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Open-base breakdown in diffused n-p-n junction transistors
350
ABSTRACTS ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
on the same sample, the precipitation number density determined using the theory of Ham on diffusion limited precipitation for spherical precipitate particles. The agreement is found to be quite good, covering a range of number densities 8 x 1011 cm 3 to approximately 1014 cm a.
Open-base breakdown in diffused n-p-n junction transistors. D. P. KENNEDYand R. R. O'BRIEN. International Journal of Electronics 18, No. 2 (February 1965), p. 133. A one-dimensional analysis is presented on the open-base breakdown characteristics of diffused n-p-n transistors. From breakdown voltage measurements upon selected devices--in conjunction with breakdown voltage calculations-"effective" values are established for the ionization rate of electrons in germanium and silicon p-n junctions, when biased substantially below avalanche breakdown. These "effective" electron ionization rates are used to calculate the open-base breakdown voltage for transistors exhibiting a large collector punch-through voltage; such calculations are graphically illustrated throughout a range of parameters applicable to many practical situations. A discussion is also presented on the influence of an abrupt conductivity increase within the collector junction space-charge layer, of the type encountered in an idealized epitaxial structure.
The role of the ionization of defects in causing systematic differences in the semiconductor properties ofundoped compounds. F. A. KR6GER.J. Phys. Chem. Solids 26 (1965), p. 1707. Undoped compounds often show either n- or p-type conduction, a variation of the activity of the lattice constituents causing a variation in the concentration of donor or acceptors, but not a change of the conductivity type. Only in a few cases can a transition from n- to p-type be achieved. It is shown that the degree of ionization of the imperfections acting as donors or acceptors is an important factor in deciding the type of atomic imperfection that is predominately formed. The insight gained is used to explain some observed trends in the semiconductor properties of the II-VI and IV-VI compounds. The direct observation of electrical leakage paths due to crystal defects by use of the scanning electron microscope. I. G. DAVIES, K. A. HUGHES, D. V. SULWAY and P. R. THORNTON. Solid-State Electronics 9 (1966), p. 275. The scanning electron microscope has been applied to the problem of localized breakdown in silicon diodes, particularly that introduced by mechanical damage. The method, which is capable of high resolution and sensitivity, can be used (a) to locate faults in or near the depletion region, (b) relate such faults to surface markings and (c) investigate the electrical effects of such faults. The results presented here essentially confirm earlier work in that they suggest scratching introduces neutral defect states which become donors in the presence of an applied bias. The operative contrast mechanisms are discussed and the limitations of the approach indicated. CIRCUIT AND SYSTEMS RELIABILITY, REDUNDANCY
Test-system design. D. K. COCKRAM. G.E.C. Journal of Science and Technology 33, No. 1 (1966), p. 9. The components used in electronic and other systems are almost all, in some degree, subject to failure. As systems increase in complexity, the number of failures increases and their detection and location become difficult. A means to detect a failure and locate the cause can be as essential as the operational system itself. The author discusses different approaches to testing and considers several aspects of test-system design. The discussion is illustrated by reference to a number of test systems designed by G.E.C. Optimizing the location of faults of electronic equipment using the theory of information. J. G6LLER and K. KARL. Nachrichtentechnik 15, No. 12 (1965), p. 455. (In German.) A method is described which makes it possible to find optimized algorithms for localizing faults and controlling equipment. It starts with systematically determining the relations between fault--measuring result, measurement--mean working hours required, controlled stages--necessary complexes of measurement. The calculation is based on methods of the theory of information. Better quality, lower costs, through designer-fabricator communication. L. V. MASON. Transactions of the American Society for Quality Control Technical Conference (May 1965), p. 639. Product release groups constantly strive to shorten lead time, prove designs more rapidly and control
ABSTRACTS ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
on the same sample, the precipitation number density determined using the theory of Ham on diffusion limited precipitation for spherical precipitate particles. The agreement is found to be quite good, covering a range of number densities 8 x 1011 cm 3 to approximately 1014 cm a.
Open-base breakdown in diffused n-p-n junction transistors. D. P. KENNEDYand R. R. O'BRIEN. International Journal of Electronics 18, No. 2 (February 1965), p. 133. A one-dimensional analysis is presented on the open-base breakdown characteristics of diffused n-p-n transistors. From breakdown voltage measurements upon selected devices--in conjunction with breakdown voltage calculations-"effective" values are established for the ionization rate of electrons in germanium and silicon p-n junctions, when biased substantially below avalanche breakdown. These "effective" electron ionization rates are used to calculate the open-base breakdown voltage for transistors exhibiting a large collector punch-through voltage; such calculations are graphically illustrated throughout a range of parameters applicable to many practical situations. A discussion is also presented on the influence of an abrupt conductivity increase within the collector junction space-charge layer, of the type encountered in an idealized epitaxial structure.
The role of the ionization of defects in causing systematic differences in the semiconductor properties ofundoped compounds. F. A. KR6GER.J. Phys. Chem. Solids 26 (1965), p. 1707. Undoped compounds often show either n- or p-type conduction, a variation of the activity of the lattice constituents causing a variation in the concentration of donor or acceptors, but not a change of the conductivity type. Only in a few cases can a transition from n- to p-type be achieved. It is shown that the degree of ionization of the imperfections acting as donors or acceptors is an important factor in deciding the type of atomic imperfection that is predominately formed. The insight gained is used to explain some observed trends in the semiconductor properties of the II-VI and IV-VI compounds. The direct observation of electrical leakage paths due to crystal defects by use of the scanning electron microscope. I. G. DAVIES, K. A. HUGHES, D. V. SULWAY and P. R. THORNTON. Solid-State Electronics 9 (1966), p. 275. The scanning electron microscope has been applied to the problem of localized breakdown in silicon diodes, particularly that introduced by mechanical damage. The method, which is capable of high resolution and sensitivity, can be used (a) to locate faults in or near the depletion region, (b) relate such faults to surface markings and (c) investigate the electrical effects of such faults. The results presented here essentially confirm earlier work in that they suggest scratching introduces neutral defect states which become donors in the presence of an applied bias. The operative contrast mechanisms are discussed and the limitations of the approach indicated. CIRCUIT AND SYSTEMS RELIABILITY, REDUNDANCY
Test-system design. D. K. COCKRAM. G.E.C. Journal of Science and Technology 33, No. 1 (1966), p. 9. The components used in electronic and other systems are almost all, in some degree, subject to failure. As systems increase in complexity, the number of failures increases and their detection and location become difficult. A means to detect a failure and locate the cause can be as essential as the operational system itself. The author discusses different approaches to testing and considers several aspects of test-system design. The discussion is illustrated by reference to a number of test systems designed by G.E.C. Optimizing the location of faults of electronic equipment using the theory of information. J. G6LLER and K. KARL. Nachrichtentechnik 15, No. 12 (1965), p. 455. (In German.) A method is described which makes it possible to find optimized algorithms for localizing faults and controlling equipment. It starts with systematically determining the relations between fault--measuring result, measurement--mean working hours required, controlled stages--necessary complexes of measurement. The calculation is based on methods of the theory of information. Better quality, lower costs, through designer-fabricator communication. L. V. MASON. Transactions of the American Society for Quality Control Technical Conference (May 1965), p. 639. Product release groups constantly strive to shorten lead time, prove designs more rapidly and control