USE OF BORON CARBIDE AS AN ETCH-STOP AND BARRIER LAYER FOR COPPER DUAL DAMASCENE METALLIZATION

摘要

USE OF BORON CARBIDE AS AN ETCH-STOP AND BARRIER LAYER FOR COPPER DUAL DAMASCENE METALLIZATION ABSTRACT A method of forming a boron carbide layer for use as abarrier and an etch-stop layer in a copper dual damascenestructure, and the structure itself are disclosed. Inaddition to providing a good barrier to copper diffusion,good insulating properties, high etch selectivity withrespect to dielectric insulators, boron carbide alsoprovides good electrical characteristics because of its lowdielectric constant of less than 5. The amorphous boroncarbide is formed in a PECVD chamber by introducing a boronsource gas such as B[err]H[err], B[err]H[err], and carbon source gas such asCH[er] and C[err]H[err] at a deposition temperature of about 400 [err]C.Any one, or any combination of the passivation, etch-stop,cap layers of the damascene structure can comprise boroncarbide.(Figure 2F)