A simultaneous observation of dislocations in 4H-SiC epilayer and n+-substrate by using electron beam induced current

With a new structure of Ni/n-SiC/n(+)-SiC/Al, we have achieved a simultaneous observation of the dislocations in n-SiC epilayer and n(+)-SiC substrate by electron beam induced current (EBIC). The EBIC images were compared to the results of a depth-controlled wet etching in KOH+Na2O2. It has been found that each type of dislocations has its own signature in EBIC images in terms of the darkness, shape and orientation of the dark contrast. By changing the accelerating voltage of the electron beam, we can also observe the depth dependent presence of each type of dislocations and where and how the dislocation conversion happens. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3597784]