Controlling isotropic etching films with atomic layers

A method of isotropically etching a film on a substrate with atomic layer control includes a) providing a substrate including a material selected from the group consisting of silicon (Si), germanium (Ge), and silicon germanium (SiGe). The method further includes b) depositing a sacrificial layer on the material in a processing chamber by cooling a lower portion of the substrate; performing one of generating an oxidant-containing plasma in the processing chamber or supplying the oxidant-containing plasma into the processing chamber; and increasing a surface temperature of the substrate for a predetermined period of time using rapid thermal heating while generating the oxidant-containing plasma in the processing chamber or supplying the oxidant-containing plasma in the processing chamber. The method further includes c) purging the process chamber. The method further includes d) etching the sacrificial layer and the material by supplying an etching gas mixture into the processing chamber and exciting a plasma in