Silicon carbide substrate, semiconductor device, and methods for manufacturing them
US-9105756-B2 · Aug 11, 2015 · US
Silicon carbide substrate, method for manufacturing silicon carbide substrate, and method for manufacturing silicon carbide semiconductor device
US11094835B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-11094835-B2 |
| Application number | US-201816483754-A |
| Country | US |
| Kind code | B2 |
| Filing date | Feb 20, 2018 |
| Priority date | Mar 28, 2017 |
| Publication date | Aug 17, 2021 |
| Grant date | Aug 17, 2021 |
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- Title
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Abstract
Official abstract text for this publication.
It is an object of the present invention to provide a silicon carbide substrate having a low defect density that does not contaminate a process device and a silicon carbide semiconductor device including the silicon carbide substrate. A silicon carbide substrate according to the present invention is a silicon carbide substrate including: a substrate inner portion; and a substrate outer portion surrounding the substrate inner portion, wherein non-dopant metal impurity concentration of the substrate inner portion is 1×1016 cm−3 or more, and a region of the substrate outer portion at least on a surface side thereof is a substrate surface region in which the non-dopant metal impurity concentration is less than 1×1016 cm−3.
First claim
Opening claim text (preview).
The invention claimed is: 1. A silicon carbide substrate comprising: a substrate inner portion; and a substrate outer portion surrounding the substrate inner portion, wherein a non-dopant metal impurity concentration of the substrate inner portion is 1×10 16 cm −3 or more, a region of the substrate outer portion at least on a surface side thereof is a substrate surface region in which the non-dopant metal impurity concentration is less than 1×10 16 cm −3 , and the substrate outer portion surrounds the substrate inner portion on upper and lower faces or on side faces. 2. The silicon carbide substrate according to claim 1 , wherein average threading screw dislocation density in the substrate surface region is 100 cm −2 or less. 3. The silicon carbide substrate according to claim 1 , wherein the non-dopant metal impurity concentration has distribution in a thickness direction of the substrate inner portion or a direction perpendicular to the thickness direction. 4. The silicon carbide substrate according to claim 1 , wherein the non-dopant metal impurity concentration has distribution in a thickness direction of the substrate surface region or a direction perpendicular to the thickness direction. 5. The silicon carbide substrate according to claim 1 , wherein an impurity concentration of the substrate inner portion is set so that the substrate inner portion has a volume resistivity of 25 m Ωcm or less. 6. The silicon carbide substrate according to claim 1 , wherein an impurity concentration of the substrate outer portion is set so that the substrate outer portion has a volume resistivity of 25 m Ωcm or less. 7. The silicon carbide substrate according to claim 1 , wherein local threading screw dislocation density has distribution in the substrate surface region. 8. The silicon carbide substrate according to claim 1 , wherein the substrate outer portion surrounds the substrate inner portion on the upper and lower faces. 9. The silicon carbide substrate according to claim 8 , wherein the substrate outer portion also surrounds the substrate inner portion on the side faces. 10. The silicon carbide substrate according to claim 1 , wherein the substrate outer portion surrounds the substrate inner portion on the side faces.
Assignees
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Classifications
Transition metal elements; Rare earth elements · CPC title
N-type · CPC title
Silicon carbide · CPC title
Silicon carbide · CPC title
Silicon carbide · CPC title
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Frequently asked questions
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- What does patent US11094835B2 cover?
- It is an object of the present invention to provide a silicon carbide substrate having a low defect density that does not contaminate a process device and a silicon carbide semiconductor device including the silicon carbide substrate. A silicon carbide substrate according to the present invention is a silicon carbide substrate including: a substrate inner portion; and a substrate outer portion …
- Who is the assignee on this patent?
- Mitsubishi Electric Corp, Univ Nagoya Nat Univ Corp
- What technology area does this patent fall under?
- Primary CPC classification H10D8/411. Mapped technology areas include Electricity.
- When was this patent published?
- Publication date Tue Aug 17 2021 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 1 related publication on this page (citations in our corpus or others sharing the same primary CPC).