Preliminary study on dependency of basic properties of porous silica ILD thin film on CMP compatibility

Adhesion, cohesive strength, modulus, and hardness of the porous silica ILD film via organic/inorganic hybrid (ALCAP-S) with various kinds of film thickness were investigated and the preliminary attempt was made to correlate the above properties with abrasion compatibility as a function of film thickness. The Stud-pull strength is drastically affected by the visco-elastic behavior of the film and necessary for correction. The corrected adhesion and cohesive strength of ALCAP-S (k=2.2) are satisfactorily high. With decreasing the film thickness, the depth-dependency of modulus induced by the substrate becomes more significant and the corresponding film is liable to abrasion. On the contrary, with increasing thickness the dependency ceases and the film appears to be more elastic, leading to lower abrasion compatibility.