The organic low-k materials microstructure study

The advancement in VLSI processes has reached such a stage that the RC delay caused by interconnects has played a major role in deciding the performance of the circuit. The low-k dielectric materials are the main research areas for next generation IC processes (N.H. Hendricks, Proc. DUMIC, pp. 17-26, 2000). The organic low-k materials are potential materials for ultra-low-k dielectrics. Due to the difficulty in TEM sample preparation, there is very little published data on microstructure study of organic low-k materials. In this paper, a few low-k organic materials are studied by TEM, EELS, FTIR and SIMS. The results show that the organic material can reach ultra low k value with good controlled nano-porous microstructure even though there is no significant change in the chemical bonding. The nano-porous structure causes the micro-roughness at the interface of dielectric layer with barrier layers.