Process combines SiGe with CMOS logic and more

A new semiconductor process combines ultra-high-speed SiGe technology with passive component integration, substrate isolation and dense CMOS logic capabilities.

A new semiconductor process combines ultra-high-speed SiGe technology with passive component integration, substrate isolation and dense CMOS logic capabilities.

QUBiC4'G' will enable Philips to supply the advanced ICs needed by the optical fibre networking industry to keep pace with today's explosive demand for broadband data communications and streaming media.

With ft and fmax figures for QUBiC4'G' transistors exceeding 75 and 100GHz, respectively, this new addition to the company's process technology portfolio provides the raw speed required for future applications such as network switches for 10 Gigabit Ethernet and Sonet optical fibre networks.

As a lead product and proof-of-process demonstrator, Philips has already succeeded in using QUBiC4'G' to produce the world's first single-chip 12.5Gbit/s optical crosspoint switch.

Enhanced performance parameters such as low noise figure and low current consumption also suit QUBiC4'G' to advanced RF and microwave applications.

"As the requirements of new markets continually evolve, so our technology portfolio adapts and grows in order to meet the specific needs of our customers", said Neil Morris, senior director of advanced technology, Philips' semiconductor division.

"This is one of the reasons why we have intentionally timed the release of our SiGe technology to coincide with the massive explosion in broadband communications.

Throughout the entire development of QUBiC4'G', we worked closely with our Optical Networking business line in order to speed up the introduction of their new products.

The result, today, is that we are the first company to market an advanced product like the new TZA2060 12.5Gbit/s optical crosspoint switch".

QUBiC4'G' provides designers of complex high-speed ICs with a unique mix of high- and low-breakdown voltage transistors that allow an optimum choice of ft, fmax and noise figure.

On the one hand it includes low-voltage (BVCE >2.7V) transistors with ft (75GHz) and fmax (100GHz) values that ensure the gain and phase margins needed to design highly linear amplifiers and transmission gates.

On the other hand it includes higher voltage (BVCE >3.8V) high-frequency transistors to implement circuits such as VCOs or to interface with external 3V logic.

Where ultra-low noise performance is required, such as in LNAs (low-noise amplifiers) for sensitive RF receivers, its SiGe transistors achieve noise figures as low as 0.68dB at 2GHz with collector currents of only 240mA.

This unique combination of noise performance and low power consumption, coupled with very high ft values, makes QUBiC4'G' ideal for battery powered wireless applications in the 5 to 10GHz range.

At the very high frequencies and ultra-fast datarates at which QUBiC4'G' chips can operate, the quality of integrated passive components is as important as the SiGe transistors.

For this reason, QUBiC4'G' retains all of the passive component integration features of Philips' standard QUBiC4 process, including high Q-factor inductors and 5nF/mm2 tantalum pentoxide capacitors.

To cope with the specific needs of gigabit per second data transfers, these passive component integration features have been enhanced with the addition of impedance-matched transmission lines in the top two thick metal layers.

To minimise crosstalk and interference, the same shallow- and deep-trench isolation techniques that were developed for QUBiC4 are also available in QUBiC4'G'.

Standard 0.25um CMOS provides the ability to integrate high-density logic.

To achieve the accurate circuit modelling required for right-first-time chip design, QUBiC4'G' transistors are supported by Mextram 504 models that accurately reflect the transistor performance at very high frequencies (even beyond the transistors' peak ft values), and also take account of effects such as avalanche, Early effect and high-current behaviour.

The extensive cell libraries that are available for Philips' standard 0.25um CMOS process can be ported into QUBiC4'G' to support logic design.

The QUBiC4'G' process is available for design now, with volume wafer processing scheduled to begin in the 3rd quarter of 2002.

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