4th SPM User Meeting - Virtual
Due to exceptional circumstances worldwide, the upcoming SPM User Meeting will take place online on Thursday, April 16th.
The standard, physical User Meeting will be organized again in Lyon in April 2021.
This year's Virtual Meeting will build on the success of its previous physical editions, and will feature a morning and an afternoon session with talks and tutorials focussed on dual-frequency resonance tracking (DFRT) and time-resolved SPM.
What to Expect
With a focus on the measurement of electrical modes at the nanoscale, the event will allow you to attend high-level scientific talks and practical tutorials. This will be a great opportunity to get more insights into SPM and share best practices.
Topics will be centered on electrical modes in SPM, including:
- Piezoresponse Force Microscopy (PFM)
- Contact resonance (e.g., DFRT)
- Electrical pump-probe methods
Speakers who will contribute to the Virtual Meeting:
- Prof. Brice Gautier, INSA Lyon and host of this event
- Dr. Mehdi Alem, Zurich Instruments, Switzerland
- Dr. Romain Stomp, Zurich Instruments, Switzerland
- Mr. Valentin Aubriet, CEA-LETI Grenoble, France
Who Should Participate?
- All Zurich Instruments users
- Researchers in the field of SPM and related areas
- All those interested in understanding how Zurich Instruments' products are used in SPM applications
Session 1: Ferroelectrics Control
10:00 - 11:30 CEST
Talk: B. Gautier, Nanoscale control of ferroelectric domains
Controlling the growth, size and stability of ferroelectric domains is of crucial importance for the integration of ferroelectric materials in future electronic devices. Although artefacts are numerous, techniques derived from scanning probe microscopies enable the direct measurement of the electrical properties of domains, including the unexpected electrical resistance of domain walls. In particular, Piezoresponse Force Microscopy has become the most commonly used tool for domain mapping and creation through voltages applied directly by the AFM tip.
In this webinar, we review the technical aspects enabling the use of PFM for domain imaging, hysteresis loops and domain engineering in the so-called Dual-Frequency Resonance Tracking mode. We evidence the most common artefacts and show how experimental conditions can influence measured properties. Eventually, we provide examples of ferroelectric domain control by means of an electric field or a mechanical stress.
Tutorial: R. Stomp, DFRT method and feedback optimization
In this tutorial, you can expect answers to questions including:
- Why does DFRT work when a PLL fails?
- What makes a good contact resonance?
- How do you choose the right modulation and demodulation settings?
- How do you optimize the feedback loop?
- How many images can be recorded at once?
Session 2: Time-Resolved SPM Methods
14:30 - 16:00 CEST
Talk: V. Aubriet, Photo-sensitive Kelvin probe force microscopy for embedded silicon-oxide interface characterization
Characterization of interfaces is essential for several types of devices such as light-emitting diodes, solar cells, photodetectors, and transistors. In the case of photodetectors, it is important to characterize such interfaces to probe the impact of passivation, where defects present in the interfaces impact the dark current of the photodetector. Moreover, parameters such as surface photovoltage or minority carrier lifetime can reflect the influence of defects on these parameters even when embedded.
For this purpose, we use heterodyne Kelvin Probe Force Microscopy (h-KPFM) under modulated illumination to characterize the silicon interfaces embedded under different types of oxides, specifically Al2O3, Al2O3/Ta2O5, HfO2, SiN, and SiO2. Besides the capability to measure the photovoltage and the minority carrier lifetime, the particularity of this setup is the analysis of these parameters as a function of different illumination wavelengths and the ability to perform in-depth dependent measurements for embedded interface characterization. In this webinar, we present the developed setup for h-KPFM (performed with the HF2LI Lock-in Amplifier) under frequency-modulated and wavelength-dependent illumination. Furthermore, we discuss the influence of different silicon-oxide interfaces on the measured parameters.
Tutorial: M. Alem, Electrical pump-probe with AWG
Here is what you can expect to learn from this tutorial:
- What are the time scales of various time-resolved methods?
- How does electrical pump-probe work in SPM?
- How can you combine fast control of delay and slow detection bandwidth?
- A step-by-step case study: pump-probe KPFM.