Two-Dimensional Materials Inserted at the Metal/Semiconductor Interface: Attractive Candidates for Semiconductor Device Contacts.
Nano Lett
; 18(8): 4878-4884, 2018 08 08.
Article
em En
| MEDLINE
| ID: mdl-30036065
ABSTRACT
Metal-semiconductor junctions are indispensable in semiconductor devices, but they have recently become a major limiting factor precluding device performance improvement. Here, we report the modification of a metal/n-type Si Schottky contact barrier by the introduction of two-dimensional (2D) materials of either graphene or hexagonal boron nitride (h-BN) at the interface. We realized the lowest specific contact resistivities (ρc) of 3.30 nΩ cm2 (lightly doped n-type Si, â¼ 1015/cm3) and 1.47 nΩ cm2 (heavily doped n-type Si, â¼ 1021/cm3) via 2D material insertion are approaching the theoretical limit of 1.3 nΩ cm2. We demonstrated the role of the 2D materials at the interface in achieving a low ρc value by the following mechanisms (a) 2D materials effectively form dipoles at the metal-2D material (M/2D) interface, thereby reducing the metal work function and changing the pinning point, and (b) the fully metalized M/2D system shifts the pinning point toward the Si conduction band, thus decreasing the Schottky barrier. As a result, the fully metalized M/2D system using atomically thin and well-defined 2D materials shows a significantly reduced ρc. The proposed 2D material insertion technique can be used to obtain extremely low contact resistivities in metal/n-type Si systems and will help to achieve major performance improvements in semiconductor technologies.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
Nano Lett
Ano de publicação:
2018
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Article