<p>Quoting from this paper: Haus R., Prinz S., Priess C. (2012) Assessment of High Purity Quartz Resources. In: Götze J., Möckel R. (eds) Quartz: Deposits, Mineralogy and Analytics. Springer Geology. Springer, Berlin, Heidelberg. <a href="https://doi.org/10.1007/978-3-642-22161-3_2" rel="nofollow noreferrer">https://doi.org/10.1007/978-3-642-22161-3_2</a></p>
<blockquote>
<p>What purity level is required in naturally occurring silica in order to be used for manufacturing semiconductors?</p>
</blockquote>
<p>As high as possible.</p>
<blockquote>
<p>...high purity quartz with total impurity levels less than 20 ppm...</p>
</blockquote>
<p>20 ppm means that the silica has to be 99.998% pure. It is extremely hard to find silica that pure in nature.</p>
<p>More specifically:</p>
<blockquote>
<p>Specific requirements as to tolerable limiting values differ from
industry to industry. In the lamp tubing and optics industries
aluminium content in the refined quartz concentrate should not exceed
20 ppm, other metals should be less than 1 ppm, and total impurities
less than 30 ppm. For semiconductor base materials and crucibles
aluminium content should be even lower, specified to less than 10 ppm,
other metals less than 0.1 ppm, and total impurities not to exceed 15
ppm.</p>
<p>Feedstock for solar silicon used in the photovoltaic industry should
generally have boron and phosphorus contents in the sub-ppm range
since these elements are most difficult to remove and negatively
affect the performance of the solar cells (Geerligs et al. 2002).</p>
<p>For microelectronics applications, e.g. in epoxy moulding compounds,
uranium and thorium, both responsible for soft errors by alpha
radiation, should be less than 2 ppb, and in low alpha applications,
even less than 0.5 ppb.</p>
</blockquote>

CC BY-SA 4.0
2020-11-16T10:17:44.403Z
2020-11-16T10:17:44.403Z
Gimelist
<p>Silica is Silicon dioxide, Sand being it's most abundant availability source. &quot;Fossil Sand&quot; contains various other rocks and crushed fossils, etc.
The Two most abundant rocks on earth, Granite and Basalt.
But quartz is it's most abundant source with an overall purity of 90+ percent.</p>

CC BY-SA 4.0
2020-11-20T00:49:54.823Z
2020-11-20T00:49:54.823Z
LazyReader
<p>Silicon is often touted as the second most abundant element in the Earth's crust. However, this can be misleading when looking at the abundance of high purity silica needed for manufacturing semiconductor wafers.</p>
<p>What purity level is required in naturally occurring silica in order to be used for manufacturing semiconductors? How abundant is it in the earth's crust?</p>

CC BY-SA 4.0
2020-10-31T17:26:32.327Z
Depends what you mean by "high purity". Ottawa ( IL ) silica sand is pretty clean .
blacksmith37
CC BY-SA 4.0
2020-11-02T23:31:33.690Z
[Very pure silicon (> **99.9%** ) can be extracted directly from solid silica or other silicon compounds by molten salt electrolysis. This method, known as early as 1854, has the potential to directly produce solar-grade silicon without any carbon dioxide emission at much lower energy consumption.
Bulk silicon wafers used in integrated circuits must first be refined to an even higher "nine nines" purity (**99.9999999%**), a process which requires repeated applications of refining technology.](https://www.addisonengineering.com/about-silicon.html)
Keith McClary
CC BY-SA 4.0
2020-11-04T08:34:55.100Z
only slightly related: [Why would India have so much thorium on its beaches?](https://earthscience.stackexchange.com/q/15381)
uhoh
<geochemistry>
How abundant is high purity silica?
gstudent
# How abundant is high purity silica?

(Asked by: username_0 on 2020-10-30)

Silicon is often touted as the second most abundant element in the Earth's crust. However, this can be misleading when looking at the abundance of high purity silica needed for manufacturing semiconductor wafers.

What purity level is required in naturally occurring silica in order to be used for manufacturing semiconductors? How abundant is it in the earth's crust?

**Tags:** geochemistry

> **Comments:**
> **username_1**: Depends what you mean by "high purity". Ottawa ( IL ) silica sand is pretty clean .  
> **username_2**: [Very pure silicon (> **99.9%** ) can be extracted directly from solid silica or other silicon compounds by molten salt electrolysis. This method, known as early as 1854, has the potential to directly produce solar-grade silicon without any carbon dioxide emission at much lower energy consumption. Bulk silicon wafers used in integrated circuits must first be refined to an even higher "nine nines" purity (**99.9999999%**), a process which requires repeated applications of refining technology.](https://www.addisonengineering.com/about-silicon.html)  
> **username_3**: only slightly related: [Why would India have so much thorium on its beaches?](https://earthscience.stackexchange.com/q/15381)  

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## 2 answers

### Answer by username_4 on 2020-11-16. Score: 3

Quoting from this paper: Haus R., Prinz S., Priess C. (2012) Assessment of High Purity Quartz Resources. In: Götze J., Möckel R. (eds) Quartz: Deposits, Mineralogy and Analytics. Springer Geology. Springer, Berlin, Heidelberg. <https://doi.org/10.1007/978-3-642-22161-3_2>

> What purity level is required in naturally occurring silica in order to be used for manufacturing semiconductors?

As high as possible.

> ...high purity quartz with total impurity levels less than 20 ppm...

20 ppm means that the silica has to be 99.998% pure. It is extremely hard to find silica that pure in nature.

More specifically:

> Specific requirements as to tolerable limiting values differ from
> industry to industry. In the lamp tubing and optics industries
> aluminium content in the refined quartz concentrate should not exceed
> 20 ppm, other metals should be less than 1 ppm, and total impurities
> less than 30 ppm. For semiconductor base materials and crucibles
> aluminium content should be even lower, specified to less than 10 ppm,
> other metals less than 0.1 ppm, and total impurities not to exceed 15
> ppm.
>
> Feedstock for solar silicon used in the photovoltaic industry should
> generally have boron and phosphorus contents in the sub-ppm range
> since these elements are most difficult to remove and negatively
> affect the performance of the solar cells (Geerligs et al. 2002).
>
> For microelectronics applications, e.g. in epoxy moulding compounds,
> uranium and thorium, both responsible for soft errors by alpha
> radiation, should be less than 2 ppb, and in low alpha applications,
> even less than 0.5 ppb.


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### Answer by username_5 on 2020-11-20. Score: 0

Silica is Silicon dioxide, Sand being it's most abundant availability source. "Fossil Sand" contains various other rocks and crushed fossils, etc.
The Two most abundant rocks on earth, Granite and Basalt.
But quartz is it's most abundant source with an overall purity of 90+ percent.


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