Semiconductor device having multiple source regions

• US 6,225,665 B1
• Filed: 07/01/1999
• Issued: 05/01/2001
• Est. Priority Date: 01/11/1999
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hirano, Yuuichi
• Primary Examiner(s): Abraham, Fetsum
• Application Number:
  US09/346,266
• Time in Patent Office: 670 Days
• Field of Search: 257/347-355
• US Class Current: 257/347
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/0214 for internal polarisation, e.g. I2L
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 29/78615 with a body contact
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile

Abstract

In a region on the left hand of FIG. 1 with respect to the gate electrode (107), a first source region (103a), a body-potential drawing region (105) and a second source region (103b) are formed in this order along the vertical direction of this figure. The first and second source regions (103a, 103b) are of n⁺ type, and the body-potential drawing region (105) is of p⁺ type. In a thin-film transistor (100), the body-potential drawing region (105) can draw and fix a body potential.

Claims

1. A semiconductor device, comprising:

an insulator;

a semiconductor layer on the insulator, the semiconductor layer having a first region, a second region, and a third region, the first region having a first conductivity type, the third region having a second conductivity type opposite to said first conductivity type;

an insulating layer above the first region; and

a control electrode provided on said insulating layer extending in a first direction,

wherein the second region comprises;

a first source region having said second conductivity type;

a body-potential drawing region having said first conductivity type and being adjacent to said first source region; and

a second source region having said second conductivity type and being adjacent to said body-potential drawing region wherein the first source region, the body-potential drawing region and the second source region are aligned along a side end of said control electrode.

2. The semiconductor device according to claim 1, wherein

the first source region, the body-potential drawing region and the second source region have the same length along said second direction orthogonal to said first direction.

3. The semiconductor device according to claim 1, wherein

the length along a second direction orthogonal to said first direction of the body-potential drawing region is shorter than those of the first source region and the second source region.

4. The semiconductor device according to claim 3, wherein

the first source region and the second source region are connected farther away from said control electrode than an end portion of the body-potential drawing region away from said control electrode.

5. The semiconductor device according to claim 1, wherein said control electrode comprises:

a straight portion extending in said first direction; and

a wide portion widened in a second direction at a position of the body-potential drawing region in said first direction, said second direction being orthogonal to said first direction.

6. The semiconductor device according to claim 5, wherein

the length along said second direction orthogonal to said first direction of the body-potential drawing region is shorter than those of the first source region and the second source region.

7. The semiconductor device according to claim 6, wherein

the first source region and the second source region are connected farther away from said control electrode than an end portion of the body-potential drawing region away from said control electrode.

8. The semiconductor device according to claim 1, wherein the first source region, the body-potential drawing region, and the second source region extend from a bottom surface of the semiconductor layer to a top surface of the semiconductor layer.

9. A semiconductor device, comprising:

a pair of semiconductor elements each including

an insulator;

a semiconductor layer on the insulator, the semiconductor layer having a first region, a second region, and a third region, the first region having a first conductivity type, the third region having a second conductivity type opposite the said first conductivity type;

an insulating layer above the first region; and

a control electrode provided on said insulating layer having a straight portion extending in a first direction and a wide portion widened in a second direction

wherein the second region comprises;

a first source region having said second conductivity type;

a body-potential drawing region having said first conductivity type and being adjacent to said first source region and

a second source region having said second conductivity type and being adjacent to said body-potential drawing region, wherein the first source region, the body-potential drawing region and the second source region are aligned along a side end of said control electrode,

wherein each of the wide portions associated with the pair of semiconductor elements is at a position of said corresponding body-potential drawing regions in said first direction and is in opposite directions to each other.

10. The semiconductor device according to claim 9, wherein said pair of wide portions are widened in such directions as to go away from a boundary between said pair of semiconductor elements.

11. The semiconductor device according to claim 9, wherein

the first source region and the second source region are connected farther away from said control electrode than an end portion of the body-potential drawing region away from said control electrode.

12. The semiconductor device according to claim 9, wherein the first source region, the body-potential drawing region, and the second source region extend from a bottom surface of the semiconductor layer to a top surface of the semiconductor layer.