Zn-implanted Pd-based ohmic contacts to p-In/sub 0.53/Ga/sub 0.47/As for the base layer of InP/In/sub 0.53/Ga/sub 0.47/As heterojunction bipolar transistors

2002 ◽  
Author(s):  
P. Ressel ◽  
H. Strusny ◽  
K. Vogel ◽  
J. Wurfl ◽  
W. Wesch ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Ohmic Contacts ◽  
Bipolar Transistors ◽  
Base Layer

Shallow and Low-Resistive Ohmic Contacts to p-In0.53Ga0. 47As Based on Pd/Au and Pd/Sb Metallizations

1996 ◽  
Vol 427 ◽  
Author(s):  
P. Ressel ◽  
L. C. Wang ◽  
M. H. Park ◽  
P. W. Leech ◽  
G. K. Reeves ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Ohmic Contacts ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Current Gain ◽  
Depth Of Penetration ◽  
Annealing Conditions ◽  
Small Base ◽  
20 Nm ◽  
Contact Resistivities

AbstractInP/In0.53Ga0.47As heterojunction bipolar transistors with high current gain for optoelectronic applications place stringent requirements on the ohmic contact to the base layer of moderately doped (p < 1×1019 cm−3) In0.53Ga0.47As. Contact resistivity should be <l×10−6 Ωcm2 and low depth of penetration is necessary considering the small base thickness of approximately 100 nm. The authors have recently presented data on Pd/Zn/Au/LaB6/Au contacts on p-In0.53Ga0.47As (doped to 4×1018 cm−3) with low contact resistivities of l×10−6 Ωcm2. In this paper, details are given on the optimization of the contact composition and annealing conditions of the metallization that resulted in shallow and low-resistive contacts. Alternatively, it is shown that Au-free Pd/Zn/Sb/Pd contacts on p-In0.53Ga0.47As have exhibited even lower resistivities, i.e. 3-6×10−7 Ωcm2. Backside SIMS measurements revealed a depth of penetration as low as 20 nm for this contact scheme. Aging tests at temperatures of 300 - 400 °C have demonstrated that the electrical characteristics of both types of metallization were sufficiently stable to withstand the typical processing steps for device passivation.

In-Based Ohmic Contacts to the Base Layer of GaAs-AlGaAs Heterojunction Bipolar Transistors

1990 ◽  
Vol 181 ◽  
Author(s):  
F. Ren ◽  
S. J. Pearton ◽  
W. S. Hobson ◽  
T. R. Fullowan ◽  
A. B. Emerson ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Heterojunction Bipolar Transistors ◽  
Ohmic Contacts ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Specific Contact Resistance ◽  
Current Transport ◽  
Specific Contact ◽  
P Type

ABSTRACTThe use of AuBe-In/Ag/Au p-ohmic contacts for the base layer of GaAs-AIGaAs heterojunction bipolar transistors (HBTs) is described. Annealing at 420°C for 20 sec produces a contact resistivity of 0.095 Ω mm and a specific contact resistance of l.5 × 10-7 Ω cm2, and the surface morphology of the contact is excellent. The role of the silver is as a diffusion barrier to prevent Au spiking into the base layer which could degrade the HBT performance. The presence of the In layer is highly desirable in order to reduce the contact resistance, probably by forming an InGaAs phase at the metal-GaAs interface. Beryllium acts as the p-type dopant, and the top Au layer is used to lower the contact sheet resistance. Current transport through the structure is dominated by tunneling through the barrier due to field emission in the highly doped base layer at p-type doping levels above ∼1019 cm−3

Prevention of InP/InGaAs/InP Double Heterojunction Bipolar Transistors from Current Gain Reduction during Passivation

2004 ◽  
Vol 833 ◽  
Author(s):  
Byoung-Gue Min ◽  
Jong-Min Lee ◽  
Seong-Il Kim ◽  
Chul-Won Ju ◽  
Kyung-Ho Lee
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Silicon Oxide ◽  
Surface Recombination ◽  
Surface States ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Current Gain ◽  
Device Structure ◽  
Double Heterojunction ◽  
Gain Reduction

ABSTRACTA significant degradation of current gain of InP/InGaAs/InP double heterojunction bipolar transistors was observed after passivation. The amount of degradation depended on the degree of surface exposure of the p-type InGaAs base layer according to the epi-structure and device structure. The deposition conditions such as deposition temperature, kinds of materials (silicon oxide, silicon nitride and aluminum oxide) and film thickness were not major variables to affect the device performance. The gain reduction was prevented by the BOE treatment before the passivation. A possible explanation of this behavior is that unstable non-stoichiometric surface states produced by excess In, Ga, or As after mesa etching are eliminated by BOE treatment and reduce the surface recombination sites.

Tri-Layer Lift-off Metallization Process Using Low Temperature Deposited SiNx

1992 ◽  
Vol 282 ◽  
Author(s):  
J. R. Lothian ◽  
F. Ren ◽  
S. J. Pearton ◽  
U. K. Chakrabarti ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Heterojunction Bipolar Transistors ◽  
Electron Cyclotron Resonance ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Lithographic Patterning ◽  
Final Stress ◽  
Lift Off ◽  
High Yields ◽  
Metallization Process

ABSTRACTA tri-level resist scheme using low temperature (<50°C) deposited SiNx ratfier than Ge for the transfer layer has been developed. This allows use of an optical stepper for lithographic patterning of the emitter-base junctions in GaAs/AlGaAs heterojunction bipolar transistors (HBTs) where a conventional lift-off process using a single level resist often leads to die presence of shorts between metallizations. The plasma-enhanced chemically vapor deposited (PECVD) SiNx shows a sligtly larger degree of Si-H bonding compared to nitride deposited at higher temperature (275°C), and is under compressive stress (-5 × 1010 dyne · cm−2) which is considerably relieved upor thermal cycling to 500°C (-1.5 × 1010 dyne · cm−2 after cool-down). This final stress is approximately a factor of two higher man conventional PECVD SiNx cycled in the same manner. The adhesion of the low temperature nitride to die underlying polydimediylglutarimide (PMGI) base layer in the tri-level resist is excellent, leading to high yields in the lift-off metallization process. These layers are etched in Electron Cyclotron Resonance (ECR) discharges of SF6 or O2, respectively, using low additional dc bias (≤-100V) on the sample. Subsequent deposition of the HBT base metallization (Ti/Ag/Au) and lift-off of the tri-level resist produces contacts with excellent edge definition and an absence of shorts between metallization.

A Microstructual Analysis of Au/Pd/Ti Ohmic Contacts for GaAs-Based Heterojunction Bipolar Transistors (HJBTs)

1991 ◽  
Vol 240 ◽  
Author(s):  
Bernard M. Henry ◽  
A. E. Staton-Bevan ◽  
V. K. M. Sharma ◽  
M. A. Crouch ◽  
S. S. Gill
Keyword(s):  
Structural Properties ◽  
Heterojunction Bipolar Transistors ◽  
Ohmic Contacts ◽  
Heat Treatments ◽  
Bipolar Transistors ◽  
Contact Resistivity ◽  
Base Region ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Contact Resistivities

ABSTRACTAu/Pd/Ti and Au/Ti/Pd ohmic structures to thin p+-GaAs layers have been investigated for use as contacts to the base region of HJBTs. The Au/Pd/Ti contact system yielded specific contact resistivities at or above 2.8 × 10−5Ω:cm2. Heat treatments up to 8 minutes at 380°C caused only limited interaction between the metallization and the semiconductor. The metal penetrated to a maximum depth of ≃2nm. Specific contact resistivity values less than 10−5Ωcm2 were achieved using the Au/Ti/Pd (400/75/75nm) scheme. The nonalloyed Au/Ti/Pd contact showed the best combination of electrical and structural properties with a contact resistivity value of 9 × 10≃6Ωcm2 and Pd penetration of the GaAs epilayer to a depth of cs30nm.

High-Power Characteristics of GaN/InGaN Double Heterojunction Bipolar Transistors with a Regrown p-InGaN Base Layer

2003 ◽  
Vol 798 ◽  
Author(s):  
Toshiki Makimoto ◽  
Yoshiharu Yamauchi ◽  
Kazuhide Kumakura
Keyword(s):  
High Power ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Collector Current ◽  
Power Characteristics ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Double Heterojunction ◽  
Extrinsic Base

ABSTRACTWe have investigated high-power characteristics of GaN/InGaN double heterojunction bipolar transistors on SiC substrates grown by metalorganic vapor phase epitaxy. The p-InGaN extrinsic base layers were regrown to improve ohmic characteristics of the base. Base-collector diodes showed low leakage current at their reverse bias voltages due to a wide bandgap of a GaN collector, resulting in a high-voltage transistor operation. A 90 μm × 50 μm device operated up to a collector-emitter voltage of 28 V and a collector current of 0.37 A in its common-emitter current-voltage characteristics at room temperature, which corresponds to a DC power of 10.4 W. A collector current density and a power density are as high as 8.2 kA/cm2 and 230 kW/cm2, respectively. These results show that nitride HBTs are promising for high-power electronic devices.

Hydrogen in carbon-doped GaAs base layer of GaInP/GaAs heterojunction bipolar transistors

1997 ◽  
Vol 44 (1-3) ◽  
pp. 337-340 ◽  
Author(s):  
E. Richter ◽  
P. Kurpas ◽  
M. Sato ◽  
M. Trapp ◽  
U. Zeimer ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Carbon Doped

EXPERIMENTAL CHARACTERIZATION AND MODELING ANALYSIS ON NPN AlGaN/GaN HBT WITH HIGH IDEALITY FACTOR IN BOTH COLLECTOR AND BASE CURRENT

2012 ◽  
Vol 19 (04) ◽  
pp. 1250043
Author(s):  
SHIH-WEI TAN ◽  
SHIH-WEN LAI
Keyword(s):  
Schottky Diode ◽  
Heterojunction Bipolar Transistors ◽  
Ideality Factor ◽  
Equivalent Circuit Model ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Collector Current ◽  
Base Current ◽  
Modeling Analysis ◽  
Good Agreement

Characterization and modeling analysis on both ideality factor of the collector current (η C ) and the base current (η B ) have higher than the excepted values of 1.0 and 2.0, respectively, for npn Al GaN/GaN heterojunction bipolar transistors (HBTs) have been reported. We employ the rapid thermal process annealing (RTP-annealing) to modify the base parasitical Schottky diode (called A-HBTs) after the as-deposited Ni/Au bilayers on the base layer for electrode with no annealing (called N-HBTs) to compare with each other. For a HBT operated in Gummel-plot configuration, experimental and modeling results indicate that the base parasitical Schottky diode (BPSD) causes the base current (I B ) and collector current (I C ) with high ideality factor and raise the base-emitter voltage (V BE ) to higher operation point, and therefore lead to more power consumption. Furthermore, the extended Ebers–Moll equivalent-circuit model together with the extracted device parameters provided simulated results that were in a good agreement with experimental ones.

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