POSTGROWTH TREATMENTS AND CONTACT FORMATION ON CVD DIAMOND FILMS FOR ELECTRONIC APPLICATIONS

Radiation detectors have been fabricated from undoped polycrystalline diamond films deposited using microwave chemical vapour deposition (CV D). We have investigated the influence of post-growth treatments on th e detection and on the electronic properties of CVD diamond devices. T he effects of various treatments, including a series of surface prepar ations and thermal annealing, are reported. The study was performed on devices fabricated with carbide- as well as non-carbide-forming conta ct materials. Devices were characterised according to the dark conduct ivity as well as to the alpha particle induced conductivity (CPIC tech nique). The study highlights the strong effects of these treatments on the detection efficiency. From the sets of results it appears that su rface effects are predominant over bulk material modifications or hydr ogen redistribution during annealing. This reinforces the need for opt imised contact formation and post treatment, for electronic and radiat ion detection applications. (C) 1998 Elsevier Science S.A.