<p>Beyond
graphene, two-dimensional (2D) atomic layered materials have drawn considerable
attention as promising semiconductors for future ultrathin layered
nano-electronic device applications, transparent/flexible devices and chemical
sensors. But, they exhibit high levels of low-frequency due to interfacial
scattering (small thickness) and interlayer coupling (large thickness). The sources
and mechanisms of low frequency noise should be comprehensive and controlled to
fulfill practical applications of two-dimensional transistors. This work seeks
to understand the fundamental noise mechanisms of 2D transistors to find ways
to reduce the noise level. It also verifies how noise can provide a
spectroscopy for analysis of device quality.</p>
<p>Most
noise analysis tend to apply classical MOSFET models to the noise and
electrical transport of 2D transistors, which put together all possible
independent noise sources in 2D transistors, ignoring the contact effects. So
this could lead to wrong estimation of the noise analysis in 2D transistors.
This work demonstrates how the noise components can come from the channel and
contact/access regions, all independently adding to the total noise. Each noise
source can contribute and may dominate the total noise behavior under the
specific gate voltage bias. Herein, the measured noise amplitude in our MoS<sub>2</sub>
and MoSe<sub>2</sub> FETs shows a direct crossover from channel- to contact-dominated
noise as the gate voltage is increased. The results can be interpreted in terms
of a Hooge relationship associated with the channel noise, a transition region,
and a saturated high-gate voltage regime whose characteristics are determined by
a voltage-independent conductance and noise source associated with the
metallurgical contact and the interlayer resistance. The approach for
separating channel contributions from those contact/access region allows clear
evaluation of the channel noise mechanism and also can be used to explain the
qualitative differences in the transition regions between contact- and
channel-dominated regimes for various devices.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/11299232 |
| Date | 14 January 2021 |
| Creators | Jiseok Kwon (8058932) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Low_Frequency_Noise_Sources_and_Mechanisms_in_Two_Dimensional_Transistors/11299232 |
Page generated in 0.0021 seconds