International Business Machines Corporation

Stmicroelectronics Gmbh

Shenzhi Yang

Gregory M Johnson

Christopher B D'Aleo

Balasingham Bahierathan

Oliver Desmond Patterson

Thomas A Wallner

Jin Zheng Wallner

Muthukumarasamy Karthikeyan

Muthukumaraamy Karthikeyan

Via chain and serpentine/comb test structures are in kerf areas of a wafer. The via chain test structures comprise a first via chain and a second via chain in a first kerf area. The via chain test structures are formed such that geometrically shaped portions of the first via chain and geometrically shaped portions of the second via chain alternate along the length of the first kerf area.

Via chains for defect localization

A static random access memory (SRAM) test structure includes a p-type source/drain implant region comprising contacts (CAs), wherein the CAs in the p-type source/drain implant region comprise a first plurality of bit line, ground, and node CAs, and wherein the CAs in the p-type source/drain implant region are grounded during an inspection of the SRAM test structure; and an ungrounded region, the ungrounded region being distinct from the p-type source/drain implant region and being ungrounded during the inspection of the SRAM test structure, the ungrounded region comprising contacts (CAs) and rectangular contacts (CArecs) comprising a second plurality of bit line, ground, and node CAs, and further comprising a first plurality of VCAs and rectangular contacts (CArecs), and wherein a CA or CArec in the ungrounded region is grounded during the inspection in the event of a short to a CA in the p-type source/drain implant region.

Static random access memory test structure

Method form via chain and serpentine/comb test structures in kerf areas of a wafer. The via chain test structures comprise a first via chain and a second via chain in a first kerf area. The via chain test structures are formed such that geometrically shaped portions of the first via chain and geometrically shaped portions of the second via chain alternate along the length of the first kerf area. The methods perform relatively low (first) magnification testing to identify a defective geometrically shaped portion that contains a defective via structure. The methods then perform relatively high (second) magnification testing only within the defective geometrically shaped portion. The first magnification testing is performed at a lower magnification relative to the second magnification testing.

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Yorktown Heights, NY, United States of America

Shenzhi Yang