Specific Process Knowledge/Characterization/SEM: Scanning Electron Microscopy

At the moment we have three SEM's.

Sample requirements

• The Nova NanoSEM analyzes a variety of samples, however, excluded are samples that may degas, disintegrate or produce dust/particles. Therefore, no wet polymers, powders etc. If you have any questions, please ask Jonas.

Sample sizes

• Up to 6" wafers.

SEM modes

• Mode 1: High Resolution SEM mode: This is the standard operation mode associated with SEM.
• Mode 2: Ultra High Resolution SEM mode: Magnetic fields generated in the chamber act as a virtual lens that engulfes the sample. Using this semi-immersion lens increased resolution may be achieved at high magnifications.
• Mode 3: EDX mode: Similar to Mode 1, but the electrons are trapped using a magnetic field.

Lateral resolution

The resolution that may be achieve is highly dependent on the type of sample and SEM operator skills. In the best cases one may expect:

• High Vacuum operation:

1.0 nm at 15 kV (TLD detector and optimum working distance)
1.8 nm at 1 kV (TLD detector and optimum working distance)

• Low Vacuum operation

1.5 nm at 10 kV (Helix detector and optimum working distance)
1.8 nm at 3 kV (Helix detector and optimum working distance)

Acceleration voltage

• 200 V - 30 kV

Detectors

• ETD: In chamber SE Detector (Everhardt Thornley Detector)
• TLD: Inlens SE detector (Through Lens Detector)
• BSED: BackScatter Electron Detector
• LVD: Low Vacuum SE Detector
• Helix: High resolution Low Vacuum detector
• GAD: Low Vacuum Backscatter Electron Detector (Gaseous Analytical Detector)
• EDX: Liquid nitrogen cooled detector of X-rays

Stage

The eucentric stage is centered in (x=0,y=0) and has eucentric point at WD 5 mm.

• X range: 150 mm
• Y range: 150 mm
• Z range: 10 mm
• Rotation: 360±
• Tilt range: -10 to 60 degrees.

Vent and pumpdown time

• Approximately 5 minutes combined.

Accuracy and reproducibility

• A standardization procedure will be introduced soon.

Energy Dispersive X-ray analysis

• Oxford Inca system installed for high performance EDX analysis.

Micromanipulator

• A Kleindiek micromanipulator with a Capres 4 point probe is installed.