Method and apparatus for the production of crystalline silicon substrates
AssigneeAMG IdealCast Solar Corporation
InventorRoger F. Clark
Life of this patent
Estimating the term…
Abstract
An apparatus and method for producing a crystalline ribbon continuously from a melt pool of liquid feed material, e.g. silicon. The silicon is melted and flowed into a growth tray to provide a melt pool of liquid silicon. Heat is passively extracted by allowing heat to flow from the melt pool up through a chimney. Heat is simultaneously applied to the growth tray to keep the silicon in its liquid phase while heat loss is occurring through the chimney. A template is placed in contact with the melt pool as heat is lost through the chimney so that the silicon starts to “freeze” (i.e. solidify) and adheres to the template. The template is then pulled from the melt pool thereby producing a continuous ribbon of crystalline silicon.
Claims16
An apparatus for producing a continuous, ribbon comprising a feed material, said apparatus comprising:
- a melt chamber for melting said feed material, said melt chamber having an outlet;
- a growth tray positioned to receive melted feed material from said outlet in said melt chamber;
- and
- a heat-extracting means spaced from but in thermal communication with said melted feed material in said growth tray and positioned downstream of said outlet in said melt chamber, said heat-extracting means including an adjustable means adapted to regulate the amount of heat which will radiate from said melted feed material in said growth tray.
A method for producing a continuous ribbon of a feed material, said method comprising:
- melting said feed material in a melt chamber;
- flowing said melted feed material from said melt chamber into a growth tray and allowing it to form a level, shallow melt pool in said growth tray;
- allowing heat loss from said melt pool through the radiation of heat from said melt pool up through a chimney which is positioned downstream from said melt chamber;
- positioning a template in contact with said melt pool at a point where said melt pool has experienced said heat loss to thereby cause said template to become attached to said melted feed material at said point;
- pulling said template away from said melt pool to thereby produce said ribbon;
- supplying heat to said growth tray to keep said feed material in said melt pool in its liquid phase during production of said ribbon;
- and
- regulating said heat loss from said melt pool by adjusting the flow through said chimney;
- wherein said template is pulled away from said melt pool at an angle of about 1.degree, to about 15.degree, with respect to the surface of said melt pool.
Dependencies are inferred from the claim text.