Schlagwort: ‘Chair of Electronic Devices’
Graphene in microelectronics – research for series production
Professor Max Lemme holds the Chair of Electronic Devices at RWTH Aachen University and is Director of the non-profit research organisation AMO GmbH. © Martin Braun
As part of the completed European 2D-Experimental Pilot Line (2D-EPL) project, AMO GmbH has realized two multi-project wafer runs for the large-scale production of electronic devices based on graphene.
The discovery of graphene and other two-dimensional materials in 2004 was seen as potentially revolutionary for advances in microelectronics. The material’s high carrier mobility, broadband optical absorption, low thickness and high mechanical strength have raised great expectations for the use of graphene in electronics, optoelectronics and sensor technology.
‘There are now plenty of publications that show prototypes of devices based on 2D materials with performances significantly beyond the state-of-the-art,’ says Cedric Huyghebaert, technical leader of the 2D-EPL project.
However, the semiconductor industry has not yet produced any commercially viable graphene devices. This is due to a number of challenges, including but not limited to graphene growth, graphene transfer and purification. The transition from scientific experiments involving only a small number of graphene devices to real applications based on reliable manufacturing processes for mass production has stagnated.
The 2D-EPL project, which was funded by the European Commission, was a €20 million initiative that sought to demonstrate the technical feasibility of manufacturing devices based on graphene and other two-dimensional materials on a large scale. The primary objective of this project was to promote market feasibility. In pursuit of this objective, all actors involved in the value chain were convened between October 2020 and September 2024, resulting in the execution of five multi-project wafer (MPW) runs. In addition to the development of process modules at an industrial level, the delivery of graphene-based devices to customers was a further objective. Each of these runs provided universities, research institutes and companies with the opportunity to customise their components on a wafer chip.
‘Our final goal is to demonstrate that it is possible to produce a wide range of devices based on two-dimensional materials in a way that is interesting for industry, and each multi-project wafer run wants to set a milestone in that direction,’ explains Professor Max Lemme, scientific director of AMO GmbH and holder of the Chair of Electronic Devices at RWTH Aachen University
AMO GmbH has successfully executed the inaugural and third multi-project wafer run in a cutting-edge clean room facility. The initial MPW run addressed the definition of graphene field-effect transistors with exposed graphene channels, with a focus on their applications in chemical and biosensor technologies. The subsequent MPW run dealt with the definition of transistors with dielectric encapsulation, which were intended for utilisation in electronic applications. The specified device performance parameters for mobility, charge neutral point, sheet resistance and contact resistivity were measured. Should the target values be realised and the optical microscopic analysis demonstrate acceptable quality with regard to lift-off and etching, the wafer would be deemed ready for delivery. The researchers confirmed the existence of challenges that had previously been identified, including the formation of residue from the resist, which can present difficulties in the context of biosensor applications, given the necessity of a pure graphene surface. Furthermore, there were still unknown problems at the time, such as unexpected customer-specific requirements and their technical realisation, which had to be solved.
‘We consider the wafer runs to be successful because the device yield and performance met or exceeded the initial specifications across the wafers. In addition, all customers were served with little or no delay,’ reads the scientific article presenting the results of the first and third multi-project wafer runs.
The results of the five multi-project wafer runs form the basis of the follow-up project 2D-Pilot Line (2D-PL). The objective of the present pilot line is to further strengthen the European ecosystem in the development of integration modules for photonics and electronics prototyping services. The work is centred on the maturation of semiconductor technologies and the provision of information to support industrial deployment. In this context, comprehensive prototyping services are offered for the integration of 2D materials, such as graphene, on established semiconductor platforms with silicon technologies.
The scientific article Multi-project wafer runs for electronic graphene devices in the European 2D-Experimental Pilot Line project provides further insights into the multi-project wafer runs one and three.
Further information on the topic can be found on the homepage of the Chair of Electronic Devices.
The 2023 Annual Report of the Graphene Flagship provides an overview of the work of the 2D Experimental Pilot Line, presenting the current status of 2D materials research in Europe and new projects.
Scholarship holder develops protective helmets made of snail shells
© Judith Peschges
Bayode Adeyanju from Nigeria is developing innovative protective helmets at the Chair of Electronic Devices (ELD) that combine natural and artificial materials.
In February of this year, the scientist arrived at the Chair of Electronic Devices at RWTH Aachen University, having been awarded a scholarship from the German Academic Exchange Service (DAAD). Until May, he will be conducting research under Professor Max Lemme’s supervision, with the objective of developing stable helmets that optimally absorb shocks and offer particularly good protection. For the purposes of his research, Adeyanju is combining artificial Kevlar fibres with natural snail shell nanoparticles. In the context of Nigeria, where snail shells are commonly viewed as a nuisance and a potential environmental concern, their high calcium content renders them of interest for materials research. The scientist crushed both materials and ground them finely. The substance was then combined with epoxy resin, and subsequently filled into a mould, where it underwent a process of hardening. Subsequent tests were then conducted to ascertain the impact resistance, hardness and density of the helmets. The combination of the favourable properties of the two base materials forms the basis for the production of high-performance protective helmets.
In his study, Adeyanju presents the results of his research, which indicates that the combination of natural and artificial materials enables the development of innovative protective materials. At RWTH, the scholarship holder utilises state-of-the-art research facilities and equipment to characterise selected materials. Such studies would not be possible at his home university in Nigeria.
‘Knowledge is power,’ says Adeyanju, adding: ‘RWTH has everything it takes to change the world.’
The first thing he noticed in Aachen was how the streets became quieter in the early evening as people went home, says Bayode Adeyanju. This is very different from his home country of Nigeria, where he is used to having friends and family over. Even though Aachen is quieter in the evenings than Nigeria, Adeyanju felt welcome from the start of his research stay. AMO GmbH, a non-profit research organisation, is also contributing to this by supporting his four-month stay. And after one month at RWTH Aachen, Bayode Adeyanju is sure that he would like to come back and continue his cooperation with the Chair of Electronic Devices (ELD).
‘I have received a great deal of support from my colleagues at the ELD and at AMO, as well as from the students, and I feel very happy here,’ says the scientist.
Adeyanju decided to apply to the DAAD two years ago and was accepted last year. The German Academic Exchange Service is a prominent funding organisation that facilitates international student and academic exchange. Funded by German universities and student bodies, the organisation aims to prepare future specialists and managers to act responsibly and to create lasting connections worldwide. This objective is pursued by fostering professional and cultural networks among scholarship holders. Since its foundation in 1925, the DAAD has sponsored more than 2.9 million young academics in Germany and abroad. It is institutionally supported by the Federal Foreign Office.
With its motto ‘Change by Exchange’, the DAAD emphasises the importance of international understanding and cooperation. Another of the organisation’s central concerns is to support developing countries in establishing efficient universities, thus contributing to social, economic and political development.
Max Lemme receives RWTH Fellow award
Vice Rector Sabine Brück (left) and Vice Rector Matthias Wessling (right) honour Professor Max Lemme as RWTH Fellow. Photo: Andreas Schmitter
Professor Max Lemme, head of the Department of Electronic Devices, and Professor Harald Müller, head of the Department of Medieval History, are new RWTH Fellows. With this title, the RWTH Aachen University honours professors who have distinguished themselves in research and have rendered outstanding services to the RWTH Aachen University.
Professor Max Lemme is a highly respected expert in the field of devices based on 2D materials and enjoys international recognition. One of his major achievements is a study on a graphene-based field-effect transistor, which has been cited 1353 times to date. He has successfully obtained research funding, including an ERC Starting Grant in 2012 and a Proof of Concept Grant from the European Research Council in 2018. He was also awarded a prestigious Heisenberg Professorship by the German Research Foundation in 2012. Max Lemme was instrumental in the establishment of the NeuroSys Cluster of Excellence and is its spokesperson. He is also an expert reviewer for the European Community and regularly participates in major conferences in the field of semiconductor devices, including IEDM, ESSDERC, DRC and ULIS.
The award he holds was introduced as part of the Excellence Initiative in 2013 and is based on nominations from the Deans of the Faculties.
Click here to go to the website of the Chair of Electronic Components.
