THE CONTEXT: Semiconductor chip manufacturing capabilities are limited to few regions worldwide. With supply chain disruptions and geopolitical tensions, many countries, including India, have realized the importance of investing in chip manufacturing infrastructure. The TATA group has partnered with Taiwan’s Powerchip Semiconductor Manufacturing Corporation (PSMC) to set up a 300mm wafer fabrication plant in Gujarat, and the Government of India has recently approved two assembly and test plants in Gujarat and Assam.
ABOUT SEMICONDUCTOR CHIPS:
- A semiconductor chip is like a tiny brain made from materials that aren’t quite metals (which let electricity flow easily) or insulators (which don’t let electricity flow at all). These materials are in the middle, allowing them to control how much electricity passes under different conditions. To make these chips work the way we want, we add tiny amounts of other materials to change how well they conduct electricity. This process is called “doping. “
- The process of creating semiconductor devices, like integrated circuits found in electronic devices, through multiple-step photolithographic and chemical processes. It mainly uses silicon, but various compound semiconductors are used for specialized applications. For advanced devices (e.g., 14/10/7 nm nodes), fabrication can take up to 15 weeks, with the industry average being 11-13 weeks.
The manufacturing of these chips is a bit like baking a complex cake, requiring many steps and a clean environment so that not even a speck of dust ruins the process. The “kitchen” for making semiconductor chips is called a fabrication plant or “fab.” Here’s a simplified version of what happens:
- Start with a Silicon Wafer: Think of this as the base layer of our cake. It’s a thin, round slice of silicon, the same material that makes up sand at the beach, but much purer.
- Add Patterns with Light: Use a special light to draw tiny patterns on the wafer. This step is like using a stencil to add designs to the cake with powdered sugar, except done with materials that can control electricity.
- Doping: Tiny amounts of other materials are added to change how well different parts of the silicon wafer conduct electricity. It’s like adding various flavors to different cake layers to make each part taste different.
- Etching and Layering: Remove unnecessary parts of the material and add new layers to build up the chip. This is like cutting out cake parts and adding new layers of icing and decorations to make it more complex.
- Testing and Cutting: Once complete, test the wafer to find the sound chips and cut it into pieces. Each piece is a semiconductor chip ready for use in electronic devices.
COMPONENTS OF SEMICONDUCTOR CHIPS:
- Transistors: These are the fundamental building blocks of semiconductor chips, acting as switches or amplifiers for electrical signals.
- Diodes: Components that allow current to flow in one direction while blocking it in the opposite direction.
- Resistors: These are devices that resist the flow of electric current. They are used to control the voltage and current within circuits.
- Wiring: Conductive pathways that connect the various components on the chip to form a complete circuit.
TRANSISTORS IN SEMICONDUCTOR CHIPS:
- Transistors in semiconductor chips are tiny devices crucial in controlling and amplifying electrical signals. They are the building blocks of modern electronics, from computers and smartphones to appliances and vehicles. Essentially, transistors work as switches or amplifiers within a chip.
- A transistor can amplify a small electrical signal, making it stronger, or act as a switch to turn the current on and off. This functionality is fundamental to digital computing, as it allows transistors to represent binary states (0s and 1s), enabling the processing and storage of data.
- Transistors are made from semiconductor materials, typically silicon, which have the unique property of being able to conduct electricity better than insulators but not as well as conductors. By adding impurities to the silicon in a doping process, manufacturers can control the flow of electricity through the transistor. This process creates two types of semiconductors within a transistor: n-type, which has extra electrons, and p-type, which has extra holes (or missing electrons).
FABRICATION TECHNOLOGY IN SEMICONDUCTOR CHIPS:
- Fabrication technology in semiconductor chips refers to the complex and highly specialized process of manufacturing semiconductor devices, typically integrated circuits (ICs) such as computer processors, microcontrollers, and memory chips. This process involves a series of photolithographic and physio-chemical steps. Electronic circuits are gradually created on a wafer made of pure single-crystal semiconducting material, with silicon being the most used material.
- The fabrication process starts with the growth of a high-quality semiconductor crystal, which serves as the base material for producing electronic devices. The most common method for crystal growth in the case of silicon is the Czochralski process. This involves melting high-purity silicon under a controlled atmosphere and cooling it to form a single crystal, extracted from the melt and sliced into thin film wafers. These wafers are then polished and cleaned to create a pristine surface for subsequent processing.
STEPS IN THE SEMICONDUCTOR FABRICATION PROCESS:
- Photolithography: This involves coating the wafer with a light-sensitive material called photoresist and then exposing it to light through a patterned mask. This creates a pattern on the wafer that matches the electronic circuits to be built.
- Etching: This step removes parts of the wafer not protected by the photoresist, creating the physical structures of the circuits.
- Ion Implantation: Here, ions are implanted into the wafer to alter its electrical properties, a process known as doping. This is crucial for creating regions within the semiconductor with different electrical characteristics.
- Deposition: Various materials are deposited onto the wafer to form the electronic devices and their connections. This can include metals for wiring and insulating materials to separate different parts of the circuit.
WAFERS IN SEMICONDUCTOR CHIPS:
- Wafers are crucial components in semiconductor manufacturing, providing the physical base upon which electronic circuits are constructed. Their production involves sophisticated techniques to ensure purity, flatness, and the appropriate electrical properties to develop integrated circuits. Wafers are characterized by their diameter and thickness, with the diameter of wafers steadily increasing over the years to improve productivity and reduce the cost per chip. The current standard wafer diameter is 300mm (about 12 inches), although there is ongoing development towards 450mm wafers. The thickness of the wafer is typically a few hundred micrometers.
- The silicon used in wafers must be highly pure, with a purity level known as “six nines” (99.9999%) to ensure that impurities do not interfere with the operation of the devices built on the wafer. The type and materials of wafers can vary depending on the semiconductor device being produced.
ISSUES IN SEMICONDUCTOR INDUSTRY:
- Skilled Workforce Shortage: India has a large pool of design engineers but lacks semiconductor engineers with expertise in device physics and process technology, which are essential for chip fabrication and manufacturing.
- High Capital Investment: The cost of setting up a semiconductor manufacturing unit is enormous, often exceeding one billion U.S. dollars, and requires well-trained teams and the capacity to support large production volumes from the outset.
- Global Competition: India faces stiff competition from established semiconductor manufacturing hubs like China, Taiwan, and South Korea, making it challenging to build a complete domestic value chain for semiconductors.
- Government Incentives and Policy Response: Global chip giants are skeptical about setting up manufacturing in India, even with government incentives under schemes like the “Modified Scheme for Semiconductors and Display Fab Ecosystem.”
- Late Entry and Cost Competitiveness: India missed early opportunities to establish itself in the semiconductor industry, making it difficult to catch up with countries that have been developing their semiconductor industries for decades. Global chip manufacturers hesitate to operate in India due to cost competitiveness and infrastructure challenges.
- Logistical Challenges: Semiconductor manufacturing facilities require significant space, uninterrupted power, and a substantial water supply, which India’s infrastructure is still developing. Customs clearance can be time-consuming, and the lack of developed infrastructure around potential fab sites poses a challenge. India must resolve supply chain issues to take a significant step in semiconductor manufacturing.
- Credible Experienced Talent: India lacks experienced talent to staff high-cost wafer fabrication facilities.
THE WAY FORWARD:
- Investment in Education and Training: To address the shortage of skilled workforce, India could invest in specialized education and training programs to develop a pool of engineers and technicians with expertise in semiconductor manufacturing.
- Public-Private Partnerships: The high capital investments required for semiconductor manufacturing could be mitigated through public-private partnerships, in which the government and private sector share the financial risks and benefits. India could seek partnerships and collaborations with established semiconductor manufacturing countries to leverage their expertise and technology.
- Policy and Incentive Structures: The government could create more attractive policies and incentives to encourage global chip manufacturers to operate in India.
- Infrastructure Development: Developing the necessary infrastructure, such as reliable power and water supply, could make India a more viable location for semiconductor manufacturing.
- Political and Cultural Adaptation: Overcoming political and cultural hurdles is crucial, and this could involve fostering an environment that supports innovation and cross-border collaboration.
- Problem-Solving Approach: Adopting a systematic problem-solving approach to define and address the specific challenges faced by the semiconductor industry in India could lead to more effective solutions.
THE CONCLUSION:
India’s strategic partnerships and investments in semiconductor manufacturing, including the TATA group’s collaboration with PSMC and the government’s approval of new assembly and test plants, demonstrate the country’s determination to develop a robust semiconductor ecosystem. By leveraging its design capabilities and offering substantial incentives, India aims to challenge Taiwan, South Korea, and China’s dominance in the semiconductor arena and position itself as a reliable and self-sufficient destination for chip manufacturing.
UPSC PAST YEAR QUESTIONS:
Q.1 How does the 3D printing technology work? List out the advantages and disadvantages of the technology. 2013
Q.2 Why is nanotechnology one of the critical technologies of the 21st century? Describe the salient features of the Indian Government’s Mission on Nanoscience and Technology and the scope of its application in the country’s development process. 2016
MAINS PRACTICE QUESTION:
Q.1 Discuss the critical aspects of semiconductor chip manufacturing, including its technology, the role of transistors, and the current state of India’s semiconductor ecosystem. Also, explain the significance of the recent investments and approvals by the Indian government in this sector.
SOURCE:
https://www.thehindu.com/sci-tech/technology/what-is-the-technology-behind-manufacturing-a-semiconductor-chip-explained/article68040447.ece/amp/