Patent ID: 9443790
Filing Date: 2016-09-13
CPC Classification: H01L

Claim Text:
1. A semiconductor device, comprising: a semiconductor substrate with a first main surface and an opposite, second main surface; and a hole penetrating the semiconductor substrate through the first and second main surfaces, the hole including a tapered portion contacting with the first main surface and a vertical portion contacting with the tapered portion and the second main surface, the tapered portion comprising at least first and second scallop openings in that order from the first main surface toward the vertical portion, each of the first and second scallop openings including a first end close to the first main surface and a second end close to the second main surface, the first and second scallop openings respectively including first and second convex side surface, the convex side surface being defined such that a diameter of the hole at the second end of each of the first and second scallop openings is smaller than a diameter of the hole at an intermediate point between the first and second ends of the respective first and second scallop openings, the second end of the first scallop opening contacting with the first end of the second scallop opening, and a first diameter of the hole at the second end of the first scallop opening being larger than a second diameter of the hole at the second end of the second scallop opening, the vertical portion comprising a plurality of scallop openings arranged in series, the plurality of scallop openings each including a convex side surface.