Electrical properties of InP irradiated with fast neutrons in a nuclear reactor

Electrical properties of single-crystal InP samples with various initial concentrations of charge carriers were studied in relation to the dose of irradiation with fast reactor neutrons and subsequent heat treatments in the temperature range of 20–900°C. It is shown that the behavior electrical properties depends on the doping level of the starting material and that the heat treatment in the aforementioned range of temperatures results in a complete elimination of radiation defects, which makes it possible to apply the method of nuclear-transmutation doping to InP samples. The contribution of nuclear reaction initiated by intermediate-energy neutrons to the total level of nuclear-transmutation doping amounts to about 10%.     

Highly integrated InP HBT optical receivers

This paper presents two highly integrated receiver circuits fabricated in InP heterojunction bipolar transistor (HBT) technology operating at up to 2.5 and 7.5 Gb/s, respectively. The first IC is a generic digital receiver circuit with CMOS-compatible outputs. It integrates monolithically an automatic-gain-control amplifier, a digital clock and data recovery circuit, and a 1:8 demultiplexer, and consumes an extremely low 340 mW of power at 3.3 V, including output buffers. It can realize a full optical receiver when connected to a photo detector/preamplifier front end. The second circuit is a complete multirate optical receiver application-specific integrated circuit (ASIC) that integrates a photodiode, a transimpedance amplifier, a limiting amplifier, a digital clock and data recovery circuit, a 1:10 demultiplexer, and the asynchronous-transfer-mode-compatible word synchronization logic. It is the most functionally complex InP HBT optoelectronic integrated circuit reported to date. A custom package has also been developed for this ASIC     

Electronic properties of p-GaN(Mg) irradiated with reactor neutrons

The effect of irradiation with full-spectrum reactor neutrons and predominantly fast reactor neutrons (up to a fluence of 8 × 10¹⁸ cm^?2) on the electrical properties of epitaxial p-GaN(Mg) films at different initial doping levels (in the range of hole concentrations p = 10¹⁷–10¹⁹ cm^?3) is analyzed. It is found that neutron irradiation induces an increase in the resistivity of the initial material to 10¹⁰ Ω cm at 300 K. It is shown that, at high neutron fluences, the resistivity of the material decreases because of the hopping conduction of charge carriers over radiation defect states. The study of isochronous annealing at 100–1000°C reveals stages of donor-defect (100–300°C, 500–700°C, 750–850°C) and acceptor-defect (300–500°C, 650–800°C) annealing in the neutron-irradiated p-GaN(Mg) samples.     

InGaAsP/InP monolithic integrated circuit with lasers and an optical switch

InGaAs/InP monolithic integrated circuits composed of a compact carrier-injection optical switch and distributed feedback laser diodes are fabricated. These integrated circuits have a variety of functions, such as monolithic modulators, switches and optical amplifiers for optical communication systems.     

Electrical properties of InSb irradiated with fast neutrons from a nuclear reactor

The effect of fast neutrons, having the full spectrum of neutrons from a reactor, on the formation and annealing of radiation defects and on the nuclear-transmutation doping of InSb single crystals is determined. The character of the change produced in the electrical properties of the material by irradiation and subsequent heat-treatments is determined. Fiz. Tekh. Poluprovodn. 33, 927–930 (August 1999)     

InGaAs/InP界面控制对InGaAs薄膜电学和光学性质 的影响

研究了全固态源分子束外延(MBE)生长InGaAs/InP异质结界面扩散对InGaAs外延薄膜电学和光学性质的影响.通过X射线衍射、变温霍尔测试和变温光致发光等方法对InGaAs薄膜样品进行细致研究.发现在InGaAs/InP界面之间插入一层利用As_4生长的InGaAs过渡层,能够显著改善上层InGaAs(利用As_2生长)外延薄膜的电学性能,其低温迁移率显著提高.同时荧光峰反常蓝移动消失,光学性质有所改善.研究表明利用As_4生长InGaAs过渡层,可显著降低As在InP中反常扩散,获得陡峭的InGaAs/InP界面,从而提高InGaAs材料电学和光学性能.     

High-speed monolithic coherent optical receiver integrated on InP substrate

A monolithic coherent receiver have a directional waveguide coupler and a balanced pair of lateral pin photodiodes was fabricated. The lateral pin photodiode has an improved structure, exhibiting a 3 dB bandwidth of 2 GHz. Heterodyne detection with this monolithic receiver was demonstrated at 1.8 GHz and 2.3 GHz.<>     

Optical and electrical properties of 4H-SiC irradiated with Xe ions

Structures with aluminum-ion-implanted p ⁺-n junctions formed in 26-μm-thick chemicalvapor-deposited-epitaxial 4H-SiC layers with an uncompensated donor concentration N _d ?N _a = (1–3) × 10¹⁵ cm^?3 are irradiated with 167-MeV Xe ions at fluences of 4 × 10⁹ to 1 × 10¹¹ cm^?2 and temperatures of 25 and 500°C. Then as-grown and irradiated structures are thermally annealed at a temperature of 500°C for 30 min. The as-grown, irradiated, and annealed samples are analyzed by means of cathodoluminescence, including the cross-sectional local cathodoluminescence technique, and electrical methods. According to the experimental data, radiation defects penetrate to a depth in excess of several tens of times the range of Xe ions. Irradiation of the structures at 500°C is accompanied by “dynamic annealing” of some low-temperature radiation defects, which increases the radiation resource of 4H-SiC devices operating at elevated temperatures.     

The far infrared optical properties of InP at 6 and 300 K

The amplitude and phase reflection spectra of InP have been determined in the far infrared at 6 and 300 K by dispersive Fourier transform spectroscopy and used to calculate values of the optical constants and dielectric functions in the region of the fundamental lattice resonance.     

On the electronic properties of GaSb irradiated with reactor neutrons and its charge neutrality level

The electronic properties and the limiting position of the Fermi level in p-GaSb crystals irradiated with full-spectrum reactor neutrons at up to a fluence of 8.6 × 10¹⁸ cm⁻² are studied. It is shown that the irradiation of GaSb with reactor neutrons results in an increase in the concentration of free holes to p _lim = (5−6) × 10¹⁸ cm⁻³ and in pinning of the Fermi level at the limiting position F _lim close to E _V + 0.02 eV at 300 K. The effect of the annealing of radiation defects in the temperature range 100–550°C is explored.

     

The effect of hydrostatic pressure on the electronic and optical properties of InP

Based on the empirical pseudo-potential method, the electronic and optical properties of the InP compound in the zinc-blende structure at ambient and under hydrostatic pressure are reported. The first-order pressure coefficients of the main band gaps (at Γ, X, and L) are given. The agreement between our calculated hydrostatic deformation potential and the available experimental data is better than 5%, whereas for the crossover pressure from direct to indirect band gap is about 10% less. The valence bandwidth increases with increasing pressure reflecting the decreased ionicity in the material of interest. Besides the electronic properties, the effect of pressure on the dielectric function is also analysed.     

Effect of substrate orientation on electrical properties of LPE-grown InP

The carrier concentrations of LPE-grown layers on (111)B substrates are about twice that of layers grown simultaneously on (100) substrates from the same solution. The analysis shows that the distribution coefficient for donor impurity is about 2.5 times larger in the case of (111)B face than that of (100) face.     

High-speed switching characteristics of integrated 4*4 InP optical switch array

High-speed switching of an InP optical switch array is achieved. Optical switch rise and fall times of 2.8 and 2.5 ns, respectively, are obtained. It is shown that the optical switch module can be utilised in a new ATM switch system.<>     

Time-resolved optical characterization of electrical activity in integrated circuits

If the rate of improvement in the performance of advanced silicon integrated circuits is to be sustained, new techniques for the measurement of electrical waveforms in operating circuits are needed. Critical factors dictating this requirement include the increased speed and complexity of circuits, the growing importance of faults that appear only during high-speed operation, and the use of flip-chip packaging technologies. Two recently developed all-optical methods for measuring the switching activity from the backside of a chip are described and compared. One is a passive approach based on the measurement of hot carrier luminescence emitted from the channel of a CMOS field-effect transistor (FET) during switching. The second uses a laser probe to sense the switching induced modulation of the silicon optical constants near an FET's source and drain.     

Some electrical and optical properties of copper-sodium-phosphate glasses

Abstract

In this paper it is proved that the dual of a code of order r + (r + 1 )_m,s which is a linear code over GF(2) obtained by annexing some vectors to the basis vectors of an rth order Reed-Muller code R(r, m), is a code of order (m ?r ?2) + (m ?r?1)_m,swhere Further, the weight distribution of such codes is obtained in some particular cases.     

用于单片集成光接收机前端的GaAs基InP/InGaAs HBT

实现了一种可用于单片集成光接收机前端的GaAs基InP/InGaAs HBT。借助超薄低温InP缓冲层在GaAs衬底上生长出了高质量的InP外延层。在此基础上,只利用超薄低温InP缓冲层技术就在半绝缘GaAs衬底上成功制备出了InP/InGaAsHBT,器件的电流截止频率达到4.4GHz,开启电压0.4V,反向击穿电压大于4V,直流放大倍数约为20。该HBT器件和GaAs基长波长、可调谐InP光探测器单片集成为实现适用于WDM光纤通信系统的高性能、集成化光接收机前端提供了一种新的解决方法。     

The effects of V/III ratio and growth temperature on the electrical and optical properties of InP grown by low-pressure metalorganic chemical vapor deposition

Electrical and optical properties of InP grown by low-pressure metalorganic chemical vapor deposition using triethylindium (TEI) and phosphine (PH₃) are described. It was found that the net ionized impurity concentration shows a monotonic decrease as the PH₃/TEI ratio increases. Similarly, the electron mobility and the photoluminescent intensity increases with the PH₃/TEI ratio. The effect of growth temperature has also been investigated in the range from 500 to 650°C. For a variety of PH₃/TEI ratios, the optimal growth temperature is in the range of 550×600éC. In terms of impurities, the dominant shallow acceptors are Zn and possibly C, and the most common deep acceptor is Mn. The best material obtained shows a net electron concentration of 1 × 10¹⁵ cm⁻³ with an associated 77K electron mobility of 41,000 cm² /Vsec, implying that the total ionized,impurity concentration is in the range of 3'4 □ 10¹⁵ cm⁻³     

Optical and electrical properties of 4<Emphasis Type="Italic">H</Emphasis>-SiC irradiated with fast neutrons and high-energy heavy ions

Photoluminescence and deep-level transient spectroscopy are used to study the effect of irradiation with fast neutrons and high-energy Kr (235 MeV) and Bi (710 MeV) ions on the optical and electrical properties of high-resistivity high-purity n-type 4H-SiC epitaxial layers grown by chemical vapor deposition. Electrical characteristics were studied using the barrier structures based on these epitaxial layers: Schottky barriers with Al and Cr contacts and p⁺-n-n⁺ diodes fabricated by Al ion implantation. According to the experimental data obtained, neutrons and high-energy ions give rise to the same defect-related centers. The results show that, even for the extremely high ionization density (34 keV/nm) characteristic of Bi ions, the formation of the defect structure in SiC single crystals is governed by energy losses of particles due to elastic collisions.     

Ka-band InP high electron mobility transistor monolithic microwave integrated circuit reliability

The reliability of AlInAs/GaInAs high electron mobility transistor (HEMT) monolithic microwave integrated circuits on InP substrates from HRL Labs has been studied with elevated-temperature lifetests on Ka-band LNAs, as well as ramped-voltage tests on individual capacitors. In the lifetests the LNAs were put under normal DC bias, and aging was accelerated by heating to channel temperatures of 190°C and 210°C. Room-temperature characterizations involved DC tests of HEMT parameters as well as 30 GHz measurements of gain, noise figure and phase. Aging caused the noise figure to drop by a few tenths of a dB, and the phase changed by ±10°. The gain dropped gradually by several dB. Taking 1 dB drop in gain as the failure criterion, we find an activation energy of 1.1 eV, and a mean time to failure (MTTF) at an operating channel temperature of 70°C of 7×10⁶ h. In the ramped-voltage tests, 10×10 μm² capacitors were taken to breakdown at two different temperatures, and several ramp rates. This yielded a voltage acceleration factor of γ=36–39 nm/V, and thermal activation energy of 0.11–0.13 eV. Next, ramped voltage tests were conducted on 200×200 μm² capacitors, typical of those in circuits. These were done at 25°C and 3.0 V/s only, and at least 1000 specimens were tested per wafer. The known acceleration factors were used to find the MTTFs at 70°C, with operating biases of 5 or 10 V. For the majority of the population the MTTFs are about 10⁹ h, while only 0.07% of the population has MTTF less than 1×10⁶ h. The combination of results from elevated-temperature lifetests and ramped-voltage capacitor tests indicates excellent reliability for this MMIC technology in terms of known “wearout” failure mechanisms.     

The electrical characteristics of InP implanted with the column IV elements

A study of the electrical characteristics of InP implanted with C, Si, Ge and Sn demonstrates that all of these column IV elements are donors, although the net electrical activation achieved with the light ion C was only about 5%. Samples implanted at temperatures of 150–200°C generally had lower sheet resistivities, higher mobilities and except for high doses, higher sheet carrier concentrations than those done at room temperatures. Implants at 150–200°C with 1 × 10¹⁴cm^?2 of the heavier ions, Si, Ge or Sn, resulted in layers with sheet carrier concentrations of 7.8 × 10¹³, 5.6 × 10¹³ and 4.7 × 10¹³cm^?2, respectively. Carrier concentration profiles of samples implanted at 200°C with 1 × 10¹⁴cm^?2 of Si agreed reasonably well with LSS theory. Higher doses gave rise to substantial diffusion of the implanted Si, whereas room temperature implants showed poor activation near the surface.