MANHASSET, N.Y. Swiss-based semiconductor supplier STMicroelectronics has unveiled the first details of a technology the company said significantly increases junction capacitance density in thin-film passive integration.
The technology extends the capabilities of ST’s IPADtechnology by allowing capacitors with densities of more than 30 nanofarads per square meter to be integrated, which the company claims represents a 50-fold improvement over existing competitive technologies that employ materials such as oxides or nitrides of silicon or tantalum.
The new technology is based on a class of materials called PZT Perovskites. These are compounds containing lead, zirconium, titanium and oxygen, with many different variations possible according to the ratio of zirconium and titanium. These materials offer advantages because of their very high dielectric constant, which, at approximately 900 depending on the particular material, is over two hundred times greater than that of silicon dioxide.
Equally importantly, the materials can be integrated cost-effectively into the IPAD manufacturing flow, according to STMicro.
ST’s IPAD technology allows large numbers of passive components to be integrated along with active devices such as ESD protection diodes into a single structure that performs a specified filtering or protection function. This includes the higher value capacitors that are typically required for decoupling and low-frequency filtering purposes.
According to STMicroelectronics, the PZT technology allows even greater integration and better frequency behavior as a result of reduced parasitic effects achieved by removing the SMD packages used today and designing shorter pc board interconnections.
ST has used this technology for a number of customer-specific devices and will shortly introduce standard devices for the open market.