A novel positive-tone and aqueous-base-developable photosensitive benzocyclobutene-based material for microelectronics

Abstract

This paper describes a positive-tone and aqueous-basedevelopable benzocyclohutene (BCB)-based dielectric material. The polymer is made from divinylsiloxane bis(henzocyc1ohutene) and BCB-acrylic acid. A diazonapthoquinone in the formulation makes it photosensitive. Patterned films have high resolution, and via openings are scnm-free without a de-scum operation. The material possesses optical, electrical, thermal, and mechanical properties desirable for many microelectronic applications, including as a planarization layer or an insulation layer in display, and in packaging.

Aqueous-Base-Developable Benzocyclobutene-Based Dielectric Material - An Emerging Dielectric Material for Microelectronics

“…In previous publications (7,10), we demonstrated by XPS study that a descum process is not required for aqueous-base-developable BCB after patterning. Three layers of aqueous-base-developable BCB with copper pad has been built and it passed reliability tests.…”

“…At 275°C, the polymer lost about 1.3 wt % per h, providing sufficient thermal stability for most microelectronic applications. The same formulation cured in nitrogen at 250°C for 60 min lost about 1 wt % per h at 275°C, which was slightly better (10). Figure 9 illustrates the residual stress of aqueous-base-developable BCB film on 4 inch silicon wafers.…”

“…Dielectric constant, dissipation factor, breakdown voltage, and water uptake of the polymer cured at the two different conditions are very similar. Water was depleted in about 2 min when the relative humidity (RH) was changed from 85% RH to 5% RH (10). Table II shows the tensile properties of aqueous-base-developable BCB film cured in nitrogen and in air.…”