CN-122002827-A - Semiconductor device with a semiconductor device having a plurality of semiconductor chips

Abstract

The present invention aims to provide a technology capable of suppressing leakage current of a collector side gate. The semiconductor device includes a collector electrode, a collector-side element trench structure, a collector-side gate pad, and a collector-side termination trench structure. The collector electrode surrounds the collector-side gate pad on a side surface of the semiconductor substrate in a plan view, and the collector-side termination trench structure penetrates the collector layer on a side surface of the semiconductor substrate with respect to a connection portion of the collector electrode and the collector layer in a cross-section.

Inventors

• Sudou Masaki
• Fujita regular
• Jitian opens up more
• SAKAMOTO SHUNSUKE
• NAKANISHI YOSUKE

Assignees

• 三菱电机株式会社

Dates

Publication Date

20260508

Application Date

20251031

Priority Date

20241106

Claims (20)

1. 1. A semiconductor device, comprising: a semiconductor substrate having a front surface and a back surface defining an element region and a terminal region surrounding the element region; an emitter electrode provided on the surface side of the semiconductor substrate; an emitter side element trench structure provided on the surface side of the element region in the semiconductor substrate and including an emitter side gate electrode insulated from the emitter electrode; an emitter-side gate pad provided on the surface side of the terminal region in the semiconductor substrate, insulated from the emitter electrode, and electrically connected to the emitter-side gate electrode; a collector electrode provided on the back surface side of the semiconductor substrate; A collector side element trench structure provided on the back surface side of the element region in the semiconductor substrate, the collector side element trench structure including a collector side gate electrode insulated from the collector electrode; A collector side gate pad provided on the back surface side of the termination region in the semiconductor substrate, insulated from and electrically connected to the collector electrode, and A collector-side termination trench structure provided on the back surface side of the termination region in the semiconductor substrate, including a collector-side termination electrode, The semiconductor substrate includes: a drift layer of a first conductivity type; A buffer layer of the first conductivity type provided on the rear surface side of the drift layer, and A collector layer of a second conductivity type provided on the back surface side of the buffer layer, In a plan view, the side surface of the semiconductor substrate and the collector electrode surround the collector side gate pad, In a cross-sectional view, the collector-side termination trench structure penetrates the collector layer on the side surface side of the semiconductor substrate with respect to a connection portion of the collector electrode and the collector layer.
2. 2. The semiconductor device according to claim 1, wherein, In a cross-sectional view, the collector-side termination trench structure penetrates the collector layer on the side surface of the semiconductor substrate.
3. 3. The semiconductor device according to claim 1 or 2, wherein, The depth of the collector side termination trench structure is deeper than the depth of the collector side element trench structure.
4. 4. The semiconductor device according to any one of claims 1 to 3, wherein, The collector side termination trench structure has a width that is wider than a width of the collector side element trench structure.
5. 5. The semiconductor device according to claim 1, wherein, In a cross-sectional view, the collector-side termination trench structure penetrates the collector layer on the connection portion side with respect to the side surface of the semiconductor substrate.
6. 6. The semiconductor device according to any one of claims 1 to 5, wherein, The semiconductor device further includes a passivation film provided on the back surface side of the semiconductor substrate and on the side surface side of the semiconductor substrate of the collector side gate pad.
7. 7. The semiconductor device according to any one of claims 1 to 5, wherein, And a passivation film provided on the rear surface side of the semiconductor substrate and on the collector electrode side of the collector side gate pad.
8. 8. The semiconductor device according to claim 2, wherein, In a plan view, a trench corner of the collector-side termination trench structure corresponding to a corner of the semiconductor substrate has roundness.
9. 9. The semiconductor device according to claim 2, wherein, In a plan view, a width of a trench corner of the collector side termination trench structure corresponding to a corner of the semiconductor substrate is wider than a width of a straight line portion of the collector side termination trench structure connecting the trench corner.
10. 10. The semiconductor device according to any one of claims 1 to 9, wherein, In a plan view, a distance between the collector side gate pad and the collector electrode is greater than a distance between the collector side gate pad and the side surface of the semiconductor substrate.
11. 11. A semiconductor device, comprising: a semiconductor substrate having a front surface and a back surface defining an element region and a terminal region surrounding the element region; an emitter electrode provided on the surface side of the semiconductor substrate; an emitter side element trench structure provided on the surface side of the element region in the semiconductor substrate and including an emitter side gate electrode insulated from the emitter electrode; an emitter-side gate pad provided on the surface side of the terminal region in the semiconductor substrate, insulated from the emitter electrode, and electrically connected to the emitter-side gate electrode; a collector electrode provided on the back surface side of the semiconductor substrate; A collector side element trench structure provided on the back surface side of the element region in the semiconductor substrate and including a collector side gate electrode insulated from the collector electrode, and A collector side gate pad provided on the back surface side of the termination region in the semiconductor substrate, insulated from and electrically connected to the collector electrode, The semiconductor substrate includes: a drift layer of a first conductivity type; A buffer layer of the first conductivity type provided on the rear surface side of the drift layer, and A collector layer of a second conductivity type provided on the back surface side of the buffer layer, In a plan view, the side surface of the semiconductor substrate and the collector electrode surround the collector side gate pad, In a cross-sectional view, the buffer layer penetrates the collector layer on the side surface side of the semiconductor substrate with respect to a connection portion of the collector electrode and the collector layer.
12. 12. A semiconductor device, comprising: a semiconductor substrate having a front surface and a back surface defining an element region and a terminal region surrounding the element region; an emitter electrode provided on the surface side of the semiconductor substrate; an emitter side element trench structure provided on the surface side of the element region in the semiconductor substrate and including an emitter side gate electrode insulated from the emitter electrode; an emitter-side gate pad provided on the surface side of the terminal region in the semiconductor substrate, insulated from the emitter electrode, and electrically connected to the emitter-side gate electrode; a collector electrode provided on the back surface side of the semiconductor substrate; A collector side element trench structure provided on the back surface side of the element region in the semiconductor substrate and including a collector side gate electrode insulated from the collector electrode, and A collector side gate pad provided on the back surface side of the termination region in the semiconductor substrate, insulated from and electrically connected to the collector electrode, The semiconductor substrate includes: a drift layer of a first conductivity type; A buffer layer of the first conductivity type provided on the rear surface side of the drift layer, and A collector layer of a second conductivity type provided on the back surface side of the buffer layer, The semiconductor device further includes a modified layer provided on a part of a surface of at least one of the collector-side gate pad and the collector in a cross-section, and having a lower wettability with respect to solder than the remaining part of the surface.
13. 13. The semiconductor device according to claim 12, wherein, The portion provided with the modified layer includes a portion of the collector side gate pad on a side surface side of the semiconductor substrate.
14. 14. The semiconductor device according to claim 12 or 13, wherein, The portion provided with the modified layer includes a portion on the collector electrode side of the collector side gate pad.
15. 15. The semiconductor device according to any one of claims 12 to 14, wherein, The portion provided with the modified layer includes at least a portion of an outer peripheral portion of the collector electrode in a plan view.
16. 16. A semiconductor device, comprising: a semiconductor substrate having a front surface and a back surface defining an element region and a terminal region surrounding the element region; an emitter electrode provided on the surface side of the semiconductor substrate; An emitter side element trench structure provided on the surface side of the element region in the semiconductor substrate and including an emitter side gate electrode insulated from the emitter electrode, and An emitter side gate pad provided on the surface side of the termination region in the semiconductor substrate, insulated from and electrically connected to the emitter electrode, The semiconductor device further includes a modified layer provided on a part of a surface of at least one of the emitter-side gate pad and the emitter electrode in a cross-section, and having a lower wettability with solder than the remaining part of the surface.
17. 17. The semiconductor device according to claim 16, wherein, The portion provided with the modified layer includes a portion of the collector side gate pad on a side surface side of the semiconductor substrate.
18. 18. The semiconductor device according to claim 16 or 17, wherein, The portion provided with the modified layer includes a portion on the collector electrode side of the collector side gate pad.
19. 19. The semiconductor device according to any one of claims 16 to 18, wherein, The portion provided with the modified layer includes at least a portion of an outer peripheral portion of the emitter electrode in a plan view.
20. 20. The semiconductor device according to any one of claims 12 to 19, wherein, The modified layer is at least one of the surface oxide layer and a sparse layer of the surface.

Description

Semiconductor device with a semiconductor device having a plurality of semiconductor chips Technical Field The present disclosure relates to semiconductor devices. Background A semiconductor device is proposed, which includes an emitter-side gate electrode forming a channel on an emitter electrode side as a front surface side and a collector-side gate electrode forming a channel on a collector electrode side as a back surface side. Various techniques have been proposed for such a semiconductor device having a double-sided gate structure. For example, patent document 1 proposes a structure in which a collector-side lead frame for electrical connection to the outside is connected to a collector-side gate pad provided on the back surface side of a semiconductor substrate by solder. According to this structure, a channel can be formed on the back surface side of the semiconductor substrate by applying a voltage from the outside to the collector-side gate electrode via the collector-side lead frame and the collector-side gate pad. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication No. 2010-123667 Disclosure of Invention Technical problem to be solved by the invention However, in the manufacturing process, solder connecting the collector-side gate pad and the collector-side lead frame may leak to the side surface of the semiconductor substrate. As a result, there is a problem in that the collector side lead frame and the side surface of the semiconductor substrate are electrically connected by solder, and the leakage current of the collector side gate electrode increases. Accordingly, the present disclosure has been made in view of the above-described problems, and an object thereof is to provide a technique capable of suppressing leakage current of a collector side gate. Technical means for solving the technical problems The semiconductor device according to the present disclosure includes a semiconductor substrate having a front surface and a back surface defining an element region and a termination region surrounding the element region, an emitter electrode provided on the front surface side of the semiconductor substrate, an emitter-side element trench structure provided on the front surface side of the element region in the semiconductor substrate and including an emitter-side gate electrode insulated from the emitter electrode, an emitter-side gate pad provided on the front surface side of the termination region in the semiconductor substrate and insulated from the emitter electrode and electrically connected to the emitter-side gate electrode, a collector-side element trench structure provided on the back surface side of the element region in the semiconductor substrate and including a collector-side gate electrode insulated from the collector electrode, a collector-side gate pad provided on the back surface side of the termination region in the semiconductor substrate and insulated from the collector electrode and electrically connected to the emitter-side gate electrode, a collector-side element trench structure provided on the back surface side of the semiconductor substrate and a second conductive layer including a drift-side termination layer provided on the back surface side of the semiconductor substrate, a second conductive layer provided on the back surface side of the drift-side trench structure, and a second conductive layer provided on the back surface side of the drift-side of the semiconductor substrate, the side surface of the semiconductor substrate and the collector electrode surround the collector side gate pad, and the collector side termination trench structure penetrates the collector layer on the side surface side of the semiconductor substrate with respect to a connection portion of the collector electrode and the collector layer in a cross-sectional view. Effects of the invention According to the present disclosure, in a cross-sectional view, the collector-side termination trench structure penetrates the collector layer on a side surface side of the semiconductor substrate with respect to the connection portion of the collector electrode and the collector layer. With this structure, the leakage current of the collector side gate can be suppressed. Drawings Fig. 1 is a plan view showing a structure of a front surface side of a semiconductor device according to embodiment 1. Fig. 2 is a plan view showing a structure of the back surface side of the semiconductor device according to embodiment 1. Fig. 3 is a cross-sectional view showing the structure of the semiconductor device according to embodiment 1. Fig. 4 is a cross-sectional view showing the structure of the semiconductor device according to embodiment 2. Fig. 5 is a cross-sectional view showing the structure of the semiconductor device according to embodiment 3. Fig. 6 is a plan view showing a structure of the back surface side of the semiconductor device according to embodiment 4. Fig