© Mark Ollig
High-purity silica sand is the starting point for the tiny integrated circuits, commonly referred to as microchips, powering our digital devices.
This extraordinary level of purity (exceeding 99.9999% silicon dioxide) is crucial in manufacturing, as even minuscule impurities can interfere with the electron flow in a microchip’s complex circuitry.
The journey of creating microchips begins with the extraction of raw sand, which is transformed into thin, round wafers that serve as the foundation for these intricate electronic components.
According to the United States Geological Survey, the US remained a major producer of industrial sand and gravel in 2023.
High-purity quartz sand, a type of silica sand and a key component in microchip manufacturing, is found in specific deposits across the country, like those in Minnesota.
Minnesota is known for its high-quality quartz sand deposits, primarily located in the southeastern and south-central parts of the state and the Minnesota River Valley.
Silica sand is used in a variety of applications, including concrete and mortar production, metal casting, sandblasting, and even recreational settings like golf courses and volleyball courts.
While silica sand has various industrial and recreational uses, only high-purity quartz sand, a specific type of silica sand, meets the strict requirements for microchip manufacturing.
The process of transforming silica sand into high-purity silicon involves extracting and purifying the sand, followed by melting and carefully growing a large cylindrical crystal of silicon. The resulting crystal is then sliced into thin, round wafers.
During the 1980s and 1990s, these wafers were six inches (150mm/millimeters) in diameter.
Today, they are 12 inches (300mm), allowing for a significantly greater number of chips per wafer.
Semiconductor industry leaders like the Taiwan Semiconductor Manufacturing Company (TSMC) and Intel are already experimenting with larger 18-inch (450mm) wafers for future production.
Larger wafers offer significantly more surface area compared to the current 12-inch standard and, with continued advancements in miniaturizing chip components, could dramatically increase chip output per wafer.
Building and operating microchip fabrication plants (fabs) are incredibly costly, often requiring investments of tens of billions of dollars.
These expenses arise from the need for strict cleanroom environments, specialized equipment, ongoing research and development, highly skilled labor, and substantial energy consumption.
GlobalFoundries, a major US chipmaker, has invested heavily in their New York Fab 8 facility, with more than $15 billion already spent and an additional $11.6 billion planned.
The company also received $1.5 billion from the US government’s CHIPS and Science Act to boost domestic chip production.
Additionally, they are investing $1 billion to modernize Fab 9 in Vermont to produce next-gen gallium nitride (GaN) semiconductors, a material enabling faster and more efficient electronics for high-performance applications like electric vehicles, renewable energy systems, and 5G or 6G infrastructure.
Samsung is developing a $17 billion semiconductor fabrication complex in Taylor, TX, which is expected to be operational in 2025 or later.
In Arizona, TSMC is investing $40 billion to build multiple fabs, with the first one expected to be operational in 2025.
Thin silicon wafers serve as the foundation for constructing the intricate circuitry of microchips.
Billions of transistors, diodes, and resistors are meticulously patterned and layered onto the wafer’s surface through a complex fabrication process.
Finally, the wafer is diced into individual integrated circuits using a diamond saw, resulting in tiny chips packed with microscopic components that power our electronic devices.
Some central processing units (CPUs) consist of multiple cores, with each core acting like a “miniature brain” within the central “brain” of the CPU.
These cores work together, like different parts of the brain, to process information, execute instructions, and perform calculations, ultimately delivering faster and more efficient performance.
High-performance processors, found in data centers and used for demanding applications like artificial intelligence, can have dozens or even hundreds of cores.
Beyond CPUs, the intricate design of various other integrated circuits, such as memory chips, graphics processors, and communication chips, enables the wide array of features and capabilities found in our smartphones, computers, and other electronic devices.
The fabrication of advanced integrated circuits involves an intricate process of layering and patterning various materials onto a silicon wafer, analogous to constructing a microscopic layer cake, where each layer serves a distinct purpose.
In each layer, conductive materials like copper or aluminum form complex wiring, while semiconductors like silicon create transistors that function as switches.
Additionally, insulators like silicon dioxide are used to separate and protect the semiconductor components, ensuring their proper functioning and preventing electrical interference.
Photolithography, a technique employing light to precisely transfer patterns onto the wafer, is a crucial step in this intricate process.
Using light, manufacturers etch intricate patterns onto the silicon wafer, creating the complex circuitry of the microchip.
Circuit sizes are measured in nanometers (nm), a unit of length equal to one billionth of a meter.
The smaller the circuit sizes, the more transistors can be packed onto a single chip, leading to increased processing power and performance.
Intel has projected that by 2030, a single chip could contain a trillion transistors, which would dramatically impact computing and AI, and unlock extraordinary technological possibilities.
As always, stay tuned.
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| One diced six-inch (150mm) silicon wafer displays small squares, each representing an individual chip or die that can be separated (cut) and packaged. (Photo taken by me) |
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| A zoomed-in view of the wafer, revealing a detailed pattern of scored microchips. (Photo by me) |