Insulated gate bipolar semiconductor device having a Schottky barrier layer and method of manufacturing the same

Claim 1

A semiconductor device comprising: - a first conductivity type semiconductor substrate (31); - a first region (32) of a second conductivity type partially formed on a first major surface of the semiconductor sub­strate (31); - a second region (33) of the second conductivity type par­tially formed on a second major surface of the semiconduc­tor substrate (31); - a third region (34) of the first conductivity type partially formed on a surface of the second region (33); - an insulation film (35) formed on the surface of the second region (33) and extending between the surfaces of the semi­conductor substrate (31) and the third region (34), the in­sulation film (35) virtually locationally corresponding to the first region (32); - a control electrode (36) formed on the insulation film (35); - a first electrode (37) formed on the second major surface extending over the third region (34) and the second region (33); - a second electrode (38) formed on the first major surface extending over the first region (32) and a region (39) adja­cent to the first region (32) of the semiconductor substra­te (31); and - a barrier layer (40) formed at a region except for the first region (32) within the first major surface of the semicon­ductor substrate (31) for restricting movement of carriers which move toward the second electrode (38) from the semi­conductor substrate (31).

Claim 14

A method of manufacturing a semiconductor device compris­ing the following steps: - a first step of preparing a first conductivity type semi­conductor substrate (31) having a first major surface and a second major surface; - a second step of introducing a second conductivity type impurity into a part of the first major surface of the semi­conductor substrate (31) to form a first region (32) of the second conductivity type; - a third step of forming a two-layer structure (42) consist­ing of an insulation film (35) and a control electrode (36) on the second major surface of the semiconductor substrate (31) so that the two-layer structure (42) virtually loca­tionally corresponds to the first region (32); - a fourth step of introducing a second conductivity type im­purity into a part of the second major surface of the semi­conductor substrate (31) by utilizing the two-layer struc­ture (42) as a mask to form a second region (33) of the second conductivity type; - a fifth step of forming a mask layer (43) on a surface of the second region (33) apart from the two-layer structure (42); - a sixth step of introducing a first conductivity type im­purity into a part of a surface of the second region (33) by utilizing the two-layer structure (42) and the mask layer (43) as masks to form a third region (34) of the first conducti­vity type; - a seventh step of forming, after removing the mask layer (43), a first electrode (37) on the second major surface extending over the third region (34) and the second region (33) so that the first electrode (37) is connected by ohmic contact with the second region (33) and the third region (34); - an eighth step of forming a second electrode (38) on the first major surface extending over the first region (32) and a region adjacent to the first region (32) of the semiconduc­tor substrate (31) so that a Schottky barrier layer (40) is formed at a connecting part between the second electrode (38) and the region adjacent to the first region (32) of the semi­conductor substrate (31).

Claim 15

A method of manufacturing a semiconductor device compris­ing the following steps: - a first step of preparing a first conductivity type semi­conductor substrate (31) having a first major surface and a second major surface; - a second step of introducing a second conductivity type impurity into a part of the first major surface of the semi­conductor substrate (31) to form a first region (32) of the second conductivity type; - a third step of forming a two-layer structure (42) consist­ing of an insulation film (35) and a control electrode (36) on the second major surface of the semiconductor substrate (31) so that the two-layer structure (42) virtually loca­tionally corresponds to the first region (32); - a fourth step of introducing a second conductivity type im­purity into a part of the second major surface of the semi­conductor substrate (31) by utilizing the two-layer struc­ture (42) as a mask to form a second region (33) of the second conductivity type; - a fifth step of forming a mask layer (43) on a surface of the second region (33) apart from the two-layer structure (42); - a sixth step of introducing a first conductivity type im­purity into a part of a surface of the second region (33) by utilizing the two-layer structure (42) and the mask layer (43) as masks to form a third region (34) of the first conducti­vity type; - a seventh step of forming, after removing the mask layer (43), a first electrode (37) on the second major surface extending over the third region (34) and the second region (33) so that the first electrode (37) is connected by ohmic contact with the second region (33) and the third region (34); - an eighth step of forming a second electrode (38) on the first major surface extending over the first region (32) and a region adjacent to the first region (32) of the semiconduc­tor substrate (31) so that a Schottky barrier layer (40) is formed at a connecting part between the second electrode (38) and the region adjacent to the first region (32) of the semi­conductor substrate (31).

Claim 16

A method of manufacturing a semiconductor device, compris­ing the following steps: - a first step of preparing a first conductivity type semicon­ductor substrate (31) having a first major surface and a second major surface; - a second step of introducing a second conductivity type im­purity into a part of the first major surface of the semi­conductor substrate (31) to form a first region (32) of the second conductivity type so that an area of a surface of the first region (32) is set to be larger than that of a region except for the first region (32) within the first major sur­face of the semiconductor substrate (31); - a third step of forming a two-layer structure (42) consist­ing of an insulation film (35) and a control electrode (36) on the second major surface of the semiconductor substrate (31) so that the two-layer structure (42) virtually locatio­nally corresponds to the first region (32); - a fourth step of introducing a second conductivity type im­purity into a part of the second major surface of the semi­conductor substrate (31) by utilizing the two-layer struc­ture (42) as a mask to form a second region (33) of the second conductivity type; - a fifth step of forming a mask layer (43) on a surface of the second region (33) apart from the two-layer structure (42); - a sixth step of introducing a first conductivity type im­purity into a part of a surface of the second region (33) by utilizing the two-layer structure (42) and the mask layer (43) as masks to form a third region (34) of the first con­ductivity type; - a seventh step of forming, after removing the mask layer (43), a first electrode (37) on the second major surface extending over the third region (34) and the second region (33) so that the first electrode (37) is connected by ohmic contact with the second region (33) and the third region (34); - an eighth step of introducing a first conductivity type im­purity into the region (58) except for the first region (32) within the first major surface of the semiconductor substra­te (31); - a ninth step of forming a second electrode (38) on the first major surface extending over the first region (32) and the region adjacent to the first region (32) of the semiconduc­tor substrate (31) so that the second electrode (38) is con­nected by ohmic contact with the first region (32) and the region (58) adjacent to the first region (32) of the semi­conductor substrate (31).

Claim 17

A method of manufacturing a semiconductor device, compris­ing the following steps: - a first step of preparing a first conductivity type semicon­ductor substrate (31) having a first major surface and a second major surface; - a second step of introducing a second conductivity type im­purity into a part of the first major surface of the semi­conductor substrate (31) to form a first region (32) of the second conductivity type so that an area of a surface of the first region (32) is set to be larger than that of a region except for the first region (32) within the first major sur­face of the semiconductor substrate (31); - a third step of forming a two-layer structure (42) consist­ing of an insulation film (35) and a control electrode (36) on the second major surface of the semiconductor substrate (31) so that the two-layer structure (42) virtually locatio­nally corresponds to the first region (32); - a fourth step of introducing a second conductivity type im­purity into a part of the second major surface of the semi­conductor substrate (31) by utilizing the two-layer struc­ture (42) as a mask to form a second region (33) of the second conductivity type; - a fifth step of forming a mask layer (43) on a surface of the second region (33) apart from the two-layer structure (42); - a sixth step of introducing a first conductivity type im­purity into a part of a surface of the second region (33) by utilizing the two-layer structure (42) and the mask layer (43) as masks to form a third region (34) of the first con­ductivity type; - a seventh step of forming, after removing the mask layer (43), a first electrode (37) on the second major surface extending over the third region (34) and the second region (33) so that the first electrode (37) is connected by ohmic contact with the second region (33) and the third region (34); - an eighth step of introducing a first conductivity type im­purity into the region (58) except for the first region (32) within the first major surface of the semiconductor substra­te (31); - a ninth step of forming a second electrode (38) on the first major surface extending over the first region (32) and the region adjacent to the first region (32) of the semiconduc­tor substrate (31) so that the second electrode (38) is con­nected by ohmic contact with the first region (32) and the region (58) adjacent to the first region (32) of the semi­conductor substrate (31).

Claim 18

A method of manufacturing a semiconductor device, compris­ing the following steps: - a first stpe of preparing a first conductivity type semicon­ductor substrate (31) having a first major surface and a second major surface; - a second step of introducing a second conductivity type im­purity into a part of the first major surface of the semi­conductor substrate (31) to form a first region (32) of the second conductivity type; - a third step of forming a two-layer structure (42) consist­ing of an insulation film (35) and a control electrode (36) on the second major surface of the semiconductor substrate (31) so that the two-layer structure (42) virtually locatio­nally corresponds to the first region (32); - a fourth step of introducing a second conductivity type im­purity into a part of the second major surface of the semi­conductor substrate (31) by utilizing the two-layer struc­ture (42) as a mask to form a second region (33) of the second conductivity type; - a fifth step of forming a mask layer (43) on a surface of the second region (33) apart from the two-layer structure (42); - a sixth step of introducing a first conductivity type im­purity into a part of a surface of the second region (33) by utilizing the two-layer structure (42) and the mask layer (43) as masks to form a third region (34) of the first con­ductivity type; - a seventh step of forming, after removing the mask layer (43), a first electrode (37) on the second major surface extending over the third region (34) and the second region (33) so that the first electrode (37) is connected by ohmic contact with the second region (33) and the third region (34); - an eighth step of sectioning a region except for the first region (32) within the first major surface of the semicon­ductor substrate (31) into a first area (59) and a second area (60), and introducing a first conductivity type im­purity into the first area (59) of the semiconductor sub­strate (31); - a ninth step of forming a second electrode (38) on the first major surface extending over the first region (32) and the region adjacent to the first region (32) of the semiconduc­tor substrate (31) so that the first area (59) is connected by ohmic contact with the second electrode (38) and a Schottky barrier layer (40) is formed at a connecting part between the second area (60) and the second electrode (38).

Claim 19

A method of manufacturing a semiconductor device, compris­ing the following steps: - a first stpe of preparing a first conductivity type semicon­ductor substrate (31) having a first major surface and a second major surface; - a second step of introducing a second conductivity type im­purity into a part of the first major surface of the semi­conductor substrate (31) to form a first region (32) of the second conductivity type; - a third step of forming a two-layer structure (42) consist­ing of an insulation film (35) and a control electrode (36) on the second major surface of the semiconductor substrate (31) so that the two-layer structure (42) virtually locatio­nally corresponds to the first region (32); - a fourth step of introducing a second conductivity type im­purity into a part of the second major surface of the semi­conductor substrate (31) by utilizing the two-layer struc­ture (42) as a mask to form a second region (33) of the second conductivity type; - a fifth step of forming a mask layer (43) on a surface of the second region (33) apart from the two-layer structure (42); - a sixth step of introducing a first conductivity type im­purity into a part of a surface of the second region (33) by utilizing the two-layer structure (42) and the mask layer (43) as masks to form a third region (34) of the first con­ductivity type; - a seventh step of forming, after removing the mask layer (43), a first electrode (37) on the second major surface extending over the third region (34) and the second region (33) so that the first electrode (37) is connected by ohmic contact with the second region (33) and the third region (34); - an eighth step of sectioning a region except for the first region (32) within the first major surface of the semicon­ductor substrate (31) into a first area (59) and a second area (60), and introducing a first conductivity type im­purity into the first area (59) of the semiconductor sub­strate (31); - a ninth step of forming a second electrode (38) on the first major surface extending over the first region (32) and the region adjacent to the first region (32) of the semiconduc­tor substrate (31) so that the first area (59) is connected by ohmic contact with the second electrode (38) and a Schottky barrier layer (40) is formed at a connecting part between the second area (60) and the second electrode (38).

Claim 20

The method of manufacturing a semiconductor device in accordance with any of claims 11 to 13, comprising a step of irradiating a radiation into a region except for the region corresponding to the first region (32) within an internal region of the semiconductor substrate (31).

Claim 21

The method of manufacturing a semiconductor device in accordance with any of claims 11 to 13, comprising a step of introducing a heavy metal for controlling the carrier life time into a region except for the region corresponding to the first region (32) within an internal region of the semicon­ductor substrate (31).