CHIP MAKING PROCESS
It all begins with a grain of sand. Seriously, it does.
Ever wonder how a computer chip is born? Here’s a quick – and simplified – rundown of the process.
Your phone, tablet, phablet, health tracking wearable, and an increasing number of household appliances are all powered by integrated circuits, or microchips. Those chips are the end product of the semiconductor lithography process that begins with sand. Sand, or silicon, is a semiconductor. That means it conducts electricity under some, but not all, conditions, making it an essential component of integrated circuits.
The silicon needs some work before it makes its way into your gadget, though. Through chemical processing it reaches 99.999% (aka five 9s) purity then, using heat to create purified silicon melt, is grown into a monocrystalline ingot. The ingots, which can reach almost seven feet in length and 1000 pounds in weight, are sliced into super-thin (less than 10 human hairs thick), round wafers (from 4 inches up to 18 inches in diameter) that are polished to create a flawlessly smooth mirrored surface.
WAFER | EXPOSURE | ETCHING
At this point the wafer undergoes a complex manufacturing process flow including the critical photolithography steps where a chip design is transferred onto the wafer. A single chip design has billions of transistors and multiple layers that are electrically interconnected. Each layer is created from a unique mask containing the circuit pattern. A Cymer deep ultraviolet (DUV) light source is used to project each pattern onto the wafer surface. The process is similar to photography: the Cymer light source is the sun or flash that illuminates the object (the mask), enabling an advanced camera to create the desire image. Without the light source, there is no picture.
Using photolithography enabled by Cymer light sources and a complex array deposition, etch, and polish steps, multiple layers of intricately patterned circuits are created. In addition, the electrical properties of a layer can be modulated by using a variety of non-Silicon elements (dopants).
WAFER SORT TEST
Every one of the hundreds or thousands of die on the wafer is tested for functionality with a wafer probe. When a die passes all tests its position is logged for the next step: packaging.
SLICING | PACKAGING
Each die that passes the wafer probe test is cut from the wafer. Fine—very fine—wires are attached to create the circuitry needed for delivering power and creating an electrical connection, then encased (packaged) to protect against damage. The final product is the integrated circuit found inside all electronic devices.