Vacancy-rich silicon for use with a gallium nitride epitaxial layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsPu-Fang CHEN, Ching Yu CHEN
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Abstract
A manufacturing process is described to evaluate and select raw semiconductor wafers in preparation for epitaxial layer formation. The manufacturing process first produces a single crystal ingot during which a seed pulling velocity and temperature gradient are closely controlled. The resulting ingot is vacancy-rich with relatively few self-interstitial defects. Selected wafers can advance to a high-temperature nitridation annealing operation that further reduces the number of interstitials while increasing the vacancies. Substrates characterized by a high vacancy density can then be used to optimize an epitaxial layer deposition process.
Claims20
A method, comprising:
- identifying, in a crystal ingot, a section comprising a vacancy-rich core surrounded by an oxidation induced stacking fault ring;
- cutting a vacancy-rich wafer from the section;
- and
- removing the oxidation induced stacking fault ring in the vacancy-rich wafer.
A method, comprising:
- identifying, among a plurality of semiconductor wafers, a vacancy-rich semiconductor wafer comprising an oxidation induced stacking fault ring at a peripheral region of the vacancy-rich semiconductor wafer;
- and
- removing the oxidation induced stacking fault ring.
A method, comprising:
- forming a crystal ingot;
- cutting a plurality of wafers from a plurality of sections of the crystal ingot;
- identifying a vacancy-rich wafer among the plurality of wafers;
- and
- removing interstitials in the vacancy-rich wafer.
Dependencies are inferred from the claim text.