Experimental method for extraction of emitter injection limited gain in bipolar transistors

Hamel, J.S.; Roulston, D.J.; Selvakumar, C.R.

doi:10.1016/0038-1101(92)90336-b

Cited by 2 publications

(5 citation statements)

References 4 publications

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“…9. In addition, values of the ideal component of base current at V are summarized in Table III for comparison with values calculated using (14). It can be seen that the ideal components of base current agree very well with the calculated values.…”

Section: Discussionsupporting

confidence: 59%

“…5, which show that the effect of the germanium on the base current saturates for germanium concentrations above about 20%. To quantitatively interpret the experimental results, (14). The measured values of Ge content, interfacial oxide thickness and emitter depth in Table II were used in the calculations, together with the values in Table I for the polysilicon parameters [10].…”

Section: Discussionmentioning

confidence: 99%

“…analysis method of Hamel [14]. This method has been applied to the measured base characteristics in Fig.…”

Section: Discussionmentioning

confidence: 99%

“…9. Ideal component of the base current I , determined using the method of Hamel [14], as a function of base/emitter voltage V for 0%, 10%, and 19% Ge.…”

Section: Discussionmentioning

confidence: 99%

“…The germanium in the polySiGe layer therefore has little effect on the base current. In this region of the characteristic, recombination in the single-crystal emitter would also be expected to have a strong influence on the base current, which is neglected in (14).…”

mentioning

confidence: 99%

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Polycrystalline silicon-germanium emitters for gain control, with application to SiGe HBTs

Kunz

Groot

Hall

et al. 2003

IEEE Trans. Electron Devices

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Abstract-This paper investigates germanium incorporation into polysilicon emitters for gain control in SiGe heterojunction bipolar transistors. A theory for the base current of a polySiGe emitter is developed, which combines the effects of the polySiGe grains, the grain boundaries and the interfacial layer at the polySiGe/Si interface into an expression for the effective surface recombination velocity of a polySiGe emitter. Silicon bipolar transistors are fabricated with 0, 10 and 19% Ge in the polySiGe emitter and the variation of base current with Ge content is characterized. The measured base current for a polySiGe emitter increases by a factor of 3.2 for 10% Ge and 4.0 for 19% Ge compared with a control transistor containing no germanium. These values are in good agreement with the theoretical predictions. The competing mechanisms of base current increase by Ge incorporation into the polysilicon and base current decrease due to an interfacial oxide layer are investigated.

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Section: Discussionsupporting

confidence: 59%

Section: Discussionmentioning

confidence: 99%

“…analysis method of Hamel [14]. This method has been applied to the measured base characteristics in Fig.…”

Section: Discussionmentioning

confidence: 99%

“…9. Ideal component of the base current I , determined using the method of Hamel [14], as a function of base/emitter voltage V for 0%, 10%, and 19% Ge.…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Polycrystalline silicon-germanium emitters for gain control, with application to SiGe HBTs

Kunz

Groot

Hall

et al. 2003

IEEE Trans. Electron Devices

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Trade-off between emitter resistance and current gain in polysilicon emitter bipolar transistors with intentionally grown interfacial oxide layers

Hamel

Roulston

Selvakumar

1992

IEEE Electron Device Lett.

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Experimental measurements of emitter resistance and current gain in polysilicon emitter bipolar transistors that have received annealing to break up an intentionally grown RCA oxide interfacial layer are presented. An anneal of 900°C for 10 min in a nitrogen ambient of the interfacial layer prior to polysilicon doping resulted in a decrease in emitter resistance by approximately a factor of 5, with an increase in base saturation current of only 25% while still maintaining a current gain of around 500. We believe that this is the largest trade-off in emitter resistance versus current gain demonstrated so far for polysilicon transistors with an RCA interfacial layer. These results support a previously proposed theory predicting that significant trade-offs between emitter resistance and current gain can be obtained if an intentionally grown interfacial oxide layer in polysilicon emitter bipolar transistors is annealed so as to induce only partial breakup such that most of the layer remains intact.

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Experimental method for extraction of emitter injection limited gain in bipolar transistors

Cited by 2 publications

References 4 publications

Polycrystalline silicon-germanium emitters for gain control, with application to SiGe HBTs

Polycrystalline silicon-germanium emitters for gain control, with application to SiGe HBTs

Trade-off between emitter resistance and current gain in polysilicon emitter bipolar transistors with intentionally grown interfacial oxide layers

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