Title Promoter Affiliations Abstract "Microelectronics for Microbiology" "Marian Verhelst" "Electronic Circuits and Systems (ECS)" "Life is all about electricity. Certain species of living cells are capable of directly exchange electrons with the surrounding for their metabolism. This remarkable feature of nature has recently gained much attention as a key link for achieving a true circular economy. Indeed, these so‐called bioelectrochemical systems where electricity is supplied to the cells via solid state electrodes and circuitry result in many novel but more importantly renewable bioprocesses. Many exciting products are enabled by this interface ranging from biosensors to self‐powered bioremediation systems and metal recovery technology. We are only on the forefront of this new and exciting evolution on the boundary between micro‐biology and micro‐electronics. However, in depth understanding on how electronic stimuli affect these microorganisms, and on how they are optimally exploited by intelligent electronics is unknown. Bioelectrochemical system control is thus far executed via rigid fixed current / fixed potential approaches. Thus, effective bioelectrochemical systems are in need for dynamic and embedded control which adapts at run‐time to the changing conditions around the microorganisms. This PhD project will, in collaboration with other PhD students in the bio‐engineering department, as well as in the electrical engineering department pursue the development of self‐adapting bioelectrical cells, with massively parallel anode and cathode arrays, with built‐in electrical measurement and stimulation circuitry. This requires a tight interplay between bio‐chemistry, micro‐electronic design, machine learning and control theory." "Modeling of the plasma chemistry in CHxFy based gas mixtures for microelectronics applications." "Annemie Bogaerts" "Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)" "This project represents a formal research agreement between UA and on the other hand Erasmus Mundus. UA provides Erasmus Mundus research results mentioned in the title of the project under the conditions as stipulated in this contract." "Plasma chemistry modeling in a capacitively coupled plasma used for microelectronics applications." "Annemie Bogaerts" "Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)" "Plasmas are widely used in the microelectronics industry for the fabrication of computer chips, i.e., in plasma etching and deposition of different materials. Nowadays there is increased interest for the use of very complex gas mixtures, such as based on CHxFy, sometimes even in combination with HBr, Cl2 and O2. In this project, we wish to obtain a better understanding of the plasma chemistry in several CHxFy plasmas, i.e., CHF3, CH2F2 , CH3F and CF4, by means of a computer model. For this purpose, we will make use of the hybrid plasma equipment model (HPEM). A reaction set will be created, based on a large number of plasma species, including various molecules, radicals, ions, excited species, as well as the electrons. These species react with each other in a large number of collisions, namely electron-neutral, electron-ion, ion-ion, ion-neutral and neutral-neutral reactions. A list of all possible reactions will be constructed, along with the corresponding cross sections and reaction rate coefficients. Subsequently, for every plasma species the various production and loss processes need to be specified, for solving the continuity equations. The transport of the species will be described based on diffusion, migration and advection. The electric field distribution inside the plasma will be calculated self-consistently from the charged species densities by solving Poisson's equation. Typical results of this model include the species densities, fluxes and energies, the electromagnetic field distribution, and information on the importance of various reactions in the plasma." "Numerical simulations of plasmas and their surface processes, used for microelectronics applications." "Annemie Bogaerts" "Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)" "The objectives for this project are to achieve a better insight in:1. the fundamental plasma behavior of novel STI gas mixtures, more specifically, Cl2/O2 in combination with CF4, CHF3, CH2F2 and HBr;2. the surface processes on the Si substrate and the reactor walls during plasma treatment, including trench profile evolution;3. the plasma uniformity in next generation 450 mm wafer reactors." "Computer modelling of plasmas used for etching applications in the microelectronics industry (postdoc.beurs S. ZHAO, China)." "Annemie Bogaerts" "Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)" "Because of the important use of gas discharge plasmas in the microelectronics industry, a good insight in the plasma behavior is desirable. During the research fellowship we will try to obtain this insight by computer simulations. The latter will be compared with experimental data, obtained at her home institution, i.e., Dalian University of Technology." "Computer modeling and experimental validation for plasmas used for etching in the microelectronics industry." "Annemie Bogaerts" "Dalian University of Technology, Plasma Lab for Applications in Sustainability and Medicine - Antwerp (PLASMANT)" "Computer simulations will be performed for describing the plasma chemistry and physics in two reactors used for etching in the microelectronics industry, i.e., inductively coupled plasmas (ICP) and dual frequency capacitively coupled plasmas (CCP). Several fluorocarbon-based gas mixtures will be considered. The effect of different operating conditions (pressure, gas ratio, power, frequency,. . .) will be investigated to predict under which conditions both discharges have optimum performance. Experimental validation of the calculations will be carried out in both types of reactors. Finally, the effect of these operating conditions on the trench formation, the etch rate, uniformity, selectivity and anisotropy will be investigated." "Theoretical and experimental investigation of thermal AC analyses with applications in microelectronics" "Gilbert De Mey" "Department of Electronics and information systems" "The use of AC heat sources, who are varying sinusoidally in function of time, will be analysed. A first application is dealing with the spatial distribution of the heat transfer coefficient through the use of phase measurements. A second application involves the introduction of a fluctuating heat source in a focal plane array thermographic camera." "Development of Microvalves for High-Performance Cooling of Microelectronics" "Dominiek Reynaerts" "Production Engineering, Machine Design and Automation (PMA) Section" "Driven by miniaturization and the continuing increase in clock speed and data transfer, power dissipation in many electronic components has exceeded the limits of conventional cooling methodologies, such as fan-blown air cooling. Given the expected increase in power density, microprocessor designers have identified cooling as one of the major challenges forthe next decade. Similar needs arise from the further development of other electronic devices such as Light Emitting Diodes (LED), where futuregenerations of high light-output multichip LED modules are being developed for general and automotive illumination applications as well as for power electronics. Hence, there is a tremendous need for innovative cooling technologies. One of the most important factors in reducing the lifetime of micro-electronic components is the high operation temperature and thermal cycling. Liquid cooling has been identified as one of the mostpromising solutions in reducing the operation temperature of high powerelectronics. Liquid cooling is often not optimized, leading to excess of cooling and large temperature variations over the IC. If the coolant is allowed to boil in the cooling channels, the heat transfer coefficientis increased with one order of magnitude. The problem of phase transition regime is the boiling instability.A solution of these problems isaddressed by implementation of valves in the cooling system. For single-phase systems they have the role of maintaining a more uniform temperature over the IC and to reduce the pumping power. For two-phase systems the valve purpose is to maintain the most optimum boiling conditions.A comparative study of different actuation principles was performed to identify the best actuation technology applied for chip cooling valves which meet the cooling requirements targeted in this PhD project. This classifies the valve size between the micro and macro-scale, a field which has been mainly overlooked by prior research and potentially promising applications have not been yet explored. It is for the first time that valves are especially designed for chip cooling applications. The principal requirements for the mechanical valves are the following: no leakage to the environment, low power consumption, continuous and proportional flow control, low cost, fast response time, small size and high reliability.The most promising actuation technology found for single-phase flow is thermopneumatic actuation. Based on this principle, a valve has been designed manufactured and tested on a cooling system. The valve actuation is performed by the thermal expansion of a liquid  (actuation  fluid)  which,  at  the  same time, actuates the valve and provides feed-back sensing. The thermopneumatic valve shows a novel actuation principle that combines the advantages of zero power consumption, small size compared with the high flow rate, and low manufacturing costs. This valve has the major advantage that it can be used together with any heat sink used for microelectronic cooling. Its small size and its independence from external energy make it suited for portable devices. No electrical connection, no wires and no electronic control are needed, increasing its simplicity and reliability. A maximum flowrate of 38 kg/h passes through the valve for a heat load up to 133 W. The valve is able to reduce the pumping power by up to 60 % and has the capability to reduce the temperature variation over the IC with up to 24 %.The most suitable actuation principle found for two-phase cooling is electro- magnetic actuation for large bandwidth, large forces, relatively high strokes and low manufacturing cost. The electromagnetic valve uses the reluctance actuation principle. It makes use of a pilot valve to reduce the size and the required actuation force. The emphasis is placed on a compact planar design to fit in planar devices. A pressure balance design allows operation at high system pressures. Because the pressure balance is used to drive the valve, an analytical and numerical model has been developed to predict the pressure distribution over the valve. The pilot valve has also been modelled as well and linearised using the results obtained from the model. The results of the model havebeen successfully validated by measurements. The valve is capable to control a flow rate up to 15 kg/h. This flow rate is sufficient to remove a heat input of 133 W equivalent with a heat flux of 500 W/cm2 at a temperature difference of 20 deg. C. Its equilibrated design allows a pressure drop control of up to 100 kPa at maximum system pressures of 600 kPa.Compared with the latest research published in literature and the latest developments in industry, this electromagnetic valve classifies on topof the list when it comes to the following combined properties in a single package: high speed proportional control, compact dimensions, high flow rates at low pressure drop, high reliability and low manufacturing cost.This research demonstrates the need for valves and the benefits of using valves in high performance cooling systems." "Study of the impact of thermal gradients on the reliability of metals used in micro-electronics" "Ingrid De Wolf" "Structural Composites and Alloys, Integrity and Nondestructive Testing (SCALINT)" "Recent developments in advanced on-chip and 3D-TSV interconnects lead to the introduction of thermal gradients during chip operation and reliability testing. Also, metal or Si-heaters for Si photonics applications require high currents leading to thermal gradients. Interconnects reliability is classically tested using constant current stresses at elevated temperatures. The interconnect failure mechanism triggered by these tests is called electromigration and the lifetime model used in this case is the classical Black’s law. Unfortunately, this model is only valid if the Joule heating induced by the stress current in the metal line is limited. If this condition is not fulfilled, the parameters extracted with this model are meaningless. While electromigration tests on nowadays interconnects fulfill the absence of Joule heating requirement, this is not the case in advanced on-chip and 3D-TSV interconnects. Obviously, for metal or Si-heaters for Si photonics thermal gradients need to be properly considered during reliability testing as well. As a result, a new approach to electromigration testing is needed. The goal of this PhD topic is to investigate and study the reliability of advanced interconnects when thermal gradients are present. The study should lead to the following achievements: • Gaining a deeper understanding of the electromigration failure mechanism when a thermal gradient is present in the line under test; • Building a reliability model calibrated and validated with experimental data measured on suitable test structures, which would allow lifetime predictions in function of the line dimensions and in presence of a thermal gradient; • Identifying by the model the suitable line dimensions, stress gradient and thermal gradient properties which guarantees the respect of the lifetime specs for the interconnections." "MICRO2: Micro-electronics for microbiology" "Marian Verhelst" "Electronic Circuits and Systems (ECS), Universiteit Gent" "Microorganisms can grow on an electrode and either give or receive electricity from it. This allows making better biosensors, or driving bioproduction processes with electricity. It is poorly understood how microorganisms actually interact with the electrical control used to drive the sensor or reactor system. Here, we wish to develop novel micro-electronic control systems and algorithms able to deal with microorganisms in terms of their low current levels, the delay they show in response to stimuli, and their behaviour as parts of an electrical circuit. In the latter context, we will evaluate the behaviour as capacitor or diode by the bacteria and this way learn much about how bacteria respond to fluctuating electron donor/acceptor supply, and what the minimal potential difference (and thus energy level) is needed to sustain metabolism."