Specific Process Knowledge/Characterization/SEM Gemini 1/ma

Technical specification

Sample requirements Any sample allowed in the cleanroom can be imaged in Gemini 1.

If you have any questions, please consult the persons responsible for the SEM.

Sample sizes: Up to 8" wafers (the ranges on the X and Y axes only provide full view of a 6" wafer)

Vacuum modes:

The SEM is usually operated in high vacuum (HV) mode where the chamber pressure is somewhere in the 2*10-4 to 10-6 mbar range. For imaging of non-conducting samples the instrument can be operated at elevated chamber pressures in the variable pressure modes.

Lateral resolution: The resolution is critically dependent on the type of sample and the SEM operator skills. In the best cases one may expect:

High Vacuum operation: 1.0 nm at 15 kV (Inlens detector and optimum working distance) 1.9 nm at 1 kV (Inlens detector and optimum working distance) VP mode operation: 2.0 nm at 30 kV (VPSE detector and optimum working distance)

Acceleration voltage: 20 V - 30 kV

Detectors:

SE2: In chamber secondary electron detector Inlens: Inlens secondary electron detector ESB: Inlens backscatter electron detector aBSD: Motorized and retractable 4 quadrant and annular backscattered electron detector VPSE: Variable pressure secondary electron detector STEM detector:

Stage: The eucentric stage is centered at approximately (X=75,Y=75).

X range: 150 mm Y range: 150 mm Z range: 50 mm Rotation: 360o Tilt range: -? to ?

Airlock:

The SEM is equipped with an airlock that allows 150 mm wafers to be transferred to the SEM chamber without breaking the vacuum thus enabling samples to be exchanged in less than two minutes. The restriction on sample heights depends on what sample holder is used. If you have large and bulky samples, please consult with Nanolab staff before mounting/loading them.

Accuracy and reproducibility:

DTU Nanolab performs quality control of the SEM every third month. The control checks the resolution and lateral measurement accuracy. The quality control instruction and results can be found on the machine page in LabManager.

Additional equipment: The Spicer Consulting SC24 EMI cancellation system consists of:

Instrument logon

Windows logon on the Operator station PC Use the Windows logon 'sem' with password 'sem1'

SmartSEM logon Use your own SmartSEM logon and password created at the training session

Sample mounting

The importance of correct sample mounting cannot be understated. This will ensure:

1. Optimum image conditions in terms of surface grounding, sample access
2. instrument safety

Sample transfer

Samples are generally loaded through the load lock so the users are not allowed to vent the SEM chamber. Certain sample holders, however, must be loaded through the SEM door - they are:

1. The 200 mm wafer holder
2. The STEM detector (requires specific training)
3. The filter holder (not sure about the purpose)

Users who want to use the sample holders above must have specific rights and/or training.

The airlock

To enable the use of the airlock, press the Exchange button on the hardpanel