Semiconductor fabrication

Source-This post on Semiconductor fabrication is based on the article “Cabinet approves 3 chip plants, including two by Tata, at estimated investment of Rs 1.26 lakh crore” published in “Business Today” on 29th February 2024.

Why in the News?

Recently, the Union Cabinet approved three semiconductor plant proposals. Two semiconductor plant will be set up in Gujarat and one will be set up in Assam.

About Semiconductor fabrication 

1. About: Semiconductor device fabrication is the intricate process used to create integrated circuits (ICs) which are the building blocks of modern electronic devices.

2. The fabrication process is the toughest part in manufacturing semiconductors, as it requires clean rooms to maintain sterile conditions and prevent contamination by air particles.

3. It’s a very lengthy process to manufacture the final product of a semiconductor, which includes around 500 and 1,500 steps in the overall manufacturing process of semiconductor wafers.

4. This process also conducts various inputs like silicon wafers, commodity chemicals, speciality chemicals along with clean water supply and uninterrupted power supply.

5. Technology used in semiconductor fabrication: In semiconductor fabrication, various technologies come together to transform raw silicon wafers into intricate integrated circuits (ICs). 

a. Wafer Preparation: The process starts with a wafer, which is typically made of pure single-crystal semiconducting material (usually silicon). The wafer undergoes several steps, including thermal oxidation and thin-film deposition, gradually forming electronic circuits.

b. Photolithography: This step involves masking and exposing the wafer to light. This creates intricate patterns on its surface which define the locations of transistors, capacitors, and other components.

c. Ion Implantation: In the process of Ion Implantation, high-energy ions are precisely implanted into the wafer to alter its electrical properties. This step helps create doped regions necessary for transistor operation.

d. Etching: In this process, unwanted material is selectively removed from the wafer using chemical etchants. This process shapes the various components.

e. Thin-Film Deposition: Thin layers of materials (such as silicon dioxide or metal) are deposited onto the wafer which serve as insulators, conductors, or gate oxides.

f. Annealing and Activation: In this process, the wafer is heated to activate dopants and repair any damage caused during previous steps. The wafer’s surface is polished to achieve a flat and smooth finish.

h. Die Singulation: The wafer contains multiple integrated circuits, known as dies. In this process, these dies are separated from the wafer in a process called die singulation or wafer dicing.

UPSC Syllabus: Science and technology