k-Space Associates, Inc.

More Robust Growth Rate Fitting Results With Damped Sine Fit

published on 07/27/2018

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.

Watch the video to see it in action!