Abstract: 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.

Abstract: A single crystal silicon wafer has a thickness between a first surface and an opposite second surface from 50 ?m to 300 ?m. The wafer includes a first region extending a first depth from the first surface. The first region has a reduced oxygen concentration relative to an adjacent region of the wafer. The wafer has a bulk minority carrier lifetime greater than 100 ?s.

Abstract: 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.

Abstract: A gettering agent for gettering metals from a solution. The gettering agent has a surface layer of SiO.sub.2 which is greater than 15 angstroms in thickness.

Abstract: Process for heat-treating a silicon wafer which includes the steps of contacting the surface of the silicon wafer with an aqueous solution containing hydrofluoric acid to remove metals from the wafer surface, contacting the hydrofluoric acid treated wafers with ozonated water to grow a hydrophilic oxide layer on the surface of the silicon wafer, and heating the ozonated water treated wafers to a temperature of at least about 300.degree. C. for a duration of at least about 1 second. The concentration of each of iron, chromium, calcium, titanium, cobalt, manganese, zinc and vanadium, on the surface of the silicon wafer at the initiation of the heating being less than 1.times.10.sup.9 atoms/cm.sup.2.

Abstract: A process and a gettering agent for gettering metals from a solution. In the process, the solution is contacted with a gettering agent having a surface layer of SiO.sub.2, the layer of SiO.sub.2 preferably being greater than 15 angstroms in thickness.

Abstract: Process for heat-treating a silicon wafer which includes the steps of contacting the surface of the silicon wafer with an aqueous solution containing hydrofluoric acid to remove metals from the wafer surface, contacting the hydrofluoric acid treated wafers with ozonated water to grow a hydrophilic oxide layer on the surface of the silicon wafer, and heating the ozonated water treated wafers to a temperature of at least about 300.degree. C. for a duration of at least about 1 second. The concentration of each of iron, chromium, calcium, titanium, cobalt, manganese, zinc and vanadium, on the surface of the silicon wafer at the initiation of the heating being less than 1.times.10.sup.9 atoms/cm.sup.2.