Semiconductor device and method for manufacturing a semiconductor device

Abstract

This semiconductor device comprises an active region and an outer peripheral region. The active region has a first-electroconductivity-type drift layer and a second-electroconductivity-type body layer. The active region has a main cell region having a main cell, a first insulating film covering the main cell, a first electrode part stacked on the first insulating film, a sense cell region having a sense cell, a second insulating film covering the sense cell, and a second electrode part stacked on the second insulating film. Between the main cell region and the sense cell region, there is formed a second-electroconductivity-type well region. The first electrode part and the second electrode part are electrically connected by the well region.

Claims

1. The device comprises an active region having a first conductive drift layer and a second conductive body layer formed on the drift layer, and an outer peripheral region surrounding the active region. The active region is It has a main cell region through which the main current flows, The first insulating film covering the main cell, A first electrode portion laminated on the first insulating film, A sense cell region is located spaced apart from the main cell region and has a sense cell through which a sense current corresponding to the main current flows, A second insulating film covering the sense cell, The second electrode portion laminated on the second insulating film, It has, A second conductivity type well region is formed between the main cell region and the sense cell region. The first electrode portion and the second electrode portion are electrically connected to the well region and are also electrically connected to each other via the resistance component of the well region. Semiconductor equipment.

2. The device comprises an active region having a first conductive drift layer and a second conductive body layer formed on the drift layer, and an outer peripheral region surrounding the active region, The active region is It has a main cell region through which the main current flows, The first insulating film covering the main cell, A first electrode portion laminated on the first insulating film, A sense cell region is located spaced apart from the main cell region and has a sense cell through which a sense current corresponding to the main current flows, A second insulating film covering the sense cell, The second electrode portion laminated on the second insulating film, It has, A second conductivity type well region is formed between the main cell region and the sense cell region. The first electrode portion and the second electrode portion are electrically connected to the well region. The impurity concentration in the well region is lower than the impurity concentration in the body layer. Semiconductor equipment.

3. Viewed from the thickness direction of the drift layer, the well region is formed to surround the sense cell region. The semiconductor device according to claim 1 or 2.

4. The second electrode portion has a sense contact that connects to the well region. The sense contact has a sense end contact formed at the end of the second electrode portion closest to the main cell region. The semiconductor device according to claim 3.

5. The device comprises an active region having a first conductive drift layer and a second conductive body layer formed on the drift layer, and an outer peripheral region surrounding the active region, The active region is It has a main cell region through which the main current flows, The first insulating film covering the main cell, A first electrode portion laminated on the first insulating film, A sense cell region is located spaced apart from the main cell region and has a sense cell through which a sense current corresponding to the main current flows, A second insulating film covering the sense cell, The second electrode portion laminated on the second insulating film, It has, A second conductivity type well region is formed between the main cell region and the sense cell region. The first electrode portion and the second electrode portion are electrically connected to the well region. Viewed from the thickness direction of the drift layer, the well region is formed to surround the sense cell region. The second electrode portion has a sense contact that connects to the well region. The sense contact has a sense end contact formed at the end of the second electrode portion closest to the main cell region. The first electrode portion has a main contact that connects to the well region. The main contact is formed to surround the sense cell region. Semiconductor equipment.

6. The main contact has a main end contact provided at a position opposite to the sense end contact when viewed from the thickness direction of the drift layer, Multiple main end contacts and multiple sense end contacts are provided, The number of main terminal contacts is greater than the number of sense terminal contacts. The semiconductor device according to claim 5.

7. Viewed from the thickness direction of the drift layer, the well region has a portion that overlaps with both the first electrode portion and the second electrode portion. A semiconductor device according to any one of claims 1 to 6.

8. Both the main cell region and the sense cell region have a plurality of trenches formed from the surface of the body layer toward the drift layer, The well region is formed between the first trench, which is closest to the sense cell region among the multiple trenches in the main cell region, and the second trench, which is closest to the main cell region among the multiple trenches in the sense cell region. The semiconductor device according to claim 7.

9. The well region is formed to extend closer to the drift layer than both the bottom of the first trench and the bottom of the second trench, and is formed to cover at least a portion of the bottom of the first trench and at least a portion of the bottom of the second trench. The semiconductor device according to claim 8.

10. The outer peripheral region is equipped with a terminal structure, The aforementioned termination structure has a second conductive type guard ring, The impurity concentration in the well region is lower than the impurity concentration in the guard ring. A semiconductor device according to any one of claims 1 to 9.

11. The first insulating film and the second insulating film are formed by a common insulating film. A semiconductor device according to any one of claims 1 to 10.

12. A step of forming a first-conductive drift layer, A step of forming a second conductive body layer on the drift layer, A process of forming a main cell region having a main cell through which the main current flows, A step of forming a sense cell region which is spaced apart from the main cell region and has a sense cell through which a sense current corresponding to the main current flows, A step of forming a second conductive well region between the main cell region and the sense cell region, A step of forming a first insulating film covering the main cell, A step of stacking the first electrode portion on the first insulating film, A step of forming a second insulating film covering the sense cell, A step of stacking the second electrode portion on the second insulating film, Equipped with, Both the first insulating film and the second insulating film have portions that cover the well region. The step of stacking the first electrode portion on the first insulating film is: The process involves forming a main-side opening that exposes the well region in the portion of the first insulating film that covers the well region, The step includes forming a main contact that contacts the well region by embedding a part of the first electrode portion in the main side opening, The step of stacking the second electrode portion onto the second insulating film is: The process involves forming a sense-side opening in the portion of the second insulating film that covers the well region, thereby exposing the well region. The process includes the step of forming a sense contact that contacts the well region by embedding a part of the second electrode portion in the sense-side opening, The first electrode portion and the second electrode portion are electrically connected to the well region and are also electrically connected to each other via the resistance component of the well region. A method for manufacturing a semiconductor device.

13. The process includes forming a terminal structure in the outer peripheral region that surrounds both the main cell region and the sense cell region. The step of forming the terminal structure includes the step of forming a second conductive type guard ring. The formation of the well region and the formation of the guard ring are carried out by the same process. The method for manufacturing a semiconductor device according to claim 12.

14. The process involves forming a plurality of trenches in both the main cell region and the sense cell region, extending from the surface of the body layer toward the drift layer, The process of forming a second conductive floating region between the plurality of trenches, Equipped with, The formation of the well region and the formation of the floating region are carried out by the same process. A method for manufacturing a semiconductor device according to claim 12 or 13.

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