A Gummel-Poon model for abrupt and graded heterojunction bipolar transistors (HBTs)

A physics-based heterojunction bipolar transistor model for integrated circuit simulation

“…The results of the HSPICE optimization for the 2u6d2f device are shown in Table 5 Aside from the agreement in saturation (which can be imputed to the bias dependence of RC and recombination), the 3uldlf and 3u5dlf models fall within the ± 5% difference criterion for model success. This level of performance is at least as good as models found in current literature [23,24,26,27]. The 2u6d2f model has fair agreement in the reverse active region, good to poor agreement in the saturation region, and excellent agreement in the forward active region (neglecting differences due to self-heating).…”

“…The other two devices were fabricated to Table 4 and changes the standard pn products at the SCR boundaries [23,24,62).…”

A thermionic-emission-diffusion model for graded base Pnp heterojunction bipolar transistors

“…[15][16][17] In addition, the model incorporates the effects of compositional grading in the base which is needed to enhance hole transport for high speed devices. [18][19][20] In Sec. II we describe the development of the thermionic-emission-diffusion model and derive expressions for the hole profile and the hole drift-diffusion current in the base.…”

A behavioural nonlinear SiGe-HBT model based on Gummel-Poon topology

“…Another viewpoint developped by Lundstroom [2] proposes that the carrier flow across the heterojunction could be modelled by the transport velocity at the interface (S). Recently, Ryum et a1 [3] used this concept (assuming transport velocity across the interface) to develop a Gummel-Poon model for the HBT. The main advantage of this model over the first one, lays in the fact that it takes in account the Early and quasi-saturation effects.…”

“…This type of model, established upon the base charge contrbl theory, is therefore fit for simulating devices that operate under voltages lower than their breakdown voltages, which is not the case for HBT(s) and particularly the SiGe-HBT. Hence, so as to take into account the specific HBT mechanisms (heterointerface recombination, high level injection barrier effect), we took care to incorporate the investigations of [3]- [4], and [5] that were developped for HBT devices with gradual and abrupt junctions to our modellisation.…”