Film thickness
Thickness of each layer from the spacing of the fringes.
Useful forOxide, metal, nitride and polymer filmsStructure & Diffraction
XRR
X-ray Reflectometry
XRR measures the thickness, density and interface roughness of thin films from how X-rays reflect off them at grazing angles. It works on crystalline and amorphous layers alike, without contact.
1 test optionFilm thickness ~2–200 nmDensity & interface roughnessTypical turnaround 4–6 working days
XRR measurement principleIllustrative
01 / Overview
What is XRR?
X-ray Reflectometry directs a fine X-ray beam at a flat film at grazing angles, typically below about 5°, and records the specularly reflected intensity. Below the critical angle the beam is totally reflected; above it, reflections from the surface and each buried interface interfere and produce fringes.
The fringe spacing gives layer thickness, the critical angle gives density, and the decay of the curve gives surface and interface roughness. Because XRR depends on electron density rather than crystallinity, it suits amorphous, polycrystalline and multilayer films, and it is non-destructive.
02 / How it works
How it works
- 01
Film is aligned
The flat sample is levelled and set to the beam height so the surface lies exactly along the beam.
- 02
X-rays graze the surface
The incidence angle is scanned from near 0° to a few degrees, with the detector following at 2θ.
- 03
Interfaces reflect
The surface and each buried interface reflect part of the beam, and the reflections interfere.
- 04
Curve is fitted
A layer model is fitted to the fringed curve to give thickness, density and roughness.
03 / What it measures
What it measures
Film density
Layer density from the critical angle where total reflection ends.
Useful forDeposited, porous or doped layersSurface & interface roughness
Roughness of the top surface and of buried interfaces.
Useful forAnnealed, etched or sputtered filmsMultilayer structure
Thickness and density of each layer in stacks and superlattices.
Useful forDevice stacks, multilayer mirrorsAmorphous layers
Measure smooth films that give no diffraction peaks.
Useful forAmorphous oxides, glasses, polymer films04 / Test options
Choose the XRR options you need
1 option · none added yet
05 / Sample requirements
Sample requirements
- Accepted forms
- Thin films and multilayers on flat, rigid substrates such as Si wafer or glass
- Size
- At least 10 × 10 mm, ideally ~20 × 20 mm; under 5 mm thick
- Film thickness
- Roughly 2–200 nm per layer
- Surface
- Smooth and flat; roughness above a few nm hides the fringes
- Smooth, flat and clean film surface
- Label the coated side, film material and substrate
- Mention the expected thickness and layer order, if known
- No bowed, curved or flexible substrates without discussing first
- No fingerprints, dust or scratches on the film
Hazardous or air-sensitive samples: mention it in your request, and attach the MSDS if you have one.
06 / Results & turnaround
Results & turnaround
What you receive
- Reflectivity curve (log intensity vs angle)
- Fitted thickness, density and roughness per layer
- Fit overlaid on the measured curve
- Raw data files
- Report PDF
Turnaround & pricing
Typically 4–6 working days after samples reach the lab.
Price confirmed in your quotation, depending on user type, options and number of samples.
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