Semiconductor Nanoelectronic Devices Based on Ballistic and Quantum Effects
(2009) Abstract
 As current siliconbased microelectronic devices and circuits are approaching
their fundamental limits, the research field of nanoelectronics is emerging
worldwide. With this background, the present thesis focuses on semiconductor
nanoelectronic devices based on ballistic and quantum effects.
<br>
The main material studied was a modulation doped In0.75Ga0.25As/InP semiconductor twodimensional electron gas grown by metalorganic vapor phase epitaxy.
The thesis covers mainly three types of devices and their twofold integration:
inplane gate transistors, threeterminal ballistic junctions and quantum
dots. Various advanced nanofabrication tools were used to... (More)  As current siliconbased microelectronic devices and circuits are approaching
their fundamental limits, the research field of nanoelectronics is emerging
worldwide. With this background, the present thesis focuses on semiconductor
nanoelectronic devices based on ballistic and quantum effects.
<br>
The main material studied was a modulation doped In0.75Ga0.25As/InP semiconductor twodimensional electron gas grown by metalorganic vapor phase epitaxy.
The thesis covers mainly three types of devices and their twofold integration:
inplane gate transistors, threeterminal ballistic junctions and quantum
dots. Various advanced nanofabrication tools were used to realize the devices, such as electron beam lithography, focused ion beam lithography and atomic layer deposition. The theories behind the analysis of the experimental data include principles of field effect transistors, the LandauerBüttiker formalism, the constant interaction model, etc.
The principles of inplane gate transistors can be explained by a classical
theory. The source, drain, onedimensional channel and two side gates were
in the same plane; a setup that can be obtained by single step lithography.
The gating efficiency of the two independent gates was voltagedependent,
which resulted in a simplified circuitry for implementing a logic function. At
room temperature, an SR latch with a signal gain of ∼4 was realized by the
integration of two inplane gate transistors.
Threeterminal ballistic junctions are nonlinear devices based on ballistic
electron transport. When two terminals are applied with voltages, the third
terminal will output a voltage close to the more negative voltage in the two
inputs, as opposed to a simple average of the two. From numerical calculations,
this ballistic effect persists up to room temperature. Threeterminal
ballistic junctions are so robust that nonlinearity is observable in asymmetric
devices and relatively large devices. They can be fabricated on several
materials by assorted techniques. The junctions find their applications in
analogue frequency mixers, phase detectors and digital SR latches and the
circuits are simpler than conventional designs. The intrinsic speed of the
devices is in the GHz or THz regime by virtue of the ballistic transport. It is believed that asbuilt junctions have a potential as building blocks in future
nanoelectronics.
Quantum dots are zerodimensional boxes for electrons with a decent
resemblance to natural atoms. Due to their nanoscale size, numerous interesting
quantum effects can be observed. Gatedefined quantum dots were
fabricated in InGaAs/InP by incorporating a highk HfO2 (2030 nm thick,
grown by atomic layer deposition) as the gate dielectric. The gate leakage
was suppressed and the gating efficiency improved. At 300 mK, charge stability
diagrams of single and double quantum dots were measured and studied
in detail. Zeeman splitting in a parallel magnetic field and charge sensing by
nearby quantum point contacts were also investigated. The single and double
quantum dots are expected to be useful in fields including single electron
logic, stochastic resonance, spintronics, quantum computing, etc. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/1467890
 author
 Sun, Jie ^{LU}
 supervisor
 opponent

 Prof. Bird, Jonathan, Electrical Engineering Department, University at Buffalo, NY, USA
 organization
 publishing date
 2009
 type
 Thesis
 publication status
 published
 subject
 keywords
 Semiconductor, Quantum Dots, Ballistic Transport, InGaAs/InP 2DEG, Nanoelectronics
 pages
 125 pages
 publisher
 Lund University (MediaTryck)
 defense location
 Lecture hall B, Fysiska Institutionen, Professorsgatan 1, Lund University Faculty of Engineering
 defense date
 20090925 13:15
 ISBN
 9789162878504
 language
 English
 LU publication?
 yes
 id
 c48d7aff22364ddfa3eac751cc4ba5ad (old id 1467890)
 date added to LUP
 20090831 13:10:25
 date last changed
 20160919 08:45:08
@misc{c48d7aff22364ddfa3eac751cc4ba5ad, abstract = {As current siliconbased microelectronic devices and circuits are approaching<br/><br> their fundamental limits, the research field of nanoelectronics is emerging<br/><br> worldwide. With this background, the present thesis focuses on semiconductor<br/><br> nanoelectronic devices based on ballistic and quantum effects.<br/><br> <br> <br/><br> The main material studied was a modulation doped In0.75Ga0.25As/InP semiconductor twodimensional electron gas grown by metalorganic vapor phase epitaxy.<br/><br> The thesis covers mainly three types of devices and their twofold integration:<br/><br> inplane gate transistors, threeterminal ballistic junctions and quantum<br/><br> dots. Various advanced nanofabrication tools were used to realize the devices, such as electron beam lithography, focused ion beam lithography and atomic layer deposition. The theories behind the analysis of the experimental data include principles of field effect transistors, the LandauerBüttiker formalism, the constant interaction model, etc.<br/><br> The principles of inplane gate transistors can be explained by a classical<br/><br> theory. The source, drain, onedimensional channel and two side gates were<br/><br> in the same plane; a setup that can be obtained by single step lithography.<br/><br> The gating efficiency of the two independent gates was voltagedependent,<br/><br> which resulted in a simplified circuitry for implementing a logic function. At<br/><br> room temperature, an SR latch with a signal gain of ∼4 was realized by the<br/><br> integration of two inplane gate transistors.<br/><br> Threeterminal ballistic junctions are nonlinear devices based on ballistic<br/><br> electron transport. When two terminals are applied with voltages, the third<br/><br> terminal will output a voltage close to the more negative voltage in the two<br/><br> inputs, as opposed to a simple average of the two. From numerical calculations,<br/><br> this ballistic effect persists up to room temperature. Threeterminal<br/><br> ballistic junctions are so robust that nonlinearity is observable in asymmetric<br/><br> devices and relatively large devices. They can be fabricated on several<br/><br> materials by assorted techniques. The junctions find their applications in<br/><br> analogue frequency mixers, phase detectors and digital SR latches and the<br/><br> circuits are simpler than conventional designs. The intrinsic speed of the<br/><br> devices is in the GHz or THz regime by virtue of the ballistic transport. It is believed that asbuilt junctions have a potential as building blocks in future<br/><br> nanoelectronics.<br/><br> Quantum dots are zerodimensional boxes for electrons with a decent<br/><br> resemblance to natural atoms. Due to their nanoscale size, numerous interesting<br/><br> quantum effects can be observed. Gatedefined quantum dots were<br/><br> fabricated in InGaAs/InP by incorporating a highk HfO2 (2030 nm thick,<br/><br> grown by atomic layer deposition) as the gate dielectric. The gate leakage<br/><br> was suppressed and the gating efficiency improved. At 300 mK, charge stability<br/><br> diagrams of single and double quantum dots were measured and studied<br/><br> in detail. Zeeman splitting in a parallel magnetic field and charge sensing by<br/><br> nearby quantum point contacts were also investigated. The single and double<br/><br> quantum dots are expected to be useful in fields including single electron<br/><br> logic, stochastic resonance, spintronics, quantum computing, etc.}, author = {Sun, Jie}, isbn = {9789162878504}, keyword = {Semiconductor,Quantum Dots,Ballistic Transport,InGaAs/InP 2DEG,Nanoelectronics}, language = {eng}, pages = {125}, publisher = {ARRAY(0x887cce0)}, title = {Semiconductor Nanoelectronic Devices Based on Ballistic and Quantum Effects}, year = {2009}, }