Advances in Selective Doping of SiC Via Ion Implantation

A range of values for the ionization energies has been reported in the literature and the values given in Table 4.1 represent approximate average ones. For A1 and B, no clear distinction has been established between the hexagonal and cubic sites. 

SiC is, indeed, a more complicated material than Si, and to understand and control the annealing processes is a major scientific challenge, as illustrated by (but not limited to) the following issues  

In addition to interstitial configurations, implanted atoms can occupy either Si- or C-sites and substitutional incorporation on the correct position to act as shallow dopants is not as straightforward as in Si. Moreover, there are nonequivalent lattice sites of either cubic or hexagonal symmetry in the different polytypes. 

Straightforward to accomplish highly doped n -layers ( 10 ° cm ) and this issue requires further attention. Moreover, in this context it should also be emphasized that not until recently viable techniques for measuring electrical carrier concentration-versus-depth profiles in the range cm have 

In this chapter, we review the current status of doping of SiC by ion implantation. Section 4.2 examines as-implanted depth profiles with respect to the influence of channeling, ion mass, ion energy, implantation temperature, fluence, flux, and SiC-polytype. Experiments and simulations are compared and the validity of different simulation codes is discussed. Section 4.3 deals with postimplant annealing and reviews different annealing concepts. The influence of diffusion (equilibrium and nonequilibrium) on dopant profiles is discussed, as well as a comprehensive review of defect evolution and electrical activation. Section 4.4 offers conclusions and discusses technology barriers and suggestions for future work. 

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