Direct photopatternable organic-inorganic hybrid materials as a low dielectric constant passivation layer for thin film transistor liquid crystal displays

Direct photopatternable and highly cross-linked organosiloxane-based organic-inorganic hybrid materials (Lt-passimer) were synthesized using a sol-gel reaction of phenyl-trimethoxysilane and tetraethyl orthosilicate as a low dielectric constant passivation layer for thin film transistor (TFT) liquid crystal displays (LCDs). Addition of hexa(methoxymethyl)-melamine into the synthesized hybrid material resin minimizes the polar silanol group in Lt-passimer film by enhancing the cross-linking reaction and improves the thermal stability. The highly cross-linked siloxane network and low concentration of silanol groups cause the Lt-passimer film to have low dielectric constant (k ∼ 2.8) and excellent electrical insulation. Compared with the conventional photosensitive acryl film (k ∼ 3.2), our Lt-passimer films are optically transparent and have a relatively low outgassing and water vapor permeability, which proves the feasibility of Lt-passimer as a low dielectric constant passivation layer in high aperture ratio TFT-LCDs.