Structure
MBE Technology Laboratory with Quality Control of Fabricated Structures: SIMS
About the Laboratory
The laboratory houses the MBE Double RIBER COMPACT 21 installation along with equipment for quality control of fabricated structures.
The MBE Double RIBER COMPACT 21 enables work with elements from Group III and V of the periodic table (first MBE growth chamber) and Group II-VI (second MBE growth chamber).
Currently, we use the following materials:
- In the III-V chamber: In, Al, Ga, As, Sb, Si, Be
- In the II-VI chamber: Te, In, CdI₂, Hg, CdTe, ZnTe
Thanks to our collaboration with the International Centre for Interfacing Magnetism and Superconductivity with Topological Matter (MagTop) – IF PAN, we have access to Cr and Mn cells, as well as the KSA BandIT temperature control system and a RHEED observation and recording system equipped with a camera and PC.
Quality Control Equipment
- Secondary Ion Mass Spectrometer (SIMS) – ION TOF
- HRXRD X-ray Diffractometer – Empyrean by PANalytical
- Optical Microscope with Nomarski Contrast – Olympus DS 1000
- 3D Laser Confocal Microscope – Olympus LEXT OLS 5100
This well-equipped laboratory enables the fabrication of quantum structures in both growth chambers using all available materials. High-vacuum transfer between the chambers allows for the creation of III-V and II-VI hybrid structures without exposure to the external environment.
Team:
- Dr Michał Marchewka
- Dr Eng. Iwona Rogalska
- Dr Eng. Małgorzata Trzyna-Sowa
- Dr Eng. Dawid Jarosz
- MSc Eng. Jakub Grendysa
- MSc Eng. Kinga Maś
- MSc Eng. Marta Ruszała
Laboratory for Magnetotransport at Low and Ultra-Low Temperatures
About the Laboratory
The laboratory is equipped with a measurement system based on an ICEoxford helium cryostat with a superconducting magnet that allows the temperature of samples to be reduced to 0.3 K in a magnetic field with an induction of up to 14 Tesla. The system allows the measurement of electron transport parameters in low-dimensional semiconductor structures (based on group II-VI and III-V elements, graphene): thin films, superlattices, quantum wells, quantum wires, topological insulators with Hall bar or Hall cross contact geometries. The main research techniques are the measurement and analysis of Shubnikov-de Haas oscillations and the quantum Hall effect. The current excitation at the sample is of the DC type with cyclic current reversal (excitation amplitudes are typically in the range of nano- and micro-amps and acquired voltage signals are in the range of 1 nV – 20 V). The system includes two interchangeable sample inserts cooled with He4 and He3.
Basic parameters of the measuring system:
− Sample temperature 1.5 K – 300 K - He4 insert
− Sample temperature 0.3 K – 300 K – He3 insert
− Magnetic fields up to ± 14 Tesla
− Sample size up to 25 mm diameter
− Capacity up to 4 samples (up to 24 signal wires)
Other system components:
· Magnet power supply: AMI430 controller, AMI4006 power supply (adjustable value, field direction, acc. 5 mT)
· Precision four-channel PID temperature controller: Lake Shore 336 (prec. 0.001K)
· Current/voltage sources: Keithley 2634B, Keithley 2400 (acc. 0.05%)
· 8 ½ - digit multimeters: Keithley 2002 (acc. 30 ppm)
· Helium recovery system: Sauer-Tornado WP 4325 compressor
Transport parameters such as carrier concentration and mobility, Hall constant, magnetoresistance and VI characteristics for low-dimensional and bulk materials as a function of temperature in the range 80-350 K are measured using the van der Pauw method with the HMS-5000 Ecopia Hall effect measurement system.
Basic parameters of the measurement system:
− Sample excitation current in the range of 1 nA – 20 mA, acquired voltage signals in the range of 1 µV to 10V.
− Sample temperature in the range 80 – 350 K with 1 K step
− Constant magnetic field 0.535 T +/-1%
− Sample size up to 15×15 mm
− Liquid nitrogen cooled
Staff:
- MSc Paweł Śliż
- MSc Eng. Piotr Krzemiński
Laboratory for Low-Temperature Luminescence
About the Laboratory
The Low-Temperature Luminescence Laboratory enables precise quality control of examined structures by analyzing the energy state positions, which allows for the determination of the optical properties of the studied materials. The laboratory is equipped with high-quality research and measurement equipment to analyze the optical properties of a wide range of materials:
- Low-Temperature Luminescence System
- InVia Micro Raman Renishaw system with Innova Bruker Atomic Force Microscope
- Vertex 80 Bruker FTIR spectrometer with photoluminescence attachment
- Lumos II Bruker IR microscope
The analysis of photoluminescence spectra allows the determination of a material's emission properties, band structure and dopants. It provides information on characteristic energies such as: localization, exciton binding, donors, radiative and non-radiative recombination information. The Low Temperature Luminescence System performs luminescence measurements at low temperatures down to 4.2K. It consists of a λ=640 nm laser as an excitation source (100 mW), optics, sample holder (cryostat) with microscope, HORIBA HR 550 monochromator equipped with three diffraction gratings: 150, 600, 900 lines/mm, a multichannel line detector (InGaAs). It allows photoluminescence measurements of solid samples in the range of 800 - 1700 nm. Measurements can be performed at room temperature or at reduced temperature (cryostat cooled with liquid nitrogen or liquid helium).
Raman spectroscopy measurements can be used to determine the physical and structural properties of an object. It allows the identification of materials and the determination of qualitative and quantitative information about them. This analysis can be applied in many areas, for the study of various types of materials (e.g. carbon materials, semiconductors, polymers, nanomaterials and biomaterials), biomedical studies of biological objects (e.g. cells, tissues, microorganisms, proteins, nucleic acids, lipids), chemical substances (e.g. chemicals, pharmaceutical materials), the study of historical objects (e.g. paintings and archaeological objects) and others. Measurements can be performed for solid samples (including powders) and liquids. The system allows measurements to be made using the SERS technique - Surface Enhanced Raman Spectroscopy.
The InVia Micro Raman Ranishaw spectrometer, with the Leica DM 2500M confocal microscope and the Innova Bruker atomic force microscope (AFM) as integral parts of the set-up, allows Raman spectra of the materials under investigation to be obtained. The instrument is equipped with three laser sources for Raman scattering excitation: λ = 488 nm (50 mW), λ= 633 nm (17 mW), λ = 785 nm (100 mW) and two diffraction grids (2400 and 1200 lines/mm). The detector is a high resolution CCD camera. Measurements are made in the Raman shift range from 50 cm-1 to 4000 cm-1. The use of a confocal microscope with a different objectives (magnification from 5x to 100x) allows to obtain the laser spot size to be reduced from about 5 µm to 1 µm, and even 0.2 µm by coupling with AFM microscopy. The instrument is mounted on a stable anti-vibration table. Point measurements (selected spot on the sample surface), mapping of a specific area of the surface (1 µm step) and measurements in the sample depth gradient (0.1 µm step) are performed.
The Innova AFM Microscope offers high resolution imaging and a wide range of features and application flexibility for demanding scientific research. The system provides atomic resolution and scanning in Contact, Tapping, Non-contact and STM modes. Maximum sample size - 45 mm x 45 mm x 18 mm.
Fourier Transform Infrared (FTIR) spectroscopy is widely used in the analysis of solid, liquid and gaseous materials, providing accurate information about the chemical composition and molecular structure of the sample under investigation. It is of particularly important in semiconductor research, where it plays a major role in material and process characterization. Thanks to its high sensitivity and ability to detect subtle changes in absorption spectra, FTIR can identify the presence of impurities, dopants and defects in the crystal lattice of semiconductors. FTIR is also used to study chemical bonds in organic compounds, and is also used to monitor epitaxial layer growth and etching and oxidation processes, allowing quality control of manufactured structures.
The laboratory is equipped with a Vertex 80 Bruker FT-IR spectrometer, based on an actively aligned UltraScan™ interferometer, which provides the highest spectral resolution, excellent sensitivity and stability. The spectral range of the instrument allows measurements in the mid-infrared from 400 to 7500 cm-1 thanks to the DTGS and LN-MCT detectors. Measurements are performed at room temperature and at reduced temperature using a liquid nitrogen cooled cryostat. The instrument is additionally equipped with a PL II module for near-infrared photoluminescence measurements (green laser excitation, InGaAs detector).
The laboratory also houses Bruker's LUMOS II automated FTIR microscope, designed for precision chemical analysis. The instrument combines high resolution imaging with the accuracy of point spectroscopy, enabling the analysis of micro areas of samples without destroying them. The LUMOS II features a fully integrated interferometer, IR source, detectors and optical cameras, eliminating the need for external components and ensuring measurement stability. LUMOS II is ideal for the analysis of semiconductor materials, polymers, microparticles, tissues and thin films.
Team:
- Dr Renata Wojnarowska-Nowak
- MSc Eng. Anna Juś
Technology Laboratory for Nanolithography and Photolithography
About the Laboratory
The Photo and Nanolithography Technology Laboratory is located in clean rooms and is divided into two workstations.
The first workstation for nanolithography utilizes a scanning electron microscope equipped with an additional ion cathode (a dual-beam microscope) along with a dedicated control system from Raith. This system enables the fabrication of nano-patterns using two methods:
- Electron beam lithography combined with chemical etching (wet etching).
- Ion beam lithography, also known as dry etching.
The second workstation is dedicated to classical photolithography using ultraviolet light. The system includes:
- A spin coater for applying photoresists (light-sensitive emulsions).
- A hot plate for photoresist curing.
- A mask aligner for sample alignment and exposure.
- A developing system for post-exposure processing.
Team:
- Dr Dariusz Płoch
- Dr Eng. Ewa Bobko
- MSc Eng. Piotr Krzemiński
- MSc Eng. Anna Juś