Semiconductor manufacturing:

Wafer fabrication, also known as semiconductor fabrication or semiconductor manufacturing, involves the process of creating integrated circuits (ICs) on semiconductor wafers. The process is highly complex and involves various steps, including chemical processes. Here's a brief overview of some key chemical aspects of wafer fabrication:

1. Cleaning:
   • Chemical Cleaning: Wafers are subjected to various chemical cleaning processes to remove contaminants and particles. Common cleaning solutions include RCA cleans (a mixture of deionized water, hydrogen peroxide, and ammonium hydroxide), piranha solution (a mixture of sulfuric acid and hydrogen peroxide), and other specialized cleaning agents.
2. Photolithography:
   • Photoresist Application: A light-sensitive material, called photoresist, is applied to the wafer. This involves a process where a liquid containing the photoresist is spin-coated onto the wafer.
   • Exposure and Development: The wafer is exposed to ultraviolet light through a photomask, creating a pattern on the photoresist. Chemical developers are then used to develop the exposed areas, revealing the desired pattern.
3. Etching:
   • Dry Etching: Plasma etching is often employed, involving the use of reactive gases to remove material from the wafer. Common gases include fluorine-based compounds.
   • Wet Etching: Chemical solutions are used to selectively remove material from the wafer. Acidic or alkaline solutions may be employed, depending on the material to be etched.
4. Deposition:
   • Chemical Vapor Deposition (CVD): Thin films are deposited onto the wafer using precursor gases. For example, silicon dioxide can be deposited using silane gas.
   • Physical Vapor Deposition (PVD): Metal films are deposited using physical methods such as sputtering.
5. Doping:
   • Ion Implantation: Doping involves introducing impurities into the semiconductor to alter its electrical properties. Ion implantation is a common method, where ions of dopant elements are accelerated and implanted into the wafer.
6. Annealing:
   • Rapid Thermal Annealing (RTA) or Furnace Annealing: Annealing processes use heat to activate dopants and repair crystal damage. RTA is a quicker process involving rapid heating and cooling.
7. Chemical Mechanical Polishing (CMP):
   • Polishing: CMP is used to planarize the wafer surface by removing excess material. Abrasive chemicals and mechanical forces are applied in this process.
8. Final Cleaning:
   • Final Cleaning Steps: After all the processes, a final cleaning step is often performed to remove any residues or contaminants that may have accumulated during fabrication.

These are just a few examples, and the actual processes can vary based on the specific technologies and materials used in semiconductor manufacturing. The chemistry involved in wafer fabrication is highly specialized and plays a critical role in producing high-performance integrated circuits.

The history of semiconductor fabrication:

The history of semiconductor fabrication is a story of continuous innovation and technological advancement, which has led to the development of ever smaller and more powerful integrated circuits. Here's an overview of key milestones in the history of semiconductor fabrication:

1. First Semiconductors (1940s): Semiconductors like germanium and silicon were first used in experimental electronic components during and after World War II. Early semiconductor devices included diodes and point-contact transistors.
2. The invention of the Transistor (1947): In 1947, physicists John Bardeen and Walter Brattain, with their supervisor William Shockley, invented the first practical point-contact transistor at Bell Laboratories. This marked a significant advancement over vacuum tubes in electronics.
3. Silicon Dominance (1950s): Silicon began to dominate the semiconductor industry due to its superior electrical properties and the development of the planar process, which allowed for the creation of reliable silicon transistors.
4. Integrated Circuits (1960s): Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor independently developed the integrated circuit in the early 1960s. This technology allowed multiple transistors to be fabricated on a single silicon wafer, revolutionizing the electronics industry.
5. MOSFET and Microprocessors (1970s): The Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) was developed, becoming the foundation for most digital integrated circuits. Intel introduced the first microprocessor, the 4004, in 1971.
6. CMOS Technology (1970s-1980s): Complementary Metal-Oxide-Semiconductor (CMOS) technology became prevalent due to its low power consumption and high noise immunity. It's still widely used in modern integrated circuits.
7. Shrinking Feature Sizes (1980s-Present): Moore's Law, formulated by Gordon Moore in 1965, predicted that the number of transistors on a semiconductor chip would double approximately every two years. This prediction largely held true until the 2010s, with continuous advancements in lithography and process technology allowing for ever smaller features on chips.
8. Advanced Materials and Techniques (2000s-Present): As transistors reached nanoscale dimensions, the semiconductor industry turned to advanced materials and techniques like FinFETs and 3D packaging to maintain performance and power efficiency.
9. Emergence of Foundries (2000s-Present): Companies specializing in semiconductor fabrication, known as foundries (e.g., TSMC, GlobalFoundries), became major players in the industry, offering manufacturing services to fabless semiconductor companies.
10. Quantum Technologies (Ongoing): Researchers are exploring new materials and techniques, including quantum dots, spintronics, and quantum computing, to take semiconductor technology beyond the limits of classical physics.

The history of semiconductor fabrication is marked by a relentless drive for miniaturization, increased performance, and reduced power consumption. These advancements have had a profound impact on the electronics industry, enabling the development of everything from microprocessors and memory chips to smartphones, laptops, and the Internet of Things (IoT) devices.

Popular semiconductor foundries:

As of my last knowledge update in September 2021, several semiconductor foundries play key roles in the global semiconductor industry. These companies specialize in the fabrication (manufacturing) of semiconductor devices on behalf of other companies that design and market the chips but don't necessarily own their own fabrication facilities. Here are some popular semiconductor foundries:

1. Taiwan Semiconductor Manufacturing Company Limited (TSMC): TSMC is one of the largest and most advanced semiconductor foundries in the world. Headquartered in Taiwan, TSMC is known for its cutting-edge process technologies and serves a wide range of customers globally.
2. GlobalFoundries: GlobalFoundries is a multinational semiconductor foundry with manufacturing facilities in the United States, Germany, and Singapore. It was created as a spin-off from AMD's manufacturing operations.
3. Samsung Foundry: Samsung, a major electronics conglomerate based in South Korea, has a semiconductor division that includes a foundry business. Samsung Foundry offers advanced process technologies and manufacturing services.
4. United Microelectronics Corporation (UMC): UMC, headquartered in Taiwan, is a leading global semiconductor foundry. It provides a variety of process technologies and serves a diverse range of customers.
5. SMIC (Semiconductor Manufacturing International Corporation): SMIC is a semiconductor foundry based in China. It offers a range of fabrication services and has been expanding its capabilities in recent years.
6. Tower Semiconductor: Formerly known as TowerJazz, this Israeli company operates as a specialty foundry, providing analog semiconductor manufacturing services.
7. Intel Foundry Services (IFS): Intel, a major player in the semiconductor industry, has entered the foundry business under the name Intel Foundry Services. It aims to provide advanced manufacturing services to a broad range of customers.
8. IBM Microelectronics: While IBM is not primarily a foundry, it has historically been involved in semiconductor research and development. IBM has occasionally offered foundry services to external clients.
9. Semiconductor Manufacturing South Africa (SMSA): This is a semiconductor foundry located in South Africa, providing services in the areas of chip design and manufacturing.