HIS grace turns a speck of sand on a beach into a chip of sparkling gold. -Tandon Sir


An integrated circuit is an monolithic circuit. It is a microscopic array of electronic circuits and electronic components (resistors, capacitors, inductors…) that are diffused or implanted into the surface of semiconductor material wafer such as silicon. 

The growth of a single crystal of silicon with device-grade quality is achieved through a process called the Czochralski method. This method allows the production of large, high-purity single crystal silicon ingots, which are later sliced into wafers for semiconductor device fabrication. Here’s an overview of the Czochralski method:

1. Starting Material: High-purity silicon is used as the starting material. It typically begins as polysilicon, which is obtained through the reduction of silicon dioxide with carbon at high temperatures in an electric furnace.

2. Crucible Preparation: A high-temperature resistant crucible made of materials like quartz or graphite is prepared to hold the molten silicon. The crucible is cleaned thoroughly to ensure minimal contamination.

3. Seeding: A small single crystal of silicon (seed crystal) is attached to a rod and dipped into the molten silicon in the crucible. This seed crystal acts as a nucleation site for the growth of the single crystal.

4. Pulling Process: The crucible is heated to melt the polysilicon, and the seed crystal is slowly pulled upwards (hence the name “Czochralski pulling”). As the seed crystal is pulled, it starts to draw silicon from the melt. The silicon atoms align with the seed’s crystal structure, causing a single crystal to grow along with the upward motion of the seed.

5. Controlled Cooling: As the crystal grows, it is slowly rotated to maintain uniformity and avoid crystalline defects. The temperature of the crucible and the pulling rate are precisely controlled to achieve the desired crystal diameter and quality.

6. Dopant Addition: If required, specific dopant elements (e.g., boron or phosphorus) can be added to the melt during the growth process to introduce controlled levels of impurities, creating desired electrical properties.

7. Crystal Annealing: After the crystal reaches the desired size, it undergoes an annealing process to relieve stress and repair defects within the crystal lattice.

8. Ingot Slicing: The resulting single crystal silicon ingot is cut into thin wafers using a diamond saw, and these wafers serve as the basis for semiconductor device manufacturing.

The Czochralski method is widely used in the semiconductor industry to produce high-quality single crystal silicon ingots. The process requires stringent control of purity, temperature, and pulling rate to ensure that the resulting wafers have the required electronic properties for advanced device fabrication.

Integrated Circuit was invented by Jack Kilby in the 1950s. He was awarded the Nobel Prize in Physics on December 10, 2000. A chip is commonly termed as Integrated circuits (IC).

Depending upon the number of transistors in an IC or Chip, the ICs are categorized into five types given below.

1-Small Scale Integration (SSI) Up to 100

2- Medium Scale Integration (MSI) From 100 to 1000

3- Large Scale Integration (LSI) From 1000 to 20K

4- Very Large Scale Integration (VLSI) FROM 20K to 1000000

5- Ultra Large Scale Integration (ULSI) From 10,00,000 to 1,00,00,000

To be continued