DOI:10.1049/pi-b-2.1959.0155

出版商:IEE    

年代:1959

数据来源: IET

DOI:10.1049/pi-b-2.1959.0156

出版商:IEE    

年代:1959

数据来源: IET

DOI:10.1049/pi-b-2.1959.0157

出版商:IEE    

年代:1959

数据来源: IET

摘要:

A new type of furnace for preparing single-crystal ingots of silicon by the Czochralski technique is described. The ingot can be conveniently pulled from a melt resting on the parent solid material which in turn rests on a cooled metal hearth. The charge is heated by four focused and deflected electron beams, and a feature of the gun design is a movable cathode for controlling the magnitude of the electron current.Infra-red absorption measurements on ingots prepared by this technique indicate that the bulk oxygen content is much less than in ingots prepared from crucible-held melts.

DOI:10.1049/pi-b-2.1959.0158

出版商:IEE    

年代:1959

数据来源: IET

摘要:

Single crystals of silicon doped with phosphorus and with a constant resistivity are prepared using a gas-phase doping technique. A constant flux of phosphorus atoms from the gas phase via the liquid into the solid is created by decomposing phosphine in the vicinity of the floating liquid zone.Experimental details and a discussion of the results obtained with phosphine are given.

DOI:10.1049/pi-b-2.1959.0159

出版商:IEE    

年代:1959

数据来源: IET

摘要:

In addition to the use of chemical etching techniques to discover the density of dislocations in silicon and germanium and to revealp-njunctions in semiconductor devices, certain etching methods are capable of revealing a number of other features of fundamental interest. Close examination of etched specimens is often highly informative and rewarding. The shapes of some etch pits can give surface orientations to within one or two degrees. Impurity anomalies giving rise to localized regions of opposite conductivity to that of the bulk may be detected, and striations due to fluctuations of impurity density can sometimes be revealed in material which is nominally of one type and homogeneous. These etching methods can be used, in particular, to examine the effect of dislocations and other defects on the redistribution of impurities during heat treatment of silicon. The motion of dislocations during annealing of germanium may be studied qualitatively, and polygonization and the formation of tilt boundaries and other arrays of minimum energy have been observed.

DOI:10.1049/pi-b-2.1959.0160

出版商:IEE    

年代:1959

数据来源: IET

摘要:

Consideration of the factors involved in the efficient production of semiconductor devices reveals the desirability of growing large single crystals of germanium. The technical specification for the material demands that this shall not be achieved at the expense of quality, i.e. the germanium must be of the correct resistivity, lifetime and dislocation density. The realization of the potential advantages has involved the solution of a range of problems.In pulling large crystals the growth must be precisely controlled to give the level interface conditions and thermal gradients associated with good crystal perfection and uniform transverse properties.A high-vacuum radiation-heated furnace is used in which the heaterbaffle assembly is fabricated from high-purity graphite, silica and molybdenum. In this assembly the mechanical construction, the heater and the disposition of the baffle system need careful design to obtain the necessary high-temperature rigidity and the correct heat field over the area involved. (The Crucible internal diameter is 150 mm.) Both stationary and rotating crucible systems have been successfully used, the rotating type having several advantages.Melt preparation demands a high standard of chemical cleanliness, and this is more difficult to attain with large quantities than with small quantities of material. A technique has been developed based on a potassium-hydroxide/hydrogen-peroxide etch which is both safe and completely satisfactory chemically.

DOI:10.1049/pi-b-2.1959.0161

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The factors influencing the crystal perfection and resistivity spread of ingots made by levelling have been examined theoretically and an attempt has been made to apply the conclusions drawn to the design of levelling equipment and the choice of process variables. The results have indicated that a low thermal gradient at the growing solid/liquid interface and high growth velocity are desirable from the point of view of crystal quality. However, the existence of such a low thermal gradient has an adverse influence on cross-sectional resistivity variations as a result, it is thought, of a micro-refining process. It is concluded that improved crystal quality with good control of crosssectional resistivity distribution can only be achieved by improved temperature control.

DOI:10.1049/pi-b-2.1959.0162

出版商:IEE    

年代:1959

数据来源: IET

摘要:

An account is given of the main principles and problems encountered by the device manufacturer in the utilization of semiconductor-grade silicon. The general types of reaction described are illustrated by an account of their application in some research done on the production of silicon in bars 1/2 in diameter, and 2 ft long. The chemical route involved is the reduction of silicon tetrachloride with hydrogen. The properties of the product obtained are described.The major importance of producing silicon in bar form suitable for zone refining, using the floating-zone technique, is described in its relation to the question of crucible contamination factors applying to conventional silicon single-crystal techniques. The development of a simplified form of floating-zone refining apparatus is described, together with experience gained in producing single crystals in the apparatus using various forms of bar silicon, including that produced in a bar silicon plant.In conclusion, an outline is given of some views held on the evaluation of silicon raw material. The main theme is that the most satisfactory trial at present is the production of single crystals in a standard manner and the conduction of observations of resistivity lifetime, conductivity type and high-voltage rectifier yield obtained in a ‘diffusion’ rectifier manufacturing line.

DOI:10.1049/pi-b-2.1959.0163

出版商:IEE    

年代:1959

数据来源: IET

DOI:10.1049/pi-b-2.1959.0165

出版商:IEE    

年代:1959

数据来源: IET