Method of controlling defect orientation in silicon crystal ribbon growth
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorMartin H. Leipold
Life of this patent
Estimating the term…
Abstract
The orientation of twinning and other effects in silicon crystal ribbon growth is controlled by use of a starting seed crystal having a specific {110} crystallographic plane and <112> crystallographic growth direction.
Claims1
In a film-fed process of growing crystalline silicon in a ribbon form by drawing molten silicon through a die, starting crystallization of silicon thus fed through said die as it cools with a seed crystal, and continuing to pull the crystal ribbon thus formed from said die as crystallization continues, the improvement consisting of using as said seed crystal a rectangular crystalline silicon of appropriate dimensions having a {110} crystallographic plane parallel to the broad surfaces of the seed and the ribbon grown, a <112<
- crystallographic direction parallel to the direction of growth of said crystal ribbon, and {111} twinning planes parallel to said growth direction and normal to said broad surfaces.
Dependencies are inferred from the claim text.