GorMet
Goniometer Measurement Control for Rutherford Backscattering Spectrometry
and Ion Channeling Experiments on Wafers up to 150 mm Ø


Rutherford backscattering spectrometry (RBS) and ion channeling are well established techniques for thin film analysis and require precise positioning of the sample with respect to the incoming ion beam and detector. We built a new, extremely precise and rigid eucentric goniometer with three perpendicular rotation axes and a x/y-translation stage capable of handling whole wafers up to 150 mm diameter. Alternatively, about 50 smaller samples can be mounted on the holder. Each point on the wafer can be moved into the center of the three rotation axes for analysis, which also allows wafer mapping. All motions are driven by UHV-compatible stepping motors and gears. The angular resolution of the rotations is 0.005º. The goniometer, which includes also a motor-driven stage for the backscattering detector was mounted in a UHV-chambe and installed at the Jülich 1.7 MV Tandetron accelerator. An attached load-lock chamber allows the change of the sample holder within a few minutes. Measurement control and data acquisition is based on a PC.

Aim
    In close collaboration with Arun Microelectronics Limited (AML, Great Britain) we designed a new, high precision, rigid, eucentric goniometer with three perpendicular rotation axes and an x/y translation stage. The goniometer was built at AML. The software for experiment control, automatic motion, counting electronics, data acquisition of accumulated spectra including automatic batch measurement and data analysis as well of a part of specialized hardware components was developed at ZEL.
Applied Technologies
  • IDL is a complete computing environment for the interactive analysis and visualisation of data. IDL integrates a powerful, array oriented language with numerous mathematical analysis and graphical display techniques. Programming in IDL is a time saving alternative to programming in FORTRAN or C - using IDL , tasks which require days or weeks of programming with traditional languages can be accomplished in hours. IDL allows you to construct and manipulate graphical user interfaces using widgets. Widgets are simple graphical objects such as pushbuttons or sliders that allow user interaction via a pointing device (usually a mouse) and a keyboard. This style of a graphical user interface called GUI offers many significant advantages over traditional command line based systems.
  • To implement hardware components in this IDL concept running under Windows95 or Windows NT we had to write special different software modules in C placed into so called dynamic link libraries (DLL). This DLL contains one subroutine for each hardware function. This is better than one subroutine whereas the first parameter selects the function.
Partners
  • Institute of Thin Films and Interfaces  (ISG1-IT),Research Centre Jülich
Contact Person : Heinz Heer +49 2461 61 3236 3990
Contact Person : M. Wagener +49 2461 61 3236 3990
last change 09.01.2003 | | Print