Why are silicon wafers round?

Lonyo

Lifer
Aug 10, 2002
21,937
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It would, if you could make them square, but a circle is the easiest way to make (grow IIRC) the silicon.
This question has been asked before I think, but basically, it's hard to make it a square shape.
 

Sea Shadow

Member
Nov 8, 2004
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They make the wafers from silicon ingots, which are round due to the process by which they are made. They have a spining starter seed of silicon that is dipped into a vat of molten silicon, as they draw it out it cools and proceeds to grow larger and larger. In the end it looks alot like a super sized Hersheys chocolate kiss.
 

stevty2889

Diamond Member
Dec 13, 2003
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Plus all of the equipment is designed around round wafers, every piece of equipment would have to be replaced, and every proccess started from scratch, because it would completly change the profile in everything. Round wafers are much easier to work with. If I ever saw a polisher trying to polish a square wafer, I'd probably have a heart attack, and think I was in the twilight zone..
 

Jeff7

Lifer
Jan 4, 2001
41,602
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It'd probably be no easier to do than to make cubic raindrops.

Silicon is melted, and the ingots are made from that. Liquid doesn't like sharp edges. :)
 

jiffylube1024

Diamond Member
Feb 17, 2002
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Originally posted by: Jeff7181
As seen here. Why round? Wouldn't square be a better choice since CPU cores have right angles?
That's awesome! You have the guy in the lab equipment wearing all kinds of body cover possible to keep the wafer clean and useable, and next to him some executive in a suit, probably breathing particles and junk all over the wafer, making it unusable.

Btw, cool looking wafer!
 

zephyrprime

Diamond Member
Feb 18, 2001
7,506
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Originally posted by: jiffylube1024
Originally posted by: Jeff7181
As seen here. Why round? Wouldn't square be a better choice since CPU cores have right angles?
That's awesome! You have the guy in the lab equipment wearing all kinds of body cover possible to keep the wafer clean and useable, and next to him some executive in a suit, probably breathing particles and junk all over the wafer, making it unusable.

Btw, cool looking wafer!
It's just a photoop so it's not attractive to have the exec in suit. It's interesting that that wafer would probably have been worth about $200G. I counted a radius of ~15 dies and assumed a price of $300 per chip.

 

tyski

Member
Oct 15, 2000
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Some of the wafers that come out of the growing process have imperfections that make them unsuitable for etching dies onto. I would be willing to bet that the wafers in the pictures are throw-aways, or ones that would have otherwise been melted back down.
 

Hacp

Lifer
Jun 8, 2005
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Originally posted by: zephyrprime
Originally posted by: jiffylube1024
Originally posted by: Jeff7181
As seen here. Why round? Wouldn't square be a better choice since CPU cores have right angles?
That's awesome! You have the guy in the lab equipment wearing all kinds of body cover possible to keep the wafer clean and useable, and next to him some executive in a suit, probably breathing particles and junk all over the wafer, making it unusable.

Btw, cool looking wafer!
It's just a photoop so it's not attractive to have the exec in suit. It's interesting that that wafer would probably have been worth about $200G. I counted a radius of ~15 dies and assumed a price of $300 per chip.

could have been chipset wafers :) Those go for less than 300 bucks.
 

Wingznut

Elite Member
Dec 28, 1999
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Originally posted by: zephyrprime
It's just a photoop so it's not attractive to have the exec in suit. It's interesting that that wafer would probably have been worth about $200G. I counted a radius of ~15 dies and assumed a price of $300 per chip.
I have little doubt that the wafer in question was some sort of experiment in which it was never expected to be actual retail product.

And what's up with the surgical mask???
 

jiffylube1024

Diamond Member
Feb 17, 2002
7,432
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Originally posted by: Wingznut
Originally posted by: zephyrprime
It's just a photoop so it's not attractive to have the exec in suit. It's interesting that that wafer would probably have been worth about $200G. I counted a radius of ~15 dies and assumed a price of $300 per chip.
I have little doubt that the wafer in question was some sort of experiment in which it was never expected to be actual retail product.

And what's up with the surgical mask???
He's trying to save Intel's Netburst architecture. Quick - it's flatlining. Clear!!!


(ok sorry, low blow. I can't help myself ;) )
 

AnandThenMan

Diamond Member
Nov 11, 2004
3,873
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They're round because off hours they use them to practice up their ninja skills. Square just does not glide very well.
 

Sea Shadow

Member
Nov 8, 2004
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That would be pretty close to impossible for several different reasons (price, ability to manufacture, etc.)

That would end up being the most expensive processor ever. On each wafer there is probably at least a couple of defective die so if you made one HUGE processor then you would probably waste hundreds of wafers just to make one perfect one. Each wafer probably costs tens of thousands of dollars to manufacture and process.
 

CheesePoofs

Diamond Member
Dec 5, 2004
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Originally posted by: jiffylube1024
Originally posted by: Wingznut
Originally posted by: zephyrprime
It's just a photoop so it's not attractive to have the exec in suit. It's interesting that that wafer would probably have been worth about $200G. I counted a radius of ~15 dies and assumed a price of $300 per chip.
I have little doubt that the wafer in question was some sort of experiment in which it was never expected to be actual retail product.

And what's up with the surgical mask???
He's trying to save Intel's Netburst architecture. Quick - it's flatlining. Clear!!!


(ok sorry, low blow. I can't help myself ;) )
Actually, thats an AMD wafer, the pic is from their opening of fab36. Even an A64 wafer wouldn't save netburst.
 

potato28

Diamond Member
Jun 27, 2005
8,966
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O ya. Teacher made us clean the whole room. Suked bcoz my hands got all cut up, and I had to clean it up. Circle=easier to work with IMO.
 

jiffylube1024

Diamond Member
Feb 17, 2002
7,432
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Originally posted by: potato28
O ya. Teacher made us clean the whole room. Suked bcoz my hands got all cut up, and I had to clean it up. Circle=easier to work with IMO.

I've always been a fan of the icosahedron. Very easy shape to work with :) .

Ok, I'm kidding :) . I had actually never even heard of an icosahedron before looking it up :p .
 

xtknight

Elite Member
Oct 15, 2004
12,974
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Originally posted by: PrayForDeath
I hear those scientists go commando in their bunny suits to avoid contamination :D
woohoo
for all the 2 people here who knows where that comes from. :D
 

Elcs

Diamond Member
Apr 27, 2002
6,278
6
81
Geeks prefer curves?

Nerds are often referred to as being Squares?

I guess this goes down as one of those unknown facts of life, such as why are pringles so addictively tasty or why are we here.
 

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