How they make silicon wafers

[Salas]

A cool video to see the way they do it. Very Hi-Tec indeed.

[smgidcumb]

While working on my PhD in physics I've been able to take a few classes involving silicon processing techniques, and every single step of it blows me away.

Even the very first step of making a single crystal silicon ingot of that size/weight, purity, and lack of defects is staggering. The forces on that seed crystal are enormous due to the rotation of the ingot, and I'm amazed they don't break.

[Salas]

Yes, very Sci-Fi processed but for real. Super strong but brittle that huge mono crystal. A thread of it can pull a train, but can't afford a hit or a fall.

[GaryB]

Thanks for the link - I agree that it's a nicely done video.
The video talks about 200mm silicon wafers but these days most manufacturing is done with 300mm wafers and there is serious discussion starting about moving to 450mm wafers. Everything in the factories is automated and there are very few people needed to run the tools. Very futuristic.

A state of the art factory costs billions of dollars and the industry is splitting into companies that only manufacture, companies that only do chip design, and a few large companies such as Intel that can afford to do both.

---Gary

[Salas]

Is FAB32 Arizona the most advanced factory?

[GaryB]

The 32nm generation is Intel's most advanced production technology. According to Intel's press releases, they are manufacturing this at fabs in Oregon and New Mexico. Fab32 is one of the New Mexico fabs.

The large memory manufacturers (Samsung, Toshiba, etc.) also have state of the art fabs that are impressively large. Since a typical PC has 4GB of memory = 16 x 2Gb DRAM chips and only 1 processor, that means memory factories need to be a lot larger than microprocessor factories to keep things in balance. The largest Toshiba factories put out >150K 300mm wafers per month - an amazing figure. That's just the number for one factory and they have many of them.

---Gary

[GaryB]

One more interesting datapoint - here is the latest ranking of capital spending by semiconductor companies in 2010. It's interesting to see who is and who is not on the list. It tells you who is building fabs and how much they cost.

Only 2 European companies make the list and only 5 from North America. The rest are from Asia (Japan (4), Korea (2), Taiwan (6), and China(1) )
---Gary

Samsung $9,200
TSMC $5,700
Intel $5,000
GlobalFoundries $3,200
Hynix $2,750
Micron $1,900
Toshiba $1,900
UMC $1,800
Inotera $1,600
SanDisk $1,400

SMIC $1,000
ASE $850
Texas Inst. $800
Renesas $748
Elpida $634
ST $600
Rohm $574
Amkor $552
Infineon $550
Siliconware $533

[Salas]

Thanks for your learned input. Those numbers are in $M? How the smaller firms obtain production? They go to the big ones with a pattern and its done OEM? Also what are the differences for making parts like we DIYers use? Small and power BJTs, JFETs, Mosfets, OP-AMPS. Those are not processors, even OP-AMPS have silly low integration compared to what's used in computers and automation. There must be other standards for wafer thickness, micron scale, clean air demands etc? Are they all done in same high integration capable fab houses even?

[Pit Hinder]

Most of the cheaper chips are the same circuits as the better ones, but from the border of the wafer. Ask your old physics prof or any photographer - the center of any photo image is sharper than the borders. You can still make good use of the lesser quality by not using the tiny leads that might be "fuzzy" and heat up too much because having higher resistance.

[Salas]

From TO-3 transistors I have opened I remember the lands were big, easy to see. Must be much easier to etch, but is the wafer any different than those in the video? Also how do they fuse the wires to the outside leads on silicon? What technique?