1. Applying X-Rays in Material Analysis
Vladimir Kogan
Philips Analytical and DANNALAB
The Netherlands

2. X-Ray Diffraction Analysis
Based on measuring the intensity of the x-rays diffracted by the sample at different angles
Delivers information about the structure and composition of material at different scales
This information is used to explain or predict the properties of a sample
Bragg's Law l
= 2d sin q d

3. Classification of Samples
Amorphous
Polycrystalline
Monocrystalline
Bulks
Powders and Foams
Thin Films

4. XRD for Amorphous Materials
SAXS Analysis of Human Serum Albumin (HSA) in the Monodisperse Solution and in the Native Serum
An understanding of the structural properties of serum albumin is extremely important in the development of new human pharmaceuticals. HSA contributes to many transport and regulatory processes in the body. Distribution, free concentration and metabolism of verious pharmaceuticals can be significantly influenced depending from the binding with HSA.
From the monodisperse curve of HSA we have determined the average parameters of the molecule - axes of ellipsoid, suface, volume, radius of gyration etc. From the polydisperse curve (native serum) we have derived the histogram of particles distribution by average radius.
DANNALAB, 2002

5. XRD for Polycrystalline Materials
Crystallography - type and dimensions of unit cell
Atomic structure - atom’s coordinates
Grain’s size and shape
Micro and macro strain
Phase composition - presence and concentration of different phases
D-Mannitol (beta form) HOCH2(CHOH)4CH2OH

6. Si Detector for XRD Applications
0.07mm pitch
No cooling required
Efficiency: > 94 % for 8KeV
Maximum 4mln cps in the complete detector
Background: < 0.1 cps
Finally, a novel detection system should not give the user a lot of additional maintenance, be it the supply of counting gas, the need for cooling water or regular recalibrations. All these issues are non-existent with the X’Celerator.

7. Specific of Thin Layers
ct > aL
at = aS
mismatch
Substrate = aS
Layer = aL ct
Strained layer
Relaxed layer

8. Different Types of Thin Films
Pseudomorphic epitaxial layers. “No” defects. Strain may be present Example : AlGaAs/GaAs, SiGe/Si Applications: Lasers, High-frequency IC’s Lattice mismatched epitaxial layers. Layers are partly (or fully) relaxed Example: ZnSe/GaAs, InAsSb/GaSb Applications: Blue LED’s, IR optopelectronic Layers with large lattice mismatch and/or dissimilar crystal structures Example: GaN/Sapphire, YBaCuO/SrTiO3, BST, PZT Applications: Blue Lasers and LED’s, High Tc Superconductors, Ferro electrics Layers where the epitaxial relationship is weak. Highly textured. Example: AuCo multilayers on Si Applications: Thin film media, heads

9. XRD for Thin Films and Layers
Reflectivity Measurements
Thickness, Density, Surface Roughness
Lateral and Depth Correlation
Curvature
In-plane Scattering
Nano-layers
Nano-structures
In-plane properties
High Resolution Diffraction
Orientation
Quality of Epitaxy, Lattice Mismatch
Phase Composition
Thickness, Density, Surface Roughness

10. Typical Setup for Reflectivity Measurementsq 2
Divergence
slit
Attenuator
Sample
Detector
Graphite
monochromator
Anti-scatter
Beam
knife
Receiving

11. The Information that can be Derived from a Reflectivity Curve

12. XRD Study of Self-Assembled Monolayers C18H37SH on Gold
Reflectivity
XRD Study of Self-Assembled Monolayers C18H37SH on Gold
Specular Reflectivity Curve
Reflectivity Map, Diffuse Scattering
Determined thickness of the layers: C18H37SH nm Au nm Au nm Si > nm
Determined Average Lateral Correlation Length: 2.5nm
DANNALAB, 2002

13. Modern High Resolution Diffractometer
The highly parallel monochromatic beam should be used to study perfect layers

14. High Resolution Diffraction
Analysis of SiGe HBT Structure
The introduction of a SiGe epitaxial layer in the bipolar transistor (HBT) brings significant gains in speed, challenging GaAs in its traditional application fields. New technological step of introducing Ge requires also an accurate method for the characterization of Ge content and gradients.
Automatic simulation and refinement of a measured rocking curve helps to identify parameters of individual layers. Method delivers 1 % accuracy for composition and 3 % accuracy for SiGe thickness.
DANNALAB, 2002

15. High Resolution Diffraction GaN/InGaN (Blue Laser Structure)

16. Relaxed GaInAs/GaAs (224)
Reciprocal Space Map
Relaxed GaInAs/GaAs (224) S L

17. Orientation and Domain Structure
Transition in YBa2Cu3O8-x Film on SrTiO3 Substrate XRD Measurements
{304} Reciprocal Space Maps
20nm tetragonal (nonsuperconducting) phase
100nm orthorhombic (superconducting) phase
With the increase of the thickness of the YBa2Cu3O8-x layer, the dependence of the structure from the SrTiO3 substrate is declining. This results in the appearance of the orthorhombic superconducting phase.
DANNALAB, 2002

18. High Resolution Diffraction
Strain Fields in Boron-implanted Silicon
DANNALAB, 2002

19. Devices and Structures
Stresses due to adhesive bonding
Different methods has been tested to make stress-free bonding of Si with steel. One of the methods (s41 and s42) delivers quality, comparable with the stress free samples (Test1 and Test2)

20. IC Chip Glued on the Ceramic Substrate
Surface Mapping by Measuring Rocking Curves
Method 1
Method 2
DANNALAB, 2002

21. Sensor on Chip Assembly Surface Mapping by Measuring Rocking Curves
Mapping of free standing Si sensor
Mapping of sensor bump-bonded to chip
Wire bonding side
DANNALAB, 2002

22. Roadmaps for new XRD detectors
Amorphous Materials
Polycrystalline Materials
Monocrystalline Materials
0D, 1D and 2D
Flat shape
Dynamical range 107
Counting speed up
to 107c/s/mm2 useful energy and 109 total
Energy resolution <250 eV
0D, 1D and 2D
Different shapes
Very low noise
Pixel size down to 0.05 mm
Counting speed up to 105c/s/mm2
Energy resolution <250 eV
0D, 2D
Flat shape
Dynamical range 107
Counting speed up to the 107c/s/mm2

23. Conclusions Special thanks to
Appearance of new technologies for x-ray detectors considered to be one of the key factors for the advances in XRD instrumentation.
The applications of XRD actively shifting nowadays to the field of high-tech materials an devices, including advanced x-ray detectors.
Both fields have a lot of synergy and may benefit from each other.
Special thanks to
J. Visschers, for inviting me to this conference
J. Woitok, M. Fransen, K. Bethke, R. de Vries for useful comments