Defect Engineering and MeV Ion Implantation

 

Motivation

Ion implantation in the energy scale from a few keV to MeV is a well established technique in modern device technology. However, during ion implantation into a crystalline semiconductor material (the most important one is Si) produces damage on the whole ion trajectory. The conventional way of annealing this irradiation damage is a thermal treatment at high temperature. This possibility is limited for a future highly integrated device tecnology because of the redistribution of the implanted dopant structure.
Therefore, the knowledge on the point defects created during ion implantation, their diffusion, interaction, recombination and agglomeration becomes more important. An intelligent sequence and way of ion implantation is able to avoid defect formation or to getter defects without disturbance of the device.
 
 

Aim

Study of irradiation defects in Si after MeV ion implantation and annealing. Development of optimal ion processing for low (doping) and high dose (ion beam synthesis) applications.
 
 

Characterization

Characterization of radiation damage and structural modification of the implanted layers:

  • Cross section transmission electron microscopy (XTEM)
  • Rutherford backscattering / Channeling (RBS/C)
  • Metal gettering at radiation damage and detection by secondary ion mass spectrometry (SIMS)

Electrical measurements:

  • Spreading resistance profiling (SRP)
 

Results

Defects have been detected in Si after ion implantation and annealing at half of the projected ion range of the implanted ion (RP/2 effect, see R. Kögler, R.A. Yankov, J.R. Kaschny, M. Posselt, A.B. Danilin and W. Skorupa, Nucl. Instrum and Meth. B142 (1998) 493 - 502).
A pre-stage of the Si-C formation has been found for the SiC ion beam synthesis by C implantation into Si (see P. Werner, S. Eichler, G. Mariani, R. Kögler and W. Skorupa, Appl. Phys. Lett. 70 (1997) 252 ).
 
 

Contacts

Dr. R. Kögler R.Koegler@hzdr.de
A. Peeva A.Peeva@hzdr.de