A Python-based layout-aware analog design methodology for nanometric technologies

International audienceThis paper presents a methodology for procedural layout-aware design for nanometric technologies. A Python-based layout generation tool generates different layout styles for the same basic analog building blocks. Moreover, layout dependent parasitic parameters such as stress effects are easily computed and compared for different layout styles. The procedural layout description is written using a Python API that ensures layout portability over different technologies. A main focus is on how the layout generation tool addresses both geometric and parasitic- aware electrical synthesis. This is made possible through an internal loop that links circularly both the sizing phase and the layout generation phase. The proposed design methodology assists the analog designer in exploring electrical and physical trade-offs. At the end, we present synthesis and characterization results that prove the effectiveness and speed of the proposed methodology

Analog layout design automation: ILP-based analog routers

The shrinking design window and high parasitic sensitivity in the advanced technology have imposed special challenges on the analog and radio frequency (RF) integrated circuit design. In this thesis, we propose a new methodology to address such a deficiency based on integer linear programming (ILP) but without compromising the capability of handling any special constraints for the analog routing problems. Distinct from the conventional methods, our algorithm utilizes adaptive resolutions for various routing regions. For a more congested region, a routing grid with higher resolution is employed, whereas a lower-resolution grid is adopted to a less crowded routing region. Moreover, we strengthen its speciality in handling interconnect width control so as to route the electrical nets based on analog constraints while considering proper interconnect width to address the acute interconnect parasitics, mismatch minimization, and electromigration effects simultaneously. In addition, to tackle the performance degradation due to layout dependent effects (LDEs) and take advantage of optical proximity correction (OPC) for resolution enhancement of subwavelength lithography, in this thesis we have also proposed an innovative LDE-aware analog layout migration scheme, which is equipped with our special routing methodology. The LDE constraints are first identified with aid of a special sensitivity analysis and then satisfied during the layout migration process. Afterwards the electrical nets are routed by an extended OPC-inclusive ILP-based analog router to improve the final layout image fidelity while the routability and analog constraints are respected in the meantime. The experimental results demonstrate the effectiveness and efficiency of our proposed methods in terms of both circuit performance and image quality compared to the previous works