Atomically precise electrical probing

System Concept

The Low Temperature NANOPROBE defines a new class of analytical instrumentation that merges SEM-navigated local transport measurements with atomic scale precision, high performance STM imaging, spectroscopy, and manipulation at LHe temperatures.



Four SPMs
The microscope stage carries four individual SPM modules with independent and guided 3D coarse positioning of XYZ = 5 x 5 x 3mm. The sample can be independently positioned by XY = 4 x 4mm. Our patented piezo-electric inertia drives provide highly reliable and efficient navigation with step sizes from a few tens of nm´s up to several hundred nm. Fine positioning and atomic resolution STM imaging is achieved by shared stack scanners with a range of 1.5µm x 1.5µm at 5K. For ultimate STM performance the microscope stage employs an effective eddy current-damped spring suspension.

Sample & tip exchange
A fast and secure tip and sample exchange is crucial for ease of use and high throughput. Samples and spring loaded tip carriers can easily be exchanged by wobble stick.

Thermal shielding
An efficient thermal shield compartment allows for temperatures well below 5 K, extremely low thermal drift and thermal equilibrium of sample and probes. In addition, high resolution SEM navigation requires a small SEM working distance and thus makes a dedicated STM concept indispensable. A sophisticated shared stack scanner allows for a very compact and flat design, while ensuring highly linear, orthogonal and stable STM scanning characteristics.

Magnetic Fields
A compact superconducting coil is mounted beneath the sample plate and provides a vertical magnetic field of 20 mT.


Transfer through the system

The possibilities for smart transfer of tips and samples throughout the complete UHV chamber and into the LT NANOPROBE stage are fundamental for comfortable routines and processes.

Fast Entry Locks
The LT NANOPROBE offers two different fast entry locks (FEL), located opposite to each other on both sides of the system. This positioning allows for easy provision of tips and samples. Two wobble sticks - both right angled to the transfer rods of the FEL - are taking over the 'inner tasks' like adjustment, handling, positioning or 'parking' of tips and samples within the 28-position-carousel. Various lock valves assure for short pump-down times as well as stable vacuum conditions.

Pumping system
The pumping is realized via efficient turbo- and ion-pumps. The manipulator in the preparation chamber allows for tip and sample preparation, sputtering and depositioning.