Defect-induced control of the structure of boron nitride
AssigneeTrustees of Boston University
InventorTheodore D. Moustakas
Life of this patent
Estimating the term…
Abstract
A method of controlling defects in boron nitride films in order to stabilize certain crystallographic structures is disclosed. Such defects include, for example, nitrogen vacancies, boron interstitials, and substitutional dopants. In particular, films produced by the method of sputtering in pure inert gas atmospheres have a tetrahedrally coordinated structure and are rich in nitrogen vacancies. Films produced by the same method in inert gas with a sufficient nitrogen overpressure have a completely stoichiometric graphitic structure. These results are expected for any defect type having a greater free energy of formation in the graphitic form of boron nitride than in the tetrahedral forms. The methods of the invention are applicable to any film growth technique capable of incorporating such defects.
Claims12
A method for depositing a nitrogen-deficient, tetrahedrally coordinated boron nitride on a substrate, comprising the steps of:
- generating a boron species and a nitrogen species by sputtering a boron and nitrogen containing target in an inert gas atmosphere containing no more than ten volume percent nitrogen;
- generating a flux of the boron species and a flux of the nitrogen species towards the substrate, the ratio of nitrogen flux to boron flux being less than or equal to one, under conditions sufficient to deposit a nitrogen-deficient, tetrahedrally coordinated boron nitride on the substrate.
Dependencies are inferred from the claim text.