A NEW FABRICATION PROCESS FOR METALLIC POINT CONTACTS

We present a new process to fabricate metallic point contacts. The key feature of this process is the use of a Si membrane. Advantages of th e process are i) the possibility to fabricate very small holes (down t o 10 nm diameter), while the lithographic resolution requirements are modest, ii) the possibility to fine-tune the size of the hole by therm al oxidation and iii) probably a better controlled filling of the hole due to its tapered shape and its sharp edge. From electrical transpor t measurements it follows that the process yields highly ballistic poi nt contacts.