Ultrahigh vacuum scanning tunneling microscope GPI 300
Purpose
The device is designed for high-precision (atomic scale) study of processes occurring on metal and semiconductor surfaces under ultrahigh vacuum. The device makes it possible to record atomic resolution topograms of clean surfaces and those of adsorbed layers, and can be integrated into any analytical or technological vacuum unit.
Download: General description of ultra-high vacuum scanning tunneling microscope GPI 300 (in Russian):
Unique Features
– Open architecture of the scanner to deliver gas, molecular and light (laser) beams directly onto the sample into the tunnel junction zone during the scanning process.
– Low noise control electronics and high vibroinsulation. The tip-sample gap deviation less than 4 pm.
– Tip positioning in X, Z coordinates in the range of 10×5 mm.
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Specification
| Operation temperature | 300 К | |
| Стандартные опции | топография | |
| Scan (and offset) range (X,Y,Z) | 1.8х1.8х2.0 mkm | |
| Minimum step size (X,Y,Z) | 0.001 nm | |
| Область позиционирования (X,Z) | 10х5 мм | |
| Точность измерения межатомных расстояний | 0.01 нм | |
| Spatial resolution | atomic resolution on metals | |
| Drift | 0.2 nm/min | |
| Механизм подвода и позиционирования | пьезо-инерционный | |
| Tunneling current setpoint | 10 пА - 50.0 нА | |
| Resonance of spring suspension | 2 kHz | |
| Feedback loop type | digital, ADSP 2181 | |
| Размер образца (X,Y,Z) | 10x10x4 мм (25х25х4 мм) | |
| Vacuum achievable | 5x10-11 Торр | |
| Maximum bakeout temperature | 160 С |
Vacuum module design
The vacuum module is a cylinder of 150 mm in diameter with eight 40CF flanges on its side. A rigid frame with the scanner suspension system, arrester and wiring are fixed inside. The cylinder with the STM head can be mounted under the upper 160CF flange of an existing vacuum chamber. Samples and tips are changed with a universal rotary-drive mechanical arm on an XYZ stage, installed on the top flange of the cylinder. The scanner is suspended from the top of the cylinder on vertical springs with a resonance frequency ≈1 Hz, which acts as the first stage of STM vibration protection.
Scanner
The scanner consists of three piezoelectric tubes fixed on top of a copper cylinder-shaped platform (STM head). The tip holder is set in the spring clip on one of the outer piezoelectric tubes. A slider with a sample holder lies on the other two piezoelectric tubes, each ending with two polished sapphire balls. Slip-and-stick slider motion is used for sample-to-tip approach and positioning in a crosswise direction. Regulated hold-down force and sapphire/sapphire sliding pair ensures reliable slider motion under any vacuum.
Результаты тестов и измерений
Атомное разрешение на плотноупакованных гранях металлов и других объектах — адсорбированных слоях:
