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Scribing and breaking of semiconductor wafers
272
World Abstracts on Microelectronics and Reliability
bonding energy and also controlling the deformation of the leads.
Advances in low temperature die bonding techniques. DAVID N. BULL. Solid State Tech. 60 (September 1974). When hybrid microcircuits were first produced, the active devices were either encapsulated in standard packages or eutectically die bonded to gold plated tabs. During assembly, these packages or tabs were attached to the film circuit with a low temperature solder. Sensitivity of the film resistors to the high temperature associated with eutectic die bonding (epoxy die bonding at this time was not reliable even if applicable) required this prepackaged approach. Since then, circuit density has increased and the requirement of many active devices further complicates the process with die parameter shifts and bond pad leaching (floating) effects. Now several techniques have been developed to attach the die directly to the module which avoids or reduces these affects. Also monolithic device assembly of heat sensitive dice can use these techniques to advantage. Scribing and breaking of semiconductor wafers. JAMESF. MARSHALL. Solid State Tech. 70 (September 1974). An analysis of the breaking characteristics of diamond scribed, laser scribed and diamond blade saw scribed semiconductor wafers is presented. Equations are derived which relate the total stress concentration factor at the scribe kerr to the die geometry and kerr geometry. A computational procedure is presented which provides a means of computing the necessary kerr structure for a given die geometry and scribing method; or alternatively, for computing the die sizes achievable for a given kerr structure and scribing method. Utilizing the expressions developed in the analysis, the minimum achievable die size is computed for each of the three scribing methods. Microprocessor directs wafer-prober. BERNARD COLE. Electronics 99 (October 1974). Fully automatic version can work over weekend without human intervention; helium-neon laser is part of pattern-recognition system for alignment. Molecular bonding conductive films. PAUL SAVERS. Solid State Tech. 66 (September 1974). A reactive bond mechanism termed "Molecular Bonding" has been developed and incorporated in conductive systems based on gold, silver, aluminum or nickel. The reactive bond mechanism is unique in that the interracial energy associated with the conductorreaction product interface is greater than the surface tension of molten aluminum or silver and these conductors may be fired at temperatures which exceed their melting points. Significantly, the leach resistance and adhesion were greatly improved for silver and gold conductors and techniques were discovered which permit standard air atmosphere firing of the base metals aluminum and nickel. The history of development, the reasons for the development and the potential advantages of these materials to thick film users are presented. The applications for these materials and their future potential is explored. *Semiconductor measurement technology: microelectronie ultrasonic bonding. Special publication~ GEORGE G. HARMAN.National Bureau of Standards, Washington D.C., Electronic Technology Div. (January, 1974). This report primarily comprises excerpts of the work done under the NBS ultrasonic wire bonding program that was previously published in 17 quarterly and other reports. The material is organized into subject groupings with the intention of presenting in convenient form sufficient information for making high quality ultrasonic wire bonds as well as imparting a basic understanding of the ultrasonic systems used. The work emphasizes problems and methods of solving
them. To accomplish this, the required measurement equipment is first introduced. This is followed by procedures and techniques used in setting up a bonding machine, and then various machine- or operator-induced reliability problems are discussed. The characterization of the ultrasonic system and its problems are followed by in-process bonding studies and work on the ultrasonic bonding (welding) mechanism. The report concludes with a discussion of various effects of bond geometry and wire metallurgical characteristics. (Modified author abstract).
*Semiconductor measurement technology: ARPA/NBS workshop I. Measurement problems in integrated circuit processing and assembly. Special publication. HARRY A. SCHh~r'r. National Bureau of Standards, Washington D.C., Electronic Technology Div. (February 1974). The dual purpose of the workshop was (1) to announce and describe the new effort, "Advancement of Reliability, Processing, and Automation for Integrated Circuits with the National Bureau of Standards", sponsored by the Defense Advanced Research Projects Agency (ARPA) and (2) to obtain additional input on critical measurement problems in integrated circuit processing and assembly to assist in planning future work in the effort. More than 130 engineers representing 61 organizations from the electronics industry and government participated in the workshop. The measurement problems in silicon, oxides, photolithography and assembly and the problems in information dissemination that were identified by the participants are summarized. Included as appendices are summaries of two talks given: one which described the results of earlier direct contacts with a cross section of industrial representatives on major measurement problems in integrated circuit processing and assembly and the other which described the initial plans for work in the new effort. Fabrication techniques for surface-acoustic-wave and thinfilm optical devices. HENRY I. SMITH. Proc. IEEE, 62 (10) 1361 (October 1974). The techniques of photolithography, electron lithography, X-ray lithography, ion bombardment etching and liftoff are reviewed, and their advantages and disadvantages assessed from the point of view of fabricating surface-acoustic-wave and thin-film optical devices. Moisture in SC packages. ROBERT W. THOMAS and DONALDE. MEYER. Solid State Tech. 56 (September 1974). Water in SC packages is known to be a necessary condition for many well known failure mechanisms. The measurement of water hermetically sealed into an SC package is a trail planted with many pitfalls. This article discusses the results of a program to establish better measurement procedures and gives the somewhat surprising results from five independent laboratories analyzing packages sealed under controlled conditions. Detection by Auger electron spectroscopy and removal by ozonization of photoresist residues. P. H. HOLLOWAYand D. W. BUSHMIRE. Proc. IEEE Reliab. Phys. Syrup. 180 (1974). Surface chemical analyses by Auger electron spectroscopy (AES) indicate that hydrocarbon residues are frequent contaminants on gold hybrid microcircuit metallization. The primary electron beam for AES cracks the hydrocarbon contaminants causing a carbonaceous residue. Lead frame bonding data demonstrated that a carbon residue approximately 10/~ thick was indicative of thermocompression bond degradation. Concentrations of two % ozone in oxygen can remove a photoresist layer approximately 200 Athick in 100 hr at room temperature. This restores thermocompression bondability of gold surfaces. LSI yield projections based upon test pattern results: an application to multilevel metal structures. A. P. TURLEY. IEEE Trans. on Parts, Hybrids and Packaging. PHP-10,
World Abstracts on Microelectronics and Reliability
bonding energy and also controlling the deformation of the leads.
Advances in low temperature die bonding techniques. DAVID N. BULL. Solid State Tech. 60 (September 1974). When hybrid microcircuits were first produced, the active devices were either encapsulated in standard packages or eutectically die bonded to gold plated tabs. During assembly, these packages or tabs were attached to the film circuit with a low temperature solder. Sensitivity of the film resistors to the high temperature associated with eutectic die bonding (epoxy die bonding at this time was not reliable even if applicable) required this prepackaged approach. Since then, circuit density has increased and the requirement of many active devices further complicates the process with die parameter shifts and bond pad leaching (floating) effects. Now several techniques have been developed to attach the die directly to the module which avoids or reduces these affects. Also monolithic device assembly of heat sensitive dice can use these techniques to advantage. Scribing and breaking of semiconductor wafers. JAMESF. MARSHALL. Solid State Tech. 70 (September 1974). An analysis of the breaking characteristics of diamond scribed, laser scribed and diamond blade saw scribed semiconductor wafers is presented. Equations are derived which relate the total stress concentration factor at the scribe kerr to the die geometry and kerr geometry. A computational procedure is presented which provides a means of computing the necessary kerr structure for a given die geometry and scribing method; or alternatively, for computing the die sizes achievable for a given kerr structure and scribing method. Utilizing the expressions developed in the analysis, the minimum achievable die size is computed for each of the three scribing methods. Microprocessor directs wafer-prober. BERNARD COLE. Electronics 99 (October 1974). Fully automatic version can work over weekend without human intervention; helium-neon laser is part of pattern-recognition system for alignment. Molecular bonding conductive films. PAUL SAVERS. Solid State Tech. 66 (September 1974). A reactive bond mechanism termed "Molecular Bonding" has been developed and incorporated in conductive systems based on gold, silver, aluminum or nickel. The reactive bond mechanism is unique in that the interracial energy associated with the conductorreaction product interface is greater than the surface tension of molten aluminum or silver and these conductors may be fired at temperatures which exceed their melting points. Significantly, the leach resistance and adhesion were greatly improved for silver and gold conductors and techniques were discovered which permit standard air atmosphere firing of the base metals aluminum and nickel. The history of development, the reasons for the development and the potential advantages of these materials to thick film users are presented. The applications for these materials and their future potential is explored. *Semiconductor measurement technology: microelectronie ultrasonic bonding. Special publication~ GEORGE G. HARMAN.National Bureau of Standards, Washington D.C., Electronic Technology Div. (January, 1974). This report primarily comprises excerpts of the work done under the NBS ultrasonic wire bonding program that was previously published in 17 quarterly and other reports. The material is organized into subject groupings with the intention of presenting in convenient form sufficient information for making high quality ultrasonic wire bonds as well as imparting a basic understanding of the ultrasonic systems used. The work emphasizes problems and methods of solving
them. To accomplish this, the required measurement equipment is first introduced. This is followed by procedures and techniques used in setting up a bonding machine, and then various machine- or operator-induced reliability problems are discussed. The characterization of the ultrasonic system and its problems are followed by in-process bonding studies and work on the ultrasonic bonding (welding) mechanism. The report concludes with a discussion of various effects of bond geometry and wire metallurgical characteristics. (Modified author abstract).
*Semiconductor measurement technology: ARPA/NBS workshop I. Measurement problems in integrated circuit processing and assembly. Special publication. HARRY A. SCHh~r'r. National Bureau of Standards, Washington D.C., Electronic Technology Div. (February 1974). The dual purpose of the workshop was (1) to announce and describe the new effort, "Advancement of Reliability, Processing, and Automation for Integrated Circuits with the National Bureau of Standards", sponsored by the Defense Advanced Research Projects Agency (ARPA) and (2) to obtain additional input on critical measurement problems in integrated circuit processing and assembly to assist in planning future work in the effort. More than 130 engineers representing 61 organizations from the electronics industry and government participated in the workshop. The measurement problems in silicon, oxides, photolithography and assembly and the problems in information dissemination that were identified by the participants are summarized. Included as appendices are summaries of two talks given: one which described the results of earlier direct contacts with a cross section of industrial representatives on major measurement problems in integrated circuit processing and assembly and the other which described the initial plans for work in the new effort. Fabrication techniques for surface-acoustic-wave and thinfilm optical devices. HENRY I. SMITH. Proc. IEEE, 62 (10) 1361 (October 1974). The techniques of photolithography, electron lithography, X-ray lithography, ion bombardment etching and liftoff are reviewed, and their advantages and disadvantages assessed from the point of view of fabricating surface-acoustic-wave and thin-film optical devices. Moisture in SC packages. ROBERT W. THOMAS and DONALDE. MEYER. Solid State Tech. 56 (September 1974). Water in SC packages is known to be a necessary condition for many well known failure mechanisms. The measurement of water hermetically sealed into an SC package is a trail planted with many pitfalls. This article discusses the results of a program to establish better measurement procedures and gives the somewhat surprising results from five independent laboratories analyzing packages sealed under controlled conditions. Detection by Auger electron spectroscopy and removal by ozonization of photoresist residues. P. H. HOLLOWAYand D. W. BUSHMIRE. Proc. IEEE Reliab. Phys. Syrup. 180 (1974). Surface chemical analyses by Auger electron spectroscopy (AES) indicate that hydrocarbon residues are frequent contaminants on gold hybrid microcircuit metallization. The primary electron beam for AES cracks the hydrocarbon contaminants causing a carbonaceous residue. Lead frame bonding data demonstrated that a carbon residue approximately 10/~ thick was indicative of thermocompression bond degradation. Concentrations of two % ozone in oxygen can remove a photoresist layer approximately 200 Athick in 100 hr at room temperature. This restores thermocompression bondability of gold surfaces. LSI yield projections based upon test pattern results: an application to multilevel metal structures. A. P. TURLEY. IEEE Trans. on Parts, Hybrids and Packaging. PHP-10,