G. A. M. Hurkx

QUBiC4plus: a cost-effective BiCMOS manufacturing technology with elite passive enhancements optimized for 'silicon-based' RF-system-in-package environment

QUBiC4plus is a RF-BiCMOS production technology tailored for silicon-based RF-SiP. The device menu includes 3 varactor styles, 7 resistor types, novel complimentary 24 V PMU devices, hi-k MIM capacitors, RC-triggered ESD protection and a choice between all-silicon, SiGe and SiGe:C bipolar transistors. Buried-p+ guardrings, DTI and very-high resistivity substrates ensure excellent circuit-block isolation and high-quality inductors. The advanced design flow features state-of-the-art models.

RF figures-of-merit for process optimization

Today, transistor y-parameters are routinely being measured for the determination of the current-gain cut-off frequency f/sub T/ and the maximum oscillation frequency f/sub max/. In this paper, it is shown that a much wider use of y-parameter measurements can be made for the RF characterization of transistors. A method is presented to determine the small-signal behavior of actual RF circuit-blocks from the measurements of the y-parameters of the individual circuit components. This is applied to define additional RF figures-of-merit for basic building blocks of analogue and digital RF circuits. No equivalent transistor circuit or compact-model parameters are needed, which is important for giving quick feedback to process developers. This approach is illustrated on three basic RF circuit blocks using bipolar transistors.

A new analytical model for the thermal resistance of deep-trench bipolar transistors

A new analytical model for the thermal resistance, temperature profile, and heat flow of deep-trench isolated (DTI) transistors is presented by taking the finite heat flow through the trenches into account. The new model is able to distinguish between the different contributions to the thermal resistance of the DTI structure and allows identification of the most dominant component. A detailed analysis of the substrate contribution shows that the substrate thermal resistance is overestimated in existing models. Results are compared with experimental data as well as numerical simulations and show a good agreement. The model can be used for process optimization and in a circuit simulator.

Simultaneous extraction of the base and thermal resistances of bipolar transistors

A method for the simultaneous extraction of the base resistance R/sub b/ and thermal resistance R/sub th/ of bipolar transistors is described. The technique can be applied to single devices without the requirement of special structures. The measurements are based on the collector-base voltage dependence of the base-emitter voltage under constant emitter current steering and accounts for the influence of Early effect and self-heating. Results are obtained for advanced HBTs with several emitter widths enabling the extraction of R/sub th/ and the intrinsic and extrinsic contribution of R/sub b/. A detailed comparison is made with other extraction techniques and reveals an excellent agreement.