Let's solve **Question 6** step by step as per your instructions: --- ### **Step 1: Introduction to the Concept** In CMOS technology, transistors are formed by creating regions with different types of doping in a silicon substrate. The **N+** and **P+** regions refer to areas with high concentrations of donor (N-type) or acceptor (P-type) impurities, respectively. The process of forming these regions is fundamental in semiconductor device fabrication. --- ### **Step 2: Correct Answer and Explanation** **Correct Answer: C. diffusion.** **Explanation:** The N+ and P+ regions in a CMOS transistor pair are created by introducing impurities (dopants) into specific areas of the silicon wafer. One of the main methods for this is **diffusion**, where dopant atoms are allowed to diffuse into the substrate at high temperatures, creating N+ (heavily doped N-type) and P+ (heavily doped P-type) regions. --- ### **Step 3: Why Other Options Are Incorrect** - **A. dielectric leakage:** This refers to unwanted current flow through a dielectric material, not a process for creating doped regions. - **B. sputtering:** Sputtering is a process used mainly for depositing thin films, not for doping silicon to create N+ and P+ regions. - **D. epitaxial growth:** Epitaxial growth is used to grow a layer of single-crystal silicon on top of a wafer, usually for improved performance, but it's not the process used to introduce N+ and P+ dopants. **Final Answer:** **C. diffusion** --- ### **Summary of Steps** - **Step 1:** Introduced the concept of forming N+ and P+ regions in CMOS transistors. - **Step 2:** Identified and explained the correct answer (**diffusion**). - **Step 3:** Explained why the other options do not apply for creating N+ and P+ regions. Would you like to continue this format for the next question?