Electrical probing of B‐doped diamond seeds embedded into the interfacial layer of a conductive diamond film

As undoped diamond seed nanoparticles remain non‐conductive after the growth of B‐doped diamond films, they represent localized regions of low conductivity and basically form a resistive barrier at the diamond film–substrate interface. This can be detrimental for diamond applications that require a good electrical contact with the substrate, such as small electrical probes and electrodes. Therefore, the use of B‐doped seeds is highly required as it can result in a well‐conductive interfacial layer. In this study, we show by electrically probing the diamond interfacial layer with nanometer‐scale resolution using scanning spreading resistance microscopy (SSRM) that B‐doped seeds indeed lead to highly conductive regions at the interface and, in our case, exhibit a resistance similar to the surrounding highly B‐doped grown diamond. We conclude that a seed layer that consists of B‐doped diamond nanoparticles will allow the formation of diamond films with a well‐conductive interfacial layer.