Silicon carbide semiconductor device and method for producing the same
AssigneePanasonic Corporation
InventorsChiaki Kudou, Kazuya Utsunomiya, Masashi Hayashi
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Abstract
A gate electrode 18 formed on a silicon carbide substrate 11 includes a silicon lower layer 18A and a silicide upper layer 18B provided on the silicon lower layer 18A, the silicide upper layer 18B being made of a compound of a first metal and silicon. A source electrode 1as formed on the surface of the silicon carbide substrate 11 and in contact with an n type source region and a p+ region contains second metal silicide different from the first metal silicide. Side faces of the silicon lower layer 18A are covered with an insulator.
Claims9
A method of producing a silicon carbide semiconductor device, comprising the steps of:
- providing a silicon carbide substrate having a silicon carbide epitaxial layer formed on a surface thereof;
- forming a source region in the silicon carbide epitaxial layer;
- forming a gate insulating film on the silicon carbide epitaxial layer;
- forming a silicon gate electrode on the gate insulating film;
- covering side faces of the silicon gate electrode with an insulator;
- depositing a first metal which is in contact with an upper face of the silicon gate electrode;
- allowing a portion of the silicon gate electrode to react with the first metal to form a gate electrode having an upper layer of first metal silicide and a lower layer of silicon;
- removing an unreacted portion of the first metal having failed to react with the silicon gate electrode;
- forming an interlayer insulating film having an opening above the source region;
- depositing on the interlayer insulating film a second metal which is in contact with a portion of the source region via the opening;
- and
- allowing a portion of the source region to react with the second metal to form a layer of second metal silicide above the source region, wherein,
- the step of covering the side faces of the silicon gate electrode with an insulator comprises the steps of:
- depositing an insulating film;
- and
- etching back the insulating film to form side wall spacers on the side faces of the silicon gate electrode, and,
- when the portion of the silicon gate electrode and the first metal are allowed to react, the portion of the first metal is in contact with the source region.
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-11. (canceled)
Dependencies are inferred from the claim text.