MEASUREMENT OF THE ELECTRICAL-PROPERTIES OF ELECTROMIGRATION SPECIMENS

A description is given of the design, implementation, and performance of a circuit to measure the electrical properties of resistive specime ns of about 10 Omega such as are used in electromigration studies. The ac bridge can measure the changes in resistance, second-harmonic ampl itude, second-harmonic phase shift, thermal noise, and excess (1/f) el ectrical noise. All the parameters can be monitored simultaneously and continuously. The performance is comparable with that of systems desi gned to measure each of the quantities only. The special features are that it is an autobalance bridge so that chan es in the measured quant ities are recorded by the feedback signal, the spectrum analyzer is no t overloaded, and the recovery of the noise signal is performed by sof tware. (C) 1995 American Institute of Physics.