X-Ray Reflection Data Analysis Update

Information can be extracted from XRR data: - Film thickness - Roughness

Pilatus 100K Detector System

Pixel size 172 x 172 μm2

Format 487 x 195 = 94 965 pixels

Active area 83.8 x 33.5 mm2

Counting rate > 2x106 counts/s/pixel

Energy range 3 – 30 keV

Readout time < 2.7 ms

Framing rate > 200 Hz

Ki is the direction of incident X-ray, pointing to sample.The recorded image is the reflected beam intensity image

Schematic of Experiment Geometry

Sb thickness: t = (# of intensity peaks* Sb film lattice) =21*1.1273 nm = 23.7 nm

Specular reflection peak

Double click the movie image or in slide show mode to play, watch the oscillation of the specular reflection peak during Sb growth

Inte

nsity

of t

he

peak

Monitor Oscillation of Specular Reflection Peak during Sb Growth

Film Thickness vs Growth Time

Film thickness obtained methods:

Quartz crystal microbalance: Directly from the calibrated QCM read out. Specular Reflection beam: Count the peak number and calculate the thickness

Two methods agree well, Confirm the Sb film growth is layer by layer

Slice 1

Linear scale Intensity vs pixel #

Log scale Intensity vs pixel #

Convert pixel # to Qz value, plot Intensity vs Qz.Note that the x axis is reversed due to the experiment set up, fringes along Qz can be observed.

Background Area

Background was subtracted to obtain accurate data.

Analysis of the image frame after deposition:off-specular reflection peak

Fourier Transform

23 nm

Transformed peak position tells Sb film thickness around 23 nm, agree well with thickness obtained from quartz crystal microbalance monitor during growth.

The signal is not so clear, may due to the background is not perfectly handled. Need to further modify the codes for background consideration.

Roughness (peak broaden), will be easier when the peak is sharper.