Carbon-doped p-type In/sub 0.53/Ga/sub 0.47/As and its application to InP/In/sub 0.53/Ga/sub 0.47/As heterojunction bipolar transistors

ABSTRACTCarbon is a promising p-type dopant in GaAs/AlxGa1−xAs heterojunction bipolar transistors (HBT) because of its low atomic mobility and its potential for achieving very high carrier concentrations. It is generally believed that carbon incorporates substitutionally on the column V sublattice. However, an anomalous behavior at carrier concentrations > 5 × 1019 cm−3 is observed in the electrical properties of carbon doped layers. The strain sustained in these layers may be explained by the presence of interstitial carbon.We used Rutherford Backscattering Spectrometry in channeling geometry utilizing the nuclear reaction 12C (d,p)13C to determine the lattice locations of carbon in GaAs. The data presented unambiguously show, that up to 25% of the carbon atoms occupy interstitial sites. The presence of interstitial carbon is of importance for applications, since interstitial carbon may exhibit an enhanced diffusivity altering nominally abrupt dopant profiles.

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Heavily carbon-doped p-type InGaAs grown by gas source molecular beam epitaxy for application to heterojunction bipolar transistors

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2006.11.050 ◽

2007 ◽

Vol 301-302 ◽

pp. 212-216 ◽

Cited By ~ 3

Author(s):

Anhuai Xu ◽

Ming Qi ◽

Fuying Zhu ◽

Hao Sun ◽

Likun Ai

Keyword(s):

Molecular Beam Epitaxy ◽

Heterojunction Bipolar Transistors ◽

Molecular Beam ◽

Bipolar Transistors ◽

Carbon Doped ◽

Gas Source ◽

P Type

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p-GaAs Base Regrowth for GaN HBTs and BJTs

MRS Proceedings ◽

10.1557/proc-622-t6.13.1 ◽

2000 ◽

Vol 622 ◽

Author(s):

G. Dang ◽

A.P. Zhang ◽

X.A. Cao ◽

F. Ren ◽

S.J. Pearton ◽

...

Keyword(s):

Heterojunction Bipolar Transistors ◽

Inductively Coupled Plasma ◽

Ohmic Contacts ◽

Contact Region ◽

Chemical Vapor ◽

Bipolar Transistors ◽

Organic Chemical ◽

Carbon Doped ◽

Inductively Coupled ◽

P Type

ABSTRACTLow resistance ohmic contacts are difficult to form to p-type GaN and AlGaN due to the unavailability of growth methods for highly p-doped GaN and AlGaN. A p-type carbon-doped GaAs regrowth on p-GaN prior to ohmic metallization has been shown in previous work to improve contact resistance to p-GaN [13]. Applying the regrowth method to the p-base regions of npn structured bipolar transistors, AlGaN/GaN heterojunction bipolar transistors and GaN bipolar junction transistors have been demonstrated. GaN/AlGaN epilayers were grown with a molecular beam epitaxy system. Highly carbon-doped p-GaAs (1020 cm−3) was regrown on the devices (∼500 Å) in the base contact region by metal organic chemical vapor deposition after emitter mesa etching. Emitter and base mesa structures were formed by Inductively Coupled Plasma etching under low damage conditions with a Cl2/Ar chemistry. SiO2 was used for emitter sidewall formation to reduce leakage current to the emitter, as well as for a mask for GaAs base regrowth. Very high current densities were obtained for common base operation in both device types. The devices were operable at 250 °C.

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