Semiconductor device and photoelectric conversion apparatus using the same

Claim 2

A semiconductor device comprising an emitter region of a first conductivity type, a base region of a second conductivity type, and a collector region of said first conductivity type, wherein at least a vicinity of an interface of an emitter region to base region junction is formed by Si; a polycrystalline or single crystalline Si l-x C x (x≦0.5) is formed on a region formed by the Si within said emitter region, and a junction between a region of the Si and a region of the polycrystalline or the single crystalline Si l-x C x is a graded hetero junction and is provided at a position distant from an edge of a depletion layer produced at a junction between said emitter and base regions.

Claim 3

A semiconductor device according to claim 1, wherein said region of Si l-x C x is an ion implanted region of Si l-x C x .

Claim 4

A semiconductor device according to claim 1, wherein on said region of Si l-x C x of said emitter region, a high concentration impurity layer is provided.

Claim 5

A semiconductor device according to claim 3, wherein said high impurity concentration layer is formed by Si l-x C x wherein x>0.0125.

Claim 6

A semiconductor device according to claim 1, wherein x is from 0.0125 to 0.075.

Claim 7

A photoelectric conversion apparatus using a semiconductor device according to claim 1.

Claim 8

A semiconductor device comprising an emitter region of a first conductivity type, a base region of a second conductivity type, and a collector region of said first conductivity type, wherein at least a vicinity of an interface of an emitter region to base region junction is formed by Si; a polycrystalline or single crystalline Si l-x C x (x≦0.5) is formed on a region formed by the Si within said emitter region, and a junction between the region of Si and the region of polycrystalline or single crystalline Si l-x C x is a graded hetero junction and is provided at a position distant from an edge of a depletion layer produced at a junction between said emitter and base regions; at least a portion under the region of Si within said emitter region is formed by a single crystalline Si doped with B and Ge, and a concentration of B is no less than 1×10 18 cm -3 .

Claim 9

A semiconductor device comprising an emitter region of a first conductivity type, a base region of a second conductivity type, and a collector region of said first conductivity type, wherein at least a vicinity of an interface of an emitter region to base region junction is formed by Si; a polycrystalline or single crystalline Si l-x C x (x≦0.5) is formed on a region formed by the Si within said emitter region, and a junction between the region of Si and the region of polycrystalline or single crystalline Si l-x C x is a graded hetero junction and is provided at a position distant from an edge of a depletion layer produced at a junction between said emitter and base regions; at least a portion under the region of Si within said emitter region is formed by a single crystalline Si doped with B and Ge, and a concentration of B is no less than 1×10 18 cm -3 .

Claim 10

A device according to claim 7, wherein said region of Si l-x C x is an ion implanted region of Si l-x C x .

Claim 11

A device according to claim 7, wherein 0.0125≦x≦0.075.

Claim 12

A device according to claim 7, wherein said B and Ge are ion implanted.

Claim 13

A device according to claim 7, wherein an impurity concentration of said emitter region is less than 1×10 19 cm -3 .

Claim 14

A device according to claim 7, wherein the polycrystalline or single crystalline Si is doped with B and Ge so that N Ge >8.25N B wherein N B and N Ge are respectively B and Ge concentrations.

Claim 15

A photoelectric conversion apparatus using a semiconductor device according to claim 7.

Claim 16

A semiconductor device comprising an emitter region of a first conductivity type, a base region of a second conductivity type, and a collector region of said first conductivity type, wherein at least a portion of the emitter side at an emitter region base region junction interface is formed by Si; a polycrystalline or single crystalline Si l-x C x (x≦0.5) is formed on a region formed by the Si within said emitter region, at least a portion under the region formed by the Si of the emitter region is formed by Si l-y Ge y (0<y<1), at least one of a junction between the region of Si and the region of polycrystalline or single crystalline Si l-x C x and a junction between the region of Si and the region of Si l-y Ge y is a graded hetero junction; wherein said junction between the region of Si and the region of polycrystalline or single crystalline Si l-x C x is provided at a position distant from an edge of a depletion layer produced at a junction between said emitter and base regions.

Claim 17

A semiconductor device comprising an emitter region of a first conductivity type, a base region of a second conductivity type, and a collector region of said first conductivity type, wherein at least a portion of the emitter side at an emitter region base region junction interface is formed by Si; a polycrystalline or single crystalline Si l-x C x (x≦0.5) is formed on a region formed by the Si within said emitter region, at least a portion under the region formed by the Si of the emitter region is formed by Si l-y Ge y (0<y<1), at least one of a junction between the region of Si and the region of polycrystalline or single crystalline Si l-x C x and a junction between the region of Si and the region of Si l-y Ge y is a graded hetero junction; wherein said junction between the region of Si and the region of polycrystalline or single crystalline Si l-x C x is provided at a position distant from an edge of a depletion layer produced at a junction between said emitter and base regions.

Claim 18

A semiconductor device according to claim 14, wherein at least one of the region of Si l-x C x and the region of Si l-y Ge y is an ion implanted region.

Claim 19

A semiconductor device according to claim 14 or 15, wherein 0.0125≦x≦0.075.

Claim 20

A semiconductor device according to claim 14 wherein 0.625≦y≦0.375.

Claim 21

A semiconductor device according to claim 14 wherein the region of Si l-y Gey is selectively formed only under the region of Si within the emitter region.

Claim 22

A photoelectric conversion apparatus using a semiconductor device according to claim 14.

Claim 23

A semiconductor device according to claim 1, 7, or 14, wherein a distance (W B ') between the edge of the depletion layer and the junction between the regions formed by Si and Si l-x C x is sufficiently smaller than a diffusion length (L p ) of carrier from said base region.