Chip Manufacturing Process
Section 2 2 Manufacturing CMOS Integrated Circuits 35 shown in Figure 2 1 features ann-well CMOS process where the NMOS transistors are implemented in thep-doped substrate and the PMOS devices are located in the n-well Increasingly modern processes are using adual-well approach that uses bothn- and p- wells grown on top on a epitaxial layer as shown in Figure 2 2