Non-contact bias voltage measurement using the electro-optic probing technique

Abstract

The traditional non-contact electro-optic (EO) probing technique is further extended to measure quasi-dc bias voltages. We propose a special external LiTaO3 probe equipped with a grounded side-electrode (GSE) and a power supply modulation (PSM) method. The GSE can improve the voltage measurement sensitivity and error due to the tip position variation. The PSM can make all bias voltages chopped and readily picked up by using a high sensitivity lock-in amplifier. Test results on model circuits demonstrated that the proposed new EO probing system can obtain voltage measurement results that are in good agreement with known values. With this extension function this new system can perform ac high frequency and dc bias voltage measurements as well.

Reactive Ion Etching of Titanium Tungsten Thin Films

“…Previously, it was reported that the magnitude of −V dc is directly related to the molecular bond strength of the feed gas molecule. 26 Here, the change of −V dc is consistent with the bond strengths of CF 4 and Cl 2 , i.e., 488 kJ/mol for C-F and 243 kJ/mol for Cl-Cl. 15 Figure 4b shows the relationship between the TiW etch rate and −V dc .…”

A Fabry–Pérot electro-optic sensing system using a drive-current-tuned wavelength laser diode

“…The optical path is similar to that of our previous study on EO sensing system and not described in detail here. 11 For the electrical path, there are two portions that are involved in this system. The EO signal generated by the ITO electrodes is detected by the lock-in amplifier and then collected by the closed-loop control computer for the wavelength-locked purpose.…”