Patent ID: 6531777
Filing Date: 2003-03-11
Classification: H01L

Abstract:
A structure for testing the integrity of a barrier layer underlying copper lines in a Cu metallization structure comprising:a semiconductor substrate (30); a lower dielectric layer {(28) and (34), FIG. 2 and FIG. 5, respectively; (28), FIG. 4} on said substrate, said lower dielectric layer having a top surface; a lower barrier layer {(38), FIG. 2; (50), FIG. 4} atop said lower dielectric layer; a lower copper feature {(36), FIG. 2 and FIG. 5; (52), FIG. 4} atop at least a portion of said lower barrier layer, said lower copper feature having a top surface; a lower cap layer {(44), FIG. 2 and FIG. 5; (54), FIG. 4}, said lower cap layer being contiguously on said top surface of said lower copper feature and being atop said top surface of said lower dielectric layer; an upper dielectric layer (48) atop said lower cap layer, said upper dielectric layer having an upper Damascene line region etched therein, said upper Damascene line region having a bottom surface and side surfaces, said upper dielectric layer having a top surface (45â€²); a first upper barrier layer portion (38â€²) being of low permeability to copper diffusion on said bottom and said side surfaces of said upper Damascene line region (36â€²) and filling a first portion of said upper Damascene line region, a remaining portion of said upper Damascene line region not being filled with said upper barrier layer; said remaining portion of said upper Damascene line region being filled with upper copper (43â€²), said upper copper having a top surface (46â€²); said upper copper being electrically isolated from said lower copper feature by said upper dielectric layer; a first upper cap layer (44â€²), said first upper cap layer being contiguously on said top surface of said upper copper and being atop said top surface of said upper dielectric layer; a second low permeability portion {(38â€²), FIG. 2 and FIG. 4; (56â€²), FIG. 5} having low permeability to copper diffusion therethrough, said second low permeability portion being contiguous to and on said top surface (45â€²) of said upper dielectric layer, said second low permeability portion also being contiguous to and below said first upper cap layer (44â€²); said second low permeability portion abutting said barrier layer on said side surface of said upper Damascene line region; a first electrical contact (51) to said top surface of said lower copper feature and a second electrical contact (49) to said top surface of said upper copper for enabling electrical characteristic measurement between said first and second electrical contacts indicative of integrity of said upper barrier layer.