How Are Computer Chips Made?

Key Points:

• The most common semiconductor materials used for manufacturing computer chips are silicon dioxide (or sand), germanium, and gallium arsenide.
• One step in the process of making a computer chip is photolithography, in which a light-sensitive material is used to transfer a pattern onto a substrate.
• The pattern formed by the etching process is called a “mask,” and it’s what gives the chip its shape and functionality.

Computer chips, also known as silicon microchips, are incredibly small electronic devices used to store and process information. They control everything from electric appliances to office equipment, digital cameras, and medical equipment. They take all this information, whether a simple digital picture or an entire movie and make it a useable product. Every time you hit send or enter on your computer, you are using the latest in microchip technology to process and send your data across the Internet or your office building. But where do these chips come from? How are they made? This article will take you through every step involved in the process of making these essential products that keep us connected and informed on a daily basis.

What Kind Of Chemicals Are Used In Making Computer Chips?

A computer chip is also known as an integrated circuit, and it is made up of semiconductor material. The most common type of semiconductor material used is silicon. Silicon dioxide, or sand (the main material in computer chips). Other materials used in making computer chips include germanium and gallium arsenide. These materials are used because they have special properties that make them good for making transistors. When you turn on a transistor by applying a voltage to its gate electrode, you cause electrons to flow from its source electrode to its drain electrode.

An insulator prevents any current from flowing until the transistor is turned on. Once turned on, the transistor acts like a conductor, allowing current to flow. If no voltage is applied to the gate electrode, no current will flow. One important point about this process is that the gate electrode only turns off the current once it reaches its drain. It does not stop the current midway through the device.

Another key element is that these operations happen very quickly, typically with periods measured in nanoseconds (billionths of a second). It’s possible to build circuits containing hundreds of thousands of transistors on one single piece of silicon wafer!

How Are Computer Chips Made? Step by Step Guide

Computer chips are made through a process called semiconductor fabrication. Semiconductors are materials that conduct electricity and can be separated into two main types: silicon (used for computer chips) and germanium. Here is an overview of the process.

Step 1: Start With Sand

The process of making a computer chip starts with a particular kind of sand called silica sand, which is made of silicon dioxide. The foundation component of semiconductor fabrication, silicon, needs to be pure in order to be employed in the production process.

Step 2: Purify to Obtain Silicon Ingot

A silicon ingot is a cylindrical piece of extremely pure silicon grown in a controlled environment. Electronic-grade silicon, which has a purity of 99.9999 percent, is produced by a number of purification and filtering procedures. It’s then cut into rectangular wafers that will eventually become computer chips. The size and shape of the wafer depend on the end use. The rough edges are smoothed off and made perfectly flat so that electrical signals can pass over its surface without interruption.

Step 3: Cut Wafers

The next step involves slicing the circular silicon ingot into wafers. Chip manufacturers first cut silicon wafers to the desired size to make a computer chip. The wafers are then polished and cleaned before any further processing can take place.  Once they are cut, they undergo a series of processes that add layers of different materials to the surface of the die. These layers serve different purposes, such as creating electrical paths or isolating different regions of the chip.

Step 4: Photolithography

A layer of photoresist is then spread thinly across the wafer. In photolithography, a light-sensitive material is used to transfer a pattern onto a substrate. The first step is to coat the substrate with a light-sensitive material called a photoresist. Next, the wafer is exposed to light using a mask that contains the desired pattern. The exposed areas of the photoresist are then developed, which creates openings in the resist that correspond to the desired pattern. The wafer is then etched, which transfers the pattern into the underlying substrate.

Step 5: Ions and Doping

Doping is the process of bombarding the silicon wafer with ions to change its conductivity once the exposed photoresist has been wiped off. After washing off the leftover photoresist, a pattern of impacted and unaffected material is revealed.

Step 6: Etching

A thin silicon layer is removed from the surface by applying reactive chemicals. These are applied at different rates depending on how deep you want them to go into the surface. If you want to remove a large amount of material, apply the chemicals for longer periods so that they can be as strong as possible. By repeatedly etching and re-imaging this way, engineers can create complex patterns for different components like memory chips and processors.

The pattern formed by the etching process is called a “mask,” and it’s what gives the chip its shape and functionality. The mask is made from photoresists, which are materials that can be chemically modified to make a pattern on a surface.

Step 7: Electroplating

The nearly finished transistor is covered in an insulating layer, and three holes are carved into it. Then, manufacturers apply copper ions to the transistor’s surface using a procedure called electroplating to create a layer of copper on top of the insulator. Only three copper deposits remain in the insulating layer holes after the extra copper has been cleaned away.

Step 8: Layering Interconnects

The computer chips that power our devices comprise many layers of interconnects, each just a few atoms thick. Interconnects are made of metal wires that connect different types of electrical components. Each wire has a specific function, designed to be compatible with each other so they can communicate with one another. Now that every transistor is interconnected, the chip can perform processor-like operations.

Step 9: Test and Slice Die

The wafer is cut into small squares, called a die. Each die contains millions of transistors. The dies are then tested and sliced into individual chips. The chips are then packaged and shipped to computer manufacturers.

Step 10: Packaging

The packaging of the dies includes a substrate and a heat spreader, and they take on the recognizable shape of a desktop CPU. Heat is transferred from the silicon by the heat spreader into the heatsink positioned on top of it. After that, processors are tested in terms of power use, maximum frequency, and other performance indicators.

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