01 / The question
How rough is a surface—and at what scale?
A surface roughness value depends on where and how it is measured. This project studied the topography of SiGe layers on silicon across samples and scan sizes.
02 / The intuition
A mechanism worth testing.
Compare measurements across length scales rather than treating one scan as the whole surface.
03 / The work
Inside the method.
Explore each part of the approach.
01Set up the measurement
The work included sample positioning, probe approach and optical-feedback alignment.
02Acquire topography
AFM images provided height information over different scan areas.
03Analyse scale dependence
RMS roughness and spectral analysis were used to compare surface texture and spatial structure.
04 / The observations
What emerged.
The notes report variation between samples and with scan area, highlighting measurement scale as part of the interpretation.
This account is based on recorded project notes. Original reports, figures and datasets are not embedded here.
05 / The limits
Where the evidence stops.
Original height maps, preprocessing choices and instrument calibration are required to substantiate roughness or periodicity values.
The academic foundations