Semiconductor device and method of manufacturing semiconductor device
AssigneeFuji Electric Co., Ltd.
InventorsTomonori Mizushima, Yusuke Kobayashi
Life of this patent
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Abstract
A donor layer that is formed by performing a heat treatment for a crystal defect formed by proton radiation is provided in an n-type drift layer of an n− semiconductor substrate. The donor layer has an impurity concentration distribution including a portion with the maximum impurity concentration and a portion with a concentration gradient in which the impurity concentration is reduce to the same impurity concentration as that of the n-type drift layer in a direction from the portion with the maximum impurity concentration to both surfaces of the n-type drift layer. The crystal defect formed in the n-type drift layer is a composite crystal defect mainly caused by a vacancy, oxygen, and hydrogen.
Claims13
A semiconductor device comprising:
- a first-conduction-type drift layer which is a semiconductor substrate including a first-conduction-type impurity and a first complex defect caused by a vacancy, an oxygen atom, and a hydrogen atom;
- a plurality of donor layers provided at different depths in a depth direction of the first-conduction-type drift layer, each of the donor layers includes donors caused by the first complex defect;
- and
- a second-conduction-type semiconductor region provided on one main surface of the first-conduction-type drift layer,
- wherein each of the donor layers has an impurity concentration distribution that includes a first portion with a maximum impurity concentration and a second portion with a concentration gradient in which the impurity concentration is reduced from the first portion to both main surfaces of the first-conduction-type drift layer,
- the first-conduction-type drift layer further includes a second complex defect caused by a divacancy, the vacancy, and the first-conduction-type impurity, and a third complex defect caused by the vacancy and the oxygen atom, and
- a signal intensity of the first complex defect measured by a deep level transient spectroscopy method is higher than a signal intensity of the second complex defect measured by the deep level transient spectroscopy method.
Dependencies are inferred from the claim text.