High Density and Low Leakage Current in $ hbox{TiO}_{2}$ MIM Capacitors Processed at 300 $^{circ} hbox{C}$

We report Ir/TiO₂/TaN metal-insulator-metal capacitors processed at only 300degC, which show a capacitance density of 28 fF/mum² and a leakage current of 3 times 10^-8 (25degC) or 6 times 10^-7 (125degC) A/cm² at -1 V. This performance is due to the combined effects of 300degC nanocrystallized high-kappa TiO₂, a high conduction band offset, and high work-function upper electrode. These devices show potential for integration in future very-large-scale-integration technologies.     

Improved High-Temperature Leakage in High-Density MIM Capacitors by Using a TiLaO Dielectric and an Ir Electrode

We have fabricated high-kappa TaN/Ir/TiLaO/TaN metal-insulator-metal capacitors. A low leakage current of 6.6 times 10^-7 A/cm² was obtained at 125degC for 24-fF/mum2 density capacitors. The excellent device performance is due to the combined effects of the high-kappa TiLaO dielectric, a high work-function Ir electrode, and large conduction band offset.     

High-Performance Metal–Insulator–Metal Capacitors Using Amorphous BaSm2Ti4O12 Thin Film

The dielectric properties of the amorphous BaSm₂Ti₄O₁₂ (BSmT) film with various thicknesses were investigated to evaluate its potential use as a metal-insulator-metal (MIM) capacitor. An amorphous 35-nm-thick BSmT film grown at 300 degC exhibited a high capacitance density of 9.9 fF/mum² at 100 kHz and a low leakage current density of 1.790 nA/cm² at 1 V. The quadratic and linear voltage coefficients of capacitance of the film were 599 ppm/V² and -81 ppm/V at 100 kHz, respectively. The temperature coefficient of capacitance of the film was also low about 236 ppm/degC at 100 kHz. These results confirmed the suitability of the amorphous BSmT film as a high-performance MIM capacitor     

High-Temperature Stable HfLaON p-MOSFETs With High-Work-Function Ir3Si Gate

We report a novel 1000 degC stable HfLaON p-MOSFET with Ir₃ Si gate. Low leakage current of 1.8times10^-5 A/cm² at 1 V above flat-band voltage, good effective work function of 5.08 eV, and high mobility of 84 cm²/Vmiddots are simultaneously obtained at 1.6 nm equivalent oxide thickness. This gate-first p-MOSFET process with self-aligned ion implant and 1000 degC rapid thermal annealing is fully compatible to current very large scale integration fabrication lines     

High-κ Al2O3−HfTiO Nanolaminates With Less Than 0.8-nm Equivalent Oxide Thickness

High quality nanolaminate stacks consisting of five Al₂O₃-HfTiO layers with an effective dielectric constant of about 22.5 are reported. A dielectric constant for binary HfTiO thick films of about 83 was also demonstrated. The electrical characteristics of as-deposited structures and ones which were annealed in an O₂ atmosphere at up to 950 degC for 5-10 min were investigated. Two types of gate electrodes: Pt and Ti were compared. The dielectric stack which was annealed up to 500 degC exhibits a leakage current density as small as ~1times10^-4 A/cm² at an electric of field 1.5 MV/cm for a quantum-mechanical corrected equivalent oxide thickness of ~0.76 nm. These values change to ~1times10^-8 A/cm² and 1.82 nm, respectively, after annealing at 950 degC     

Investigation on the Electric Properties of $ hbox{Bi}_{1.5}hbox{ZnNb}_{1.5}hbox{O}_{7}$ Thin Films Grown on TiN Substrate for MIM Capacitors

A small crystalline phase was formed in the Bi_1.5ZnNb_1.5O₇ (BZN) film grown at 300degC on TiN/SiO₂/Si substrate using RF-magnetron sputtering. A 46-nm-thick BZN film exhibited a high capacitance density of 13.6 fF/mum² at 100 kHz with a dielectric constant of 71, which did not change even in the gigahertz range (1-6 GHz). The quality factor was high, approximately 50, at 2.5 GHz. The leakage-current density was low, approximately 5.66 nA/cm², at 2 V. The quadratic voltage and temperature coefficients of capacitance were approximately 631 ppm/V² and 149 ppm/degC at 100 kHz, respectively. These results indicate that the BZN film grown on TiN substrate at 300degC can be a good candidate material for metal-insulator- metal capacitors.     

Good High-Temperature Stability of TiN/ Al2O3/WN/TiN Capacitors

For the first time, good thermal stability up to an annealing temperature of 1000degC has been demonstrated for a new TiN/Al₂O₃/WN/TiN capacitor structure. Good electrical performance has been achieved for the proposed layer structure, including a high dielectric constant of ~ 10, low leakage current of 1.2times10^-7 A/cm² at 1 V, and excellent reliability. A thin WN layer was incorporated into the metal-insulator-metal capacitor between the bottom TiN electrode and the Al₂O₃ dielectric suppressing of interfacial-layer formation at Al₂ O₃/TiN interfaces and resulting in a smoother Al₂O₃/TiN interface. This new layer structure is very attractive for deep-trench capacitor applications in DRAM technologies beyond 50 nm.     

DC Characteristics of AlGaAs/GaAs/GaN HBTs Formed by Direct Wafer Fusion

We have fabricated AlGaAs/GaAs/GaN heterojunction bipolar transistors (HBTs) formed by direct wafer fusion with different fusion temperatures. By employing a low wafer fusion temperature of 550 degC, current gains as high as ~9 and output currents as high as ~65 mA (emitter size of 100times120 mum²) were obtained. The effective minority carrier lifetime in the base was estimated to have decreased ~20 times due to the fusion process. In comparison, HBTs produced with higher wafer fusion temperatures (600 degC and 650 degC) exhibit lower current gains (~2-3) and higher base-collector leakage currents     

Electromigration Reliability and Morphologies of 62Sn–36Pb–2Ni and 62Sn–36Pb–2Cu Flip-Chip Solder Joints

The near-eutectic Sn-Pb-Cu and Sn-Pb-Ni ternary solder alloys were developed based on the consideration of strength and fatigue reliability enhancement of solder joints in part via the altering of formation of interfacial intermetallic compounds. In this work, we examine electromigration reliability and morphologies of 62Sn-36Pb-2Ni and 62Sn-36Pb-2Cu flip-chip solder joints subjected to two test conditions that combine different average current densities and ambient temperatures: 5 kA/cm² at 150 degC and 20 kA/cm² at 3 degC. Under the test condition of 5 kA/cm² at 150 degC, 62Sn-36Pb-2Cu is overwhelmingly better than 62Sn-36Pb-2Ni in terms of electromigration reliability. However, under the test condition of 20 kA/cm2 at 30 degC, the electromigration fatigue life of 62Sn-36Pb-2Ni shows a profuse enhancement and exceeds that of 62Sn-36Pb-2Cu. Electromigration-induced morphologies are also examined on the cross sections of solder joints using scanning electron microscopy.     

Novel Integration of Metal–Insulator–Metal (MIM) Capacitors Comprising Perovskite-type Dielectric and Cu Bottom Electrode on Low-Temperature Packaging Substrates

In this letter, a novel integration scheme, for metal-insulator-metal capacitors comprising perovskite-type dielectrics and Cu-based bottom electrodes, has been demonstrated on low-temperature FR4 packaging substrates. Cu oxidation during dielectric deposition and postannealing is completely avoided by a dielectric-first process flow with Ti as oxygen-getter. By using evaporated barium strontium titanate as capacitor dielectric, a maximum capacitance density (~1250 nF/cm² at 100 kHz) and moderate leakage current (< 4 times 10^-5 A/cm² at 2 V) have been achieved with rapid thermal annealing at 700degC. Higher temperature leads to dielectric degradation. Combined with advanced deposition techniques, this integration scheme enables realization of high-performance embedded capacitors that can be integrated with printed circuit board technology.     

Very low threshold current density 1.29 μm GaInNAs triple quantum well lasers grown by MBE

Very low threshold Ga_0.62In_0.38N_0.007As_0.993/GaN_0.011As_0.989/GaAs triple quantum well (QW) lasers emitting at 1.29 mum are demonstrated. The laser structure was grown by molecular beam epitaxy after extensive optimisations of growth and in situ annealing conditions. As- cleaved broad area lasers with a cavity length of 1 mm showed a record low threshold current density of 400 A/cm² (~130 A/cm² / QW), a high differential efficiency of 0.32 W/A/facet and a characteristic temperature of 94 K in the temperature range 10 to 110degC.     

Very Low Dark Current CCD Image Sensor

Very low dark current in charge-coupled-device image sensors is established by means of multipinned phase combined with vertical antiblooming, so-called all-gates pinning. Hereby, dark-current generation at the surface and diffusion from the bulk are suppressed. Using a conventional 6 times 6 mum² image pixel with an additional n-type implant, a dark-current level of 1.5 pA/cm² is obtained at 60degC without loss of optical performance. This means that the pixel dark current is reduced by a factor 80.     

High-Temperature Operation of AlGaN/GaN HFET With a Low on-State Resistance, High Breakdown Voltage, and Fast Switching

Improved characteristics of an AlGaN/GaN HFET are reported. In this paper, the authors introduce a new ohmic electrode of Ti/AlSi/Mo and a low refractive index SiN_x to decrease the contact resistance and gate leakage current. The AlGaN/GaN HFET showed a low specific resistance of 6.3 mOmega middot cm² and a high breakdown voltage of 750 V. The switching characteristics of an AlGaN/GaN HFET are investigated. The small turn-on delay of 7.2 ns, which was one-tenth of Si MOSFETs, was measured. The switching operation of the HFET showed no significant degradation up to 225 degC     

Thermal Boundary Resistance Between GaN and Substrate in AlGaN/GaN Electronic Devices

The influence of a thermal boundary resistance (TBR) on temperature distribution in ungated AlGaN/GaN field-effect devices was investigated using 3-D micro-Raman thermography. The temperature distribution in operating AlGaN/GaN devices on SiC, sapphire, and Si substrates was used to determine values for the TBR by comparing experimental results to finite-difference thermal simulations. While the measured TBR of about 3.3 x 10^-8 W^-1 ldr m² ldr K for devices on SiC and Si substrates has a sizeable effect on the self-heating in devices, the TBR of up to 1.2 x 10^-8 W^-1 ldr m² ldr K plays an insignificant role in devices on sapphire substrates due to the low thermal conductivity of the substrate. The determined effective TBR was found to increase with temperature at the GaN/SiC interface from 3.3 x 10^-8 W^-1 ldr m² ldr K at 150degC to 6.5 x 3.3 x 10^-8 W^-1 ldr m² ldr K at 275degC, respectively. The contribution of a low-thermal-conductivity GaN layer at the GaN/substrate interface toward the effective TBR in devices and its temperature dependence are also discussed.     

Effect of SiNx Gate Dielectric Deposition Power and Temperature on a-Si:H TFT Stability

The stability of thin-film transistors (TFTs) of hydrogenated amorphous-silicon (a-Si:H) against gate-bias stress is improved by raising the deposition power and temperature of the silicon nitride gate dielectric. We studied the effects of power density between 22 and 110 mW/cm² and temperature between 150degC and 300degC . The time needed to shift the threshold voltage by 2 V varies by a factor of 12 between low power and low temperature, and high power and high temperature. These results highlight the importance of fabricating a-Si:H TFTs on flexible plastic with the SiN_x gate dielectric deposited at the highest possible power and temperature.     

High-Performance Directly Modulated 1.3- μm Undoped InAs–InGaAs Quantum-Dot Lasers

In this letter, we report on experimental results of directly modulated single-transverse mode 1.3-mum InAs-InGaAs quantum-dot (QD) lasers in a wide temperature range. A 3.125-Gb/s data modulation over temperature with an extinction ratio up to 10 dB is reported. Moreover, 10-Gb/s eye patterns at 15 degC and 50 degC and 5-Gb/s modulation in the whole explored temperature range (15 degC-85 degC) are demonstrated. These results were obtained by exploiting heterostructures containing six layers of high modal gain InAs QDs grown without incorporation of p-doping in the active region or tunnelling injection structure implementation. QD lasers exhibited a saturation modal gain as high as 36.3 cm^-1, ground state lasing from short cavities down to 400-mum length and a characteristic temperature of about 110 K in a large temperature range between 15 degC and 85 degC     

32 Gbit/s multimode fibre transmission using high-speed, low current density 850 nm VCSEL

Error free transmission over multimode fibre at data rates up to 3 2 Gbit/s at 25degC and 25 Gbit/s at 85degC using an oxide confined 850 nm VCSEL biased at a current density of 11-14kA/cm² is demonstrated. The VCSEL is optimised for high-speed by reducing capacitance and self-heating and by using strained InGaAs quantum wells for high differential gain.     

Highly Reliable 1.5-μm DFB Laser With High-Mesa SIBH Structure

The degradation behavior of 1.5-mum uncooled distributed feedback (DFB) lasers with a semi-insulating buried heterostructure during constant-power aging is investigated. Long-term stability is achieved by suppressing the t^0.5 deterioration in the current increase rate (second-stage degradation). The improvement in reliability is attributed to the fact that some defects on the grating interface are simultaneously suppressed by the mutual diffusion that occurs when growing the SI-InP layer. We realized a DFB laser with high reliability (< 1000 failure digits) at 95 degC that is capable of error-free 2.5-Gb/s 80-km transmission at -20degC to 100 degC     

A Sub-2 W Low Power IA Processor for Mobile Internet Devices in 45 nm High-k Metal Gate CMOS

This paper describes a low power Intel Architecture (IA) processor specifically designed for Mobile Internet Devices (MID) with performance similar to mainstream Ultra-Mobile PCs. The design relies on high residency in a new low-power state in order to keep average power and idle power below 220 and 80 mW, respectively. The design consists of an in-order pipeline capable of issuing 2 instructions per cycle supporting 2 threads, 32 KB instruction and 24 KB data L1 caches, independent integer and floating point execution units, times86 front end execution unit, a 512 KB L2 cache and a 533 MT/s dual-mode (GTL and CMOS) front-side-bus (FSB). The design contains 47 million transistors in a die size under 25 mm² manufactured in a 9-metal 45 nm CMOS process with optimized transistors for low leakage. Maximum thermal design power (TDP) consumption is measured at 2 W at 1.0 V, 90degC using a synthetic power-virus test at a frequency of 1.86 GHz.     

High-Performance Bound-to-Continuum Quantum-Cascade Lasers for Broad-Gain Applications

Based on the bound-to-continuum active region design, we shall present a high performance continuous-wave (CW) quantum-cascade laser. In contrast to high performance lasers based on a two-phonon resonance transition and a narrow linewidth (< 165 cm^-1), the device presented here exhibits a spontaneous emission full-width at half-maximum as large as 295 cm^-1. Thus, such devices are very suitable for broadband tuning. At 30degC, it shows a maximum output power and slope efficiency of 188 mW and 500 mW/A, as well as a threshold current density of only 1.79 kA/cm². Furthermore, at this temperature, the device demonstrates an internal differential quantum efficiency of 71% and a wall plug efficiency of 2.0%. The maximum CW operation temperature reached is 110degC. A thermal resistance of 4.3 K/W was attained by epi-down mounting on diamond submounts. The waveguide losses of 14 cm^-1 are explained by intersubband absorption in addition to free-carrier absorption.