The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 1977
Filed:
May. 19, 1975
Lawrence Dean Dyer, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
The disclosure relates to the growth of semiconductor single crystals, i.e., either by the pedestal method or by the Czochralski method, free from dislocations, particularly in the difficult directions of growth, such as <110>. The method causes dislocations parallel to the growth axis to grow away from the axis under the influence of a changing crystal diameter. The thickness of the stem portion of the crystal is controlled so that it has first a long thin portion to get rid of dislocations on the {111} planes that are inclined to the <110> axis and then a portion in which the residual dislocations are permitted to terminate at the surface. The latter portion may be generated in several ways. One way is to follow the long narrow diameter portion with a section of substantially larger diameter followed by a further narrow diameter portion. This combination is repeated one or more times to insure freedom from dislocations in the resulting crystal. By having the alternate thin and thick regions, the dislocations are gradually moved away from the axis of the crystal and toward the periphery where they will have a greater probability of terminating on a surface, thereby removing the dislocations.