EP0345380A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Manufacture of a semiconductor device
Assignee: Mitsubishi Electric Corp
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Filing: 1988-10-11
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Granted: —
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Expires: 2008-10-11
Abstract
Abstract Floating well regions (10) are provided just under trenches in which buried gates (5) are formed. The floating well regions (10) moderate an electric field concentration in the vicinity of the corner and bottom portions of the trenches, in the OFF state of the semiconductor device.
Inventors
- 👤 Masana C/O Mitsubishi Denki K.K. Harada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 10:43
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D30/668; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/105; H10D62/106; H10D62/107; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/512; H10D64/513
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
208 words
A semiconductor device comprising: - a first conductivity type semiconductor layer (1, 2) having first and second major surfaces; - a second conductivity type first semiconductor region (3) formed on the first major surface of the semiconductor layer (1, 2), the first semiconductor region (3) having a trench (19) which reaches the semiconductor layer (1, 2) through the first semiconductor region (3); - an insulation film (4) formed on a surface of the trench (19); - a gate electrode layer (5) formed on the insulation film (4); - a first conductivity type second semiconductor region (6) formed in a portion of a surface of the first semiconductor region (3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (3), which extends between the second semiconductor region (6) and the semiconductor layer (1, 2) adjacent to the trench (19), being defined as a channel region (7); - a second conductivity type floating region (10) formed in the semiconductor layer (1, 2) just under the bottom of the trench (19); - a first electrode layer (8) formed on the first and second semiconductor regions (3, 6); and - a second electrode layer (9) formed on the second major surface of the semiconductor layer (1, 2).
Claim 2
Dependent Claim
208 words
A semiconductor device comprising: - a first conductivity type semiconductor layer (1, 2) having first and second major surfaces; - a second conductivity type first semiconductor region (3) formed on the first major surface of the semiconductor layer (1, 2), the first semiconductor region (3) having a trench (19) which reaches the semiconductor layer (1, 2) through the first semiconductor region (3); - an insulation film (4) formed on a surface of the trench (19); - a gate electrode layer (5) formed on the insulation film (4); - a first conductivity type second semiconductor region (6) formed in a portion of a surface of the first semiconductor region (3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (3), which extends between the second semiconductor region (6) and the semiconductor layer (1, 2) adjacent to the trench (19), being defined as a channel region (7); - a second conductivity type floating region (10) formed in the semiconductor layer (1, 2) just under the bottom of the trench (19); - a first electrode layer (8) formed on the first and second semiconductor regions (3, 6); and - a second electrode layer (9) formed on the second major surface of the semiconductor layer (1, 2).
Claim 3
Dependent Claim
21 words
The semiconductor device in accordance with claim 1, wherein the trench (19) is filled up by the gate electrode layer (5).
Claim 4
Dependent Claim
41 words
The semiconductor device in accordance with claim 1 or 2, wherein the trench includes a U-shaped trench (19), the bottom of which is located under an interface of the semiconductor layer (1, 2) and the first semiconductor region (3) (Fig. 4).
Claim 5
Dependent Claim
42 words
The semiconductor device in accordance with claim 1 or 2, wherein the trench includes a V-shaped trench (19), the bottom edge of which is located under an interface of the semiconductor layer (1, 2) and the first semiconductor region (3) (Fig. 11).
Claim 6
Dependent Claim
235 words
A semiconductor device comprising: - a first conductivity type first semiconductor layer (2) having first and second major surfaces; - a second conductivity type first semiconductor region (3) formed on the first major surface of the first semiconductor layer (2), the first semiconductor region (3) having a trench (19) which reaches the first semiconductor layer (2) through the first semiconductor region (3); - a first conductivity type second semiconductor layer (1) which is larger in impurity concentration than the first semiconductor layer (2) and formed on the second major surface of the first semiconductor layer (2); - an insulation film (4) formed on a surface of the trench (19); - a gate electrode layer (5) formed on the insulation film (4); - a first conductivity type second semiconductor region (6) formed in a portion of the surface of the first semiconductor region (3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (3), which extends between the second semiconductor region (6) and the semiconductor layer (2) adjacent to the trench (19), being defined as a channel region; - a second conductivity type floating region (10) formed in the first semiconductor layer (2) just under the bottom of the trench (19); - a first electrode layer (8) formed on the first and second semiconductor regions (3, 6); and - a second electrode layer (9) formed on the second semiconductor layer (1).
Claim 7
Dependent Claim
235 words
A semiconductor device comprising: - a first conductivity type first semiconductor layer (2) having first and second major surfaces; - a second conductivity type first semiconductor region (3) formed on the first major surface of the first semiconductor layer (2), the first semiconductor region (3) having a trench (19) which reaches the first semiconductor layer (2) through the first semiconductor region (3); - a first conductivity type second semiconductor layer (1) which is larger in impurity concentration than the first semiconductor layer (2) and formed on the second major surface of the first semiconductor layer (2); - an insulation film (4) formed on a surface of the trench (19); - a gate electrode layer (5) formed on the insulation film (4); - a first conductivity type second semiconductor region (6) formed in a portion of the surface of the first semiconductor region (3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (3), which extends between the second semiconductor region (6) and the semiconductor layer (2) adjacent to the trench (19), being defined as a channel region; - a second conductivity type floating region (10) formed in the first semiconductor layer (2) just under the bottom of the trench (19); - a first electrode layer (8) formed on the first and second semiconductor regions (3, 6); and - a second electrode layer (9) formed on the second semiconductor layer (1).
Claim 8
Dependent Claim
223 words
A semiconductor device comprising: - a first conductivity type first semiconductor layer (2) having first and second major surfaces; - a second conductivity type first semiconductor region (3) formed on the first major surface of the first semiconductor layer (2), the first semiconductor region (3) having a trench (19) which reaches the first semiconductor layer (2) through the first semiconductor region (3); - a second conductivity type second semiconductor layer (1) formed on the second major surface of the first semiconductor layer (2); - an insulation film (4) formed on a surface of the trench (19); - a gate electrode layer (5) formed on the insulation film (4); - a first conductivity type second semiconductor region (6) formed in a portion of the surface of the first semiconductor region (3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (3) which extends between the second semiconductor region (6) and the first semiconductor layer (2) adjacent to the trench (19), being defined as a channel region; - a second conductivity type floating region (10) formed in the first semiconductor layer (2) just under the bottom of the trench (19); - a first electrode layer (8) formed on the first and second semiconductor regions (3, 6); and - a second electrode layer (9) formed on the second semiconductor layer (1).
Claim 9
Dependent Claim
223 words
A semiconductor device comprising: - a first conductivity type first semiconductor layer (2) having first and second major surfaces; - a second conductivity type first semiconductor region (3) formed on the first major surface of the first semiconductor layer (2), the first semiconductor region (3) having a trench (19) which reaches the first semiconductor layer (2) through the first semiconductor region (3); - a second conductivity type second semiconductor layer (1) formed on the second major surface of the first semiconductor layer (2); - an insulation film (4) formed on a surface of the trench (19); - a gate electrode layer (5) formed on the insulation film (4); - a first conductivity type second semiconductor region (6) formed in a portion of the surface of the first semiconductor region (3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (3) which extends between the second semiconductor region (6) and the first semiconductor layer (2) adjacent to the trench (19), being defined as a channel region; - a second conductivity type floating region (10) formed in the first semiconductor layer (2) just under the bottom of the trench (19); - a first electrode layer (8) formed on the first and second semiconductor regions (3, 6); and - a second electrode layer (9) formed on the second semiconductor layer (1).
Claim 10
Independent Claim
219 words
A method for manufacturing a semiconductor device, comprising the following steps: - preparing a first conductivity type semiconductor layer (1, 2); - forming a second conductivity type floating region (10) in a surface of the semiconductor layer (1, 2); - forming a second conductivity type first semiconductor region (14, 3) on the surface of the semiconductor layer (1, 2); forming a trench (19) in the first semiconductor region (14, 3), the trench (19) reaching the floating region (10), so that the surface of the floating region (10) lies below the surface of the semiconductor layer (2); - forming an insulation film (4) on the surface of the trench (19); - forming a first conductivity type second semiconductor region (6) in a portion of the surface of the first semiconductor region (14, 3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (14, 3), which extends between the second semiconductor region (6) and the semiconductor layer (14, 3) adjacent to the trench (19), being defined as a channel region; - forming a gate electrode layer (5) on the insulation film (4); - forming a first electrode layer (8) on the first and second semiconductor regions (3, 6); and - forming a second electrode layer (9) on a back surface of the semiconductor layer (1, 2).
Claim 11
Independent Claim
219 words
A method for manufacturing a semiconductor device, comprising the following steps: - preparing a first conductivity type semiconductor layer (1, 2); - forming a second conductivity type floating region (10) in a surface of the semiconductor layer (1, 2); - forming a second conductivity type first semiconductor region (14, 3) on the surface of the semiconductor layer (1, 2); forming a trench (19) in the first semiconductor region (14, 3), the trench (19) reaching the floating region (10), so that the surface of the floating region (10) lies below the surface of the semiconductor layer (2); - forming an insulation film (4) on the surface of the trench (19); - forming a first conductivity type second semiconductor region (6) in a portion of the surface of the first semiconductor region (14, 3) adjacent to the trench (19); - a portion (7) of the first semiconductor region (14, 3), which extends between the second semiconductor region (6) and the semiconductor layer (14, 3) adjacent to the trench (19), being defined as a channel region; - forming a gate electrode layer (5) on the insulation film (4); - forming a first electrode layer (8) on the first and second semiconductor regions (3, 6); and - forming a second electrode layer (9) on a back surface of the semiconductor layer (1, 2).
Claim 12
Dependent Claim
33 words
The method for manufacturing a semiconductor device in accordance with claim 7, wherein the step of forming a first semiconductor region (14, 3) includes the step of epitaxially growing the first semiconductor region.
References Cited (Backward Citations)
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