The wafers are put into a copper sulphate solution at this stage. Copper ions are deposited onto the transistor through a process called electroplating. The copper ions travel from the positive terminal (anode) to the negative terminal (cathode) which is represented by the wafer.

The copper ions settle as a thin layer on the wafer surface.

The excess material is polished off leaving a very thin layer of copper.

Multiple metal layers are created to interconnects (think wires) in between the various transistors. How these connections have to be “wired” is determined by the architecture and design teams that develop the functionality of the respective processor (for example, Intel’s Core i7 processor). While computer chips look extremely flat, they may actually have over 20 layers to form complex circuitry. If you look at a magnified view of a chip, you will see an intricate network of circuit lines and transistors that look like a futuristic, multi-layered highway system.

This fraction of a ready wafer is being put through a first functionality test. In this stage test patterns are fed into every single chip and the response from the chip monitored and compared to "the right answer."

After tests determine that the wafer has a good yield of functioning processor units, the wafer is cut into pieces (called dies).

The dies that responded with the right answer to the test pattern will be put forward for the next step (packaging). Bad dies are discarded. Several years ago, Intel made key chains out of bad CPU dies.

This is an individual die, which has been cut out in the previous step (slicing). The die shown here is a die of an Intel Core i7 processor

The substrate, the die, and the heatspreader are put together to form a completed processor. The green substrate builds the electrical and mechanical interface for the processor to interact with the rest of the PC system. The silver heatspreader is a thermal interface where a cooling solution will be applied. This will keep the processor cool during operation.

A microprocessor is the most complex manufactured product on earth. In fact, it takes hundreds of steps and only the most important ones have been visualized in this picture story.

During this final test the processors will be tested for their key characteristics (among the tested characteristics are power dissipation and maximum frequency).

Based on the test result of class testing processors with the same capabilities are put into the same transporting trays. This process is called "binning". Binning determines the maximum operating frequency of a processor, and batches are divided and sold according to stable specifications.

The manufactured and tested processors (again Intel Core i7 processor is shown here) either go to system manufacturers in trays or into retail stores in a box. Many thanks to Intel for supplying the text and photos in this picture story.