Space Charge Region Visualization Under Diamond Schottky Diode by Electron Beam Induced Current and Correlation with Defects Observed by Cathodoluminescence

The Schottky diodes will be the first components commercially available for diamond technology. However, we have to manage the surface defects which are still too high for large contact, with the current requirement and the rectification behavior. Even though a number of studies have already been performed, some questions are still without answers. One of them is how is the electric field into the stack of the diamond layer. From the theory and by doing simulation we know how it should be but experimentally we are able to see only the lateral electric field distribution by performing electron beam induced current (EBIC) and that gives us only a partial view of the problem and not the entire picture The second major problem is the study of the interface and the identification of defects that could lead to a modification of the Schottky barrier.<br/>With this study, we propose a new approach combining growth technic and electrical characterization in order to see what is happening underneath the Schottky contact in the depth of the material. The first part was to grow and fabricate the stack for diamond Schottky diode <i>i.e</i> heavily doped p++ layer on top of an HPHT substrate. And after a thick non intentionally doped layer (p-) was grown. Once the sample was ready, polishing was performed to remove the lateral overgrowth. Thus, the stack was directly accessible to different electronic probes. We performed EBIC measurements and Cathodoluminescence. For instance, with EBIC we observed the space region extension directly under the contact for different polarization of the diode. We also observed some specific inhomogeneities related to defects at the interface between metal and semiconductor.