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Uniform and ultrathin high-κ gate dielectrics for two-dimensional electronic devices
- Source :
- Nature Electronics. 2:563-571
- Publication Year :
- 2019
- Publisher :
- Springer Science and Business Media LLC, 2019.
-
Abstract
- Two-dimensional semiconductors could be used as a channel material in low-power transistors, but the deposition of high-quality, ultrathin high-κ dielectrics on such materials has proved challenging. In particular, atomic layer deposition typically leads to non-uniform nucleation and island formation, creating a porous dielectric layer that suffers from current leakage, particularly when the equivalent oxide thickness is small. Here, we report the atomic layer deposition of high-κ gate dielectrics on two-dimensional semiconductors using a monolayer molecular crystal as a seeding layer. The approach can be used to grow dielectrics with an equivalent oxide thickness of 1 nm on graphene, molybdenum disulfide (MoS2) and tungsten diselenide (WSe2). Compared with dielectrics created using established methods, our dielectrics exhibit a reduced roughness, density of interface states and leakage current, as well as an improved breakdown field. With the technique, we fabricate graphene radio-frequency transistors that operate at 60 GHz, and MoS2 and WSe2 complementary metal–oxide–semiconductor transistors with a supply voltage of 0.8 V and subthreshold swing down to 60 mV dec−1. We also create MoS2 transistors with a channel length of 20 nm, which exhibit an on/off ratio of over 107. Using a monolayer molecular crystal as a seeding layer, hafnium oxide dielectrics with an equivalent oxide thickness of only 1 nm can be deposited on graphene, molybdenum disulfide and tungsten diselenide.
- Subjects :
- Materials science
business.industry
Graphene
Equivalent oxide thickness
Dielectric
Electronic, Optical and Magnetic Materials
law.invention
Atomic layer deposition
chemistry.chemical_compound
chemistry
law
Monolayer
Optoelectronics
Tungsten diselenide
Electrical and Electronic Engineering
business
Instrumentation
Layer (electronics)
Molybdenum disulfide
Subjects
Details
- ISSN :
- 25201131
- Volume :
- 2
- Database :
- OpenAIRE
- Journal :
- Nature Electronics
- Accession number :
- edsair.doi...........4cc9f215e10383c420a7ff33591b9769