era of NMOS-dominated LSI and the emergence of VLSI, the fundamental scaling laws of MOS technology were codified and broadly applied. It was also during this period that TCAD reached maturity in terms of realizing robust process modeling (primarily one-dimensional) which then became an integral technology design tool, used universally across the industry. At the same time device simulation, dominantly two-dimensional owing to the nature of MOS devices, became the work-horse of technologists in the design and scaling of devices. The transition from NMOS to CMOS technology resulted in the necessity of tightly coupled and fully 2D simulators for process and device simulations. This third generation of TCAD tools became critical to address the full complexity of twin-well CMOS technology (see Figure 3a), including issues of design rules and parasitic effects such as latchup. An abbreviated perspective of this period, through the mid-1980s, is given in; and from the point of view of how TCAD tools were used in the design process, see. See also Diode modelling Transistor models Compact Model Coalition Technology CAD References Electronic Design Automation For Integrated Circuits Handbook, by Lavagno, Martin, and Scheffer, A survey of the field of electronic design automation. This summary was derived (with permission) from Vol II, Chapter 25, Device Modeling—from physics to electrical parameter extraction, by Robert W. Dutton, Chang-Hoon Choi and Edwin C. Kan. R.W. Dutton and A.J. Strojwas, , IEEE Trans. CAD-ICAS, vol. 19, no. 12, pp. 1544–1560, December, 2000. Electronic device modeling Electronic design automation