Measurement of electric potential fields in integrated circuits with nanometer resolution

TO-116 • PT 1.2691 • As of 10/2023
Peter Grünberg Institute
Quantum Nanoscience (PGI-3)

Technology

Our new technology aims to overcome the limitations of conventional approaches by enabling the measurement of electric potential fields with high spatial resolution. Unlike traditional techniques, our invention allows for the exclusive detection of electric potential fields, eliminating interference from other forces such as van der Waals interactions. At the heart of our innovation is a scanning probe microscope equipped with a quantum dot positioned at its tip. This quantum dot serves as a local probe for the electric potential field, filtering out unwanted signals and amplifying the desired measurements. The energy levels of the quantum dot can be finely tuned, enabling precise detection of even small changes in the local electric potential field.

Problem addressed

Common techniques to measure electrical potentials or fields with nanometer resolution, Kelvin Probe Force Microscopy (KPFM) or Electrostatic Force Microscopy (EFM), have limitations. EFM measures forces from distant parts of the microscope tip due to long-range electric fields, while KPFM is influenced by the contact potential difference from distant parts of the tip. The size of the metal tip, particularly the tip radius, limits the achievable lateral resolution of both KPFM and EFM. EFM can only measure forces, not electric fields, or potential differences, making it difficult to determine the electric field. KPFM's resolution depends on the tip-sample distance and tip radius, and it can only measure two-dimensional maps of contact potential difference. Additionally, the measured force with the scanning probe microscope is nonspecific, capturing all forces including van der Waals forces, requiring complex analysis to extract the electric force.

Solution

Our new approach offers several advantages over existing methods. Firstly, it allows for the measurement of electric potential fields with high spatial resolution, independent of the tip radius and distance to the sample. This means that even areas further away from the tip's endpoint do not affect the measurement, resulting in superior resolution compared to conventional approaches. Additionally, our invention enables the exclusive detection of electric potential fields, eliminating interference from other forces. This ensures accurate and reliable measurements. Furthermore, our technology is capable of generating three-dimensional maps of the potential field, providing valuable insights into the sample's properties. With its contactless measurement capability, our innovation is also suitable for non-conductive samples, expanding its applicability in various fields.

Benefits and Potential Use

The application of our new technology enables researchers to measure electric potential fields with high resolution in fields such as nanotechnology, materials science, and surface analysis. The users can thus utilize our invention to study the electrical properties of nanostructures, investigate charge distribution in materials, and analyse the behaviour of electric storage devices at the atomic level. The contactless nature of our technology makes it particularly suitable for reading information stored in nanoscale memory devices without the risk of unintended writing. Furthermore, the ability to generate three-dimensional maps of potential fields provides valuable insights for designing and optimizing electronic devices. Our innovation offers a powerful tool for scientists and engineers seeking to understand and manipulate electric potential fields at the nanoscale.

Development Status and Next Steps

Forschungszentrum Jülich has extensive expertise in this field and holds several patents. The technology described above has already been initially verified through prototypes and is continuously being developed further.

The Peter Grünberg Institute (PGI-3) – Quantum Nanoscience – already cooperates with numerous national and international companies and scientific partners. Forschungszentrum Jülich focuses on energy and cost-efficient devices, suitable for various emerging technologies. We are continuously seeking for cooperation partners and/or licensees in this and adjacent areas of research and applications.

More technologies