416
WORLD
ABSTRACTS
ON MICROELECTRONICS
Rapid photomask m e a s u r e m e n t using video scanning t i m e intervals. D. T. GAFFNEY and R. FEDER. Solid State Technol., March (1972), p. 35. Mask linewidths and spacing proportions can be rapidly and accurately measured. The technique described uses the video scanning time as a measuring tool, and lends itself readily to automation. The system uses off-the-shelf items, minimizing construction costs.
Assembling large-array IC m e m o r i e s . M. E. HOFE, Jr., Electron. Des. 4 (1972), p. 76. Calls for these circuits to sense output, provide timing and control signals, refresh the memory and reduce power.
Probleme
schneller
integrierter
Schaltungen.
VON H.-M. REIN. Frequenz 26 (1972), p. 30. (In German.) The reduction of signal delay in digital system is discussed. This time is due to the delay t/) of the integrated circuit and the propagation delay tL on the interconnection lines (including package delay), tD can be reduced to values below one nanosecond if fast transistors and suitable circuit concepts are employed. The necessary technological provisions and the most important circuit concepts are described and the corresponding problems are discussed. Low values of tL can be realized by a high packing density requiring complex integrated circuits. Insufficient yield and high power dissipation are problems, yielding high costs for the devices and the cooling technique. One way for the reduction of these problems is described.
Standard parts and c u s t o m design m e r g e in fourchip processor kit. F. FAGGIN and M. E. HOFF. Electronics, April (1972), p. 112. Processors of various degrees of complexity can be designed from three standardized chip elements and a fourth, a read-only memory, customized five to each user's specific purpose by his own microprogram.
Computer-aided evaluation of circuits and test structures. G. POSDZIECH. Nachrichtentech. 22 (1972), p. 51. (In German.) The kind and extent of data measured of integrated circuits and of their rest structures are reviewed, with a description of computer programmes suited for their concentration in conformity with technical and organizational aspects.
Factory cleanliness for the manufacture of microelectronic devices. M. K. BRUMBACH. Soltd State Technol., February (1972), p. 45. Airborne particle behavior as affected by special facilities, housekeeping and personnel control is used as a base to establish factory cleanliness levels for manufacture of microelectronic devices. Clean room technology, which is normally employed to achieve ultraclean environments, is not considered in this article. Instead, specific needs are given for general factory space in which a necessary but somewhat lesser degree of cleanliness is required.
Packaging with integrated circuits. A. SOCOLOVSKY and S. B. RUTH. Electron. Engnr, February (1972), p. 51.
AND RELIABILITY
There is hardly a piece of electronic equipment designed today without integrated circuits, lots of them. More importantly, most of them come packaged in the imperfect, yet already classic, dual-in-line package. And this little bug-like package, more than any other factor, has effected a major revolution in the design of today's electronic hardware. Used not only for ICs, DIPs find their way into passive components and even relays and switches. Their regular size and lead-spacing are reflected in the myriads of plated-through holes in printed circuit boards. Their numbers have been responsible for the multiplicity of pins and wires in back panels, the numbers of contacts in connectors and the many conductors in cable harnesses and flat cables. It is t~, this rev,lution that this course is dedicated.
Do not be confused by IC switching t i m e specifications. J. SPRINGER, EDN/EEE, March (1972), p. 34. A full understanding of such specifications is necessary in order to properly design an M S t / L S I system. This step-by-step analysis will help to eliminate the confusion,
Problems of large-scale integration (Part i). , \ l ~ ARDENNE, A. MOSCHWITZER and K. GABER. Nachrichtentech. 22 (1972), p. 39. (In German.) The authors proceed from universal development trends in the realization of integrated electronic systems to discuss in particular the development of the degree of integration of integrated circuits in M I S and bipolar technique. For this purpose, the development of decisive factors is estimated perspectively, such as minimmn surface of component and optimum surface of chip. From a description of the variants to be realized, and of the advantages presented by the system of large-scale integration, requirements are derived for cutting c,)~t , f preparation, and possibilities are given for attaininrz this aim. Finally, possibilities offered by the electron beam technology for microelectronics are described and information on own experimental work about electron beam doping are given. Implanted depletion loads boost MOS array performance. B. CRaWFOaD. Electronh'.~, April (1972), p. 85. Ion-implanted depletion-load circuits arc giving 2-to-10-fold improvement in output when used with enhancement-mode devices; alternative to C/MOS can operate with logic power as low as q [xW per ffatc at 200 kHz. A simple
equivalent circuit for the M N O S T m e m o r y element. M. A. C. S. BROWN, J~ E. BOt~NDEN and G. F. VANSTONE. Solid State Electron. 15 (1972), p. 707. In this paper we use the equivalent circuit of Svensson and Lundstrom to derive expressions for the memory properties of the M N O S T . Writing speed, the hysteresis loop and memory decay are predicted and compared with experimental results; reasons for observed differences are considered. Fundamental properties of this type of device become apparent because we restrict our argument to relatively simple explicit mathematical expressions. A new measurement tech-