N-type semiconductor diamond and its fabrication method
AssigneeJapan Science and Technology Agency
InventorsToshihiro Ando, Yoichiro Sato, Eiji Yasu, Mika Gamo, Isao Sakaguchi
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Abstract
A substrate is polished and made an inclined substrate, which is exposed to a hydrogen plasma and is thereby smoothened. The substrate is then heated controlledly until it surface temperature reaches 830° C. Meanwhile, a gas mixture of 1% methane, 50 ppm hydrogen sulfide and hydrogen is introduced in a tubular reaction vessel to flow therethrough at 200 ml/min, where microwave plasma is excited to cause n-type semiconductor diamond to epitaxially grow on the substrate. An ion doped n-type semiconductor is thus formed that has a single donor level of an activation energy at 0.38 eV and is high in mobility and of high quality.
Claims6
An n-type semiconductor diamond, characterized by a making method comprised of:
- mechanically polishing a (100) diamond surface to make it in an inclined diamond substrate;
- subjecting a surface of said inclined diamond substrate to a hydrogen plasma treatment to make said substrate surface to consist of steps each in the order of an atomic layer;
- and
- subjecting said substrate surface consisted of steps each in the order of an atomic layer to an exited raw material gas made of a volatile hydrocarbon compound, a sulfur compound and a hydrogen gas by a microwave plasma to cause n-type semiconductor diamond to grow epitaxially on said surface consisted of steps each in the order of an atomic layer,
- wherein said n-type semiconductor has a single donor level of 0.38 eV, which is sufficient to allow operation of said n-type semiconductor diamond as p-n junction device.
A method of making an n-type semiconductor diamond, characterized in that it comprises:
- mechanically polishing a diamond substrate to make it in an inclined diamond substrate, which is formed by mechanically polishing a diamond (100) face oriented substrate so that its face normal is inclined at an angle between 1.5 and 6 degrees with respect to its <100> direction in a plane made by either its <100> and <010> directions or its <100> and <001> directions;
- subjecting a surface of said inclined diamond substrate to a hydrogen plasma treatment to make it even;
- and
- exciting a raw material gas made of a volatile hydrocarbon compound, a sulfur compound and a hydrogen gas by a microwave plasma while maintaining at a given temperature said substrate surface smoothened as aforesaid to cause an n-type semiconductor diamond to grow epitaxially on said smoothened substrate.
Dependencies are inferred from the claim text.