World Abstracts on Microelectronics and Reliability
Chip carriers, lids and sots---an analysis of cost and performance tradeoffs for hybrid applications. SUBASHKHADGE, Proc. Electron. Components Conf. Arlington, Va, May 16-18, 1977. p. 30. A typical hybrid microcircuit consists of active and passive devices interconnected on a ceramic substrate. The passive components are either in the form of discrete chips or are deposited directly onto the substrate using thick film or thin film techniques. The active devices are attached separately to the substrate and interconnected to the appropriate passive components. The selection of these add-on active components is based on various factors such as cost, size, electrical performance, thermal requirements and compatibility with assembly processes. Usually these devices are procured in one of three forms; (a) bare dice, (b) dice premounted in carriers, or (c) prepackaged, fully tested units. This paper discusses the relative merits of each of these approaches. In particular, the LID, SOT-23 and the Ceramic Chip Carrier Pack-
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Thin silicon ion-implanted p-i-n photodiodes. R. G. PLUMB and J. E. CARROLL. Solid St. Electron. Devices. 1, (3) 89 (April 1977). Thin (6 pm) thick Si has been ion implanted to fabricate a p-i-n photodiode with an overall rise time probably better than 80ps. The narrow depletion region gives short transit times, and the shallow ion-implanted junctions lead to minimal amounts of minority carrier storage, thus eliminating any slow tail to the voltage-output response to a step change of light input. Composition and stress state of thin films deposited by ion beam sputtering. R. N. CASTELLANO. Vacuum 27, (3) 109 (1977). The ion beam sputtering technique offers several advantages over conventional sputtering systems. This technique operates at a lower pressure and substrate temperature than conventional sputtering. In addition, the angle of deposition which is easily varied with ion beam sputtering is essentially fixed in dc and rf diode sputtering. As a result of these advantages, many of the parameters which effect film stress, resistivity, and grain size can be varied independently. Several properties of ion beam sputtered Ni, A1, Ni3AI and Au thin films have been evaluated as a function of ion beam current density, target material, and the angle and distance of the substrate from the target. The grain size and stress were found to vary with the angle of deposition. There is an apparent correlation between electrical resistivity,and the oxygen content in the films. Both properties depend upon the grain size. The stress levels of the films are shown to be influenced by the oxygen content. These experimental results are discussed in light of models proposed to explain the origin of stress in thin films. Formation of various metal-semiconductor junctions by means of ion evaporation. P. GLASER, A. HERMAN and Gv VAGO. Vacuum 27, (3) 197 (1977). The paper deals with the result of some preliminary experiments of applying ionevaporated metal layers to silicon and heat treatment of the samples. Ion evaporation is based on the electron beam evaporation, namely, the ions arising from the 180° deflection type e-gun are accelerated to cause implantation effects during the condensation of the neutral particles. The accelerating voltage is typically 20kV, the ion current 5 20 mA. Four metals have been chosen for the experiments: A1, Ni, Cu and Mo. The 1-V-characteristics of the contacts deposited by ion evaporation were ohmic. The curves appreciably changed after heat treatment of the samples at 400, 500 and 580°C. M.R. 16/6---c
ages are discussed in terms of cost and performance tradeoffs for hybrid applications.
Oscillator devices using thick-film technology. LEO WILLIAMSJR. IEEE Trans. Parts, Hybrids, Packaging PHP-13, (1) 91 (March 1977). The Electrical Engineering Department of North Carolina Agricultural and Technical State University has developed a microelectronics laboratory as a result of research involving microelectronics and metallic oxide studies over the past five years. Work on characterization and applications of metallic oxide devices is currently being conducted. This paper reports on the fabrication of eight oscillator devices on a 1-in square alumina substrate using metallic oxide materials developed at NC A & T State University as a result of the research program. Significant technological capabilities of the laboratory relative to the microelectronics industry in the area of microelectronic component evaluation is also discussed.
The A1-Si contacts had very high resistivity after the treatment at 40if'C, but then A1 alloyed diode type contacts were achieved at 500°C. Ni and Mo formed alloyed type contacts at 580°C, and similar results were obtained in case of Cu. Very interesting results were obtained for Ni and Mo at 500°C, where we obtained I-V-characteristics of the Schottky-diode type, but with the reverse polarity.
Mechanism and control of post-trim drift of laser trimmed thick film resistors. J. S. SHAH and L. BERR1N. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 254. Laser trimming is an established produFtion technique for adjustment of thick film resistors to their nominal values. The initial precision of laser trimming can be +0.1~o. However, during storage at room temperature, the laser trimmed thick film resistors exhibit positive changes of their resistance values. This post-laser trim drift can be large and unpredictable, which causes manufacturing and reliability problems for tight tolerance (+ 1.0% for 20 year life time) thick film resistors. In this study, we have investigated and established the parameters controlling the post-trim drift of 100, 1K, 10K, and 100K f2/D resistors. Inspecting IC masks with a differential laser scanning inspection system. J. D. KNOX, P. V. GOEDERTIER, D. FAIRBANKSand F. CAPRARI. Solid St. Technol. p. 48 (May 1977). As LSI continues to force further integrated circuit miniaturization it is becoming more and more important to produce a defect free mask. Along with this increase in pattern densities an efficient method for rapid inspection of such masks is essential. Conventional mask inspectiom methods utilizing a microscope are grossly deficient both in throughput rates and inspection efficiency. A new approach to mask inspection utilizing laser scanning methods has been successfully demonstrated to overcome these deficiencies and provide 100% mask inspection in a considerably shorter time. Gallium alnminium arsenide heterostructure lasers" factors affecting catastrophic degradaiion. G. D. HENSHALL. Solid-St. Electron. 20, p. 595 (1977). Catastrophic degradation in (GaA1)As/GaAs heterostructure lasers is characterised by an irreversible fall in output power together with associated facet damage. The importance of near-field uniformity in interpreting catastrophic degradation is described. The power emission per unit area should primarily determine the onset of catastrophic degradation. It is