History of chip manufacturing

   The aforementioned integrated circuits, which are manufactured on the surface of semiconductor chips, are also known as thin-film integrated circuits. Another type of integrated circuit is the thick-film hybrid integrated circuit, which consists of independent semiconductor devices and passive components integrated into a substrate or circuit board to form a miniaturized circuit.

The integrated circuit industry is characterized by a winner-takes-all mentality, with giants like Intel achieving profit margins as high as 60% at their peak. So, compared to CPUs that often cost hundreds or even thousands of dollars, what is the actual cost of production?

Let's first look at the manufacturing process.

The complete chip manufacturing process includes chip design, wafer fabrication, packaging, and cost testing, among other stages, with wafer fabrication being particularly complex. The manufacturing process for precision chips is extremely complex. First comes chip design, where a “blueprint” is generated based on design requirements.

1. The raw material for chips is silicon wafers.

Silicon wafers are made of silicon, which is refined from quartz sand. Silicon is purified to 99.999% purity, then formed into silicon ingots, which serve as the raw material for manufacturing integrated circuits. These ingots are sliced into wafers, which are the specific materials needed for chip production. Thinner wafers reduce production costs but require higher manufacturing precision.

2. Wafer coating

The wafer coating provides resistance to oxidation and high temperatures, and its material is a type of photoresist.

3. Wafer photolithography, development, and etching

This process uses chemicals sensitive to ultraviolet light, which soften when exposed to UV light. By controlling the position of the mask, the shape of the chip is determined. A photoresist is applied to the silicon wafer, which dissolves when exposed to UV light. At this point, the first mask is applied, causing the areas directly exposed to UV light to dissolve. These dissolved areas are then rinsed away with a solvent. The remaining areas retain the shape of the mask, which is the desired outcome. This process yields the required silicon dioxide layer.

4. Adding impurities

Ions are implanted into the wafer to create corresponding P-type and N-type semiconductors. The specific process involves exposing areas of the silicon wafer and immersing them in a chemical ion solution.

This process alters the conductivity of the doped regions, enabling each transistor to conduct, block, or carry data. Simple chips may only require a single layer, but complex chips typically have multiple layers, in which case this process is repeated multiple times. Different layers can be connected by opening windows, similar to the principle behind the production of multi-layer PCB boards. More complex chips may require multiple silicon dioxide layers, which are achieved by repeating the lithography process and the steps described above to form a three-dimensional structure.