Annealing processes are carried out to convert grown layers into a thermodynamically stable state or to trigger reactions in the sample.
Annealing processes are mostly used to convert grown layers into a thermodynamically stable state. In this way, lattice defects (atoms on interstitial places and vacancies) can be healed or atomic point defects can be saturated in reactions with hydrogen/forming gas and thus deactivated. Reactions can also be triggered in the sample (e.g. crystallisation, dopant activation). Different furnaces are used depending on the specific task.
Several Rapid Thermal Processing (RTP) ovens are available for fast and short thermal processing. Using high-intensity infrared lamps, substrates can be processed at very high heating rates and under different atmospheres/vacuum and cooled down again just as quickly. These annealing processes trigger reactions in the sample (e.g. crystallisation, dopant activation). Ultra-thin layers can also be grown on the surface in a controlled manner by reacting with the process gas (e.g. oxides or nitrides).