THIN FILM CAPACITORS ON SILICON GERMANIUM SUBSTRATE AND PROCESS FOR MAKING THE SAME

An integrated circuit capacitor (10, 25, 30, 402) containing a thin film of dielectric metaloxide (20, 420) is formed above a silicon germanium substrate (12, 406). A silicon nitride diffusion barrier layer (24, 324, 414) is deposited on a silicon germanium substrate to prevent evaporation of the substrate in subsequent heating steps. A silicon dioxide stress reduction layer (26) is deposited on the diffusion barrier layer. A bottom electrode (16, 418) is formed on the stress reduction layer, then a liquid precursor is spun on the bottom electrode, dried at about 400 °C, and annealed at between 600 °C and 850 °C to form a BST capacitor dielectric (20, 420). A top electrode (22, 422) is deposited on the dielectric and annealed. The integrated circuit may also include a BiCMOS device, a HBT device or a MOSFET.