Title :
Optical charge modulation as an internal voltage probe for CMOS ICs
Author :
Koskowich, Gregory N. ; Soma, Mani
Author_Institution :
Dept. of Electr. Eng., Washington Univ., Seattle, WA, USA
fDate :
10/1/1988 12:00:00 AM
Abstract :
The use of optical charge modulation of refractive index as a probe for internal voltages in CMOS integrated circuits is examined. The Kramers-Kronig relations are used to calculate the index of refraction from absorption coefficient measurements. Both free-carrier depletion and the internal electric field of the p-n junction modulator are shown to affect the measurement sensitivity of this technique. The sensitivity is calculated from experimental results and is dependent on which device, NMOS or PMOS, is under test. These results contradict the predictions of a previous model which was developed using the Drude theory of free-carrier modulation of the refractive index
Keywords :
CMOS integrated circuits; Kramers-Kronig relations; electro-optical effects; elemental semiconductors; integrated circuit testing; optical modulation; refractive index; sensitivity; silicon; voltage measurement; CMOS integrated circuits; Drude theory; Kramers-Kronig relations; NMOS; PMOS; Si; absorption coefficient measurements; experimental results; free-carrier depletion; free-carrier modulation; internal electric field; internal voltage measurement; internal voltage probe; measurement sensitivity; optical charge modulation; p-n junction modulator; refractive index modulation; semiconductors; CMOS integrated circuits; Integrated circuit measurements; Integrated optics; Optical modulation; Optical refraction; Optical sensors; Optical variables control; Probes; Refractive index; Voltage;
Journal_Title :
Quantum Electronics, IEEE Journal of
