How is the chip made? How is the chip made?

1, wafer material

The composition of silicon wafer is silicon, which is extracted from quartz sand. The silicon wafer is purified by silicon ele

How is the chip made? How is the chip made?

1, wafer material

The composition of silicon wafer is silicon, which is extracted from quartz sand. The silicon wafer is purified by silicon element (99.999%) and made into a silicon rod, which becomes a timely semiconductor material for manufacturing integrated circuits. A chip is a specific wafer required for chip manufacturing. The thinner the wafer, the lower the production cost, but the higher the requirements for the process.

2. Wafer coating

Wafer coating can resist oxidation and high temperature, and its material is photoresist.

3, photoetching, developing and etching the wafer.

First, a layer of photoresist is coated on the surface of the wafer (or substrate) and dried. The dried wafer is transferred to the mask aligner. The light passes through the mask and projects the pattern on the mask onto the photoresist on the surface of the wafer to realize the exposure and chemiluminescence reaction. After the exposed wafer is baked twice, that is, the so-called post-exposure baking, the photochemical reaction after baking is more sufficient.

Finally, the developer is sprayed on the photoresist on the wafer surface to form an exposure pattern. After development, the pattern on the mask remains on the photoresist. Glue coating, baking and developing are all done in homogeneous developer, and exposure is done in mask aligner. Generally, both the homogenizer and the mask aligner operate online, and the wafer is transferred between the unit and the machine by robots.

The whole exposure and development system is closed, and the wafer is not directly exposed to the surrounding environment, thus reducing the influence of harmful components in the environment on photoresist and photochemical reaction.

Step 4 add impurities

The corresponding P and N semiconductors are formed by implanting ions into the wafer.

The specific process is to start from the exposed area on the silicon wafer and put it into the chemical ion mixture. This process will change the conduction mode of the doped region, so that each transistor can be turned on, off or carry data. Simple chips can only use one layer, and complex chips usually have many layers.

Repeat this process at this time, and you can connect different layers by opening the window. This is similar to the manufacturing principle of multilayer pcb. More complex chips may require multiple layers of silicon dioxide. At this time, the three-dimensional structure is formed by repeating lithography and the above process.

5.pancakes

After the above treatment, lattice particles are formed on the wafer. The electrical properties of each grain were tested by needle method. Generally speaking, each chip has a large number of grains, and it is a very complicated process to organize a pin test pattern, which requires mass production of chips with the same specifications and models as much as possible. The larger the quantity, the lower the relative cost, which is also a factor of the low cost of mainstream chip equipment.

6. Packaging

The same chip core can have different packaging forms, because the chip is fixed and the pins are tied, and different packaging forms can be made according to needs. For example: Dipper, QFP, PLCC, QFN, etc. This mainly depends on the user's application habits, application environment, market form and other peripheral factors.

7, testing and packaging

After the above process, the chip production has been completed. This step is to test the chip, eliminate defective products and package.