Monocrystalline silicon used for integrated circuits: still on the way

With the rapid development of semiconductor technology, highly integrated circuits (ICs) and future nano-scale devices require large diameter and defect-free monocrystalline silicon wafers. The ongoing innovation from silicon materials is one of the driving forces in future micro and nano-technologies. In this work, the recent developments in the controlling of large diameter silicon crystal growth processes, the improvement of material features by co-doping with the intend-introduced impurities, and the progress of defect engineered silicon wafers (epitaxial silicon wafer, strained silicon, silicon on insulator) are reviewed. It is proposed that the silicon manufacturing infrastructure could still meet the increasingly stringent requirements arising from ULSI circuits and will expand Moore’s law into a couple of decades.     

Aluminum alloying in silicon integrated circuits

The metallization step in the fabrication of silicons devices and integrated circuits requires the alloying of silicon to aluminium to create ohmic contacts in the window regions. This heat treatment often results “spearing” which, especially in integrated circuits, represents a significant failure mode. The topology and kinetics of the spearing process are discussed and evidence is presented which tendsto suggest a liquid phase reaction between silicon and aluminium. A variety of metallization techniques, involving aluminium, by which it is believed spearing can be prevented are also discussed.     

与标准集成电路工艺兼容的硅基光学器件研究

着重介绍了与标准集成电路工艺兼容的硅基光学器件的最新研究进展,包括硅基光发射器、硅基光波导和调制器件、硅基光电探测器和接收机以及硅基光电子集成回路的工作原理、制作工艺和集成技术.与标准集成电路工艺兼容的硅基光电子集成回路能有效地解决电互连芯片内部串扰、带宽和能耗等问题,并能够充分利用现有成熟的集成电路工艺,实现大规模生产,具有广阔的实用前景.     

Large arrays of spatial light modulators hybridized to silicon integrated circuits

Large, high-frame-rate spatial light modulators are key components required for the realization of real-time optical processors. We report a 128 × 128 array of GaAs-based optical modulators that we hybridized to a Si integrated circuit by using In bump bonds to form a spatial light modulator. These optical modulators are composed of a series of quantum wells within an asymmetric Fabry-Perot cavity to control the optical properties. The resulting 128 × 128 element array operates in an intensity-only reflection mode at greater than 100,000 frames per second. This array interfaces to a 486-based personal computer through a standard industry standard architecture bus.     

Building blocks for integrated graphene circuits

The observation of single sheets of graphite (graphene) presents new possibilities for carbon-based nanoelectronics. We report defect tolerant configurations for a nearly reflectionless 120 degrees turn and nearly reflectionless symmetric and asymmetric splitters, which can be cut from graphene. Connections between zigzag strips of different widths can be made with either low or high reflectance depending on the connection shape.     

纳米集成电路用大直径硅及硅基材料研究进展

本文叙述了大直径硅单晶生长、杂质缺陷行为、表面质量控制及硅基材料的研究现状,讨论了应变硅与绝缘体上硅(SOI)相结合的发展趋势,展望了纳米集成电路用大直径硅及硅基材料的技术经济前景.     

Thin diamond films for integrated circuits

We propose a technology for the synthesis of thin diamond films, which allows integrated emission elements of the vacuum triode type to be created on a substrate surface. The process includes three main stages: (i) deposition of a thin diamond film onto a silicon substrate; (ii) lithographic procedure with an aluminum mask; and (iii) post-growth in a regime ensuring required emission properties. An emission triode design is presented that can be realized using the proposed technology.     

Low-loss, silicon integrated, aluminum nitride photonic circuits and their use for electro-optic signal processing

Photonic miniaturization requires seamless integration of linear and nonlinear optical components to achieve passive and active functions simultaneously. Among the available material systems, silicon photonics holds immense promise for optical signal processing and on-chip optical networks. However, silicon is limited to wavelengths above 1.1 μm and does not provide the desired lowest order optical nonlinearity for active signal processing. Here we report the integration of aluminum nitride (AlN) films on silicon substrates to bring active functionalities to chip-scale photonics. Using CMOS-compatible sputtered thin films we fabricate AlN-on-insulator waveguides that exhibit low propagation loss (0.6 dB/cm). Exploiting AlN's inherent Pockels effect we demonstrate electro-optic modulation up to 4.5 Gb/s with very low energy consumption (down to 10 fJ/bit). The ultrawide transparency window of AlN devices also enables high speed modulation at visible wavelengths. Our low cost, wideband, carrier-free photonic circuits hold promise for ultralow power and high-speed signal processing at the microprocessor chip level.     

Plasma anodization of silicon and its application to the fabrication of devices and integrated circuits

Plasma anodization was studied from the viewpoint of its application to the fabrication of devices and integrated circuits.First, the application of plasma anodization to the growth of oxide films by the localized oxidation of silicon process was investigated. A double-mask Al₂O₃/SiO₂ structure was employed as a mask and it was found that the bird's beak structure was suppressed.Secondly, the application of plasma-anodized oxide as the gate oxide of metal/oxide/semiconductor field effect transistors (MOS FETs) was considered. The interface state density in the plasma-anodized SiO₂/Si system was annealed almost completely in an Ar-CCl₄ mixture at 1000°C. P-channel MOS FETs were fabricated. The devices had a threshold voltage of -1.7 V and a mobility of 225 cm² V^-1 s^-1. The dominant neutral trapping centre in the plasma-anodized oxide was found to be the same as that in the thermally grown oxide, and its density was reduced by one order of magnitude after annealing at 1000°C.The feasibility of applying plasma anodization as a low temperature oxidation process for the fabrication of MOS FETs on neutron-irradiated silicon as a semi-insulating substrate and on a film of silicon on sapphire (SOS) was demonstrated. For MOS FETs prepared with neutron-irradiated silicon, the hole mobility was about 100 cm²V^-1s^-1 and the electron mobility was about 300 cm²V^-1s^-1. In addition, depletion mode MOS FETs made with SOS had the same characteristics as those of MOS FETs made by the high temperature process.     

Application of Ti: W barrier metallization for integrated circuits

Aluminum metallization is the most widely used for contacts and interconnections in integrated circuits. However, the solid state diffusion of aluminum in silicon during contact sintering or high temperature packaging can result in junction shorting or leakage in shallow (<1 μm) emitter-base junction devices. The interposition of a barrier metal between the aluminum and the silicon is one solution to this problem. A sputter-deposited pseudo-alloy of Ti:W (10:90 wt.%) with PtSi contacts is suitable for this application. Resistivity ratio measurements on SiO₂/ ti:W/Al film test samples have shown that the resistivity of aluminum increases owing to diffusion of titanium or tungsten into the aluminum. However, the kinetic data show that no more than a 10% increase in the resistivity of the aluminum can be expected in the useful life of a device. High current stress data show that Ti:W/Al interconnections are comparable with those of aluminum films. Auger depth profiling of si/Ti:W/Al samples annealed at 450, 500 and 550°C in N₂ shows no aluminum at the Si-(Ti:W) interface. Application of the PtSi/Ti:W/Al metallization system for large-scale integrated circuits is described.     

Short-length gauges for monitoring the manufacture of integrated circuits

Translated from Izmeritel'naya Tekhnika, No. 1, pp. 21–22, January, 1992.     

强度调制型光纤传感器用电路研究

在强度调制型光纤传感器中,光源发光强度和光电接收器工作的稳定性,是决定测量精度的关键因素。设计了具有软启动功能和恒亮度控制的光源驱动电路,所用光电接收器能满足测量系统要求。实验表明,该电路软启动效果明显,能抑制电压波动冲击,输出电压稳定度优于0.8%,为提高该类传感器测量精度提供了有效的手段。     

State-of-the-art technologies and devices for high-voltage integrated circuits

The current status of high-voltage power semiconductor devices and technologies for high-voltage integrated circuits is reviewed and the new trends in this field are discussed. The paper focuses on the concepts of the novel reduced surface field and state-of-the-art silicon technologies such as high-voltage silicon on insulator, which are expected to play an increasingly important role in power system on-chip manufacturing. Lateral devices such as LDMOSFETs, superjunctions and lateral insulated gate bipolar transistors are discussed. The paper also touches on emerging technologies such as unified MEMS-IC for enhanced breakdown capability and isolation. Finally, an overview of the fierce fight of technology survival in terms of specific on-state resistance against breakdown voltage is given.     

Monte Carlo reliability model for microwave monolithic integrated circuits

A Monte Carlo simulation is reported for analog integrated circuits and is based on the modification of the failure rate of each component due to interaction effects of the failed components. The Monte Carlo technique is the methodology used to treat such circuits, since they are independent of the number of components and the degree of system complexity. The reliability model is applicable over a wide temperature and bias range and may be used to predict reliability of microwave systems. The model is compared with accelerated test results of two analog microwave circuits. Excellent agreement has been obtained for a low noise amplifier as well as for a transimpedence amplifier. Copyright © 2007 John Wiley & Sons, Ltd.