５
MEASUREMENT OPERATION
5-128
TMPM5200-2
re in the Lock-in-Amplifier window.
cally.
7.
Increase the input sensitivity of the lock-in amplifier (from 1 mV to 100 nV
direction) using the Sensitivity setting key (
▼
) in the range in which the
signa
lifier do not saturate.
When using Model 5110 and the signal becomes saturated, the OLVD LED
lights
8.
To start scans, click on the Repeat button of the Advanced tab in the SPM
Parameters window.
The following images will be obtained.
6.
Click on Auto Configu
The Lock-in-Amplifier will adjust the phase and gain automati
ls from the lock-in amp
up.
Topography
(Topography
image)
Acos
φ
Asin
φ
(Friction
image)
The area in which Asin
φ
(friction image) becomes white is the one in which
friction is large.
9.
Specify the SPM parameters for usual operation so that you can obtain an
n range is scanned, the voltage of 300Vp-p
will be applied to the scanner. Therefore, there is the following relationship be-
optimum topography image.
10.
Change the following parameters so that you can obtain an optimum friction
image.
•
Oscillation level (OSC Level/V)
Oscillation level depends upon the scan range.
In this system, if the maximum sca
tween the scan range and the voltage applied to the scanner.
15
ty
Sensitivi
Y
128
range
n
Observatio
p
Vp
÷
÷
=
−
(It is difficult to determine an exact Y sensitivity, since you have to execute dis-
tortion correction. However, the Y sensitivity can be estimated all the observa-
tion range/300 V.)
In practice, the output value is a little smaller than the calculated one, because a
low pass filter is contained in the high voltage amplifier. In lateral modulation
FFM, set an excitation voltage to lateral amplitude of several nm to several tens
mes larger than the ampli-
tude input to the ADY. To obtain exact Y/20, use the optional oscilloscope.
of nm of the voltage applied to the scanner.
The voltage amplitude applied to the scanner is 20 ti
