Ive been looking at how Intel and other Microprocessor producing companies build their chips. If I understand correctly, they design the chips layers on a computer, then they print each layer and project it through a lens which greatly reduces it's size and burns it on to a silicon wafer, lastly, they fill the mini canals in with copper and then combine they layers. But I was wondering how they manage to fit the 250 million transistors on the chip?

Thank you for viewing!

 

... by making the transistors smaller in physical size. Transistors on a chip now are 1000 times smaller than what they were in 1970.

The way you describe the manufacturing process is not accurate.

Check out:

http://en.wikipedia.org/wiki/Semiconductor_device_fabrication

 

They lie all in one plane next to each other with interconnects in the above layers. For example with 45nm technology one transistor has size of 60x80nm.

 

So they use some processing method to make tiny transistors along a flat plane, and each transistor is only a few molecules wide, and they are interconnected by layers. Wow, that's a lot more efficient than what I though. Thanks guys!

 

... "only a few molecules wide" is a bit of a stretch.
The C - C bond length is 154pm. Hence a 45nm structure is about 300 molecules wide.

 

Basicly they use etching and covering with different layers repeated many times before the interconnects are made.

 

I will be watching you closely Mr. Copycat.

 

The transistors and other active components are made by high temperature diffusions of desired impurities through masks into the pure silicon wafer to generate the required P and N areas, and then depositing several layers of interconnect on the silicon surface. Here's a good overview of the process.

 

Most of the PN junctions are now created using precise ion implantation with diffusion mainly used to drive the dopants and heal (anneal) the crystal lattice damage created during the implant process. Back 20+ years ago when I started we used diffusion for almost everything but with modern batch and serial ion machines on 8 inch or larger wafers it's faster, cleaner and you get better yield with fine line structures devices.

http://www.eng.utah.edu/~gale/mems/Diffusion.pdf
http://www.jhaj.net/jasjeet/tcad/Learn3/l3l.htm

Today even Solar production is going implant instead of diffusion with special wide ion beam machines.
http://www.greentechmedia.com/articles/read/Varian-Takes-Ion-Implantation-in-PV-to-China/