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.
 
 

BROWNY

One 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°
2 translations
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