LCT live contact tester
The Live Contact Tester Module (LCT) is at the heart of the Kleindiek Advanced Probing Tools. It provides visual feedback on each tip’s contact to the substrate by simultaneously sweeping a voltage on up to eight tips at up to ten sweeps per second.
This functionality is especially important since the contacts can be covered by a thin, non-conductive contamination layer that is invisible in the SEM. Thus, while it is easy to visually confirm that the tip is in physical contact with the specimen, without the LCT, it is very difficult to know if all tips are in electrical contact with the specimen, as well.
Together with iProbe, the Live Contact Tester constitutes the core of the Advanced Probing Tools. Achieving physical contact with the specimen surface is a straightforward task. However, it is often difficult to confirm that the individual probe tips are in electrical contact with the device under test. Thin oxide layers or other contaminants can prevent good ohmic contact to the substrate. After initial touch down, the LCT provides a means
for visualizing each tip’s electrical status by simultaneously recording ten I-V-curves per second on each tip. Thus, the tips’ electrical response to a given bias voltage can be seen in real-time. This allows the user to reposition the tip - without the use of the electron beam - until all tips are in contact with the desired points on the sample.
The LCT is augmented by two additional modules: the Tip2Tip tester (T2T ) and the Transistor Test module. The latter is used to optimize the probe tip’s position on the gate contact. As the gate is not connected to bulk, this tip’s contact can’t be confirmed using the LCT’s display. Rather, the Transistor Test Module is used to record an entire family
of Ids vs. Vds curves ten times per second. Again, this yields live feedback on the gate contact quality.
The T2T module can be used to measure the resistance between two tips. This can be used e.g. to break through contaminating oxide layers on the tips.
The LCT can be used in combination with Kleindiek MM3A-EM micromanipulators and various plug-in tools. See an overview of the range here.
Tip voltage range: -10 to +10 V (16 bit DAC)
Current range: 100 μA to 2 mA
Three predefined scan speeds