Real-time measurement of substrate temperature in molecular beam epitaxy using low-coherence tandem interferometry

•Low-coherence interferometry method of temperature evaluation in MBE is presented.•This technique allows real-time measurements during growth.•Low temperatures in MBE growth process could be measured directly.•Growth interruptions needed for temperature change can be shortened significantly.•Si:Sb delta-doped layers was formed using this technique with abrupt boundaries.

It was demonstrated that the low-coherence interferometry technique can be successfully applied to real-time substrate temperature evaluation during molecular beam epitaxy in a wide range down to room temperature. The proposed technique was used for formation of silicon layers delta-doped by antimony. Due to shortening of the growth interruptions needed for temperature switching the low-coherence interferometry technique allows improving the crystal quality of the grown samples and reducing the material and time consumption. These advantages become extremely beneficial with lowering of the growth temperatures.