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what tapping Engage (and other) settings are needed in V4.43r8 to prevent Engage damage to a FIB Tip (spike) Fres~260 Khz

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Mark posted on Fri, Sep 17 2010 1:24 AM

Hi,

I am resurrecting an ancient NS3 Phase Extended Multimode. ( a wonderful classic instrument )  I loaded up an FIB tip and began normal engage with default Tapping Engage settings in this software, and saw evidence the $200  FIB2-110s tip (spike section) did not survive the engage

:-(. 

For the next month or so I will have to continue with this software version. I'd be grateful for any pointers to proper MMAFM operation in V443R8 with a FIB tip ( I am lucky to have a J vertical engage scanner - so scanner / sample tilt is not an issue - I had excellent level scans of the same sample with a regular lower aspect ratio tapping tips.

These are defaults? in the Tapping Engage Panel which I used and munched the sharp spike immediately upon engage is my guess.

Engage Delta Setpoint            -0.0200

Engage Final Setpoint                 0.00

Engage Test Threshold              100

Engage Minimum Setpoint %      25

Tapping Mode Engage Gain     3.00

Sew Tip Yes

Sew Trig ( grey'd)                         100

Trigger Safety ( grey'd)             20um

Pre Engage Set Point %               90

Trig Channel                                  Off

Trig Threshold ( grey'd)                  0

Scan Rate                                1.00hz  ( I am guessing this is the sew tip cycling frequency fwiw )

Ramp Step (grey'd)               1.00um

>>>>>>   I will remark I set scan rate to ~0.3 Hz nice and slow, initial XY to ~300nm, then upped to 1um, gains were set to typical 0.7 0.7 ( p&i)  and was attempting to scan a chip with nominal 100nm steps that I imaged prior with a conventional tapping tip.

I have a decent sum signal ~5v and the response spectra looked typical in tuning the cantilever resonance and amplitude. Laser spot near the lever end - nice and clean reflected signal.

When I had setup the tapping frequency tune ( resonance search ) it found a nice peak ~266Khz which was fine, set target oscillation RMS amplitude at ~1.5v no problem, and then initial 1.3v setpoint on approach automatically reduced to ~0.85 v which indicated the settings in tapping engage ( default ) chopped off the FIB spike near immediately ( as corroborated in the image data which was worse acuity / edge resolution than std tapping tips which imaged fine.

Evidence in the image height data indicated the tip was stumpy ( spikeless?).

I'd be grateful for any pointers to proper FIB tip operation ( Veeco Nanoprobe model - p/n FIB2-100s ) with V443R8 software on a Multimode ( I suspect there might be settings outside of the Tapping Engage panel that might be relevant too )

Thanks !

 

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Answered (Verified) Mark replied on Sat, Sep 18 2010 12:13 PM
Verified by Mark

I tried someone's suggestion to set in the OTHER Controls Panel - to set Engage Setpoint to 1.00 ... Turns out this was set as such all along ( ie not the fix ).

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Verified by Mark

Hi Mark,

 

I have not used FIB tips, but I do use a variety of probes with very delicate tips that require the engage parameters to be changed.

The most important parameters in the tapping engage panel seem to be the engage gain (I usually reduce this to ~0.1 for delicate tips) and the engage test threshold (which I usually raise to ~500). Also, ensure that tip sewing is turned on.

Either the manual for the Multimode or the Command Reference manual (I don't recall which) has in depth descriptions of the exact function of each of the parameters in the tapping engage panel. The parameters themselves are the same for all of the software versions that I have used. I believe that the engage parameters in the other controls panel are only relevant for STM, so changing these will not have an effect on a tapping mode engage.

For scanning with delicate tips, slow, small scans (to keep the tip velocity low), small amplitudes (0.5 V or so), high setpoints (i.e. close to the free amplitude) and as much feedback gain as you can get away with tend to minimise the chances of tip damage.

I hope that is of some help.

 

Best,

Nic

 

 

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Top 150 Contributor
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Points 77
Answered (Verified) Mark replied on Sat, Sep 18 2010 12:13 PM
Verified by Mark

I tried someone's suggestion to set in the OTHER Controls Panel - to set Engage Setpoint to 1.00 ... Turns out this was set as such all along ( ie not the fix ).

  • | Post Points: 13
Top 50 Contributor
20 Posts
Points 220
Verified by Mark

Hi Mark,

 

I have not used FIB tips, but I do use a variety of probes with very delicate tips that require the engage parameters to be changed.

The most important parameters in the tapping engage panel seem to be the engage gain (I usually reduce this to ~0.1 for delicate tips) and the engage test threshold (which I usually raise to ~500). Also, ensure that tip sewing is turned on.

Either the manual for the Multimode or the Command Reference manual (I don't recall which) has in depth descriptions of the exact function of each of the parameters in the tapping engage panel. The parameters themselves are the same for all of the software versions that I have used. I believe that the engage parameters in the other controls panel are only relevant for STM, so changing these will not have an effect on a tapping mode engage.

For scanning with delicate tips, slow, small scans (to keep the tip velocity low), small amplitudes (0.5 V or so), high setpoints (i.e. close to the free amplitude) and as much feedback gain as you can get away with tend to minimise the chances of tip damage.

I hope that is of some help.

 

Best,

Nic

 

 

  • | Post Points: 13
Top 150 Contributor
7 Posts
Points 77
Mark replied on Tue, Sep 21 2010 10:15 AM

Hi Nic,

Thanks for the kind suggestions. I am doing some involved? KFM

( kelvin voltage imaging, without an EFM tipholder ! that is a trick )

this week and will test these settings out early next week.

Mark

 

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