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Contents: Physical origins of burst noise in transistors; Noise in phototransistors and photodiodes; Impurity concentration dependent density of states at the Fermi level; Recombination and trapping of the photo-excited carriers in gold-doped silicon; Unified modeling of field-effect devices; Simultaneous automated ac and dc design of linear semiconductor integrated circuit amplifiers; The effect of crystallization on the strength of Li2O-SiO2 glass-ceramics; The early stages of crystallization in a Li2O-SiO2 glass; Electrical properties of glass; Solid solution decomposition of aluminum-rich aluminum-zinc-silver alloys; Metal tip holder for field-ion microscope., See also report dated 10 Mar 1970, AD0711848. Sponsored in part by DARPA.

The report evaluates all the factors governing the electronic conductivity, the activation energy for conduction, and the dielectric constant of glasses as well as their interdependence in order to assess the possibility of developing a glass with certain characteristics as outlined in the text. Because no theoretical treatments have been published which may be used as a guidance for the preparation of the glasses of the desired properties, theoretical studies and experimental preparation of new glasses were undertaken. Although both oxide and non-oxide glasses were measured, emphasis was ultimately placed on oxide glasses. Preliminary calculations of fluoride and chalcogenide glasses imply that these are able to exceed the oxide glasses. (Modified author abstract)

A study of one of the groups of amorphous semiconductors, the chalcogenide glasses, was made. From a review of existing literature, the physicochemical, electrical, thermal and optical properties of several of the typical glasses are presented quantitatively and discussed qualitatively. Several of the unusual features of the theorized band structure in these disordered systems are discussed. Several explanations of the Hall effect-Seebeck effect anomalies are reviewed. These include postulates on ambipolar and impurity-type conduction, as well as those on second phases and potential barriers. Several recommendations for further studies are given.

The report describes technical findings in three main areas. The first area concerns semiconductors and semiconductor devices. Noise in integrated operational amplifiers is characterized, with special emphasis given to burst noise. Measurements are made of the photomagnetoelectric and photoconductive effects in n-type silicon at cryogenic temperatures and attendant theory is developed. Another study delineates issues basic to device modeling for the computer-aided analysis and design of integrated circuits. The second main area deals with measurement techniques. Use of the field ion microscope is discussed for the analysis of dislocations and stacking faults in crystals. A new method for studying the structure of thin films during the earliest stages of growth is described; the techniques of electrically recording diffraction patterns are reviewed and applied to characterizing surfaces and surface layers on an atomic scale. The application of quantitative dielectric relaxation receives attention as an analytical tool in the investigation of insulating and semiconducting materials. The third main area concerns insulating and semiconducting glasses. One study describes the effects of neutron bombardment on nucleation and growth processes. Another deals with the information on the nucleation sequence provided by hot-stage transmission microscopy of Lithia-silica glass. A final study reports concerning the effect of environment on the dielectric properties of high alumina substrates. (Author)

Glasses in the system Si-As-Ag-Te-Se were found to have much higher softening temperatures than any chalcogenide glasses previously investigated. One heat treated glass had a softening temperature of 670C, which is 220 degrees higher than that of the Si-As-Se base glass. Ir transmission in relevant ranges was essentially maintained. Ag is instrumental in allowing the introduction of Se otherwise rejected in silicon chalcogenide glasses. The development of microstructure is more important than the intended increase in average bonding by the substitution of Se for Te. The microstructure involves glass-glass phase separation, with one of the phases having a much higher Tg, and, possibly, some microcrystallinity. (Modified author abstract), See also report dated 31 Aug 72, AD-749 958.

The five-year research program sponsored by this contract has produced technical findings in several areas: Characterization of semiconductor devices and integrated circuits, electronic ceramics, quantum and electronic properties of semiconductors and related devices, noise in solids and in solid- state devices, magnetic films, high current regimes in transistor collector regions, quantum yield of p-i-n photodiodes, cluster model calculations of silicon defects, investigation of recombination and trapping processes in 3As2Se3-2Sb2Se3 amosphous films by photoconductivity method, and dielectric properties of lithium-disilicate glass-ceramics.