Analog statistical simulation for bipolar integrated circuits

Abstract

Analog circuit design automation continues to gain attention in methods to improve, automate, and reduce design cycle time. These techniques address the needs of improving design for functionality, however the importance of design for manufacturability continues to be neglected. The emphasis of design for manufacturability is shown when the quality of a part is measured. Parts designed with no consideration for process/design variations result in poor yield. To address the need in analog design for manufacturability, new techniques that involve the areas of physical process, geometric modeling of electrical parameters, and statistical simulation techniques using independent process parameters, yield and Cpk analysis are defined and implemented. Results from these techniques provide the analog designer with the ability to simulate and predict circuit quality with process and design variations. To support the defined techniques, a design tool called MSTAT (Motorola Statistical Analysis Tool) is developed. Results of these techniques accompanied with MSTAT output is presented.