What is an Integrated Circuit(IC)? How it’s made?
Everyone would have heard about ENIAC (Electronic Numerical Integrator And Calculator).
It was developed in 1946 at Princeton University. It was big, loud and made calculations during the second world war. They used ENIAC to create a path for bomb trajectories back in those days. A human would take more than a day to figure out the trajectory, the ENIAC would do it less than 30 minutes.
But,
- It costed about $6,000,000.
- It was about 8 feet high, 3 feet deep, and… 80 feet long.
- It weighed 30 tons!
- It used a lot of power and it was very hot!
And… it was down half the time to replace vacuum tubes gone bad.
AND THEN CAME THE 8th WONDER OF THE WORLD.
This technology revolutionized the world, the way we see things, the way we communicate and the powerful devices that we use.
It all started when John Bardeen, Walter Brattain, and William Shockley discovered the transistor in 1947.
But transistors alone weren’t good enough as the size of the logic board increased, Jack Kilby along with Robert Bob Noyce created the first integrated circuit in late 1950s. Gordon Moore at Intel looked at the trend of transistors getting smaller, and observed the famous Moore’s Law — which some people think is on the verge of an end.
Number of transistors and resistors on a chip doubles every 18 months — Gordon Moore
Then what it possible was the invention of the Integrated Circuit (IC) in 1958. Here transistors are put into the tiny chips of silicon. It contains hundreds, thousands, millions, or even billions of electronic components which are no bigger than a fingernail. Let’s take a closer look at ICs and how they work!
On the top is an iPhone X logic board. If compared to the giant ENIAC:
- It cost 20,000X less
- It is 80,000,000X smaller
- It uses 500,000X less power
- It is 150,000X lighter
- And it’s 2,000X more powerful.
What actually goes into IC:
It all starts with sand. After oxygen and water, sand is the widely available element in the world. From sand we make silicon, from silicon we make transistors, from transistors we make IC’s , from IC’s we make devices that ease our lives up.
So, the most common element on earth’s surface (~28%). Sand has a high percentage of Silicon Dioxide (SiO2) and is an important ingredient of semiconductor processing.
Once silicon is extracted from sand, it gets purified. Initially, it is converted to a molten state (high purity liquid) achieved by a process known as Czochralski (chokh-RAL-skee) process.
Before the ingot gets cooled completely, the cone-shaped ends of the ingot are cut off into slices called silicon wafers.
These silicon wafers are cut using diamond saw blades and are cut usually to 12 inches in diameter.
After this, the wafer is dopes with ions and this process is called ion implantation.
First, the wafer is masked by applying photo resistive layer (layer which covers the unwanted parts of the wafer).
Then the wafer is bombarded with a beam of ions (positively or negatively charged atoms) which embed themselves beneath the surface of the wafer.
Later they remove the photo resistive layer for further more processing
High k- dielectric Deposition
Instead of a traditional insulator between a transistor’s gate and its channel. Adding multiple layers of High k- dielectric, one atomic layer at a time. This process is critical as this reduces leakage current from the gate terminal to the channel. They add 3 layers of this deposit.
Photolithography
Now they pour a photo resistive layer which is blue in colour liquid over the wafer which is evenly spread by centrifugal force (that’s absolutely brilliant).
They etch (print) circuits in this process.
Metal deposition
The closer step to final to finish the process of making a chip. Holes are drilled in required places and copper, or a good conductor is electroplated.
Copper ions are settled as copper layer in the wafer.
Silicon Wafer discs.
1. Chip: Electronic circuit patterns on a tiny piece of silicon.
2. Scribe Lines: The gaps provided for the diamond edge saw blades to cut individual chips
3. TEG (Test Element Group): a prototype which is used to test whether the design is working properly or not, if not the whole batch of the design will be rejected.
4. Edge Die: Silicon chips in the end of the die is a production loss, because the whole chip cannot be printed, so a larger wafer will be used (12 inch diameter wafers are used currently.
5. Flat Zone: The wafer is cut flat at one edge to identify the type and orientation of the wafer.
Then comes the wafer slicing. The wafers is cut into pieces called dies.
When wafer processing is complete, the wafers are transferred from the fabrication to an assembly/test facility. Here individual chips are tested, and faulty ones are removed from the wafer.
Finally, all the chips are cut using a laser cutter or a diamond edge saw. They are sent for packaging.
Entire Process of making a chip or a Processor.
Thanks for reading.
Until next time
Peace, Love and Gratitude.
SS
Source: Intel, Samsung
Photo Source: Google
