In the Dual-well Process or Twin-tub Process, during Step 9, ion implantation is performed to dope the source and drain regions of the PMOS and NMOS transistors. Which of the following is formed as a result of ion implantation during Step 9 of the Dual-well Process or Twin-tub Process?

Correct option is B

​$$\text{In the Dual-well (Twin-tub) CMOS fabrication process, Step 9 involves ion implantation for forming:} \\[6pt]\bullet \ n^+ \text{ source/drain regions for NMOS} \\[2pt]\bullet \ p^+ \text{ source/drain regions for PMOS} \\[6pt]\text{During this step, the polysilicon gates are also doped:} \\[4pt]\bullet \ \text{NMOS gate becomes } n^+ \text{ polysilicon} \\[2pt]\bullet \ \text{PMOS gate becomes } p^+ \text{ polysilicon} \\[6pt]\text{This happens because ion implantation penetrates the exposed polysilicon regions, doping them appropriately.}$$​​