CW measurement of HBT thermal resistance

Abstract

istics and simulation results of the SiGe HBTs. The extracted value of R th using our method is 500.7 K/W and the extracted value from the two-temperature method is about 500 K/W. We also compared the results taken from pulsed I-V measurements with 1% duty circle of pulsed V BE . Excellent agreement is still obtained. In Figure 5, the extracted values of R th show good agreement compared to the results taken from the isothermal measurements [8]. The RMS error obtained is less than 0.35%. CONCLUSIONA simple and robust, but accurate, method was presented to extract the BJT/HBT thermal resistance. The thermal resistance has been extracted from the DC I-V curves at a constant base current at room temperature. This eliminates the necessity to perform cumbersome temperature measurements or expensive pulsed measurements. The validity of our proposed approach is verified by extensive measurements using different kinds of bipolar transistors. Without any optimization, all extracted values are in excellent agreement with the measured results.

Electrical measurement of the junction temperature and thermal resistance of HBTs

“…2 This relationship can be linear as in [2], or almost linear (within 10% of a straight line) as in [3]. However, and , can be assumed to be univocal functions of only.…”

“…Moreover, it can be demonstrated that if one assumes a dependence on the output power for , such as (6) the relative error in the junction temperature of points A and C in Fig. 1, having the same (but a different ) is given by (7) 3 Neglecting the dc power dissipated at the base. Also the RF input power has been neglected as the power gain is normally quite high in HBTs.…”

“…Moreover, indirect techniques such as [2] rely on a linearization of the or characteristics around a certain operating condition. As the reported variations of with case temperature can deviate from a straight line up to 10% [3], small increments of the case temperature might be necessary during the measurement, thus involving greater errors. To mitigate this problem, we propose a direct technique which, differently from [1], can be applied under any bias condition (i.e., not only under high self-heating, as required in [1] …”

A statistical approach to characterizing the reliability of systems utilizing HBT devices

“…The third factor is to note that the current bias and junction temperature are not totally independent since junction temperature is a function of current injection. Methods and techniques for estimating junction temperatures of HBTs under current/voltage biases are discussed elsewhere [12][13][14][15][16] and are not the subject of this paper.…”

Scaling influence on the thermal behavior of toward-THz SiGe:C HBTs

“…The extraction method is based on DC measurements only, and can be considered as an improved CB variant of the classic approach proposed by Dawson et al [10]. The procedure is articulated in two steps, namely, (1) the calibration of the temperature coefficient of the base-emitter voltage, which is …”