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An overview of laser functional trimming techniques
World Abstracts on Micruelectronics and Reliability and M. DE SARIO. PFOC.5th CoUoauiumMicrowave Commun. Vol. IV, p. 9. Akaden~al Kiado, Budapest (1974). The stripline structures are generally employed in the microwave integrated circuits as matching networks in distributed form. Their simplest configuration is cascaded fines and stubs, but there are also interdigital and quarter-wave transformers which, however, present some problems for their realization in microstrips, because they may imply shieldings or
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grounding. For this reason, it is more convenient to use meander lines realized by means of coupled strip-lines which allow a considerable design flexibility too. In this paper we analyze two computer aided designs of modular amplifiers, employing fine-stub or meander matching networks in the 3-4 GHz band. We have also realized the modular amplifier, which uses the simplest matching networks, whose characteristics are shown.
9. ELECTRON, ION AND LASER BEAMS X-ray IltbeIFal~, highlights move to tiny IC ~tterm, Electronics 29 (30 May 1974). In the quest for smaller and smaller geometries on integrated-circuit masks, two techniques have been pursued: the use of electron beams and X-rays instead of light for exposing sensitized wafers. Both overcome resolution problems by operating at much shorter wavelengths than the u.v. fight presently used. And now X-rays appear to have features that may give them the edge over electron beams, as well as over conventional approaches. These features include: Resolution of 0" 1 micrometer; Depth of field of 10/an, which permits non-contact printing for longer mask life; Insensitivity to dust particles and other contaminants--critical factors with conventional systems; Constant depth of exposure; Capability to be used with positive or negative resists. Excess aoise m e u a ~ m m t s tm iea-imld~ted sincm redstor~ H. R. B~LGe~, J. L. T~ax3N and M.-A. NlcoLtrr. Solid St. Electron. 17, 599 (1974). The low-frequency noise spectra of partially annealed boron-implanted silicon resistors with various geometries are measured. The implantation energies are 50, 80 and 110 keV and the doses are 2"5 × 1012 cm -2, 1.0 × 10x3 cm -2 and 1.0 × 1014 cm -2. The spectra exhibit thermal noise and f - " (excess) noise exclusively. Investigntions indicate that the contacts from the implanted layer to the electrode generally contribute small amouhts to the total excess noise observed. The excess noise exhibits a strong dependence on the sheet resistance of the layers, while the dependence on substrate bias, implantation energy, and on temperature is relatively weak. A discussion of the results is given in terms of a volume effect. Noise measurements on implanted layers, produced under carefully controlled conditions, show promise as a tool to investigate excess noise. Patterm created wiflseat masks. Electronics 130 (30 May 1974). Electron-beam system exposes wafers directly and reduces design time. Electrical d a r s c t e r b t ~ of i e a - l l F l ~ m l p e S u a ¢ ! MOS trnd~tors. K. N ~ and M. ~ m D A . NEC Res. Develop. 29 (Apr. 1974). 1011 ~ 1012/cm 2 11B+ ions were implanted through 800 ~ 2000 A gate-oxides into the channel regions of p-channel MOS transistors. For 50-keV implantation, the dose dependence of threshold voltage could be explained by Swanson and Meindl's theory. In
the case of implantation at above 100 keV, a slight deviation of the threshold voltage from the theoretical values was observed. Corresponding to this, the gate-oxide-thickness dependence of the threshold voltage was slightly deviated from the theoretical values in the range of less than 1300 A. For more than 1500 A, the measured threshold voltages coincided with calculated values. The energy dependence of the dose limit for "ability to turn On-Off" showed good agreement with the curve calculated on the basis of Swanson and Meindl's theory within the limits of this experimental error. Source-drain current in the saturation region was slightly increased with increasing the dose at least up to 5 × 1011/cm2, presumably due to the carrier compensation (band bending) and increase in mobility. No significant change due to the implantation was observed in the breakdown voltages within the examined dose and energy ranges. Device stability was confirmed by positive or negative BT (Bias Temperature) treatments (125°C, 100 hr and 300°C, 1 hr). Again, no significant instabilities resulting from the implantation process were detected in this experiment. Further, static transfer characteristics of the ion implanted enhancement-depletion inverter could be well explained by Hayashi, Tarui and Hashimoto's theory. An overview of laser fuactimal trimmla~_ tedlklmS. G. HV-g~G and E. J. SWENSON.Proc. IEEE 1974 24th Electron. Comport. Conf. Washington, D.C. 13-15 May 240 (1974). Functional trimming using lasers is gaining acceptance throughout the industry for a wide variety of applications. This paper is intended to provide a summary of the most important concepts involved. References are provided to allow the reader to research specific areas in greater detail. Algorithmic trimming oa active circuitry. M. FALSER.Proc. IEEE 1974 241h Electron. Compon. Conf. Washington, D.C. 13-15 May 248 (1974). An entire digital autoranging multimeter has been manufactured utilizing a single small printed circuit board in conjunction with a hybrid substrate. Thin film resistors on the hybrid substrate are laser trimmed while the multimeter circuitry is operating. This "active trimming" process has been instrumental in making the production of the instrument possible. When the decision is made to trim actively, the trim algorithm becomes an important aspect of the design. This paper outlines three types of trim algorithms, and discusses specific problems concerning the marriage of active circuitry with a laser trim system.
453
grounding. For this reason, it is more convenient to use meander lines realized by means of coupled strip-lines which allow a considerable design flexibility too. In this paper we analyze two computer aided designs of modular amplifiers, employing fine-stub or meander matching networks in the 3-4 GHz band. We have also realized the modular amplifier, which uses the simplest matching networks, whose characteristics are shown.
9. ELECTRON, ION AND LASER BEAMS X-ray IltbeIFal~, highlights move to tiny IC ~tterm, Electronics 29 (30 May 1974). In the quest for smaller and smaller geometries on integrated-circuit masks, two techniques have been pursued: the use of electron beams and X-rays instead of light for exposing sensitized wafers. Both overcome resolution problems by operating at much shorter wavelengths than the u.v. fight presently used. And now X-rays appear to have features that may give them the edge over electron beams, as well as over conventional approaches. These features include: Resolution of 0" 1 micrometer; Depth of field of 10/an, which permits non-contact printing for longer mask life; Insensitivity to dust particles and other contaminants--critical factors with conventional systems; Constant depth of exposure; Capability to be used with positive or negative resists. Excess aoise m e u a ~ m m t s tm iea-imld~ted sincm redstor~ H. R. B~LGe~, J. L. T~ax3N and M.-A. NlcoLtrr. Solid St. Electron. 17, 599 (1974). The low-frequency noise spectra of partially annealed boron-implanted silicon resistors with various geometries are measured. The implantation energies are 50, 80 and 110 keV and the doses are 2"5 × 1012 cm -2, 1.0 × 10x3 cm -2 and 1.0 × 1014 cm -2. The spectra exhibit thermal noise and f - " (excess) noise exclusively. Investigntions indicate that the contacts from the implanted layer to the electrode generally contribute small amouhts to the total excess noise observed. The excess noise exhibits a strong dependence on the sheet resistance of the layers, while the dependence on substrate bias, implantation energy, and on temperature is relatively weak. A discussion of the results is given in terms of a volume effect. Noise measurements on implanted layers, produced under carefully controlled conditions, show promise as a tool to investigate excess noise. Patterm created wiflseat masks. Electronics 130 (30 May 1974). Electron-beam system exposes wafers directly and reduces design time. Electrical d a r s c t e r b t ~ of i e a - l l F l ~ m l p e S u a ¢ ! MOS trnd~tors. K. N ~ and M. ~ m D A . NEC Res. Develop. 29 (Apr. 1974). 1011 ~ 1012/cm 2 11B+ ions were implanted through 800 ~ 2000 A gate-oxides into the channel regions of p-channel MOS transistors. For 50-keV implantation, the dose dependence of threshold voltage could be explained by Swanson and Meindl's theory. In
the case of implantation at above 100 keV, a slight deviation of the threshold voltage from the theoretical values was observed. Corresponding to this, the gate-oxide-thickness dependence of the threshold voltage was slightly deviated from the theoretical values in the range of less than 1300 A. For more than 1500 A, the measured threshold voltages coincided with calculated values. The energy dependence of the dose limit for "ability to turn On-Off" showed good agreement with the curve calculated on the basis of Swanson and Meindl's theory within the limits of this experimental error. Source-drain current in the saturation region was slightly increased with increasing the dose at least up to 5 × 1011/cm2, presumably due to the carrier compensation (band bending) and increase in mobility. No significant change due to the implantation was observed in the breakdown voltages within the examined dose and energy ranges. Device stability was confirmed by positive or negative BT (Bias Temperature) treatments (125°C, 100 hr and 300°C, 1 hr). Again, no significant instabilities resulting from the implantation process were detected in this experiment. Further, static transfer characteristics of the ion implanted enhancement-depletion inverter could be well explained by Hayashi, Tarui and Hashimoto's theory. An overview of laser fuactimal trimmla~_ tedlklmS. G. HV-g~G and E. J. SWENSON.Proc. IEEE 1974 24th Electron. Comport. Conf. Washington, D.C. 13-15 May 240 (1974). Functional trimming using lasers is gaining acceptance throughout the industry for a wide variety of applications. This paper is intended to provide a summary of the most important concepts involved. References are provided to allow the reader to research specific areas in greater detail. Algorithmic trimming oa active circuitry. M. FALSER.Proc. IEEE 1974 241h Electron. Compon. Conf. Washington, D.C. 13-15 May 248 (1974). An entire digital autoranging multimeter has been manufactured utilizing a single small printed circuit board in conjunction with a hybrid substrate. Thin film resistors on the hybrid substrate are laser trimmed while the multimeter circuitry is operating. This "active trimming" process has been instrumental in making the production of the instrument possible. When the decision is made to trim actively, the trim algorithm becomes an important aspect of the design. This paper outlines three types of trim algorithms, and discusses specific problems concerning the marriage of active circuitry with a laser trim system.