Detailed technical information on the FEI Quanta 3D dual-beam scanning electronmicroscope

Basic unit

The scanning electron microscope can investigate conductive, non-conductive and biological samples without any peculiar preliminary sample preparation with its three operating modes: high-vacuum-, low-vacuum- and environmental operating modes.

Electron gun

The electron gun is a Schottky field emission emitter. The accelerating voltage can be varied in the 100 V - 30 kV range. The electron current is continuously adjustable. The maximum value of the electron current in the sample is 80 nA.

Operating modes

Conductive samples can be measured in high vacuum mode (p ~ 10-3 Pa) . The low vacuum operating mode (p < 130 Pa) is for measuring non-conductive samples without conductive surface cover. Biological samples can be measured in the environmental operating mode. In this operating mode the sample is in environment of 100% humidity and therefore there is no water loss.
The pressure is < 4,000 psi.
The vacuum system is completely oil-free.

Detectors

The Quanta 3D scanning electron microscope has the following detectors:

  1. Secondary electron detector (SED) for each of the three operating modes;
  2. Backscattered electron detector (BSED);
  3. sSilicon drift X-ray detector (EDX), which is a Peltier-cooled detector allowing elemental analysis from Be up to U;
  4. Scanning transmission (STEM) detector, capable of transmission measurement of thin samples;
  5. Hikari camera, allowing electron backscattered diffraction (EBSD) measurements;
  6. Infrared CCD camera for optical observation of the sample chamber.

The ultimate resolution of the detectors under ideal circumstances:

SED detector in high vacuum mode, at 30 kV accelerating voltage: 1.2 nm.
SED detector in high vacuum mode, at 1 kV accelerating voltage: 2.9 nm.
SED detector in low vacuum mode (charge compensation) at 30 kV accelerating voltage: 1.5 nm.
SED detector in low vacuum mode (charge compensation) at 3 kV accelerating voltage: 3 nm.

BSED detector in high vacuum mode at 30 kV accelerating voltage: 2.5 nm.
BSED detector in high vacuum mode at 1 kV accelerating voltage: 4 nm.
BSED detector in low vacuum mode at 30 kV accelerating voltage (requires beam deceleration): 3 nm.

STEM detector at 30 keV accelerating voltage: 0.8 nm. Both bright-field and dark-field images can be taken.

The resolution of EBSD measurement is material-dependent, but typically it is 50 nm.

EDX detector energy resolution: 130 eV @ Mn Kα. The speed of the detector is 105 cps.

Focused ion beam (FIB)

The Quanta 3D dual device has a focused ion beam (FIB) unit for nano-machining of the sample. The ion gun accelerates Ga ions up to energy of 30 kV. The accelerating voltage can be continuously decreased down to 500 V. The ion current can be changed in the 2 - 70 nA range. The apparatus has a detector, which enables to take secondary ion image as well (CDEM detector). The device is capable of gas chemistry. Platinum, carbon and insulator material deposition can be achieved by the gas injection system (GIS). FIB includes software and hardware systems that allow automatic operation (AUTO FIB) and TEM lamella preparation.

Sample chamber

The inner diameter of the sample chamber allows to measure samples with maximum diameter of 200 mm and thickness of 50 mm. The mobility of the sample holder stage: xmax = 50 mm, ymax = 50 mm and zmax = 25 mm. The sample holder stage can be tilted in the range of -15° – +75° and rotated 360°. The beam coincidence point is at 10 mm working distance, which is also the eucentric working distance of the stage.

Other acessories

Closed water-cooling system (chiller).
Air compressor.
Uninterruptible power supply (UPS).

Computer software and hardware

The FEI device control program runs under Windows XP operating system, with a user interface of 32 bit. The image display screen is a 19" LCD monitor with a resolution of 1280x1024 pixels. Other software: 3D reconstruction software, image analysis and archiving software, automation packages (AUTO FIB, AUTO TEM).