ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
This paper presents a homodyne pulse-sampling electrostatic force microscopy technique using a pulse position modulation method for the noncontact measurement of internal voltage waveforms in integrated circuits. The measurement system operates by monitoring the mechanical deflection of a micromachined probe as it responds to electric forces induced by the circuit voltage waveform. Although the mechanical response of typical probes used in such systems is limited to few kHz, measurement of high frequency repetitive waveforms is enabled by applying a high speed sampling pulse signal to the probe with the pulse position modulated at a rate below the probe mechanical resonance. This results in down conversion of the circuit induced electric force harmonics to within the probe mechanical response, thus allowing the measurement of high frequency signals. The proposed technique is modeled using Fourier analysis of the measurement system response, and is demonstrated by the measurement of a 0.8 Mbit/s digital pattern on a CMOS test pad. The performance of the measurement system is analyzed based on obtained measurements and simulated system response. An analysis of the method capabilities shows a measurement sensitivity of 13 mVrms/(square root of)Hz. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1430549
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