VERTICAL SCALING OF TYPE I InP HBT WITH FT > 500 GHZ

2004 ◽  
Vol 14 (03) ◽  
pp. 625-631 ◽  
Author(s):  
J. W. LAI ◽  
W. HAFEZ ◽  
M. FENG
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Impact Ionization ◽  
Cutoff Frequency ◽  
Current Gain ◽  
Vertical Scaling ◽  
Physical Parameters ◽  
Type I ◽  
Peak Current Density ◽  
Rf Performance

We have fabricated the high-speed InP/InGaAs -based single heterojunction bipolar transistors (SHBTs) with current gain cutoff frequency, fT from 166GHz to over 500GHz by the approach of vertical scaling. Collector thickness is reduced from 3000Å to 750Å and the peak current density is increased up to 1300kA/cm2. In this paper, device rf performance has been compared with respect to materials with different vertical dimensions. The scaling limitation is also studied by analytical approach. The extracted physical parameters suggest that the parasitic emitter resistance is the major limit on further enhancing ultra-scaled HBT intrinsic speed due to the associated RECBC delay. The cut-off frequency of a 500Å collector SHBT has been measured and the results indicate a dramatic drop on fT, supporting the conclusion projected by model analysis. It is also commented that for deeply downscaled HBTs, impact ionization could be another degrading mechanism limits device bandwidth.

FUNDAMENTALS, PERFORMANCE AND RELIABILITY OF III-V COMPOUND SEMICONDUCTOR HETEROJUNCTION BIPOLAR TRANSISTORS

1995 ◽  
Vol 06 (01) ◽  
pp. 1-89 ◽  
Author(s):  
GUANG-BO GAO ◽  
S. NOOR MOHAMMAND ◽  
GREGORY A. MARTIN ◽  
HADIS MORKOÇ
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Compound Semiconductor ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Processing Technologies ◽  
Recent Developments ◽  
Improved Performance ◽  
Oscillation Frequencies ◽  
Recorded Performances

Recent developments in the physics and technology of III-V compound heterojunction bipolar transistors (HBTs) are reviewed. The technologies discussed are AlGaAs/GaAs, GaInP/GaAs, InP/InGaAs, and AlInAs/InGaAs based heterostructures. WIth current gain cut off frequencies over 100 GHz and maximum oscillation frequencies of about 200 GHz, the III-V compound semiconductor based HBTs have advanced to the point of commercialization. These developments also had the fortuitous effect of providing impetus and theoretical base to advance Si based HBT technologies, such as SiGe HBTs, to advance also. Recent SiGe HBTs, taking advantage of advanced Si processing technologies, have also recorded performances in excess of 100 GHz with applications envisioned in high speed analog-digital converters. While there remain some voids in the fundamental understanding of HBTs, the state-of-the-art of the GaAs HBT technology, concerning reproducibility and reliability, is at a point where problems related to production are at the forefront. The next few years are going to prove interesting with each technology recording improved performance.

SCALING OF InGaAs/InAlAsHBTs FOR HIGH SPEED MIXED-SIGNAL AND mm-WAVE ICs

2001 ◽  
Vol 11 (01) ◽  
pp. 159-215 ◽  
Author(s):  
M. J. W. RODWELL ◽  
M. URTEAGA ◽  
Y. BETSER ◽  
T. MATHEW ◽  
P. KRISHNAN ◽  
...  
Keyword(s):  
Current Density ◽  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Ohmic Contacts ◽  
Logic Gate ◽  
Cutoff Frequency ◽  
Contact Resistivity ◽  
Power Gain ◽  
Minimum Width ◽  
Collector Junction

High bandwidths are obtained with heterojunction bipolar transistors by thinning the base and collector layers, increasing emitter current density, decreasing emitter contact resistivity, and reducing the emitter and collector junction widths. In mesa HBTs, minimum dimensions required for the base contact impose a minimum width for the collector junction, frustrating device scaling. Narrow collector junctions can be obtained by using substrate transfer processes, or -if contact resistivity is greatly reduced -by reducing the width of the base Ohmic contacts in a mesa structure. HBTs with submicron collector junctions exhibit extremely high f max and high gains in mm-wave ICs. Logic gate delays are primarily set by depletion-layer charging times, and neither fτ nor f max is indicative of logic speed. For high speed logic, epitaxial layers must be thinned, emitter and collector junction widths reduced, current density increased, and emitter parasitic resistance decreased. Transferred-substrate HBTs have obtained 21 dB unilateral power gain at 100 GHz. If extrapolated at -20 dB/decade, the power gain cutoff frequency f max is 1.1 THz. Transferred-substrate HBTs have obtained 295 GHz f τ . Demonstrated ICs include lumped and distributed amplifiers with bandwidths to 85 GHz, 66 GHz master-slave flip-flops, and 18 GHz clock rate Δ-Σ ADCs.

High Speed GaAs Based Devices on Si Substrates

1986 ◽  
Vol 67 ◽  
Author(s):  
Hadis Morkoc
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Bipolar Transistors ◽  
Annealing Process ◽  
Current Gain ◽  
Device Performance ◽  
Microwave Frequencies ◽  
Si Substrates ◽  
Cutoff Frequencies ◽  
Oscillation Frequencies

ABSTRACTRemarkably good device performance at both dc and microwave frequencies has recently been obtained from GaAs based devices grown on Si substrates. In GaAs MESFETs on Si, current gain cutoff frequencies and maximum oscillation frequencies of fT = 13.3 GHz and fmax = 30 GHz have been obtained for 1.2μm devices, which is nearly identical to the performance achieved in GaAs on GaAs technology for both direct implant and epitaxial technology. For heterojunction bipolar transistors, current gain cutoff frequencies and maximum oscillation frequencies of fT = 30 GHz and fmax = 11.3 GHz have been obtained for emitter dimensions of 4×20μm2. In GaAs AlGaAs MODFETs. current gain cut-off frequencies of about 15 GHz with lμm gates were obtained on GaAs and Si substrates. The pseudomorphic InGaAs/GaAs MODFETs were also fabricated and found to be comparable to GaAs MODFETs although they should perform better. The structures were also shown to maintain their properties when put through ion implantation and annealing process. Given the performance already demonstrated in GaAs on Si devices and the advantages afforded by this technology, the growth of III-Vs on Si promises to play an important role in the future of heterojunction electronics.

scholarly journals Thermal Effect and Frequency Response Analyses on Heterojunction Bipolar Power Transistor

2001 ◽  
Vol 24 (4) ◽  
pp. 265-287
Author(s):  
K. F. Yarn ◽  
K. H. Ho
Keyword(s):  
Frequency Response ◽  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Carrier Transport ◽  
Bipolar Transistors ◽  
Junction Temperature ◽  
Current Gain ◽  
Material System ◽  
Current Voltage ◽  
Analytical Thermal Model

Heterojunction bipolar transistors (HBT) based on Npn AlGaAs/GaAs material system have attracted considerable attention for microwave power and digital applications due to their high speed and high current capabilities. In this paper, a numerical model based on the Npn AlGaAs/GaAs HBT structure for the carrier transport is presented. Three figures of merit on device operation, current gain, cut-off frequency and maximum oscillation frequency are calculated. Besides, thermal instability plays an important role on power HBT resulted from the low thermal conductivity in GaAs. The generated heat will increase the junction temperature and cause self-destruction. Therefore, the thermal runaway study of the junction temperature, current–voltage (IV) characteristics and frequency response using an analytical thermal model is described.

Evidence for localization effects in GaAsSb/InP heterostructures from optical spectroscopy

2003 ◽  
Vol 799 ◽  
Author(s):  
Houssam Chouaib ◽  
Catherine Bru-Chevallier ◽  
Taha Benyattou ◽  
Hacene Lahreche ◽  
Philippe Bove
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
Careful Analysis ◽  
Bipolar Transistors ◽  
Excitation Density ◽  
Type I ◽  
Carrier Localization ◽  
Recombination Energy ◽  
Interface Quality ◽  
New Generation

ABSTRACTGaAsSb is a promising material for the base of a new generation of Heterojunction Bipolar Transistors (HBT) on InP, as it is expected to allow the elaboration of high-speed digital circuits (80 to 100 Gbits/s). Emitter-base interfaces between GaAsSb and InP need to be well controlled to ensure good performance of the HBT, and this requires a careful analysis of both material and interface quality. Photoluminescence (PL) experiments as a function of temperature and of power excitation density, as well as photoreflectance (PR) measurements are performed on GaAsSb/InP heterostructures in order to get information about ordering and segregation effects in antimonide alloys.From the PL recombination energy across the type II interface and at the GaAsSb band-edge, the band offset ΔEC between InP and GaAsSb is calculated. The evolution of the band to band PL recombination is studied as a function of temperature: the energy and intensity of the type I PL transition are shown to exhibit specific behaviors, which are typical of carrier localization effects in semiconductor alloys. At low temperature, the shape of the PR spectrum results in an atypical steplike background, which is analyzed as a band filling effect in consequence of the carrier localization on potential fluctuations.

ULTRAHIGH fmax AlInAs/GaInAs TRANSFERRED-SUBSTRATE HETEROJUNCTION BIPOLAR TRANSISTORS FOR INTEGRATED CIRCUITS APPLICATIONS

1998 ◽  
Vol 09 (02) ◽  
pp. 643-670 ◽  
Author(s):  
BIPUL AGARWAL ◽  
RAJASEKHAR PULLELA ◽  
UDDALAK BHATTACHARYA ◽  
DINO MENSA ◽  
QING-HUNG LEE ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Heterojunction Bipolar Transistors ◽  
Integrated Circuit ◽  
High Speed ◽  
Bipolar Transistors ◽  
Fabrication Process ◽  
Material System ◽  
Rf Performance ◽  
Consequent Increase ◽  
Very High

Transferred-substrate heterojunction bipolar transistors (HBTs) have demonstrated very high bandwidths and are potential candidates for very high speed integrated circuit (IC) applications. The transferred-substrate process permits fabrication of narrow and aligned emitter-base and collector-base junctions, reducing the collector-base capacitance and increasing the device f max . Unlike conventional double-mesa HBTs, transferred-substrate HBTs can be scaled to submicron dimensions with a consequent increase in bandwidth. This paper introduces the concept of transferred-substrate HBTs. Fabrication process in the AlInAs/GaInAs material system is presented, followed by DC and RF performance. A demonstration IC is shown along with some integrated circuits in development.

TEM study of phosphorus-implanted pseudomorphic Si0.88Ge0.12 on Si(100)

1995 ◽  
Vol 53 ◽  
pp. 468-469
Author(s):  
N. David Theodore ◽  
Donald Y.C Lie ◽  
J. H. Song ◽  
Peter Crozier
Keyword(s):  
Integrated Circuits ◽  
Heterojunction Bipolar Transistors ◽  
Integrated Circuit ◽  
High Speed ◽  
Room Temperature ◽  
Strain Relaxation ◽  
Bipolar Transistors ◽  
Sige Hbt ◽  
Integrated Circuit Manufacturing ◽  
Microstructural Behavior

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.

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