Journal
SCIENTIFIC REPORTS
Volume 5, Issue -, Pages -Publisher
NATURE RESEARCH
DOI: 10.1038/srep18000
Keywords
-
Categories
Funding
- National University of Singapore Faculty Research Committee (NUS-FRC) [R-263-000-B21-133, R-263-000-B21-731]
- A*STAR Science and Engineering Research Council [R-263-000-B89-305]
- National Research Foundation, Prime Minister's Office, Singapore
Ask authors/readers for more resources
Black phosphorus (BP) is a new class of 2D material which holds promise for next generation transistor applications owing to its intrinsically superior carrier mobility properties. Among other issues, achieving good ohmic contacts with low source-drain parasitic resistance in BP field-effect transistors (FET) remains a challenge. For the first time, we report a new contact technology that employs the use of high work function nickel (Ni) and thermal anneal to produce a metal alloy that effectively reduces the contact Schottky barrier height (phi(B)) in a BP FET. When annealed at 300 degrees C, the Ni electrode was found to react with the underlying BP crystal and resulted in the formation of nickel-phosphide (Ni2P) alloy. This serves to de-pin the metal Fermi level close to the valence band edge and realizes a record low hole FB of merely similar to 12 meV. The FB at the valence band has also been shown to be thickness-dependent, wherein increasing BP multi-layers results in a smaller FB due to bandgap energy shrinkage. The integration of hafnium-dioxide high-k gate dielectric additionally enables a significantly improved subthreshold swing (SS similar to 200 mV/dec), surpassing previously reported BP FETs with conventional SiO2 gate dielectric (SS > 1 V/dec).
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available