Next CMOS generation offers copper,
low-k dielectric in six-metal process

SGS-Thomson Microelectronics (Lincoln, MA) has evidently got control of process development at its large wafer fab in Crolles, France. After a rough startup year when yields reportedly stayed low far longer than anticipated, catch-up has been correspondingly rapid, with the 0.25-µm HCMOS-7 brought to release in one year.

HCMOS-7 is available now for customer designs. The process uses deep-UV lithography to produce contacts and vias that can stack throughout six metal layers. The process supports dense SRAM cells and embedded DRAM, both required for many system-on-chip applications in both telecommunications and multimedia.

A complete range of tools and dedicated design support will be in place by midyear. These will include elementary cells, I/Os, and memory generators, as well as 16- and 32-bit microprocessor cores, DSP cores, and specialized peripherals–all the elements needed for system-on-chip projects. Normally, the ICs produced will use 2.5-V power, but low-power variants that can operate down to 1 V will be available in a few months.

A derivative process, HCMOS-8F, will use
copper lines instead of aluminum. These will be
patterned by the dual-damascene technique.

The company is also characterizing its 0.18-µm HCMOS-8 process, which, according to the company, has already met target specifications. The process uses a dielectric with a lower constant than silicon dioxide (k = 3) between the six-layer metal interconnect structure. This will reduce RC delays for improved performance, and will reduce crosstalk as well.

A derivative process, HCMOS-8F, will use copper lines instead of aluminum. These will be patterned by the dual-damascene technique (see Electronic Products , February, p. 23). Prototyping in HCMOS-8F will begin at the end of the year for products that require the lower resistivity of copper.

As the low-k dielectric becomes a normal part of fabrication, it will be incorporated in HCMOS-7 to create HCMOS-7X. This will also be released in the second half of the year. For more information, call SGS-Thomson Microelectronics at 781-259-0300 or visit http://www.st.com.