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.
Claims7
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.
Dependencies are inferred from the claim text.