Properties of borophosphosilicate glass films deposited by different chemical vapor deposition techniques

Abstract

Borophosphosilicate glass films prepared by chemical vapor deposition techniques based on atmospheric pressure, low pressure with liquid and gaseous sources, and low pressure plasma enhanced processes in the temperature range of 390–680 °C have been studied. Films with low B (1.5 wt %) and high P (9.0 wt %) content were used for this study. To evaluate the effect of different thermal treatments, the films were annealed in a horizontal furnace at 920 °C for 30 min in three different ambients, i.e., N2, N2/O2, and H2/O2 and with rapid thermal annealing at 1050 °C for 10 s in a N2 ambient. The main properties of the as-deposited and annealed samples such as elemental content, thickness uniformity, shrinkage, density, refractive index, wet etch rate, stress, step coverage, and reflow are reported. Infrared absorption measurements were performed to study the water and Si–OH group presence in the films and P=O, B–O, Si–O bond behavior and interactions. The best physical and chemical film properties were obtained using liquid sources in a low pressure system. These films were tested as the interlevel dielectric in 1 Mbit erasable programmable read-only memory devices and good electrical performances were obtained, comparable with atmospheric pressure deposited films.