An apparatus for drawing a crystalline sheet from a melt. The apparatus may include a crucible configured to contain the melt and having a dam structure, where the melt comprises an exposed surface having a level defined by a top of the dam structure. The apparatus may further include a support apparatus disposed within the crucible and having an upper surface, wherein the crystalline sheet is maintained flush with the exposed surface of the melt when drawn over the support apparatus, and may include a melt-back heater directing heat through the upper surface of the support apparatus to partially melt the crystalline sheet when the crystalline sheet is drawn over the support apparatus.

An apparatus for drawing a crystalline sheet from a melt. The apparatus may include a crucible configured to contain the melt and having a dam structure, where the melt comprises an exposed surface having a level defined by a top of the dam structure. The apparatus may further include a support apparatus disposed within the crucible and having an upper surface, wherein the crystalline sheet is maintained flush with the exposed surface of the melt when drawn over the support apparatus, and may include a melt-back heater directing heat through the upper surface of the support apparatus to partially melt the crystalline sheet when the crystalline sheet is drawn over the support apparatus.

A ribbon is formed such that the ribbon floats on a melt using a cold initializer facing an exposed surface of the melt. The ribbon is single crystal silicon. The ribbon is pulled from the silicon melt at a low angle off the melt surface. The ribbon is formed at a same rate as the pulling. The ribbon is separated from the melt at a wall of the crucible where a stable meniscus forms. The ribbon has a thickness between a first surface and an opposite second surface from 50 m to 5 mm. The ribbon includes a first region extending a first depth from the first surface. The first region has a reduced oxygen concentration relative to a bulk of the ribbon.

A ribbon is formed such that the ribbon floats on a melt using a cold initializer facing an exposed surface of the melt. The ribbon is single crystal silicon. The ribbon is pulled from the silicon melt at a low angle off the melt surface. The ribbon is formed at a same rate as the pulling. The ribbon is separated from the melt at a wall of the crucible where a stable meniscus forms. The ribbon has a thickness between a first surface and an opposite second surface from 50 m to 5 mm. The ribbon includes a first region extending a first depth from the first surface. The first region has a reduced oxygen concentration relative to a bulk of the ribbon.

An apparatus for controlling heat flow within a melt. The apparatus may include a crucible configured to contain the melt where the melt has an exposed surface. The apparatus may also include a heater disposed below a first side of the crucible and configured to supply heat through the melt to the exposed surface, and a heat diffusion barrier assembly comprising at least one heat diffusion barrier disposed within the crucible and defining an isolation region in the melt and an outer region in the melt.

An apparatus for controlling heat flow within a melt. The apparatus may include a crucible configured to contain the melt where the melt has an exposed surface. The apparatus may also include a heater disposed below a first side of the crucible and configured to supply heat through the melt to the exposed surface, and a heat diffusion barrier assembly comprising at least one heat diffusion barrier disposed within the crucible and defining an isolation region in the melt and an outer region in the melt.

An apparatus for controlling heat flow within a melt. The apparatus may include a crucible configured to contain the melt where the melt has an exposed surface. The apparatus may also include a heater disposed below a first side of the crucible and configured to supply heat through the melt to the exposed surface, and a heat diffusion barrier assembly comprising at least one heat diffusion barrier disposed within the crucible and defining an isolation region in the melt and an outer region in the melt.

An apparatus for forming a crystalline ribbon grown on a surface of a melt includes an inner chamber. A crucible in the inner chamber is configured to hold a melt. A cold initializer in the inner chamber faces an exposed surface of the melt. A process gas feed is in fluid communication with a process gas inlet of the inner chamber. An outer chamber surrounds at least part of the inner chamber and defines an opening for the process gas feed and a sump inlet. A sump gas feed is in fluid communication with the sump inlet. The sump gas feed is configured to deliver a sump gas to the sump region. The sump region also can include heaters and insulation.

An apparatus for forming a crystalline sheet. The apparatus may include a crystallizer comprising a first gas channel and a second gas channel, wherein the first gas channel and second gas channel extend through the crystallizer to a lower surface of the crystallizer between an upstream edge and a downstream edge. The first gas channel may be disposed closer to the downstream edge than the second gas channel. A first gas source may be coupled to the first gas channel, where the first gas source comprises helium or hydrogen, and a second gas source may be coupled to the second gas channel, where the second gas source does not contain hydrogen or helium.

An apparatus for forming a crystalline sheet. The apparatus may include a crystallizer comprising a first gas channel and a second gas channel, wherein the first gas channel and second gas channel extend through the crystallizer to a lower surface of the crystallizer between an upstream edge and a downstream edge. The first gas channel may be disposed closer to the downstream edge than the second gas channel. A first gas source may be coupled to the first gas channel, where the first gas source comprises helium or hydrogen, and a second gas source may be coupled to the second gas channel, where the second gas source does not contain hydrogen or helium.