BCD Process for Consumer &nApplications

Staff -- Semiconductor International, 6/1/1999

The silicon-on-insulator (SOI) specialist wafer manufacturer SOITEC (Bernin, France) announced it completed collaborative work with Philips Semiconductors (Eindhoven, The Netherlands) to create the first thin film SOI Smart Power technology for consumer applications. This Bipolar-CMOS-DMOS (BCD) process on SOI is said to provide greater power handling, improved robustness and easier design. It was developed using SOITEC Smart Cut technology.

Philips Semiconductors said this new process technology enables typical power efficiencies of 95% to be obtained, which may be compared with a typical 50% value for Class AB amplifiers. The reduction of wasted power minimizes the need for heat sinks, reduces power supply size and increases the battery life in portable audio products.

SOITEC said the key to the reduced power loss is the low resistance of advanced BCD transistors when they are turned on. The isolation of all of the components formed on the chip by the oxide layer improves the audio quality by removing problems with parasitic capacitance and latch-up. The process technology also protects the devices from voltage spikes and fault conditions that can occur in automobile radio applications.

This SOI-based BCD process is a single poly, double metal technology aimed at 12 V to 60 V applications. It was used to form a new family of Class D single chip, digital audio power amplifiers with higher efficiencies than those from currently available designs. It uses a 1.5 µm active silicon layer on a 1 µm buried oxide (BOX), allowing for complete isolation of all the components formed on the chip with important advantages.