Re: Dark rectangular area in SEM
From: G.Frank (frank_at_ww.uni-erlangen.de)
Date: 10/12/04
- Next message: wilf_at_ltic.moc: "Re: Dark rectangular area in SEM"
- Previous message: Yung-Jen Lin: "Dark rectangular area in SEM"
- In reply to: Yung-Jen Lin: "Dark rectangular area in SEM"
- Next in thread: wilf_at_ltic.moc: "Re: Dark rectangular area in SEM"
- Messages sorted by: [ date ] [ thread ]
Date: Tue, 12 Oct 2004 17:54:34 +0200
Yung-Jen Lin schrieb:
> Hello, everyone,
> when I wanted to take SEM pictures of a Au-coated ceramic surface, I
> often encounter one problem. I used a higher magnification image to
> get a better focus. When I turned down to the desired (lower)
> magnification, I usually found a rectangular dark area, which was the
> scanning area of higher magnification. People suggested me to take
> pictures of the nearby area.
> My question is: what causes such a darken area after scanning of
> e-beam? Some said it was caused by the contamination of the sample
They are right: hydrocarbons present in the chamber vacuum (from the pumps)
are cracked by the high energetic electrons of the beam and deposited on the
surface.
Additionaly you have surface contamination with the same species which
diffuses to the location of your scanning window and is deposited there as well.
Cooling the specimen to reduce surface diffusion may help the problem.
Another trick I used with some success is to irridiate the specimen with low
magnification but high beam current to 'pin' the contamination. Afterwards the
effect you described should be strongly reduced but not stopped.
HTH
> surface. Others said it was caused by the defects of ceramics due to
> high energy electron bombardment. Which one is correct? Or, what is
> the real reason for it?
> Thanks in advance.
-- Gerhard Frank [Vorname]dot[Nachname]@ww.uni-erlangen.de
- Next message: wilf_at_ltic.moc: "Re: Dark rectangular area in SEM"
- Previous message: Yung-Jen Lin: "Dark rectangular area in SEM"
- In reply to: Yung-Jen Lin: "Dark rectangular area in SEM"
- Next in thread: wilf_at_ltic.moc: "Re: Dark rectangular area in SEM"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
