More Robust Growth Rate Fitting Results With Damped Sine Fit
The kSA 400 RHEED analysis tool has a new damped sine fit analysis feature to measure growth rate from RHEED intensity oscillations in real-time and in post-process data analysis. The new method automatically calculates initial estimates of the fitting parameters, leading to more robust fitting results with minimal user intervention required.
In the case of layer-by-layer growth, the intensity of the RHEED spots oscillates with a period equal to the time required to deposit a single monolayer. These oscillations can be fit by a damped sine function to determine the growth rate of the material in monolayers/sec or nm/sec (if the monolayer thickness is known). kSA 400 uses a least-squares method, which requires initial estimates of the fitting function’s parameters. By implementing a simplified model to automatically calculate these estimates, kSA’s new damped sine analysis fits more quickly and reliably. It also works well with strongly varying backgrounds.