Extraction of Compact Static Thermal Model Parameters for SiGe HBTs

Towards Monolithic Indium Phosphide (InP)-Based Electronic Photonic Technologies for beyond 5G Communication Systems

“…Then, in the high-current region, HiCuM/L2 model parameters are extracted by optimizing the region where f T reaches the peak along with the Gummel plot high-V BE region. The extraction of thermal resistance is of particular importance [18] since it is strongly coupled with other model parameters in the high-current regime. To obtain a good estimation of the self-heating effects, we used the intersection method [14] to extract the values of R TH from measurements.…”

“…The reduction in the transit time with emitter width scaling has been observed at high current densities, which can be attributed to a pronounced collector current spreading in smaller emitter dimensions [34], leading to larger critical current and smaller transit time values. Small emitter dimension particularly poses a challenge to maintain an acceptable current gain (β), of which rather low (15)(16)(17)(18)(19)(20) values have been reported for the 0.13 µm InP HBT process [1,33]. On the other hand, the prediction for the current generation shows an extrapolated current gain of 25-30 for the 0.13 × 2 µm 2 DHBT (Figure 22b).…”

A Critical Review of Techniques for the Experimental Extraction of the Thermal Resistance of Bipolar Transistors from DC Measurements—Part I: Thermometer-Based Approaches

“…In simple terms, R TH00 represents the thermal resistance of the transistor if the thermal conductivities of all materials are equal to their k(T 0 ) value. The low-power thermal resistance R THB0 at an arbitrary T B in the range 250 to 450 K (nonlinear thermal effect due to the backside temperature) can be calculated as [22,26,47,53]…”

“…In gallium arsenide (GaAs)-based heterojunction bipolar transistors (HBTs) like InGaP/GaAs and AlGaAs/GaAs, considered the dominant technology for handset power amplifier design, the high thermal resistances are a consequence of (i) the low thermal conductivity of the GaAs substrate (one third of that of silicon), (ii) the lateral heat confinement due to mesa isolation, and (iii) the interlevel dielectric films [9,10,[12][13][14][15]. In silicon/silicongermanium (Si/SiGe) HBTs for mm-wave and near-THz applications, namely, wireless and optical communication, medical equipment, and automotive radars, the increase in thermal resistances is due to technology strategies devised to boost the frequency performance, like (i) adoption of oxide-based shallow/deep trenches and reduction of the spacing between intrinsic transistor and trenches, which hinder the lateral heat propagation from the power dissipation region, and (ii) horizontal scaling of the emitter, which drives higher current (and power) density; such factors have contributed to push the thermal resistances of single-finger HBTs into the thousands of K/W [16][17][18][19][20][21][22].…”

BEOL Thermal Resistance Extraction in SiGe HBTs

“…Here, κ(T 0 ) is the thermal conductivity of Si at the nominal temperature, T 0 . While extracting the thermal resistance parameters for accurate modeling purpose, the parameter α in the Si thermal conductivity model plays a crucial role; and sometimes its value deviates from the physically expected values due to the negligence of a finite R m component [9], [10]. Also, a proper estimation of the R m component from characterization data can help us obtain a reliable model for R m depending on the number of BEOL metal layers and their design configurations.…”