Silicon Integration Initiative adopts compact model for FD-SoI

The Compact Model Coalition (CMC) has adopted a model from French lab Leti for fully-depleted silicon-on-insulator (FD-SoI) chip simulation.

Called L-UTSOI, it was “proven by the industry and its standardisation will ensure long-term access and maintenance in EDA tools for FD-SOI designers”, according to Leti.

Available to Coalition members now, it will be implemented in major versions of circuit-simulation software, and its source code will be released publicly in June 2021.

‘Compact models’ are used for chip simulation prior to manufacture. They express function though a set of equations for SPICE. “Such compact models are approved and supported by the standard-setting arm of Si2, the CMC, which is an international working group focused on standardising SPICE device models,” said Leti. Si2 is the Silicon Integration Initiative.

“As a member-driven organisation, the CMC strives to provide value for its members and the semiconductor supply chain,” said CMC chair Peter Lee. “With 15 models now available, CMC members have a distinct competitive advantage with early access to new features and bug fixes, and an 18-month lead on standard models released to the public. Adding L-UTSOI to the mix of models was a direct response to our customer request for model support as we continue to add value to their membership.”

Leti has been working on FD-SoI since 1992, in which transistors are made in an silicon thin-film over an insulating buried-silicon-oxide layer. This increases speed though reducing substrate capacitance, and biasing the substrate allows the spead and leakage of the transistors above to be traded. L-UTSOI is derived from the Leti-UTSOI compact model, which has been implemented in circuit-simulation software and used in industrial process design-kits for several years.

“This is of paramount importance for large chip makers who will use this model in the future,” said Leti simulation head Thierry Poiroux. “It also positions CEA-Leti among the few compact-model developer teams able to develop and support a standard model. With a standard model, they [users] are assured that a team of model developers is able to take care of the model improvements and bug fixes they need during the lifetime of their technology,”