Voltage Controlled Hot Carrier Injection Enables Ohmic Contacts Using Au Island Metal Films on Ge

John Quilter

Research output: Contribution to journalLetterpeer-review


We introduce a new approach to creating low-resistance metal–semiconductor ohmic contacts, illustrated using high conductivity Au island metal films (IMFs) on Ge, with hot carrier injection initiated at low applied voltage. The same metallization process simultaneously allows ohmic contact to n-Ge and p-Ge, because hot carriers circumvent the Schottky barrier formed at metal/n-Ge interfaces. A 2.5× improvement in contact resistivity is reported over previous techniques to achieve ohmic contact to both n- and p- semiconductor. Ohmic contacts at 4.2 K confirm nonequilibrium current transport. Self-assembled Au IMFs are strongly orientated to Ge by annealing near the Au/Ge eutectic temperature. Au IMF nanostructures form, provided the Au layer is below a critical thickness. We anticipate that optimized IMF contacts may have applicability to many material systems. Optimizing this new paradigm for metal–semiconductor contacts offers the prospect of improved nanoelectronic systems and the study of voltage controlled hot holes and electrons.
Original languageEnglish
Pages (from-to)27357-27364
Number of pages8
JournalACS Applied Materials & Interfaces
Issue number33
Early online date7 Aug 2017
Publication statusPublished - 23 Aug 2017

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