Why are computer CPUs so expensive? Here are the reasons

The CPU you see looks like this: 

This is the packaged form. The shell and silicon circuit board are actually worthless. The most expensive part comes from the chip inside. The chip is in this wafer form before it is cut:

Those who have no idea about chips and the semiconductor industry can watch this film to catch up.

The longer you stay in this industry, the more you will feel that the chip business is really super difficult to do. Why is our country now developing the semiconductor/chip industry with the whole country's strength instead of relying on the spontaneous behavior of the market?

One of the most important reasons is that the cost is too high. Without policy and financial support from the national level, almost no company can survive the huge, money-burning investment in the R&D and startup stages.

In what aspects are the costs high?

1. High tape-out cost

Before mass production, a small number of wafer verifications are required. Although the number of wafers is small, the number of photomasks is not less. The photolithography steps of the CPU are about one or two hundred steps, and each step requires a photomask. The cost of the photomask accounts for a large part of the cost of the wafer production stage.

The patterns in the mask are extremely fine and difficult to manufacture, so they are expensive.

After tape-out, it is often discovered that the pattern design in the mask needs to be optimized, and this optimization is not limited to one layer of the mask. In many cases, multiple layers of masks need to be modified at the same time, which further increases the cost.

2. High process cost

The process steps of advanced CPU chips are about 1000-3000 steps. Each step has material costs. Cheap processes like scrubbing cost about one cent or one gross per chip. The cost of some steps may reach hundreds of yuan, for example, if expensive materials are used. The sum of all the steps is a relatively large number.

The more advanced the chip, the more complex the chip structure and the more process steps there are, so the cost per wafer will be higher.

Take the simplest MOSFET (metal oxide semiconductor field effect transistor) structure as an example. The early MOSFET had the following physical structure:

Now, MOSFET has evolved into FinFET (Fin Field Effect Transistor), and the process steps have obviously increased. It looks like this:

In addition to material costs, the production clean room needs to be powered 24 hours a day, 365 days a year. Air purification, humidity maintenance, constant temperature maintenance, and pollution particle removal in such a large space all require electricity costs. Some media even broke the news that about one-third of the increase in Taiwan's electricity consumption was contributed by TSMC. This shows how much electricity semiconductor production lines consume.

3. High equipment cost

Semiconductor factory production equipment is extremely expensive, and the price of consumable parts of many equipment is enough to easily buy a Land Rover. The depreciation cost of the equipment will naturally be converted into the cost of the chip.

The most expensive one is the photolithography machine because the process it needs to achieve is too sophisticated.

4. High risk cost

The more advanced the process and product, the higher the requirements for product technology. From the first step to the final processing of the wafer, advanced chips often take several months to complete this process. They can "die" halfway at any time, including but not limited to the following ways of death:

1) The technician was distracted by his girlfriend and installed the wrong equipment part.

2) Equipment malfunctions but no alarm is given, resulting in process deviation.

3) The automation system crashed...

4) The wafers were not used to the local climate and for unknown reasons broke into pieces in the FOUP (container for wafers).

5) He was thrown away during the rotation and smashed to pieces...

There are many reasons. Let’s not talk about the failure of the process itself. It’s lucky to be able to avoid various accidents and rush to the last step. And those “dead” wafers cannot die in vain, and they will be reflected in the selling price of the chip.

Even the most advanced factories cannot avoid these risk events. TSMC once scrapped 100,000 wafers due to risky processes, of course, this was due to its poor supplier Dow Chemical.

TSMC's 10,000 wafers scrapped may be caused by Japanese companies Shin-Etsu, JSR and Dow Chemical

In addition to these, there are also chip design costs, labor costs, packaging costs, transportation costs, sales promotion costs...

After reading this, do you still think that CPU is expensive? A CPU that has gone through thousands of processing steps and is the product of almost all the wisdom of mankind, only costs a few thousand yuan after adding up all the costs. It is really cheap.