Hemt having heavily doped N-type regions and process of forming the same
AssigneeSumitomo Electric Industries, Ltd.
InventorKen Nakata
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Abstract
A HEMT made of nitride semiconductor materials and a process of forming the same are disclosed, where the HEMT has n-type regions beneath the source and drain electrodes with remarkably increased carrier concentration. The HEMT provides the n-type regions made of at least one of epitaxially grown ZnO layer and MgZnO layer each doped with at least aluminum and gallium with density higher than 1×1020 cm−3. The process of forming the HEMT includes steps of forming recesses by dry-etching, epitaxially growing n-type layer, removing surplus n-type layer except within the recesses by dry-etching using hydrocarbon, and forming the electrodes on the n-type layer.
Claims9
A process of forming a high electron mobility transistor (HEMT) made of nitride semiconductor materials, comprising steps of:
- forming, a semiconductor stack on a substrate by epitaxially growing the nitride semiconductor materials;
- forming recesses by etching portions of the semiconductor stack;
- epitaxially growing n-type film within oxygen plasma at a temperature lower than 700° C. using a solidified zinc (Zn), the n-type film being made of at least one of zinc oxide (ZnO) and magnesium zinc oxide (MgZnO) each doped with at least one of aluminum (Al) and gallium (Ga);
- forming n-type regions by partially removing the n-type film except within the recesses by a dry-etching using hydrocarbon;
- and
- forming source and drain electrodes on the n-type regions.
Dependencies are inferred from the claim text.