X-RAY REFLECTOMETER

MINILAB - 6

Advanced analytical system for nanostructure investigations

Introduction

        X-ray reflectometry is now widely used in science and technology to measure and monitor thin film thickness, roughness of super- smooth surfaces, period of multilayer nanostructures and surface layer density. An X-ray Reflectometer X-Ray MiniLab manufactured by the Institute for Roentgen Optics (IRO) is now the most powerful tool in this X-ray metrology due to its unique features providing simultaneous measurements with a number of spectral lines. The X-ray reflectometer is specifically designed for diagnostics of thin films and interfaces. But due to flexible scheme it can also ensure standard X-ray techniques.

The IRO X-ray Reflectometer is based on latest developments in semitransparent monochromators, Kumakhov polycapillary optics, and unique patented design. We offer a genuine Minilab with unmatched combination of analytical features.

Complex of X-ray devices

Based on X-ray Reflectometer

5 Basic Operation Modes:

¨      Reflectometry

¨      Diffractometry

¨      Refractometry

¨       Small-angle scattering

¨       X-ray fluorescence

Try and enjoy advantages of simultaneous measurements in different spectral bands

Technical Specification

Controlled parameters:

¨      Surface and interface roughness (down to 0.05 nm)

¨      Thin layer thickness (1-300 nm)

¨      Structure period ( 0.1 nm )

¨      Surface layer density                                       

¨      Radius and concentration of nano-particles    

¨      Composition of layers        

¨      Radius of curvature  (up to 300m)

Software codes for:

◊ system operation

◊ system testing

◊ reflectometry and refractometry data procession

Goniometer system:

Minimum angle step – 0,0002^o (0,7²)

angle range -145^o (2q-detector axis)

-180 (w-sample axis)

sample linear translation with 2,5 mm step, range 100 mm

X-ray tube power supply:

High voltage range 10-45 kV

Power – 300 W (500 W optional)

Power stability – 0,01%

Detection system:

◊ 3 scintillation channels

Dimensions, mm (length x width x hight):

◊ Reflectometer X-ray scheme – 950 ´ 500 ´ 450

◊ Operation table – 1200 ´ 700 ´ 780

System weight, kg:

◊ Reflectometer X-ray scheme – 35

New patented X-ray optical scheme of X-ray reflectometer MiniLab

Spectral lines are selected from the beam by tuning semitransparent monochramators to the predetermined Bragg angles. The X-ray scheme provides simultaneous measurements with two spectral lines (standard anode) and with three ones (composed anode) in this X-ray reflectometer

Short Application Notes on X-ray Reflectometer

Measurements of nano-size oxide layers

Mode 1:

Relative reflectometry mode

Provided now only by X-Ray reflectometer MiniLab

Unique method of intensity contrast development

Sample description

Substrate: Si wafer

Film: Ni (900 nm) deposited by magnetron sputtering

Fig.1. Angle dependence of reflected intensity ratio I(CuK_a)/I(CuK_b):

dots –experiment, solid line - mathematical simulation for idea.

Measured data: film thickness d(NiO_x)=3,0 nm, NiO_x composition x=1,9, film density r(NiO_x)=5,5 g/cm³, surface roughness s=0,5 nm

EXAMPLE 2         Investigation of ion-implanted samples      

Sample description

Substrate: Si wafer with 42,5 nm oxide film

Fig. 2. Angle dependence of reflectivity for F⁺ -implanted sample

Absence of intensity contrast in small angle range 2q<1^o.

Fig. 3. Angle dependence of the reflectivity ratio R(l₁)/R(l₂) for F⁺ -implanted sample

Intensity contrast development in small angle range 2q<1^o.

    Mode 2:

Diffraction

EXAMPLE 2

Bragg-Brentano focusing scheme

Samples – powders of aspirin and zeolite/

X-ray power – 28 kV, 10 mA

Fig. 2. q-2q diffraction scan of aspirin powder.

EXAMPLE 3        

Repeatability test

Fig. 3. q-2q diffraction scan of zeolite powder

Mode 3:

X-ray fluorescence

      EXAMPLE 4   

Sample:

magnetic memory disc

Detection: Semiconductor Si-detector, 7 mm²

X-ray source: Cu-anode X-ray tube, 30 kV, 1 mA

Collimation: Polycapillary Kumakhov lens, focus spot 400 mm.

Fig. 4. X-ray fluorescence spectrum from magnetic memory layer.

Mode 4:

X-ray refraction

EXAMPLE 5    

Sample description

Substrate: Si wafer

Direct determination of the thin film density

Fig. 5. Refractogram of bilayer structure  C-Ni/Si, grazing angle  Θ=-0,08^o.