Extraction of speculative SOI MOSFET models using self-heating-free targets

Speculative SPICE models (also referred to as evaluation-level or guess models), which are extracted based on projected device electrical characteristics (called `targets¿) rather than actual measurement data, are required to support concurrent IC designs. The self-heating effect in silicon-on-insulator (SOI) technologies presents additional challenges in obtaining quality speculative SOI MOSFET models. A novel `shift-and-ratio¿ technique is developed to generate self-heating free device targets from raw targets provided only at room temperature, and a corresponding speculative model extraction methodology is proposed. The shift-and-ratio technique is validated by using silicon data of 65 nm partially-depleted (PD) SOI technologies. The adequacy and self-consistency of the speculative model extraction methodology is demonstrated in field testing where a large number of 65 nm and 45 nm PD SOI speculative models are extracted. Availability of self-heating free targets proves to be critical not only for improved speculative model extraction efficiency, but also for model quality in general by ensuring physical and reasonable temperature dependences in the resulting speculative models.