Nippon Steel Corporation

Yukihiro Okeda

Yasuo Sato

Yugo Tomioka

A part of a polycrystalline silicon film forming a grounding line in a memory cell of a high-resistance load type SRAM, located immediately below a contact hole for connection between a polysilicon power supply line part and an aluminum power supply line part, is separated and isolated from the remaining part of the polycrystalline silicon film to form an island-like part. The contact hole extends through an interlayer insulating film below the aluminum power supply line part, the polysilicon power supply line part and another interlayer insulating film above the island part, and reaches the island part, whereby the aluminum power supply line part contacts even the island part through the contact hole. The island part also contacts the polysilicon power supply line part through another contact hole, whereby low-resistance contact can be obtained between the aluminum and polysilicon power supply line parts through the island part. Since the contact hole can be provided at a position above a grounding line, the area of the cell can be reduced. In this case, even when the contact hole reaches the polycrystalline silicon film of the grounding line due to difficulties in its etching control, undesirable short-circuiting can be avoided between the grounding and power supply lines.

Growing community of inventors

Sagamihara, Japan

Yukihiro Okeda