Mobil Tyco Solar Energy Corporation

Arthur E Hatch

Douglas A Yates

Jeff M Goldsmith

The growth of a crystalline body of a selected material is controlled so that the body has a selected cross-sectional shape. The apparatus is of the type which includes the structure normally employed in known capillary die devices as well as means for observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position. The improvement comprises reference object means positioned near the solid/liquid/vapor junction and capable of being observed by the means for observing so as to define said reference position so that the problems associated with convection current jitter are overcome.

Method for crystal growth control

Apparatus for crystal growth control

A system for and method of growing a crystalline body of a selected material is described, whereby the body grown is of a selected cross-sectional shape. The system and method are used in accordance with known capillary die techniques and further includes observing opposite edge portions of the growing body, preferably just above the meniscus (of melt material from which the body is being pulled). The cross-sectional size of the growing crystalline body can be controlled by determining when horizontal shifts occur in the edge portions relative to each other as well as the same predetermined reference position.

Method and apparatus for crystal growth control

Apparatus is disclosed for controlling the growth of a crystalline body of a selected material so that the body has a selected cross-sectional shape. The apparatus includes the structure normally employed in known capillary die devices and further includes means for observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position.

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Waltham, MA, United States of America

Arthur E Hatch