Sheet Resistance Measurement of Non-Standard Cleanroom Materials Using Suspended Greek Cross Test Structures

S. Enderling, C.L.S. Smith, M.H. Dicks, J.T.M. Stevenson, M. Mitkova, M.N. Kozicki, A.J. Walton
2006 IEEE transactions on semiconductor manufacturing  
This paper presents work on the development, fabrication and characterization of a suspended Greek cross measurement platform that can be used to determine the sheet resistance of materials that would contaminate Complementary Metal Oxide Semiconductor (CMOS) processing lines. The arms of the test structures are made of polysilicon/silicon nitride (Si 3 N 4 ) to provide a carrier for the film to be evaluated and thick aluminum (Al) probe pads for multiple probing. The film to be evaluated is
more » ... ply blanket deposited onto the structures and because of its design automatically forms a Greek cross structure with (Al) probe pads. To demonstrate its use, 1) gold (Au), 2) copper (Cu), and 3) silver (Ag) loaded chalcogenide glass Ag (Ge 30 Se 70 ) 1 have been blanket evaporated in various thicknesses onto the platform in the last processing step and autopatterned by the predefined shape of the Greek crosses. The suspension of the platform ensured electrical isolation between the test structure and the surrounding silicon (Si) substrate. The extracted effective resistivity for Au (5 1 10 8 m), Cu (1.8-2 5 10 8 m) and Ag (Ge 30 Se 70 ) 1 (2 27 10 5 m 1 88 m) agree with values found in articles in . These results demonstrate that the proposed Greek cross platform is fully capable to measure the sheet resistance of low (Au, Cu) and high Ag (Ge 30 Se 70 ) 1 resistive materials. Index Terms-Critical dimension metrology, Greek cross, nonstandard cleanroom materials, self patterning, sheet resistance, test structure, Van der Pauw.
doi:10.1109/tsm.2005.863248 fatcat:qxnk2ia7qrbo5m2zoqms6cpmem