EXPERIMENTAL FACILITIES AT THE 3 MV TANDETRON
The implantation beam line houses a scanning system for 5" wafers.Two irradiation chambers are arranged in line. One chamber is designed for RT implantations at a low contamination level. Here up to 13 wafers of 125 mm (5") diameter can be implanted in one vacuum cycle.
The second chamber is a research grade implantation station (HVEE).
A simple heating stage for implantation temperatures up to 1000 K and a LN2 cooling stage for single wafers up to 4" diam. are available.
HERBST (High Energy RBS at the Tandetron)For RBS and NRA an HVEE Mod. 941 two axis goniometer chamber is installed. Due to the wide energy range and the variety of available ions RBS with heavy ions is possible and as well as He resonance scattering above 3MeV.
Here two examples (click the picture to enlarge) :
Two charged particle detectors, one at a fixed angle of 165° and a second one setable to glancing geometry, can be supplemented by a PIXE detector.
ROMICA (Rossendorf MICrobeam Analysis)At the third beamline the nuclear microprobe is installed. A particular feature of it is a triplet lens with a focusing power of 45 MeV/q2 , which offers the possibility to focus MeV heavy ions. A minimum spot size of about 1 µm at a beam current of 100 pA can be attained with protons ( 3µm routinely ).
Detectors for secondary electrons, backscattered particles and X-rays are installed and ERDA measurements with a foil-covered silicon detector are possible.
Click here for a detailed description under "Nuclear microprobe" !
The forth beamline is directed by means of two 30° magnets to the second switching magnet. At the 0° port of the first bending magnet the detection system for the accelerator mass spectrometry (AMS) is mounted.
BROWNYOne of that extension beamlines crosses the beamline of the 500 kV implanter. At this point a double beam facility with a 450 mm UHV scattering chamber has been installed.
The picture shows the chamber with some of its auxilliary equipment, among which are
- two UHV electron beam evaporators
- RHEED system
- sputter gun for sample cleaning.
A precision goniometer is utilized for channeling measurements and for accurate sample positioning.
The main parameters are :
5-axis-goniometer with UHV stepping motors
3 rotational axes : F(vertical), range ±180°
J (horizontal), range -15° to +90°
Y (horizontal (J= 0°)), range ±95°
X -Y-table, range ±25 mm each
A magnetic spectrometer provides high energy resolution.
Type : Browne-Buechner (circular pole shapes)
Mean deflection radius : 0.65 m
Energy range Emax / Emin : ~ 2
Mass-energy-product : 16 amu MeV
Energy resolution DE/E (theor.) : < 10-3
Solid angle : 1 msr