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

Author(s):  
N. David Theodore ◽  
Donald Y.C Lie ◽  
J. H. Song ◽  
Peter Crozier

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.

Author(s):  
N. David Theodore ◽  
Gordon Tam

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. SiGe is typically used as an epitaxial base material in HBTs. To obtain extremely high-performance bipolar-transistors it is necessary to reduce the extrinsic base-resistance. This can be done by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however with the use of implantation is that blanket implants have been found to enhance strain-relaxation of SiGe/Si. Strain relaxation will cause the bandgap-difference between Si and SiGe to decrease; this difference is maximum for a strained SiGe layer. The electrical benefits of using SiGe/Si arise largely from the presence of a significant bandgap-difference across the SiGe/Si interface. Strain relaxation reduces this benefit. Furthermore, once misfit or threading dislocations result (during strain-relaxation), the defects can give rise to recombination-generation in depletion regions of the device; high electrical leakage currents result.


1998 ◽  
Vol 09 (02) ◽  
pp. 643-670 ◽  
Author(s):  
BIPUL AGARWAL ◽  
RAJASEKHAR PULLELA ◽  
UDDALAK BHATTACHARYA ◽  
DINO MENSA ◽  
QING-HUNG LEE ◽  
...  

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.


1990 ◽  
Vol 01 (03n04) ◽  
pp. 245-301 ◽  
Author(s):  
M.F. CHANG ◽  
P.M. ASBECK

Recent advances in communication, radar and computational systems demand very high performance electronic circuits. Heterojunction bipolar transistors (HBTs) have the potential of providing a more efficient solution to many key system requirements through intrinsic device advantages than competing technologies. This paper reviews the present status of GaAs and InP-based HBT technologies and their applications to digital, analog, microwave and multifunction circuits. It begins with a brief review of HBT device concepts and critical epitaxial growth parameters. Issues important for device modeling and fabrication technologies are discussed. The paper then highlights the performance and the potential impact of HBT devices and integrated circuits in various application areas. Key prospects for future HBT development are also addressed.


2001 ◽  
Vol 11 (01) ◽  
pp. 115-136 ◽  
Author(s):  
TOHRU OKA ◽  
KOJI HIRATA ◽  
HIDEYUKI SUZUKI ◽  
KIYOSHI OUCHI ◽  
HIROYUKI UCHIYAMA ◽  
...  

Small-scale InGaP/GaAs heterojunction bipolar transistors (HBTs) with high-speed as well as low-current operation are demonstrated. To reduce the emitter size SE and the base-collector capacitance CBC simultaneously, the HBTs are fabricated by using WSi/Ti as the base electrode and by burying SiO 2 in the extrinsic collector region. WSi/Ti metals simplify and facilitate processing to fabricate small base electrodes, and the buried SiO 2 reduces the parasitic CBC under the base electrode. The cutoff frequency fT of 156 GHz and the maximum oscillation frequency f max of 255 GHz were obtained at a collector current Ic of 3.5 mA for the HBT with SE of 0.5 μ m ×4.5 μ m , and fT of 114 GHz and f max of 230 GHz were obtained at IC of 0.9 mA for the HBT with SE of 0.25 μ m ×1.5 μ m . A 1/8 static frequency divider operated at a maximum toggle frequency of 39.5 GHz with a power consumption per flip-flop of 190 mW. A transimpedance amplifier provides a gain of 46.5 dB·Ω with a bandwidth of 41.6 GHz at a power consumption of 150 mW. These results indicate the great potential of our HBTs for high-speed. low power integrated circuit applications.


1988 ◽  
Vol 144 ◽  
Author(s):  
Han-Tzong Yuan

ABSTRACTThe status and progress of AlGaAs/GaAs heterojunction bipolar transistor integrated circuits are reviewed. The challenge of fabricating large-scale integrated circuits using heterojunction bipolar transistors is discussed. Specifically, the issues related to low defect epitaxial materials, localized impurity doping techniques, simple and reliable ohmic contacts, and multilevel interconnects are examined.


1994 ◽  
Vol 05 (03) ◽  
pp. 473-491 ◽  
Author(s):  
B.S. MEYERSON ◽  
D.L. HARAME ◽  
J. STORK ◽  
E. CRABBE ◽  
J. COMFORT ◽  
...  

Recent advances in thin film growth techniques, notably the maturation of low temperature silicon epitaxy, have enabled the routine fabrication of highly controlled dopant and silicon:germanium alloy profiles. These capabilities, combined with refinements in heterojunction bipolar transistor designs, have led to the first integrated circuits in the silicon:germanium materials system. Utilizing a commercial (Leybold-AG) UHVCVD tool for SiGe epitaxy on a standard 8" CMOS line, medium scale integration has been achieved, with the first IC components being SiGe HBT based 1 Ghz, 12 bit, digital to analog converters.


2016 ◽  
Vol 25 (03n04) ◽  
pp. 1640011 ◽  
Author(s):  
D. Coquillat ◽  
V. Nodjiadjim ◽  
S. Blin ◽  
A. Konczykowska ◽  
N. Dyakonova ◽  
...  

Compact and fast detectors, for imaging and wireless communication applications, require efficient rectification of electromagnetic radiation with frequencies approaching 1 THz and modulation bandwidth up to a few tens of GHz. This can be obtained only by using a mature technology allowing monolithic integration of detectors with low-noise amplifiers. One of the best candidates is indium phosphide bipolar transistor (InP HBT) technology. In this work, we report on room temperature high sensitivity terahertz detection by InP double-heterojunction bipolar transistors (DHBTs) operating in a large frequency range (0.25–3.1 THz). The performances of the DHBTs as terahertz sensors for communications were evaluated showing the modulation bandwidth of investigated DHBTs close to 10 GHz.


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