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Big bubble chips point the way to low-cost memories
356
World Abstracts on Microelectronics and Reliability
bipolar components in the 12L format, with capabilities comparable to and better than those of some of the MOS technologies. The main significance of these findings is that an existing production line for analogue integrated circuits can be employed for the manufacture of densely-packed digital circuits as well, without any major reorganization. In addition, new possibilities for both analogue and digital circuitry on the same chip are created.
Optical emission end-point detecting for monitoring oxygen plasma photoresist stripping. BILL B. STAFFORDand GEORGES J. GORIN. Solid St. Technol. p. 51 (Sept. 1977). A process monitoring system is described which automatically detects and signals completion of stripping processes in which an oxygen plasma removes photoresist from etched wafers. Photoresist stripping data monitored at 519.8 nm. (CO) are presented for both negative and positive photoresists at 125 °C. starting temperature. The end-point of plasma stripping and the amount of stripped photoresist are determined quantitatively. The dedicated end-point detector is ,small (0.5" cube), sensitive and is incorporated as an integral part of commercially available photoresist strippers.
Photoelectric scanning of wafer inhomogeneities.
H. F.
MATARE. Solid St. Technol. p. 56 (Sept. 1977). The methods for testing wafer homogeneity are reviewed and a newly perfected wafer test equipment is described. The method is based on photoelectrically producing a replica of a wafer subject to a multitude of Schottky barriers. As the equipment works with a contact grid, no wafer preparation other than cleanliness (deoxidation) is necessary. Some typical scannograms taken with the equipment are discussed.
Preloading compliant bonding tape with beam-lead integrated circuits. RAYMOND F. GRUSZKA. Solid St. Technol. p. 61 (Sept. 1977). Immediately after manufacture, beam-lead integrated circuit chips are loaded into chip windows in compliant bonding tape. A transfer arm removes an electrically acceptable chip from an interdigitated array to a visual inspection station. If visually acceptable, the chip is put on a chip pedestal and flipped into a chip window to which resin has been applied. The tape is indexed into a tension-free take-up reel activated by a photoelectric mechanism. Dimples in the tape maintain sufficient separation between adjacent coils of wound tape to protect the chips during loading and handling. Equipment monitors resin application, chip placement, and loaded-tape quality. Compared to conventional processing that requires chip pickup and alignment, the preloaded-tape system doubles the bonding rate and reduces bonding costs 42 percent.
The particulate matter in semiconductor chemicals. E. M. JULEFF, S. FAWCETT and S. E. GAYDA. Microelectronics 8, (3) 35 (1977). Quantitative results are given for the level of particulate matter contained in a range of chemicals commonly associated with semiconductor processing. It is shown that although membrane filtration methods can be very effective in reducing the concentration of contaminants,
in order to achieve ultimate cleanliness the bottle material and cleansing procedures are critical.
Raising yield and throughput in front-end wafer processing. WILLIAM L. LOVELESS.Solid St. TechnoL p. 47 (SepL 1977). Because current semiconductor processing techniques permit the use of larger 3- and 4-inch wafers in batch processing, a small processing error can be extremely costly. To eliminate machine-introduced-rework (MIR), vital parameters have to be monitored continuously; hence the automated microprocessor-based master controller has become a significant cost-saver by preventing entire batches of wafers from being wasted. Such control techniques in front-end processing are discussed, following a wafer completely through a typical microprocessor monitored "wet" process. The controller's ability to identify "when" and "where" malfunctions occur. and to diagnose the malfimctions are also discussed A new short channel MOSFET structure (UMOST). C. A. T. SALAMA.Solid-St. Electron. 20, 1003 (1977). A new MOSFET structure with a trapezoidal U-shaped channel defined by anisotropic etching is described. The structure results in very short channel devices almost free of short channel effects and achieves higher speed without the use of submicron photolithography. A simplified theory for the structure is presented and compared with experimental results obtained on 1 - 10 #m channel length devices. This structure may prove useful in the study of conduction in short channel MOSFETs without introducing the complicating two dimensional short channel effects.
Potential and field distribution in high resistivity microresistors and halltrons for MOS integrated circuits. N. B. VELCHEV. Solid-St. Electron. 20, 943 (1977). Some results from a detailed analysis of the basic equations for silicon high resistivity diffused and implanted channels with an opposite substrate conductivity are presented. The computer aided calculations permit the finding of potential and electrical field distribution along the conductive channel as a function of all parameters of the structures. The numerical data are necessary for design and application of microresistors and Halltrons for MOS integrated circuits. An experimental Hall effect study of the theory in the case of p-type diffused and implanted Halltrons on n-type silicon substrates is given.
Flex-mount polishing of silicon wafers. ANTHONY C. BONORA. Solid St. Technol. p. 55 (October 1977). The basic current material of solid state electronics is the silicon wafer_ Stringent high technology requirements for high yield wafers demand new and improved polishing methods to replace wax and template processes. A new flex-mount wafer polishing process is described and compared with the traditional techniques. Big bubble chips point the way to low-cost memories. Electronics p. 31 (8 December 1977). Rockwell is developing 1-megabit bubble memory chips -- but production is at least three years off.
6. MICROELECTRONICS- COMPONENTS, SYSTEMS AND EQUIPMENTS C-MOS converters resolve 12 bits. LARRY WALLER. Electronics p. 141 (24 November 1977). Hybrid digital-to-analog units are the first such equipment to combine direct microprocessor compatibility with the low power dissipation of C-MOS.
the results of benchmark tests of several different microprocessors. The results are given in terms of speed of execution, size of source program (number of statements) and of memory requirements for the compiled programs. An analysis of these results is given in terms of the microprocessor architectures.
The implications of microprocessor architecture on speed, programming and memory size. BRIAN K. PENNEY. Radio
Dynamic testing of control systems. Prof. D. R. TOWILL.
Electron. Engr 47, (11) 522 (Nov. 1977). This paper gives
Radio Electron. Engr 47, (11) 505 (Nov. 1977). The paper
World Abstracts on Microelectronics and Reliability
bipolar components in the 12L format, with capabilities comparable to and better than those of some of the MOS technologies. The main significance of these findings is that an existing production line for analogue integrated circuits can be employed for the manufacture of densely-packed digital circuits as well, without any major reorganization. In addition, new possibilities for both analogue and digital circuitry on the same chip are created.
Optical emission end-point detecting for monitoring oxygen plasma photoresist stripping. BILL B. STAFFORDand GEORGES J. GORIN. Solid St. Technol. p. 51 (Sept. 1977). A process monitoring system is described which automatically detects and signals completion of stripping processes in which an oxygen plasma removes photoresist from etched wafers. Photoresist stripping data monitored at 519.8 nm. (CO) are presented for both negative and positive photoresists at 125 °C. starting temperature. The end-point of plasma stripping and the amount of stripped photoresist are determined quantitatively. The dedicated end-point detector is ,small (0.5" cube), sensitive and is incorporated as an integral part of commercially available photoresist strippers.
Photoelectric scanning of wafer inhomogeneities.
H. F.
MATARE. Solid St. Technol. p. 56 (Sept. 1977). The methods for testing wafer homogeneity are reviewed and a newly perfected wafer test equipment is described. The method is based on photoelectrically producing a replica of a wafer subject to a multitude of Schottky barriers. As the equipment works with a contact grid, no wafer preparation other than cleanliness (deoxidation) is necessary. Some typical scannograms taken with the equipment are discussed.
Preloading compliant bonding tape with beam-lead integrated circuits. RAYMOND F. GRUSZKA. Solid St. Technol. p. 61 (Sept. 1977). Immediately after manufacture, beam-lead integrated circuit chips are loaded into chip windows in compliant bonding tape. A transfer arm removes an electrically acceptable chip from an interdigitated array to a visual inspection station. If visually acceptable, the chip is put on a chip pedestal and flipped into a chip window to which resin has been applied. The tape is indexed into a tension-free take-up reel activated by a photoelectric mechanism. Dimples in the tape maintain sufficient separation between adjacent coils of wound tape to protect the chips during loading and handling. Equipment monitors resin application, chip placement, and loaded-tape quality. Compared to conventional processing that requires chip pickup and alignment, the preloaded-tape system doubles the bonding rate and reduces bonding costs 42 percent.
The particulate matter in semiconductor chemicals. E. M. JULEFF, S. FAWCETT and S. E. GAYDA. Microelectronics 8, (3) 35 (1977). Quantitative results are given for the level of particulate matter contained in a range of chemicals commonly associated with semiconductor processing. It is shown that although membrane filtration methods can be very effective in reducing the concentration of contaminants,
in order to achieve ultimate cleanliness the bottle material and cleansing procedures are critical.
Raising yield and throughput in front-end wafer processing. WILLIAM L. LOVELESS.Solid St. TechnoL p. 47 (SepL 1977). Because current semiconductor processing techniques permit the use of larger 3- and 4-inch wafers in batch processing, a small processing error can be extremely costly. To eliminate machine-introduced-rework (MIR), vital parameters have to be monitored continuously; hence the automated microprocessor-based master controller has become a significant cost-saver by preventing entire batches of wafers from being wasted. Such control techniques in front-end processing are discussed, following a wafer completely through a typical microprocessor monitored "wet" process. The controller's ability to identify "when" and "where" malfunctions occur. and to diagnose the malfimctions are also discussed A new short channel MOSFET structure (UMOST). C. A. T. SALAMA.Solid-St. Electron. 20, 1003 (1977). A new MOSFET structure with a trapezoidal U-shaped channel defined by anisotropic etching is described. The structure results in very short channel devices almost free of short channel effects and achieves higher speed without the use of submicron photolithography. A simplified theory for the structure is presented and compared with experimental results obtained on 1 - 10 #m channel length devices. This structure may prove useful in the study of conduction in short channel MOSFETs without introducing the complicating two dimensional short channel effects.
Potential and field distribution in high resistivity microresistors and halltrons for MOS integrated circuits. N. B. VELCHEV. Solid-St. Electron. 20, 943 (1977). Some results from a detailed analysis of the basic equations for silicon high resistivity diffused and implanted channels with an opposite substrate conductivity are presented. The computer aided calculations permit the finding of potential and electrical field distribution along the conductive channel as a function of all parameters of the structures. The numerical data are necessary for design and application of microresistors and Halltrons for MOS integrated circuits. An experimental Hall effect study of the theory in the case of p-type diffused and implanted Halltrons on n-type silicon substrates is given.
Flex-mount polishing of silicon wafers. ANTHONY C. BONORA. Solid St. Technol. p. 55 (October 1977). The basic current material of solid state electronics is the silicon wafer_ Stringent high technology requirements for high yield wafers demand new and improved polishing methods to replace wax and template processes. A new flex-mount wafer polishing process is described and compared with the traditional techniques. Big bubble chips point the way to low-cost memories. Electronics p. 31 (8 December 1977). Rockwell is developing 1-megabit bubble memory chips -- but production is at least three years off.
6. MICROELECTRONICS- COMPONENTS, SYSTEMS AND EQUIPMENTS C-MOS converters resolve 12 bits. LARRY WALLER. Electronics p. 141 (24 November 1977). Hybrid digital-to-analog units are the first such equipment to combine direct microprocessor compatibility with the low power dissipation of C-MOS.
the results of benchmark tests of several different microprocessors. The results are given in terms of speed of execution, size of source program (number of statements) and of memory requirements for the compiled programs. An analysis of these results is given in terms of the microprocessor architectures.
The implications of microprocessor architecture on speed, programming and memory size. BRIAN K. PENNEY. Radio
Dynamic testing of control systems. Prof. D. R. TOWILL.
Electron. Engr 47, (11) 522 (Nov. 1977). This paper gives
Radio Electron. Engr 47, (11) 505 (Nov. 1977). The paper