A computer chip is a tiny wafer of semiconducting material with an embedded electronic circuit. It contains millions of microscopic electronic components called transistors that transmit data signals. Initially, chips were physically large, and computing was only something done in national labs, universities, or large companies. Further innovation in computer chip technology resulted in the development of high-performance processors that power all types of advanced analytics, graphics, and machine learning applications. As the size of the computer chip reduced, it became possible to create smaller computers that could be used at home. Today, the computer chip is omnipresent in our lives—in everything from our microwaves to our toothbrushes.
How are computer chips made?
Computer chips are typically manufactured in factories called fabrication plants or fabs. They are made from silicon, a common chemical element found in sand. Silicon is a semiconductor, which means its electrical conductivity falls somewhere between metals like copper and insulators like glass.
Here’s a summary of the chip manufacturing process.
Silicon extraction and shaping
Single crystal silicon ingots are extracted by melting and refining sand. The ingots are nearly 100% pure. They are cut into wafer-thin chips that are cleaned, polished, and coated with a layer of silicon dioxide. An additional coating of a chemical known as photoresist is added on top of the silicon wafers to increase photosensitivity. Strict precautions are taken to ensure there is no contamination of dust or other foreign substances during this process. Once the basic silicon chips are ready, electronic circuits are etched onto them.
Circuit etching
The silicon wafer is covered by a circuit-patterned plate, called a mask, and exposed to ultraviolet light. The light hardens the exposed photoresist material in the circuit pattern. Hot gases then melt the exposed material to reveal the silicon dioxide beneath. A 3D landscape is left behind, replicating the mask’s circuit design pattern.
In the chip manufacturing process, etching is the chemical removal of layers from the wafer, and doping is the introduction of impurities to modify the wafer. The process of etching and doping may be repeated hundreds of times on the same computer chip to create more complex integrated circuitry.
How do computer chips work?
Computer chips work by transmitting electrical signals through the circuit elements.
Analog integrated circuits
Analog circuits transmit continuous, varying signals in a given time period. The output signal is a linear function of the input with directly proportional voltages. This type of integrated circuit is used for device functionality like timers, comparators, voltage regulators, and operational amplifiers. Analog chips are used in sweep generators, oscillators, audio amplifiers, and filters.
Digital integrated circuits
Digital circuits transmit discontinuous or binary signals. The output voltage may be high or low. The high voltage represents the Boolean value 1, and the low voltage represents the value 0.
Digital circuits are designed to perform different logical operations like AND, OR, and NAND. For example, the logical OR operation corresponds to Boolean addition and is the basis of computer addition operations. So, digital integrated circuits form the basis of all computing operations. They are crucial for all programmable devices, logic boards, microcontrollers, and memory.
Mixed-signal integrated circuits
Mixed chips combine elements from both analog and digital chips. The hybrid design makes it possible to have chips that act as digital-to-analog and analog-to-digital converters. These advanced integrated circuits are another core component of modern computing.
Quantum circuits
Quantum circuits are the next stage of computing evolution. A quantum circuit is a computing routine that defines a series of logical quantum operations on underlying qubits, or quantum bits. Qubits are represented by quantum particles which are different from boolean digital signals. Boolean signals are 1 or 0, but qubits can be placed in a superposition of states. Chips with quantum circuits form the basis of quantum computing, which is an emerging technology.
What are the types of computer chips?
Computer chips are classified into four broad categories according to functionality.
Memory chips
Memory chips store programs and data on computers and storage devices. RAM chips provide temporary storage, whereas flash drives and solid state drives (SSDs) can hold information permanently. Flash memory units can store data even when the electrical current is switched off.
Logic chips
Logic or processor chips process data to complete tasks. They are the brains of modern electronic devices. CPUs are the main type of logic chips found in the microprocessors of servers and other computing hardware. However, logic chips can also be designed for specific functions. Here are some examples:
- Graphical processing units are designed to optimize visual displays
- Neural processing units are designed for deep learning and machine learning applications
ASICs
Application-specific integrated chips (ASICs) are designed to perform repetitive processing routines for a specific application. These modern chips are produced in large batches for single-purpose appliances like barcode scanners. Another example is bitcoin mining, where ASICs perform the complex mathematical routines required for producing new bitcoins.
SoCs
The system on a chip (SoC) is a newer type of chip. All electronic components needed for an entire system are built into one chip. SoC capabilities are more extensive than microcontrollers. A microcontroller generally combines the CPU with memory and I/O processing. However, the SoC may integrate graphics, audio, camera, and video processing.
