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Message ID: 151     Entry time: Sat Oct 29 10:12:39 2016
Author: Gabriele 
Type: General 
Category: Measurements 
Subject: S1600448 post annealing 


  • venting at 10:00am 10/29
  • sample installed, pumping down started at 10:12am, turbo pump on at 10:29am
  • Started automatic excitation at 10:46am. The first excitation will go off in 2 hours, then more at intervals of three hours. Amplitude 3kV, duration 30s

As with #447, the wafer moved during pum down. I clearly saw that the beam was moving as if the disk got kicked and rang down. Not sure what's going on, I've never seen such a behavior in past pump downs

Excitation at 1161805607 (30 s)
Excitation at 1161820052 (30 s)

There is something strange happening at frequencies below a few kHz. I tried stopping the autocenter, but that's not what is causing the problem. It looks like some king of saturations.


I tried to move the beam, but I still see the same behavior in the spectrum. I think the disk has shift and it now touching the ESD. Stopped all pumps at 11:58am.

Chamber open at 12:50pm. I realigned all the optical setup to the horizontal reference, and moved the ESD a bit up. The sample was installed and leveled at 1:10pm, started again pumping down at ~1:12pm. Turbo pump started at ~1:19pm.

When the frequency of the turbo pump gets to ~150-200 Hz, the wafer gets highly excited. Apart from that and the slow drift of the QPD signals that is almost always present, everything looks ok.

Started autocentering at 1:27pm. Started a set of automatic excitations: initial wait is 2 hours, then three excitation intervalled by 3 hours wait, each 30s long at 3kV.

I noticed once again that switching on the IGM vacuum gauge moved the disk.

List of excitation times:

  • Excitation at 1161901681 (30 s)
  • Excitation at 1161912526 (30 s)
  • Excitation at 1161923370 (30 s)


Excited at 7:56pm, duration 60s, amplitude 3kV


Excitation at 1161901681 (30 s)

% Freq        Q                 Q (C.I. 95%)      Q (C.I. 95%)
1111.6        8.3731e+06        8.3256e+06        8.4210e+06
2591.0        8.2131e+05        8.0451e+05        8.3882e+05
4440.0        4.2299e+06        4.2263e+06        4.2335e+06
6773.1        3.2093e+06        3.2065e+06        3.2121e+06
6851.1        2.3048e+06        2.2687e+06        2.3421e+06
9538.3        2.5313e+06        2.5159e+06        2.5469e+06
14207.1       8.7731e+06        8.7408e+06        8.8057e+06
16115.0       2.6277e+06        2.6276e+06        2.6278e+06
16131.2       1.0409e+07        1.0379e+07        1.0439e+07
16344.5       2.1568e+06        2.1496e+06        2.1640e+06
18681.9       5.9537e+06        5.9390e+06        5.9685e+06
21409.8       7.7496e+06        7.7163e+06        7.7832e+06
23619.8       4.7146e+06        4.6909e+06        4.7386e+06
24106.0       1.7430e+06        1.7430e+06        1.7430e+06
24750.5       1.3804e+06        1.3804e+06        1.3804e+06
27200.5       5.4690e+06        5.4689e+06        5.4691e+06
28928.5       3.1942e+06        3.1941e+06        3.1942e+06
29029.0       2.2298e+06        2.2298e+06        2.2299e+06
29638.0       1.5518e+06        1.5518e+06        1.5518e+06
30320.6       1.9414e+06        1.9413e+06        1.9414e+06
31178.0       8.7520e+05        8.7519e+05        8.7522e+05

Results from the measurement on 11/01

% Freq        Q                 Q (C.I. 95%)      Q (C.I. 95%)
1112.0        9.3290e+06        9.3025e+06        9.3556e+06
2549.7        6.1599e+06        6.1549e+06        6.1648e+06
2591.0        1.0033e+06        9.9970e+05        1.0070e+06
4440.3        4.3031e+06        4.3021e+06        4.3041e+06
4508.3        1.7553e+05        1.7503e+05        1.7602e+05
6773.0        3.3336e+06        3.3331e+06        3.3341e+06
6789.2        4.1646e+06        4.1566e+06        4.1727e+06
6851.2        2.4309e+06        2.4265e+06        2.4353e+06
9538.7        2.5711e+06        2.5677e+06        2.5745e+06
10233.2       3.5483e+05        3.5481e+05        3.5485e+05
10390.0       1.3584e+06        1.3537e+06        1.3632e+06
12728.4       1.8895e+06        1.8895e+06        1.8896e+06
14207.0       8.8861e+06        8.8676e+06        8.9047e+06
16115.5       2.7365e+06        2.7200e+06        2.7533e+06
16131.5       1.0602e+07        1.0564e+07        1.0640e+07
16344.7       2.2292e+06        2.2184e+06        2.2401e+06
18682.0       6.7655e+06        6.7553e+06        6.7756e+06
20331.9       1.6072e+06        1.6011e+06        1.6134e+06
23620.0       5.5499e+06        5.5263e+06        5.5736e+06
24750.6       1.5454e+06        1.5453e+06        1.5454e+06
27201.0       6.6957e+06        6.6956e+06        6.6958e+06
28929.0       2.6420e+06        2.6419e+06        2.6420e+06
29029.4       1.7762e+06        1.7762e+06        1.7763e+06
29133.8       9.1385e+06        9.0987e+06        9.1787e+06
29406.0       9.3479e+06        9.3477e+06        9.3480e+06
29601.0       5.6104e+05        5.6103e+05        5.6105e+05
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