Semiconductor device

• US 10,157,903 B2
• Filed: 08/23/2017
• Issued: 12/18/2018
• Est. Priority Date: 08/31/2016
• Status: Active Grant

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Inventors: Higashi, Masahiko
• Primary Examiner(s): Nicely, Joseph C
• Assistant Examiner(s): GOODWIN, DAVID J
• Application Number:
  US15/683,883
• Publication Number:
  US 20180061821A1
• Time in Patent Office: 482 Days
• CPC Class Codes: H01L 2224/83385 Shape, e.g. interlocking features
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
• CPC Class Codes: H01L 27/0255 using diodes as protective elements
• CPC Class Codes: H01L 29/0649 Dielectric regions, e.g. SiO2 regions, air gaps
• CPC Class Codes: H01L 29/0692 Surface layout
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/8613 Mesa PN junction diodes
• CPC Class Codes: H01L 29/872 Schottky diodes
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A semiconductor device that improves the discharge capacity with respect to ESD without increasing the surface area of the semiconductor device includes a first conductive portion including plural portions, each of the plural portions having a first type of conductivity, and each of the plural portions extending in a first direction and being arranged in parallel at a distance from each other in a second direction that intersects the first direction; and a second conductive portion including an island portion provided between the respective plural portions of the first conductive portion and extending in the first direction, the second conductive portion having a second type of conductivity that is different from the first type of conductivity.

Claims

1. A semiconductor device, comprising:

a first conductive portion, formed at a surface of the semiconductor device, including a plurality of portions, each of the plurality of portions having a first type of conductivity, and each of the plurality of portions extending in a first direction and being arranged in parallel at a distance from each other in a second direction that intersects the first direction;

a first low concentration layer formed below the first conductive portion with respect to the surface of the semiconductor device, the first low concentration layer having the first type of conductivity and having a lower impurity concentration than the first conductive portion;

a second conductive portion, formed at the surface of the semiconductor device, including an island portion provided between respective ones of the plurality of portions of the first conductive portion and extending in the first direction, the second conductive portion having a second type of conductivity that is different from the first type of conductivity;

a second low concentration layer formed below the second conductive portion with respect to the surface of the semiconductor device, the second low concentration layer having the second type of conductivity and having a comparatively lower impurity concentration than the second conductive portion; and

an insulator formed between the first conductive portion and the second conductive portion, the insulator extending further below the first low concentration layer and into the second low concentration layer from the surface of the semiconductor device.

2. The semiconductor device according to claim 1, wherein

the plurality of portions of the first conductive portion includes at least three portions, and

the island portion of the second conductive portion includes a plurality of island portions respectively provided between each of the at least three portions.

3. The semiconductor device according to claim 1, wherein the second conductive portion further includes a ring portion having the second type of conductivity and having a ring-shaped pattern that surrounds the first conductive portion.

4. The semiconductor device according to claim 3, wherein the ring portion has a rectangular ring-shaped pattern that includes portions that extend in the first direction and portions that extend in the second direction.

5. The semiconductor device according to claim 4, wherein the first conductive portion further includes a portion, having the first type of conductivity, that extends in the second direction at an inner side of the ring portion and that faces a portion from among the portions of the ring portion which extends in the second direction.

6. The semiconductor device according to claim 1, wherein

the first conductive portion has a grid pattern formed by at least three portions from among the plurality of portions of the first conductive portion, and by another plurality of portions from among the plurality of portions of the first conductive portion that intersect with each of the at least three portions;

and

the island portion of the second conductive portion includes a plurality of island portions that are respectively provided at an inner side of each grid in the grid pattern of the first conductive portion.

7. A semiconductor device, comprising:

a first protective element including

a first conductive portion, formed at a surface of the semiconductor device, including a plurality of portions, each of the plurality of portions having a first type of conductivity, and each of the plurality of portions extending in a first direction and being arranged in parallel at a distance from each other in a second direction that intersects the first direction,

a first low concentration layer formed below the first conductive portion with respect to the surface of the semiconductor device, the first low concentration layer having the first type of conductivity and having a lower impurity concentration than the first conductive portion,

a second conductive portion, formed at the surface of the semiconductor device, including an island portion provided between respective ones of the plurality of portions of the first conductive portion and extending in the first direction, the second conductive portion having a second type of conductivity that is different from the first type of conductivity, and

a second low concentration layer formed below the second conductive portion with respect to the surface of the semiconductor device, the second low concentration layer having the second type of conductivity and having a lower impurity concentration than the second conductive portion;

a second protective element including

a third conductive portion, formed at the surface of the semiconductor device, including a plurality of portions, each of the plurality of portions of the third conductive portion having the second type of conductivity, and each of the plurality of portions of the third conductive portion extending in the first direction and being arranged in parallel at a distance from each other in the second direction,

a third low concentration layer formed below the third conductive portion with respect to the surface of the semiconductor device, the third low concentration layer having the second type of conductivity and having a lower impurity concentration than the third conductive portion,

a fourth conductive portion, formed at the surface of the semiconductor device, including an island portion provided between respective ones of the plurality of portions of the third conductive portion and extending in the first direction, the fourth conductive portion having the first type of conductivity, and

a fourth low concentration layer formed below the fourth conductive portion with respect to the surface of the semiconductor device, the fourth low concentration layer having the first type of conductivity and having a lower impurity concentration than the fourth conductive portion; and

an insulator formed between the first conductive portion and the second conductive portion and between the third conductive portion and the fourth conductive portion, the insulator extending below the first low concentration layer and the third low concentration layer, and into the second low concentration layer and the fourth low concentration layer, from the surface of the semiconductor device.