Method of forming three-dimensional semiconductors structures
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorRobert W. Fathauer
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Abstract
Silicon and metal are coevaporated onto a silicon substrate in a molecular beam epitaxy system with a larger than stoichiometric amount of silicon so as to epitaxially grow columns of metal silicide embedded in a matrix of single crystal, epitaxially grown silicon. Higher substrate temperatures and lower deposition rates yield larger columns that are farther apart while more silicon produces smaller columns. Column shapes and locations are selected by seeding the substrate with metal silicide starting regions. A variety of 3-dimensional, exemplary electronic devices are disclosed.
Claims12
A method of making three dimensional semiconductor devices comprising:
- directing a first molecular beam selected from a metal or a first semiconductor-material and a second molecular beam of a second semiconductor material at the surface of a single crystal semiconductor in a vacuum in proportions that include an excess of said second semiconductor material so as to simultaneously form on said surface an epitaxial growth of a single crystal matrix of said second semiconductor material having columns of single crystal of a compound of said metal or said first semiconductor with said second semiconductor material embedded in said matrix.
A process for fabricating conductive structures in a silicon matrix comprising the steps of:
- placing a silicon substrate in a molecular beam epitaxy system in high vacuum;
- cleaning the surface of the substrate;
- heating the substrate to a temperature to support molecular mobility thereon;
- evaporating a silicon rich mixture of metal and silicon onto the surface so as to epitaxially grow metal silicide conductors perpendicular to the substrate surface within a matrix of single crystal silicon, said matrix being formed from the excess silicon.
Dependencies are inferred from the claim text.