Chip manufacturing history

The foregoing integrated circuit for fabricating a circuit on the surface of a semiconductor chip is also referred to as a thin film integrated circuit; another thick film hybrid integrated circuit is a miniaturized circuit composed of an independent semiconductor device and a passive component integrated into a substrate or a wiring board.

The characteristics of the integrated circuit industry are that the winners take all the time, and giants like Intel can make profits of up to 60% during the peak period. Then, what is the actual cost of a CPU that is relatively hundreds or thousands of dollars?

Let’s take a look at the manufacturing process

   The complete process of chip fabrication includes chip design, wafer fabrication, package fabrication, and cost testing. The wafer fabrication process is particularly complicated. The precision of the manufacturing process of the chip is very complicated. First of all, the chip design, according to the design requirements, the generated "pattern".

1, the chip raw material wafer

   The composition of the wafer is silicon, the silicon is refined by quartz sand, the wafer is purified by silicon (99.999%), and then the pure silicon is made into a silicon ingot, which becomes the quartz semiconductor for manufacturing integrated circuits. The material, which is sliced, is the wafer that is specifically needed for the chip fabrication. The thinner the wafer, the lower the cost of production, but the higher the process requirements.

2, wafer coating

   The wafer coating film is resistant to oxidation and temperature resistance, and its material is a kind of photoresist.

3, wafer lithography development, etching

   This process uses chemicals that are sensitive to ultraviolet light, which is soft when exposed to ultraviolet light. The shape of the chip can be obtained by controlling the position of the shade. The silicon wafer is coated with a photoresist such that it dissolves when exposed to ultraviolet light. At this time, the first shade can be used so that the portion of the direct ultraviolet light is dissolved, and the dissolved portion is then washed away with a solvent. The rest of this is the same shape as the shade, and this effect is exactly what we want. This gives us the silicon dioxide layer we need.

4, add impurities

   Ions are implanted into the wafer to generate corresponding P and N semiconductors. The specific process is to start with the exposed area on the silicon wafer and place it in a chemical ion mixture.

   This process will change the way the doping region conducts, allowing each transistor to turn on, off, or carry data. A simple chip can use only one layer, but a complex chip usually has many layers. At this time, the process is repeated continuously, and different layers can be connected by opening windows. This is similar to the principle of making multi-layer PCB boards. More complex chips may require multiple layers of silicon dioxide, which is achieved by repeated photolithography and the above process to form a three-dimensional structure.