Heavily doped GaAs(Be)/GaAlAs HBTs grown by MBE with high device performances and high thermal stability

Jourdan, N.; Alexandre, François; Dubon‐Chevallier, C.; Dangla, J.; Gao, Yuqing

doi:10.1109/16.127463

Cited by 32 publications

(11 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1͑b͒ and 2͑b͔͒, where the As/Ga flux ratio has no significant influence on Be diffusion from the base layer, ⌬* being ϳ110 nm for sample AЈ and 120 nm for sample BЈ. This last observation seems to conflict also with the results reported by Jourdan et al, 4 who showed that during postgrowth annealings Be redistribution is strongly reduced in HBT structures when a BEPR of 40 is used instead of 20.…”

Section: Sims Observationscontrasting

confidence: 54%

“…2 This feature is very important in the fabrication of GaAs-based n/p/n heterojunction bipolar transistors ͑HBTs͒, where highly doped p-type base layers are required to reduce the base resistance and to fully exploit the device capabilities. However, the high diffusivity of Be is detrimental for HBTs: indeed, the undesired diffusion of Be during growth, 3 during high-temperature device fabrication, 4 or under current stress 5 causes a degradation of the device performances due to the shift of the base/emitter p/n junction into the emitter layer.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, it has been reported that Be diffusion during growth can be reduced by increasing the As/Ga flux ratio, 7,8 while HBTs with record reliability have been obtained by combining low substrate temperatures and high As/Ga flux ratios during base layer deposition. 9,10 The use of low substrate temperatures and high As/Ga flux ratios has been reported to minimize Be diffusion also during high temperature postgrowth annealings, 4 so that heavily doped base HBTs have been obtained by processing MBE-grown structures with an ion implantation technology. Nevertheless, these results seem to conflict with those recently reported by the authors, 11 who showed that, after hightemperature annealings, the As 4 /Ga flux ratio does not affect Be diffusion in p/p ϩ /p GaAs structures, while in p/p ϩ ones, where Be redistribution is definitely weaker than in the p/p ϩ /p counterparts, the influence of the V/III flux ratio can be easily pointed out.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Be diffusion in molecular beam epitaxy-grown GaAs structures

Mosca

Bussei

Franchi

et al. 2003

Journal of Applied Physics

View full text Add to dashboard Cite

Beryllium diffusion is considered in heavily doped p-type GaAs structures grown by molecular beam epitaxy (MBE). Secondary ion mass spectrometry (SIMS) measurements performed on samples which underwent rapid thermal processing (RTP) experiments at 850 °C for 30 s show that (i) Be diffusion is faster in p/p+/p structures than in p/p+ ones and (ii) an increase of the As4/Ga flux ratio during the MBE growth affects Be diffusion only in p/p+ structures. These results are discussed by modeling Be diffusion according to a substitutional–interstitial diffusion mechanism where Be transition from substitutional to interstitial takes place by a kick-out process. The modeling procedure, which has been previously used to simulate Be and Zn diffusion in GaAs and in other related compounds, has been modified in order to account for the lacking of equilibrium in the initial concentration of Ga interstitials. It is shown that when the lacking of equilibrium is accounted for at the beginning of the annealing experiment, a satisfactory description of the SIMS results has been achieved in both p/p+ and p/p+/p structures, also considering samples grown by different As4/Ga flux ratios. The modeling results allow us to conclude that in the p/p+/p structures the concentration of point defects (e.g., IGa) in the regions cladding the base layer affects, to a major extent, Be diffusion during RTP, so that an efficient reduction of Be diffusivity is expected only when the whole structure is grown by high V/III flux ratios.

show abstract

Section: Sims Observationscontrasting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Be diffusion in molecular beam epitaxy-grown GaAs structures

Mosca

Bussei

Franchi

et al. 2003

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Heavily doped GaAs epilayers are very important for making low resistive ohmic contacts [1] and device applications such as heterojunction bipolar transistor [2][3][4] and high electron mobility transistor [5,6]. Sn is one of promising n-type dopants for heavy doping of GaAs grown by molecular-beam epitaxy (MBE) because of its possible higher electron concentration compared with the other dopants.…”

Section: Introductionmentioning

confidence: 99%

Characterization of heavily Sn-doped GaAs grown by migration-enhanced epitaxy

Chavanapranee

Horíkoshi

2007

Journal of Crystal Growth

View full text Add to dashboard Cite

“…Moreover, if optimization of both molecular beam epitaxy (MBE) growth conditions and HBT structure (insertion of an undoped spacer layer between base and emitter layers) allows suitable Beryllium-doping profile for high device performances, it also results in unflexible processes [5][6][7]. Therefore, carbon is now the reference p-doping element for the base layer of AlGaAs-GaAs and GaInP-GaAs HBTs, and seems to be the favourite candidate for heavy p doping of InGaAs base, a critical issue for very high speed InP-based HBTs.…”

Section: Introductionmentioning

confidence: 99%