;
• and wherein:
• the heating further comprises heating the substrate to the second temperature in about 250 milliseconds or less, and
• the cooling further comprises actively cooling the substrate to the first temperature in about 250 milliseconds or less.