Semester and Master theses
Thin Films - FS12

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Textile Electronics: Development of a Flow Sensor in a Textile Filter of Air Conditions [D-ITET, 1]

To increase the value and the use of textile products electronic components are integrated into textiles to enhance their functionality. This is done by micro fabrication of electronic components directly on yarns or strips and weaving them with commercial weaving machines into a textile. One idea is to integrate a flow sensor consisting of two interdigitated meander shaped resistors into a textile. One resistor acts as heating element the other as temperature sensor. Depending on the flow of i.e. air, the temperature changes due to the heat transport. This can be used in an air conditioning system to controll the flow rate. A student would have to design and implement the sensor system and demonstrate the feasability of the concept. The work is done in the cleanroom facilities of ETH and in the labs of the institute.

Distribution: 10% literature study, 50% fabrication, 40% evaluation
Requirements: Knowledge of sensors and micro technologies
Main supervisor: Thomas Kinkeldei, H61.1, E-Mail: kinkeldei@ife.ee.ethz.ch, Telephone: 24727
Second supervisor: Christoph Zysset, H61.1, E-Mail: zysset@ife.ee.ethz.ch, Telephone: 0446326126
Project Title: Smart Textiles
Professor: Prof. Tröster

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Plastic Electronics: Artificial olfaction using an electronic nose [D-ITET, 1..2]

Producing thin films on flexible substrates opens new domains for electronic applications. One idea is monitoring of wound healing using a so called electronic nose. A textile with an integrated flexible electronic nose on a plastic substrate can be used directly as the upper bandage of a wound dressing. With the use of micro fabrication techniques in the FIRST clean room a student will improve the electronic nose system. Our electronic nose system consists of several gas sensors, made out of different polymer with integrated conductive filler material. As filler materials carbon black is used, that is itself sensitive to humidity and othe chemicals. The change from the carbon black to less reactive materials like metals will make the system more stable and improve the sensing behavior. For this theses a student would develop new sensing materials based on metal filler and test the new sensors in a gas measurement system at the lab to different odorouse species.

Distribution: 10% literature study, 50% fabrication, 40% evaluation
Requirements: Knowledge of sensors and micro technologies
Main supervisor: Thomas Kinkeldei, H61.1, E-Mail: kinkeldei@ife.ee.ethz.ch, Telephone: 24727
Second supervisor: Christoph Zysset, H61.1, E-Mail: zysset@ife.ee.ethz.ch, Telephone: 0446326126
Project Title: Smart Textiles
Professor: Prof. Tröster

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Amplifier circuits based on IGZO thin-film transistors [D-ITET, MT, 1..2]

Thin-film electronics are a key component for integrating sensors into woven smart textiles. Many sensor types require an amplification of their analogue voltage or current output. Therefore, we started to build amplifier circuits for voltage and current signals made of IGZO thin-film transistors on flexible substrates and obtained promising results. The goal of this thesis is to improve on these amplifiers in terms of speed, gain and circuit complexity. To achieve this goal we are looking for a student who is interested in simulation, design and evaluation of analogue electronics, such as operational amplifiers and low noise amplifiers. Simulation and design comprise tasks such as improving our existing transistor model, designing and simulating amplifier circuits and layout the circuits. The evaluation tasks involve testing fabricated amplifier circuits and improving the measurement set-up. This work is an unique opportunity to apply and deepen your knowledge on transistors and analogue circuits.

Distribution: 10% literature study; 50% modeling, simulation, layout; 40% testing
Requirements: Interest in simulation and measurement and basic knowledge of analog electronics
Main supervisor: Christoph Zysset, H61.1, E-Mail: zysset@ife.ee.ethz.ch, Telephone: 0446326126
Second supervisor: Niko Münzenrieder, H61.1, E-Mail: niko.muenzenrieder@ife.ee.ethz.ch, Telephone: 20411
Project Title:
Professor: Prof. Tröster

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Flexible p-type TFTs based on oxide semiconductors [D-ITET, MT, 1]

Nowadays thin film transistors (TFTs) are one of the most important electronic devices because of their low price and the possibility of large area fabrication - just think about the great success of TFT displays or touch screens in the last few years! By comparison to high performance transistors used in modern microprocessors, flexible thin film transistors are produced on bendable, substrates like plastic, and not on bulky semiconductor wafers. Therefore they have to be fabricated a low temperatures (200 °C). As the name suggests a TFT consists of various very thin layers deposited one after the other using different semiconductor fabrication technologies.
The Electronics Laboratory is fabricating TFTs using novel oxidic semi-conducing materials such as polycrystalline amorphous indium-gallium-zinc-oxide (IGZO). The deposition of this material is done using a sputter tool. Nearly all oxidic semiconductors are n-type, and therefore no CMOS circuits are possible. This is probably the most important problem which has to be solved before the large scale commercial production of flexible electronic devices can start.
The aim of this thesis will be the deposition and characterization of p-type semiconductors like NiO or SnO on plastic substrates. In a second step flexible p-type TFTs will be fabricated. The ultimate project goal is the production of simple CMOS circuits like inverters by combining the new p-type and the established n-type process.
This thesis is a great opportunity to work inside the FIRST Lab, the cleanroom facility of the ETH, and to gain experience with different semiconductor manufacturing technologies.


Distribution: 30% characterization, 70% cleanroom work
Requirements: Curiosity
Main supervisor: Niko Münzenrieder, H61.1, E-Mail: niko.muenzenrieder@ife.ee.ethz.ch, Telephone: 20411
Second supervisor: Christoph Zysset, H61.1, E-Mail: zysset@ife.ee.ethz.ch, Telephone: 0446326126
Project Title:
Professor: Prof. Tröster

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Bending flexible transistors [D-ITET, ST/MT, 1]

Nowadays thin film transistors (TFTs) are one of the most important electronic devices for example because of their low price and the possibility of large area fabrication. The maybe biggest advantage of TFTs ? the possible fabrication on flexible substrates ? is not jet commercially used, even though the potential of artificial skins or smart textiles is huge. One problem is the partially still unknown influence of mechanical strain on the performance of single TFTs or circuits.
The Electronics Laboratory fabricates TFTs on flexible plastic substrates using novel oxidic semi-conducing materials like amorphous indium-gallium-zinc-oxide (IGZO).
The aim of this thesis will be the characterization of TFTs and circuits exposed to mechanical strain, induced by bending. These experiments will answer questions concerning the impact of mechanical stain on the TFT performance, or the minimum possible bending radius. But also the influence of different material combinations and device structures is a open research problem. Answers to these questions are e.g. important for the reliable fabrication of flexible displays.



Distribution: 70% measurements, 30% evaluation
Requirements: Interest in thin film technology, and characterization techniques
Main supervisor: Niko Münzenrieder, H61.1, E-Mail: niko.muenzenrieder@ife.ee.ethz.ch, Telephone: 20411
Second supervisor: Christoph Zysset, H61.1, E-Mail: zysset@ife.ee.ethz.ch, Telephone: 0446326126
Project Title:
Professor: Prof. Tröster

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Stretchable transistors [D-ITET, ST/MT, 1]

Nowadays thin film transistors (TFTs) are one of the most important electronic devices especially because of their low price and the possibility of large area fabrication. In the last time the fabrication of TFTs on flexible substrates has also become an important research field. Flexible substrates are for example plastic foils which are bendable. The next step in this development is the replacement of the flexible substrates by elastic ones; this means e.g. deformable and stretchable polymers. Unfortunately the resistivity of plastic foils against high temperatures and chemicals is limited; therefore it?s difficult to fabricate devices like TFTs on flexible substrates. This problem gets even worse if we want to use elastic polymers.
The aim of this thesis will be the fabrication of TFTs on elastic substrates. This will be done using a shadow mask process. This process enables the device fabrication at room temperature without the need to use any chemical etchants or solvents. Nevertheless problems correlated e.g. with the high surface roughness of the available elastic substrates have to be solved. The characterization of the fabricated TFTs is also a part of this thesis.
This thesis gives you the opportunity to work inside a state-of-the-art cleanroom, and to gain experience with different semiconductor deposition and analysis tools.


Distribution: 60% cleanroom work, 40% measurement
Requirements: Interest in thin film technology
Main supervisor: Niko Münzenrieder, H61.1, E-Mail: niko.muenzenrieder@ife.ee.ethz.ch, Telephone: 20411
Second supervisor: Thomas Kinkeldei, H61.1, E-Mail: kinkeldei@ife.ee.ethz.ch, Telephone: 24727
Project Title:
Professor: Prof. Tröster

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Smart Textiles: Development of a new micro patterning approach for smart textiles [D-ITET/D-INFK, 1]

Smart textiles are an increasing field of interest in research. Recent approaches use micro fabrication methods on planar substrates. Electronic components are fabricated in a design to fit on a strip with a small width in the same range like common textile yarns. The single strips are then cut receiving multiple yarn like bands. One arising problem here is the transfer from small scale production to big industry scale and the conflicts with other textile yarns in weaving machines. A different approach would be to fabricate micro sensors on a heat transfer foil, that can be laminated onto textiles by ironing. The method here would be i.e. to use MEMS techniques and fabricate electronic micro temperature sensors in similar way. The student would have to first develop a feasible method for structuring micro sensors on those foils. Second the student needs to characterize the advantages and limitations of his method and then compare it to micro components made on flat substrates. The work will be carried out in the clean room facilities FIRST at ETH and in the labs of the Electronics Laboratory. A demonstrator can be made by laminating the temperature sensors on underwear and measer the body temperature.

Distribution: 10% Literatur, 40% Fabrication, 50% Testing
Requirements: Interest in micro fabrication technologies and smart textiles
Main supervisor: Thomas Kinkeldei, H61.1, E-Mail: kinkeldei@ife.ee.ethz.ch, Telephone: 24727
Second supervisor: Christoph Zysset, H61.1, E-Mail: zysset@ife.ee.ethz.ch, Telephone: 0446326126
Project Title: Smart Textiles
Professor: Prof. Tröster

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2D MsO2 semiconductor transistor on plastic [D-ITET, ST/MT, 1]

Thin film transistors (TFTs) are important electronic devices because of their low price and the possibility of large area fabrication. Two-dimensional materials have interesting physical properties, and are attractive for use in next-generation TFTs because, compared to one-dimensional materials, it is relatively easy to fabricate complex structures from them. The most widely studied two-dimensional material is graphene both because of its rich physics and its high electron mobility; however, it does not have a bandgap, a property that is essential for many applications, including transistors. Although, single layers of MoS2 have a large intrinsic bandgap of 1.8 eV and high mobility; moreover its integration in a transistor like structure has been already demonstrated showing a room-temperature mobility of at least 200 cm2/Vs, a current on/off ratio of 1x108 and ultralow standby power dissipation.
The main goal of the project is to fabricate MsO2 Thin Film Transistors (TFTs) on flexible plastic substrate. This could path the way to a new generation of TFTs for plastic electronics. The MsO2 will be deposited through exfoliation, this means thin layers of the material are transferred to the plastic substrate using a sticky tape. The main part of this work will be performes in the FIRST cleanroom. This gives you the opportunity to get familiar with the most important semiconductor processing technologies. The finished TFTs will be electricaly characterized using state of the art characterization equipment.


Distribution: 10% literature study, 60% fabrication, 30% characterization
Requirements: Knowledge of transistors and interest in micro technologies
Main supervisor: Giovanni Salvatore, H1000, E-Mail: giovanni.salvatore@ife.ee.ethz.ch, Telephone: 666666
Second supervisor: Niko Münzenrieder, H61.1, E-Mail: niko.muenzenrieder@ife.ee.ethz.ch, Telephone: 20411
Project Title:
Professor: Prof. Tröster

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Simulation of Negative Capacitance Ferroelectric Transistor [D-ITET, MT, 1]

It is generally accepted that the ongoing scaling of field effect transistors (FETs) will be eventually limited by the inability to remove the heat generated in the switching process, making it very important to find ways to reduce the power dissipated per switching event. In a FET, the most important limiting factor to the power dissipation is the inverse subthreshold slope (SS) that essentially is how much voltage is needed to increase the drain to source current of one decade. In silicon transistor this limit is set to 60mV/dec. Very recently it has been proposed by a Prof. in Berkeley that a ferroelectric gate stack could operates as a step-up voltage amplifier, thanks to a Negative Capacitance effect, and lower the SS below the 60mV/dec limit. Moreover a proof of concept has been also achieved at EPFL through the integration of a ferroelectric polymer.
However, a complete numerical model has not been developed yet. Hence the main goal of the project is to simulate the voltage and temperature dependence of the ferroelectric material and its multi-domains structure and integrate it on top of a transistor like structure. Moreover a scaled device will be also compared to other emerging devices (TFETs, CNT transistors).


Distribution: 30% literature study, 70% simulation
Requirements: Knowledge of transistors and device simulation
Main supervisor: Giovanni Salvatore, H1000, E-Mail: giovanni.salvatore@ife.ee.ethz.ch, Telephone: 666666
Second supervisor: Niko Münzenrieder, H61.1, E-Mail: niko.muenzenrieder@ife.ee.ethz.ch, Telephone: 20411
Project Title:
Professor: Prof. Tröster