Method and apparatus for characterizing shared contacts in high-density SRAM cell design

摘要

Test structures are provided for accurately quantifying shared contact resistance. The test structures are built based upon an actual memory cell, which is self-aligning to allow shared contact chains through an array of test cells. A main array of test cells is built to provide a chain of shared contact resistance. Using the main array of test cells, a resistance in the shared contact chain may be measured. Supplemental arrays of test cells is built to provide a chain of poly side resistance, a chain of island side resistance, a chain of island connection line resistance, and a chain of poly connection resistance. A tester measures resistance using the test structures and uses the values to accurately determine shared contact resistance.