Our equipment at the EMRL in Aachen and Jülich comprises a broad spectrum of facilities for the fabrication and characterization of electronic materials and devices. Emphasis is placed upon oxide deposition technologies, ranging from laser MBE, atomic layer deposition by MOCVD, and high pressure sputtering through to chemical solution deposition (CSD). These facilities are complemented by integration technologies such as optical and nanoimprint lithography, various metallization techniques, plasma-based and ion beam-based dry etching, as well as scanning probe-based manipulation and self-assembly methods. In addition, we are equipped with a large variety of tools for the characterization of processes, structures, and electronic properties. In particular, we provide a large range of dedicated scanning probe tools in order to analyze specific properties with atomic resolution. Circuit design is utilized for the development of hybrid and integrated circuits which comprise new electronic functions as well as advanced measurement systems. Furthermore, our competences include numerical simulation and modelling methods which aim at the quantitative description of the electronic phenomena and materials under study as well as the corresponding devices.
The EMRL is a founding member of the section Fundamentals of Future Information Technologies of the Jülich-Aachen Research Alliance (JARA-FIT) and, as such, in addition to our own equipment, we have access through our partner institutes in the alliance to almost every conceivable nano-fabrication and nano-characterization technique.
Atomic Scale Deposition and Self-assembly - Electronic Oxides and Molecular Systems
The EMRL provides a very wide spectrum of electronic oxide thin film deposition techniques. Our laser-based molecular beam epitaxy (laser-MBE) allows for the growth of heteroepitaxial oxide layers, termination controlled interfaces, oxide superlattices, and artificial electronic oxides. Metal-organic chemical vapour deposition (MOCVD) including the atomic layer deposition from the vapour phase (ALD) is used for conformal coverage of micro- and nanoelectronic structures on chips by complex oxides. Multi-head high-pressure sputtering systems offer a versatile and flexible opportunity for the deposition of epitaxial oxide thin films. Chemical solution deposition (CSD) is a very flexible method mainly for producing polycrystalline or textured oxide films ranging from 50 nm to 5 m. In addition, our laboratory offers deposition techniques for molecular systems based on solution processes and UHV evaporation methods
Probing the Nanoworld
Progress in nanoscience and nanotechnology is closely related to the evolution of novel techniques in experimental analysis. Tip-based scanning probe systems represent the workhorses of our equipment at the EMRL for probing nanoscale structures and objects with atomic resolution. These include dedicated environments such as local conductivity microscopy (LC-AFM), tunnelling microscopy (STM) and conductance spectroscopy (STS) of low-dimensional structure on oxide surfaces and of molecular systems, piezoresponse force microscopy (PFM) of polar oxide nanostructures and ferroelectric domain configurations, as well as nano-Raman and tip-enhanced Raman spectroscopy (TERS).
This is complemented by our studies of electronic materials and fabricated nanostructures using our close ties with the Ernst Ruska-Centre for ultra-high resolution transmission electron microscopy and spectroscopy as well as with the institutes of JARA-FIT which operate modern synchrotron beam lines with a multitude of analytical techniques for the investigation of structural and electronic properties of electronic materials.
Our laboratories provide a wide variety of general and dedicated measuring systems for the electrical characterization of electronic thin film materials and demonstrator devices under controlled conditions (temperature, atmosphere, bias voltage, ageing history, etc.). Our equipment includes, for example, ultra-broad band impedance analyzers, ferroelectric and piezoelectric hysteresis set-ups, a double beam laser interferometer with a resolution down to 0.1 pm(!), ultra-fast transient analyzers for a temperature range between 4 K and 1500 K, microwave network analyzers, semiconductor parameter analyzers, electrochemical potentiostats, etc.
A range of dedicated measuring systems has been developed in our laboratories which led to the foundation of the company aixACCT Systems GmbH in the year 2000, which successfully develops, produces, and sells customer-specific advanced measurement equipment. Today, the focus of our own development activities at the EMRL lies in the design and realization of complex ultra-high resolution scanning probe systems for dedicated applications.
Circuit and System Design
The analysis and design of circuits depends crucially on the utilization of suitable tools for simulation and synthesis. EMRL provides a professional infrastructure for the design and prototyping of the measurement equipment at its disposal. This comprises design tools for ASIC design, FGPA design, and PCB design, a complete PCB prototyping facility, and test equipment for digital and analog circuit evaluation.
Simulation and Modelling
Our main interest lies in modelling, on different scales and with a variety of approaches, performed for the investigation of phenomena, materials, and devices. Model-based numerical simulations are employed using both self-developed program modules and commercial standard tools. The approaches comprise Finite Element/Difference Methods (FEM / FDM), Monte Carlo (MC) and Molecular Dynamics (MD) methods, as well as analytical calculations based on band theory, thermodynamics, and drift-diffusion transport theory.
For example, we model the point defect disorder in oxides, electrostatic and electromagnetic fields using FEM/FDM, electron injection and transport on the microscopic scale of single molecules and on the macroscopic scale for metal-insulator-metal systems, redox processes and electrochemical metallization employing MD methods. We cooperate closely with theoretical scientists in order to link our micro and nanoscale simulations to ab-initio quantum mechanical models in which, for example, local electron densities in crystal dislocation can be calculated on the atomic scale.