Zeolite-Inspired Low-kDielectrics Overcoming Limitations of Zeolite Films

Abstract

Spin-on zeolite films deposited from Silicalite-1 nanocrystal suspensions prepared by hydrothermal treatment of clear solutions have the required properties for insulating media in microelectronics. However, on the scale of the feature sizes in on-chip interconnects of a few tens of nanometers, their homogeneity is still insufficient. We discovered a way to overcome this problem by combining the advantages of the clear solution approach of Silicalite-1 synthesis with a sol-gel approach. A combination of tetraethyl orthosilicate and methyltrimethoxysilane silica sources was hydrolyzed and cocondensed in the presence of an aqueous tetraalkylammonium hydroxide template. The resulting suspension of nanoparticles of a few nanometers in size together with residual oligomeric silica species were spun onto support. The final zeolite-inspired low-k films (ZLK) with respect to pore size and homogeneity satisfied all requirements and presented excellent hydrophobicity, stiffness, and dielectric constant. The size and content of initially formed nanoparticles and the spatial hindrance promoted by occluded tetraalkylammonium molecules were found to be crucial elements in the definition of the final pore network.

Non‐Porous Low‐k Dielectric Films Based on a New Structural Amorphous Fluoropolymer

“…[ 1c − 15 ] In principle there are two strategies to scale down the k value of a dielectric layer: one is to reduce the polarizability by using the least polarizable groups such as C-H, C-C, C-Si, C-O and C-F bonds in molecule design; [ 1c ] the other is to decrease the density of the fi lm through increasing the free volume [ 4 , 6 , 7 ] and/ or introducing well-controlled nanopores into the fi lm. [ 1a , [9][10][11][12][13][14][15] Although porous fi lms generally show much lower k values (which could be as low as 1.6 [ 15 ] ), precise controlling the size and distribution of the pores still remains a challenging task. [ 1a ] Moreover, uncontrolled generation and distribution of pores usually leads to moisture absorbance, resulting in deterioration of the dielectric properties.…”

Advances in Ultra Low Dielectric Constant Ordered Porous Materials

“…26 Eslava et al have used a similar approach and produce a composite film with 5 nm sized zeolite particles. 28 They also used a UV-cure means to harden the assynthesised films and this allowed the film to remain hydrophobic whilst pendant -CH 3 groups on the amorphous silica component allowed the dielectric constant to be reduced to around 2.2. However, leakage currents were not reported.…”

The Mechanical Property, Microstructure, and Pore Geometry of a Methyltrimethoxysilane Modified Silica Zeolite (MSZ) Film

“…Another dominant factor for the degradation of modulus is the presence of terminal groups. 14,18 In this paper, the MTMS/TEOS ratio of MSZ film is 4.0, which is much higher than 1.0 of ZLK film. Hence, it is predicable that the modulus of MSZ film will be degraded due to the presence of large amount terminal groups.…”