Uniform Silicon p-n Junctions. I. Broad Area Breakdown

Abstract

Small area silicon p-n junctions have been made which are free from exposed edges and dislocations passing through the space-charge region. It is believed that the space-charge regions of these junctions more closely resemble plane parallel geometries than any studied similarly hitherto. The avalanche breakdown phenomena in these uniform junctions are shown to be drastically different from those occuring in junctions that contain many dislocations. A comparison is made between the uniform junctions and one that is similar except that it possesses two breakdown-inducing sites, probably dislocations. In the latter junction the reverse characteristic shows two slightly separated rapid increases in current which coincide, biaswise, with the formation of two isolated light-emitting microplasmas, the occurrence of characteristic microplasma noise, and two singularities in the charge-multiplication characteristics. The uniform junctions show no such phenomena at intermediate voltages, breakdown occurring at a voltage roughly twice that at which the microplasmas form and which was previously thought typical for the given material resistivity. The light emission pattern accompanying breakdown in the uniform junctions appears more diffuse (giving rise to the term—macroplasma) than in nonuniform junctions where it normally appears as an array of intense local spots (microplasmas). It is concluded that microplasmas are not a necessary accompaniment of avalanche breakdown in silicon, but that they tend to occur where there are field or lattice inhomogeneities.

Principles and Early Historical Development of Silicon Avalanche and Geiger-Mode Photodiodes

“…Indeed, multiplication can occur within microplasmas (up to an observed ratio of 1x10 6 ), refuting the classifications in [79]. To continue efforts in classification, two kinds of avalanche were noted, the first through microplasma action, and the second through entire-area avalanche breakdown observed in custom fabricated "guard-ring" diodes by Batdorf et al [82]. Proposing a theory for multiplication, Haitz and Goetzberger note that rather than continuous multiplication, photon arrivals cause a microplasma to turn on again, thus multiplication is by virtue of an increased time in which the microplasma is conducting.…”

“…after-pulsing, (iii) Zener/Shockley band-to-band tunnelling and (iv) minority carrier diffusion from elsewhere in the substrate, triggering an avalanche (see also Tager, 1964). Continuing his studies on noise, Haitz investigated an optical cross-talk mechanism [81,82], although the re-absorption of light emitted by radiative recombination during avalanche had been discussed by Newman in 1955 [67] and Champlin in 1959 [77]. This supplemented the coupling experiments conducted by Ruge and Keil in 1963 [89], along with Conradi (1963), where the distances between and non-clustering of triggered microplasmas precluded thermal phenomena, thereby giving credence to Haitz's 1962 hypothesis of optical coupling.…”

“…In July of 1960, Batforf and Chynoweth et al [82] proposed the use of a planar "guard ring" that surrounds the active area (also see [102]). The reasoning being that if there were no dislocations within the junction, and if doping was uniform, then the periphery of the junction would be the next preferred breakdown site [70].…”

Selection and calculation of parameters of strip optical waveguides

“…It is apparent that although scattering probability increases above the ionization threshold it does not represent an absolute limit to the energies attainable by hot electrons, since electron emission has been observed from silicon junctions which have not been treated to lower the work function. The problem of the relative importance of phonon scattering and ionization scattering has been treated by Shockley (19611, by Bartelink, Moll and Meyer (1963) and by Baraff (1962). All of these treatments, however, contain simplifications which limit their applicability.…”

Electroluminescence and Other Optical and Electrical Characteristics of p-n Junctions in Zinc Sulfide

“…It has been recently established that the luminous microplasmas are concentrated at dislocations which penetrate the junction. A reduction of the length of the dislocations by improvement of the technology of preparation gives a more or less uniform emission over the whole junction [34]. Table 1 lists some of the characteristics of the luminescence emitted by seven semiconductors ranked in the order of increasing forbidden band width.…”