TMPM5200-2
5-107
es not reach the maximum voltage, it is
the Approach On button on the Tip window.
In such a case, check the following points.
•
Make sure that Loop Gain is not so low.
If Loop Gain is set to a low number, the gain of the feedback circuit is so small that
the feedback voltage is not applied up to the maxim
•
Make sure that the AFM value indicated on the AFM AMP unit is
.
If the AFM value is near 0 V, it is judged that approaching has already been com-
pleted. The following two reasons can be considered.
•
The photodiode position has changed.
Readjust the photodiode position according to the procedure.
•
Approaching has already been
d, or the cantilever tip has collided with
the specimen.
Retract the cantilever tip from the specimen using. Then, try to readjust.
ween the specimen surface and the cantilever tip might affect the
es are
due to an electrostatic force. Try the following steps.
the cantilever to a conductive one (an Si cantilever or a cantilever with
holder. A non-contact
lly grounded via the operational amplifier in the SPM
•
Add a bias voltage to the specimen specifying it in the Sample Bias/V input box
from 0 V to both positive and negative values.
n the specimen and the specimen
pe or conductive
paste (Conductive paste). If possible, apply the conductive paste not only to the
surface but to the side of the specimen as well.
If the voltage applied to the Z scanner do
judged that the approaching has already been completed. So, approaching will not
start even if you click on
um voltage.
not near 0 V
complete
•
Make sure that the cantilever is not too close to the specimen.
When the cantilever tip gets fairly close to the specimen surface, the electrostatic
force acting bet
cantilever, thus sometimes making approaching impossible. Most of such cas
•
Change the cantilever to a hard one (a cantilever with a high resonance fre-
quency).
•
Change
both sides gold-coated), and use a non-contact cantilever
cantilever holder is virtua
head unit.
•
Make sure that good conductivity is kept betwee
stub.
Affix the specimen to the specimen stub using a conductive ta
Specimen
Conductive paste
Specimen stub
as shown in the above figure.
4.
Click on the Approach On button on the Tip window.
If the specimen is an insulating material, make the specimen smaller or coat the
masked observation area of the specimen with gold or any other suitable metal.
Then, stick the specimen onto the stub
