A new entrant in the emerging timing-chip market plans to create the world's first hybrid timing chips that include both quartz crystals and MEMS components.
Silicon Clocks Inc. is sampling its first timing chip, which is slated for mass production in 2007. The quartz crystal-based device will offer frequencies as high as 650 MHz, whereas existing quartz crystals peter out around 150 MHz. The chip has a unique architecture for which several patents have been filed, said company founder Andrew McCraith. In the future, the architecture will be extended to MEMS-based oscillators, he said, the first models of which will integrate multiple resonators on the same chip.
Most MEMS timing-chip companies use polysilicon for MEMS resonators, but Silicon Clocks uses silicon germanium. Because polysilicon is processed at higher temperatures than SiGe, it's harder to add polysilicon MEMS resonators to a CMOS chip, McCraith said. SiGe deposition is done at temperatures low enough so that MEMS resonators can be added to a finished CMOS chip without damaging it, he said.
Today, applications that need clock speeds higher than 150 MHz use SAW oscillator chips, but Silicon Clocks claims its high-speed quartz crystal-based oscillator will be much cheaper than SAW. Its target applications include fiber channels, 100-Gbit Ethernet networks, high-speed telecommunications and storage, with customers to include Cisco, Sun Microsystems and Hewlett-Packard.
The company is promising that its first MEMS-based timing chips will deliver multiple oscillators on the same CMOS chip. They will target applications that already have multiple clocks but that today must use separate quartz crystals for each. Such apps include cell phones, digital cameras, digital TVs and MP3 players.