- Email: [email protected]
Combined ferrite-dielectric substrates for integrated circuits in microwave technique
410
World Abstracts on Microelectronics and Reliability
CAN effectively attacked and removed the Cr20~ while the KI+ I2 attacked the underlying gold film. The KI+ I: improved the TC bondability both by undercutting some of the Cr20~ and by roughening the gold, thereby allowing more deformanon to occur during bonding. The implications of these results on selection of a chemical cleaning agent are discussed. The ability of CAN to dissolve a chromium adhesion layer under the gold metallization has also been investigated. It was shown that a heat treatment of 300°C for 2 hr in air prevented this undercutting; possible reasons are discussed.
Process control by means of accelerated testing. J. E. BRODEUR. 13th Ann. Proc. Reliability Physics Syrup., Nevada. p. 255. High temperature operating life test gives quick feedback on the processes used in fabrication of semiconductor wafers. The relatively high failure rate of the (so-called) freaks is quickly demonstrated in such a test and can indicate a marginal or out of control process. This method of process control concentrates on the initial fallout as a means of determining the reliability of final products. Greater than 150°C stress temperatures should not be applied to plastic encapsulated devices. Since most epoxies have glass transition temperatures in the range of 150°C to 180°C permanent damage to the package could result. Determination of useful life of two-layer metallization systems via accelerated stressing. 13th Ann. Proc. Reliability Physics Syrup., Nevada. p. 263, 1975. Accelerated testing was utilized as a means of rapidly determining the reliability, under usage conditions, of a two-level aluminum metallization --SiO2 structure with level-tolevel via contacts. A specially designed test vehicle containing 0-25-mil square and 0.50-rail square via contact structures was used. Electromigration was identified as the failure mechanism by SEM analysis. Calculation of the activation energy was in agreement with an electromigration mechanism. In using the described evaluation technique, only a small quantity of units was required to arrive quickly at valid results. During step-stressing, two-level metallization test vehicles passivated with deposited SiO: layer showed greater immunity from electromigration than unpassivated structures. Further, the 0.25-mil via contacts failed sooner during constant accelerated stress testing than the 0.50rail via contacts. The data presented here deal specifically with the outcome of accelerated testing of passivated and unpassivated via contacts. Based on these test results from 0.25rail and 0.50-mil via contacts, the 0-50-mil via contact (fully passivated) was adopted as a design rule. A metallization system for microwave and UHF power transistors. L. W. DANLEY. Solid State Techn. June 1975. p. 35. Metal migration, a problem prevalent in aluminuminterconnected semiconductors operated at high current densities and elevated temperatures, has necessitated an industry search for production-grade metallization systems of higher reliability. Although the use of copperaluminum, silicon-aluminum or other aluminum alloys, (plus rigorously controlled processing conditions), greatly reduces the risk of premature metal contact failure, the performance achieved is often just barely adequate. Various parameters of importance in a system that eliminates the problems associated with aluminum are discussed. Equipment procurement, process finalization and results (using SEM photo-micrographs) are described.
Small field effect transistors, Research on the normally-off channel type. A BOBONRHTH. Rev. Tech. Thomson-CSF, 7 (2) 229 (1975). (In French). The electronic masking, ionic etching and ion implantation techniques have led to the development of junction field effect transistors (JFET) and Schottky gate field effect transistors (MESFET) of very small size (hence very fast), consuming little current and having zero threshold voltage (~% ~0). Improvements to these new technological processes should make it possible to develop JFETs with a threshold voltage in the same direction as the drain voltage. The author computes two examples of such components (one taken to extreme limit, the other normal) with V-r~0'4 V (n-type channel), with due allowance for the corrections introduced into the classic formulae by the small dimensions of the channel. These new components, which are intermediate between conventional JFETs and bipolar transistors, should make it possible to manufacture high-density digital integrated circuits (logic and memorv units). Circuits employing small-size field effect transistors. G. CACHIER. G. BERT, J-P. PURON and S. VOLMIER. Re~. Tech. Thomson-CSF, 7 (2). 399. (1975). (In French). Small FETs are fast, low-consumption components of simple technology that can readily be integrated. The article deals mainly with logic integrated circuits. Their theoretical performance characteristics (gain, logic levels) arc expressed analytically in the case of a simple switch by means of a transistor model discussed in the previous article [7]. The shift voltage required to couple two DC circuits is also calculated. Some examples of feasible logic functions are given, particularly the NORDEC gate, which is as rapid as the ECL type with less dispersion and a power requirement about two orders of magnitude lower. The so-called "normally-off'" transistor gates (see first article in this issue [6]) will already enable logics of a few txW, with propagation times of a few nsec, to be produced. FETs with a higher threshold voltage (in absolute value), find applications in high-performance analog gates. Circuit-analysis program can model many digital ICs automatically. J. BOWERS and G. SHAW. Electronics May 1st, 1975. p. 93. By describing logic devices functionally, Super-Sceptre can quickly simulate systems that contain digital integrated dircuits as well as other components: users do not need differential equations. Impulse-bonded wiring is economical alternative to multilayer boards. F. G. SHULZ, D. C. FRENCH, B. E. CRISCENZO and P. T. KLOTZ. Electronics. March 6, 1975. p. 75. For a complex system design that remains volatile well into production, impulse bonding creates densely wired boards that, unlike multilayer circuits, are easy and inexpensive to alter. Combined territe-dielectric substrates tor integrated circuits in microwave technique. A. I. OBRAZCOV, M. A. CHARINSKAYA, T. A. KRYLOVA, S. V. YAKOVLEV,G. A. MATVEEV and N. I. SAVCHENKO. Nachrichtentechnik. Elektronik 25 (5), 182 (1975). (In German). Possibilities of realizing integrated circuits in extra-high frequency technique are investigated, explaining technological, circuit-technique and constructive aspects and presenting laboratory samples realized.
6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S , SYSTEMS AND EQUIPMENTS 4 GI-I~ band Iow-nolse preamplifier. C. DEPRET. Rev. technology preamplifiers to meet satellite or earth station Tech. Thomson-CSF 7 (l) 125 (1975). This article transponder specifications. describes the design of 4 GHz. hybrid microelectronics Amplification of the intermediate frequency mixing
World Abstracts on Microelectronics and Reliability
CAN effectively attacked and removed the Cr20~ while the KI+ I2 attacked the underlying gold film. The KI+ I: improved the TC bondability both by undercutting some of the Cr20~ and by roughening the gold, thereby allowing more deformanon to occur during bonding. The implications of these results on selection of a chemical cleaning agent are discussed. The ability of CAN to dissolve a chromium adhesion layer under the gold metallization has also been investigated. It was shown that a heat treatment of 300°C for 2 hr in air prevented this undercutting; possible reasons are discussed.
Process control by means of accelerated testing. J. E. BRODEUR. 13th Ann. Proc. Reliability Physics Syrup., Nevada. p. 255. High temperature operating life test gives quick feedback on the processes used in fabrication of semiconductor wafers. The relatively high failure rate of the (so-called) freaks is quickly demonstrated in such a test and can indicate a marginal or out of control process. This method of process control concentrates on the initial fallout as a means of determining the reliability of final products. Greater than 150°C stress temperatures should not be applied to plastic encapsulated devices. Since most epoxies have glass transition temperatures in the range of 150°C to 180°C permanent damage to the package could result. Determination of useful life of two-layer metallization systems via accelerated stressing. 13th Ann. Proc. Reliability Physics Syrup., Nevada. p. 263, 1975. Accelerated testing was utilized as a means of rapidly determining the reliability, under usage conditions, of a two-level aluminum metallization --SiO2 structure with level-tolevel via contacts. A specially designed test vehicle containing 0-25-mil square and 0.50-rail square via contact structures was used. Electromigration was identified as the failure mechanism by SEM analysis. Calculation of the activation energy was in agreement with an electromigration mechanism. In using the described evaluation technique, only a small quantity of units was required to arrive quickly at valid results. During step-stressing, two-level metallization test vehicles passivated with deposited SiO: layer showed greater immunity from electromigration than unpassivated structures. Further, the 0.25-mil via contacts failed sooner during constant accelerated stress testing than the 0.50rail via contacts. The data presented here deal specifically with the outcome of accelerated testing of passivated and unpassivated via contacts. Based on these test results from 0.25rail and 0.50-mil via contacts, the 0-50-mil via contact (fully passivated) was adopted as a design rule. A metallization system for microwave and UHF power transistors. L. W. DANLEY. Solid State Techn. June 1975. p. 35. Metal migration, a problem prevalent in aluminuminterconnected semiconductors operated at high current densities and elevated temperatures, has necessitated an industry search for production-grade metallization systems of higher reliability. Although the use of copperaluminum, silicon-aluminum or other aluminum alloys, (plus rigorously controlled processing conditions), greatly reduces the risk of premature metal contact failure, the performance achieved is often just barely adequate. Various parameters of importance in a system that eliminates the problems associated with aluminum are discussed. Equipment procurement, process finalization and results (using SEM photo-micrographs) are described.
Small field effect transistors, Research on the normally-off channel type. A BOBONRHTH. Rev. Tech. Thomson-CSF, 7 (2) 229 (1975). (In French). The electronic masking, ionic etching and ion implantation techniques have led to the development of junction field effect transistors (JFET) and Schottky gate field effect transistors (MESFET) of very small size (hence very fast), consuming little current and having zero threshold voltage (~% ~0). Improvements to these new technological processes should make it possible to develop JFETs with a threshold voltage in the same direction as the drain voltage. The author computes two examples of such components (one taken to extreme limit, the other normal) with V-r~0'4 V (n-type channel), with due allowance for the corrections introduced into the classic formulae by the small dimensions of the channel. These new components, which are intermediate between conventional JFETs and bipolar transistors, should make it possible to manufacture high-density digital integrated circuits (logic and memorv units). Circuits employing small-size field effect transistors. G. CACHIER. G. BERT, J-P. PURON and S. VOLMIER. Re~. Tech. Thomson-CSF, 7 (2). 399. (1975). (In French). Small FETs are fast, low-consumption components of simple technology that can readily be integrated. The article deals mainly with logic integrated circuits. Their theoretical performance characteristics (gain, logic levels) arc expressed analytically in the case of a simple switch by means of a transistor model discussed in the previous article [7]. The shift voltage required to couple two DC circuits is also calculated. Some examples of feasible logic functions are given, particularly the NORDEC gate, which is as rapid as the ECL type with less dispersion and a power requirement about two orders of magnitude lower. The so-called "normally-off'" transistor gates (see first article in this issue [6]) will already enable logics of a few txW, with propagation times of a few nsec, to be produced. FETs with a higher threshold voltage (in absolute value), find applications in high-performance analog gates. Circuit-analysis program can model many digital ICs automatically. J. BOWERS and G. SHAW. Electronics May 1st, 1975. p. 93. By describing logic devices functionally, Super-Sceptre can quickly simulate systems that contain digital integrated dircuits as well as other components: users do not need differential equations. Impulse-bonded wiring is economical alternative to multilayer boards. F. G. SHULZ, D. C. FRENCH, B. E. CRISCENZO and P. T. KLOTZ. Electronics. March 6, 1975. p. 75. For a complex system design that remains volatile well into production, impulse bonding creates densely wired boards that, unlike multilayer circuits, are easy and inexpensive to alter. Combined territe-dielectric substrates tor integrated circuits in microwave technique. A. I. OBRAZCOV, M. A. CHARINSKAYA, T. A. KRYLOVA, S. V. YAKOVLEV,G. A. MATVEEV and N. I. SAVCHENKO. Nachrichtentechnik. Elektronik 25 (5), 182 (1975). (In German). Possibilities of realizing integrated circuits in extra-high frequency technique are investigated, explaining technological, circuit-technique and constructive aspects and presenting laboratory samples realized.
6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S , SYSTEMS AND EQUIPMENTS 4 GI-I~ band Iow-nolse preamplifier. C. DEPRET. Rev. technology preamplifiers to meet satellite or earth station Tech. Thomson-CSF 7 (l) 125 (1975). This article transponder specifications. describes the design of 4 GHz. hybrid microelectronics Amplification of the intermediate frequency mixing