US 2026/0313992 A1Published application

Semiconductor device

AssigneeFuji Electric Co., Ltd.

InventorsYuki KARAMOTO, Kaname MITSUZUKA

Life of this patent

Estimating the term…

Loading patent…

Abstract

Provided is a semiconductor device including a semiconductor substrate having upper and lower surfaces and provided with a drift region of a first conductivity type, and a buffer region provided between the drift region and the lower surface and having a higher doping concentration than the drift region. The buffer region has at least four doping concentration peaks at different positions in a depth direction of the semiconductor substrate, which include two doping concentration peaks closest and second closest to the lower surface and are separated from each other by a first peak-to-peak distance, and two doping concentration peaks closest and second closest to the upper surface and are separated from each other by a second peak-to-peak distance. The buffer region includes a region that has a third peak-to-peak distance larger than the first and second peak-to-peak distances.

Claims15

Dependent claims

A semiconductor device comprising:

a semiconductor substrate having an upper surface and a lower surface and provided with a drift region of a first conductivity type;
and
a buffer region provided between the drift region and the lower surface and having a higher doping concentration than the drift region, wherein
the buffer region has at least four doping concentration peaks provided at different positions in a depth direction of the semiconductor substrate,
the at least four doping concentration peaks include:
two doping concentration peaks that are closest and second closest to the lower surface and are separated from each other by a first peak-to-peak distance;
and
two doping concentration peaks that are closest and second closest to the upper surface and are separated from each other by a second peak-to-peak distance, and
the buffer region includes a region that is provided between two adjacent doping concentration peaks among the at least four doping concentration peaks and has a third peak-to-peak distance that is larger than the first peak-to-peak distance and the second peak-to-peak distance.

6 more elements

A semiconductor device comprising:

a semiconductor substrate having an upper surface and a lower surface and provided with a drift region of a first conductivity type;
and
a buffer region provided between the drift region and the lower surface and having a higher doping concentration than the drift region, wherein
the buffer region has M doping concentration peaks provided at different positions in a depth direction of the semiconductor substrate, and
each of the doping concentration peaks has a local maximum at which the doping concentration exhibits a maximum value,
when the semiconductor device is turned off in a state where a voltage, which is 0.7 times a rated voltage of the semiconductor device, is applied as a power supply voltage and twice a rated current flows as a collector-emitter current, a position of a lower end of a space charge region at a time when a collector-emitter voltage matches the power supply voltage is arranged between the local maximum of an i-th doping concentration peak and the local maximum of an (i+1)-th doping concentration peak when counted from the lower surface, and
M is an integer of 2 or more and 100 or less, and i is an integer of 1 or more and M-1 or less.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 19/462,995Filed 28 Jan 2026
Priority: JP 2022-04124416 Mar 2022
Published: 8 Oct 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

H10D 62/393
Semiconductor regions connected to electrodes not carrying current to be rectified, amplified or switched, e.g. channel regions: body regions of…
H10D 12/481
Having non-planar surfaces, e.g. having trenches, recesses or pillars in the surfaces of the emitter, base or collector regions: having gate…
H10D
Inorganic electric semiconductor devices

Family

Application18/172,348Continuation · filed 22 Feb 2023
Application19/462,995Continuation
US 12,543,357 B2Related patent
US 2023/0299145 A1Published application
US 2026/0313992 A1This patent

From the US filing history. Foreign family members aren’t listed.