To dispel the notion that integration is the advantage of silicon, TriQuint Semiconductor, Inc. has combined two GaAs processes to integrate previously incompatible functional blocks onto a single die. The result is TQBiHEMT, its latest foundry process for wireless/RF design engineers seeking higher integration to cut parts count, save board space and improve overall system costs.

TQBiHEMT is designed for highly integrated RF front-end radio modules typically found in wireless applications with high data rates and frequencies. These types of applications require a semiconductor process that allows front-end functional blocks to be optimized individually. As a result, according to TriQuint, TQBiHEMT enables the optimal integration of high power amplifiers in HBT on the same die as pHEMT low noise amplifiers and pHEMT switches, while remaining a cost-effective design solution.

TriQuint uses its high-volume InGaP HBT process, TQHBT3, for high power, high efficiency and linear power amplifiers used in mobile phones. And its InGaAs E/D pHEMT process, TQPED, is used to make high isolation switches and low-noise amplifiers (LNAs) for the handset and wireless data markets. The TQBiHEMT is an innovative combination of these two processes, noted TriQuint.

Mike Peters, director of marketing for TriQuint’s commercial foundry service noted, “TQBiHEMT provides wireless communications system designers the circuit component and 3-layer interconnect technology required to optimize performance goals for next-generation RFICs. Together, with our proven manufacturing capabilities, reputation for quality and reliability and excellent design tools, engineers can be confident the new TQBiHEMT process will help them successfully create highly integrated wireless front ends.”

In summary, the TQBiHEMT process incorporates three transistor types: a highly reliable InGaP HBT transistor, a depletion mode pHEMT transistor and an enhancement mode pHEMT transistor. These three active device types are complemented by high-Q passive circuit elements like precision-thin film, nichrome resistors, high value bulk epi resistors and high value/small area capacitors. Three interconnecting metal layers (two global, one local) and an optional backside grounding via technology complete the circuit component suite available to designers. The process is fabricated on 150-mm (6-inch) wafers. According to TriQuint, device samples and designs kits will be available in the first quarter of 2008.
www.triquint.com

Table: Process specifications