TOKYO The University of Hiroshima has teamed with Japan's Semiconductor Technology Academic Research Center (Starc) to unveil a transistor design methodology for both CMOS and analog-based circuits that they hope will replace the troubled BSIM4 method.
The MOS transistor model, called MiSIM, uses an open-source HiSIM code that drastically simplifies circuit simulation, cutting design times for 100-nm and below to a single afternoon, said Michiko Mirua-Mattausch, professor of quantum and functional electronics at Hiroshima University.
"For an 80-nm gate circuit design, we were able to reduce the parameters down to 71, compared with 400 for BSIM4 and cut the design time down to half a day, as opposed to four days for present methods, with more accurate results," she said.
The MiSIM/HiSIM tool, developed with HSpice/CMI, has been thoroughly tested on 0.13-micron design rules and proven consistently more accurate and faster on designs at 0.11 micron and deeper, she said.
MiSIM uses a numerical calculation method that describes all transistor current and capacitance characteristics using only the potential distribution within the transistor. Despite being simplified compared with BSIM4, for example, the new model consistently turns out more calculations of current and capacitance across all operating current ranges, said Mirua-Mattausch.
The release caps a three-year development program sponsored by Starc, one of several Japanese government-backed groups trying to keep Japan in step with the United States, Europe, South Korea and Taiwan in rolling out 100-nm and 70-nm node platform technologies.
Engineers need an update of the problematic BSIM4 methodology, which is starting to cause designers nightmares as process geometries and design complexities deepen, said Shigetaka Kumashiro, expert engineer at NEC Electron Devices' ULSI device development division.
Kumashiro said NEC, which was involved in writing the source code, has agreed to keep the code open to promote it as a new de facto standard. Nine organizations, including LSI Logic, Infineon and Japan's National Space Development Agency, have tried out MiSIM, all with satisfactory results, he said. The code will be available on the Web next month.
"This is still in evaluation stage, and we haven't yet officially adopted it," Mirua-Mattausch told EE Times. "If it becomes a de facto standard, we will use it. We are very happy with it . . . its scalability and traceability through the process changes are simply excellent."
One route Kumashiro hopes to open is through adoption by Chenming Hu's group at the University of California at Berkeley, which is busily updating BSIM4. The group released its latest version, BSIM4.2.1, on Oct. 5.