Fuji Electric Co., Ltd Patent Portfolio Statistics

Publication number: US20220028735A1
Application number: 17/496,360

Abstract:
In a contact hole of an interlayer insulating film, a tungsten film forming a contact plug is embedded via a barrier metal. The interlayer insulating film is formed by sequentially stacked HTO and BPSG films. The BPSG film has an etching rate faster than that of the HTO film with respect to a hydrofluoric acid solution used in wet etching of preprocessing before formation of the barrier metal. After the contact hole is formed in the interlayer insulating film, a width of an upper portion of the contact hole at the BPSG film is increased in a step-like shape, to be wider than a width of a lower portion at the HTO film by the wet etching before the formation of the barrier metal, whereby an aspect ratio of the contact hole is reduced. Thus, size reductions and enhancement of the reliability may be realized.

Publication date: 2022-01-27
Applicant: Fuji Electric Co., Ltd.
Inventors: Suzawa Takaaki

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Publication number: US20220013368A1
Application number: 17/486,977

Abstract:
Provided is a semiconductor device, including a semiconductor substrate having an upper surface and a lower surface and including a bulk donor, wherein a hydrogen chemical concentration distribution of the semiconductor substrate in a depth direction is flat, monotonically increasing, or monotonically decreasing from the lower surface to the upper surface except for a portion where a local hydrogen concentration peak is provided; and a donor concentration of the semiconductor substrate is higher than a bulk donor concentration over an entire region from the upper surface to the lower surface. Hydrogen ions may be irradiated from the upper surface or the lower surface of the semiconductor substrate so as to penetrate the semiconductor substrate in the depth direction.

Publication date: 2022-01-13
Applicant: Fuji Electric Co., Ltd.
Inventors: Hiroshi Takishita

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Publication number: US20220013635A1
Application number: 17/486,984

Abstract:
Provided is a semiconductor device including: a semiconductor substrate including a bulk donor; and a first buffer region of a first conductivity type, the first buffer region being provided on a lower surface side of the semiconductor substrate and having one or more doping concentration peaks and one or more hydrogen concentration peaks in a depth direction of the semiconductor substrate, in which a doping concentration at a shallowest concentration peak, out of the doping concentration peaks of the first buffer region, closest to the lower surface of the semiconductor substrate is 50 times as high as a concentration of the bulk donor of the semiconductor substrate or lower. The doping concentration at the shallowest concentration peak may be lower than a reference carrier concentration obtained when current that is 1/10 of rated current flows between an upper surface and the lower surface of the semiconductor substrate.

Publication date: 2022-01-13
Applicant: Fuji Electric Co., Ltd.
Inventors: Tamura Takahiro

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