Archived from groups: comp.sys.ibm.pc.hardware.chips (
More info?)
johnno <johnno@nospam.invalid> wrote:
> "YKhan" <yjkhan@gmail.com> wrote in
>> Yeah, that cost sort of surprised me too. However, I don't
>> think that's the cost of a 300mm wafer, that's probably the
>> cost of 200mm wafers. I had heard somewhere that the cost
>> of a 300mm wafer is about $5000! And I'd assume that that
>> means non-SOI 300mm. If the cost of converting natural to
>> SOI wafers is a fixed cost, then a $5000 wafer would go upto
>> $5700 (i.e. additional $700). If the cost is proportional
>> to the area of the wafer, then the cost will go up by $1400
>> -- 300mm wafers have double the area of 200mm ones. In
>> either case it looks like the proportionate cost increase
>> of natural vs. SOI is much lower with 300mm than with 200mm.
> $5000 for a processed 300mm 90nm wafer sounds about right to me,
> maybe a bit high, but I'm only familiar with 200mm, and .18um
> at that. But we're still looking at either 14% or 28% increase
> in wafer cost - either way it makes a big dent in your margins.
Some perspective? A 300mm wafer should yield about 500 dice
(100mm2 ea, incl kerf & layout losses). So that's $10/ea, multiplied
by some yield factor. 28% is $2.80/CPU -- say 3% on $100 ASP.
I wouldn't call that a big dent unless your yields are < 60%
-- Robert
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