Responsible: Taras Golod, Adrian Iovan
| The Laser End Point Detection system on the Plasmalab 100 consist of a laser which beam illuminates a spot on the sample to be etched. The laser light is reflected from the sample surface and detected by a CCD camera mounted on top of the plasma chamber. |
End Point Detection, Laser, presentation principles and details, most relevant pages 40 - 65.
Trouble shooting guide Andy Goodyear, Oxford Instruments.
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| Parameter suggestions | Principle: Reflectometry | Principle: Interferometry |
| The capture of the video from the camera is handled by an extra software, start it from the desktop, if it is not already running. |
| Capture should start in a separate window, like above. |
| Load your sample, align and focus the laser spot. |
| Laser spot must be on a pattern-free area. Here correctly positioned, the laser spot is the white dot. |
| It is convenient to add an alignment step in your recipe. |
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The alignment step should look like this. All gas flows
are set to zero, as is the "Set Pressure" and
the RF-generator
powers.
Set the "Step Time" to some time more than enough for you to align, then use "Jump" when you are ready. |
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When you have done the laser spot alignment, proceed to
the etch step using "Jump". Some adjustments of
the parameters are necessary.
Here is shown good parameters for metal on Si (SiO2) wafer. Note! It is always possible to stop etching process manually based on the measured reflectance. To prevent software from stopping your process, set "overetch time" much longer than expected process time. |
End Point Detection, Laser, presentation principles and details, most relevant pages 40 - 65.
Trouble shooting guide Andy Goodyear, Oxford Instruments.
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| Parameter suggestions | Principle: Reflectometry | Principle: Interferometry |