Float Zone (FZ) Silicon Wafers High Purity for Research

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Float Zone Silicon Wafers

A large semiconductor company requested pricing for the following:

"I am look for the Silicon wafer for optics windows, can you let me know which grade is the best  for optics images application?

Which one is Float Zone Silicon , I am look for dia 100mm, thickness 500um"

Reference #222232 for the quote.

Most people don't know that there are different types of silicon wafers, and even fewer know that float zone silicon wafers, also called undoped and intrinsic, are the best type for certain applications.

UniversityWafer, Inc. supplies only the highest quality float zone silicon wafers to its customers because we believe that our products make a difference in their work. We have been supplying Silicon Valley companies with these superior wafers for over 10 years and our experience makes us your perfect choice for a supplier.

Get our FZ Silicon Quote Fast and start researchering today!


What NTD Float Zone Silicon Wafers Used to Make Diodes?

Researchers use the following silicon specs to fabricate Schottky barrier and heterojunction diodes:

100mm NTD FZ wafer Resistivity: 10 Ohm-mm Orientation: <111>

Please ask for your quote today.

What Silicon Wafer is Transparent to the Infrared (IR)

Silicon wafers, especially those very high resistivity, are transparent to IR. I attach article in pdf format, providing many details on the si transparency subject. If you need silicon which is less IR transparent, we recommend using highly doped CZ wafers.

Item   Qty.   Description
GP15. 50/100   Silicon wafers, per SEMI Prime, P/P 4"Ø×380±5µm,
FZ Intrinsic undoped Si:-[100]±0.5°, Ro > 20,000 Ohmcm,
Both-sides-polished, SEMI Flat (one),
Sealed in Empak or equivalent cassette,
MCC Lifetime>1000µs.

Please let us know and we return with the offer.

What is the IR Transmission of DSP Undoped Silicon Wafers?

The Infrared (IR) Transmission through undoped FZ crystallized double-side-polished Silicon wafer is >52% but only in the wavelength range (1.2-6.5) µm. Again, absorption is nill and transmission is limited by surface reflections. However, at longer wavelengths, specifically (8-14)µm, lattice absorption becomes significant and  transmission drops markedly.  



What are Float Zone Silicon Wafers Used For?

Float-zone (FZ) silicon wafers also called undoped or intrinsic are used in applications that require purity that is much higher than Czochralski (CZ) grown silicon.

Examples include:

  • Power devices & detectors
  • Highly transparent to terahertz radiationcy, so it's used to fabricate optical components - lenses and windows
  • Satellite solar arrays

We have a large selection in stock, but we can customize any order in small and large quantities.

Intrinsic Silicon to Fabricate Diamond Membranes

An material science engineer requested a quote for the following:

Do you have any silicon wafers (for growing boron doped diamond membranes) that are electrically non-conductive? I have a need for a 5 or so and would like to use these instead of having my end user do further processing. 

I think I would like them to be 200-350um thick because I’ll need to etch an open aperture in places.  A 2” diameter would be fine with us.

UniversityWafer, Quoted the following intrinsic silicon. Lifetime <1,000

Item Orient. Diam. Thick
Surf. Resistivity
7121 [100] 2" 300 P/P FZ >20,000
B0128 [100] 2" 280 P/E FZ >20,000
K324 [111] ±0.5° 2" 330 P/P  FZ >20,000

Reference #275414 for pricing and quantity.

Can you obtain float zone high purity Silicon wafers with Arsenic (As)-doping?

A university researcher asked us if aresenic doped FZ Silicon wafers are possible?


"The As-doped FLOAT ZONE wafers can be any diameter from 2” to 8”.  They should ideally be 500 microns thick, but we can perhaps use other thicknesses.  The doping should be heavy, and must be pure Arsenic (not Phosphorous), and should result in a low total resistivity in the range 0.001 to 0.01 Ohm-cm.   The most important property is the wafer purity.  The wafers should consist of only pure Silicon and pure Arsenic.  We would need a total wafer area equal to 5 to 10 wafers of nominal 4” diameter.

We intend to use this material to fabricate Silicon filaments that we will pass current through, and heat to high temperatures so as to provide Si-doping for a GaAs MBE growth process."

UniversityWafer, Inc. Replied with the following. Reference #221299 for other Si wafer options.

Float Zone crystallized Silicon is never doped with Arsenic. However, the Silicon within CZ crystallized material is just as pure as the Silicon in FZ crystallized material. The only difference is that CZ Silicon contains about 20ppma of dissolved Oxygen and anywhere between 0.4 and 2.0ppma of Carbon, whereas FZ silicon contains <0.4ppma of Oxygen and < 0.4ppma of Carbon.. At Ro=0.005 Ohmcm Si:As contains about 250ppma of Arsenic. at Ro=0.001 Ohmcm it is more than 1,250ppma. The Arsenic used for doping is normally better than 6N pure.

Are Float Zone Silicon Wafers Transparent?

Float-zone silicon wafers are very transparent to terahertz radiation, and is typically used for fabricated optical components, including lenses and windows, for terahertz applications. Float-zone silicon applications include high-efficiency solar panels, power devices, and detectors. Float-zone silicon wafers, can be ordered with P-type boron and N-type phosphorous formulations. Unlike CZ Silicon, FZ Silicon has a very high resistivity. We carry wafers with greater than 20,000 Ohm-cm, and in all orientations and more diameters from 1 inch to 12 inch.

What is Terahertz Radiation?

The Terahertz range refers to electromagnetic waves between 100 GHz and 10 THz, or wavelengths of 3 mm and 30 mm. The main benefit of terahertz waves (with frequencies sub-terahertz of 0.1 THz-0.3 THz) is that many materials which block visible and IR spectrum seem to be transparent in the terahertz range. The attenuation of terahertz waves by media is generally stronger than that for microwaves, and therefore limits the depth possible for imaging. 

Intrinsic Float Zone (FZ) Silicon Wafer

25.4mm Intrinsic (100) >2,000 ohm-cm SSP 280 micron

N-type Phosphorous Float Zone (FZ) Silicon Wafer

50.8mm N-Type Phosphorous Float Zone (FZ) (111) >200 ohm-cm SSP 200um

Undoped Float Zone (FZ) Silicon Wafer

76.2mm Undoped (100) >5,000 ohm-cm SSP 500um

Float Zone (FZ) Silicon Wafers

100mm, 150mm and 200umm Undoped Silicon Wafers in stock. All orientations, resistivities and other specs in stock.

High-Resistivity Silicon Wafers

Float-Zone Silicon Wafer Applications

When researchers need the higher purity Silicon, they use FZ Silicon substrates instead of  Czochralski grown silicon.

Or simply put, Float Zone Si is most ly used low volume applications that require high-efficiency while CZ Silicon is used for high volume, less expensive applications.

Below are just some of the Float Zone wafers that we have in stock.

There are a number of interesting applications of silicon wafers, largely due to the addition offloat zone fz silicon substrates technological sophistication, but also due to their practical and easy application. [Sources: 5, 7]

Speaking of product range: The study divides the market for float zone silicon wafers into P-type and N-type. On the demand side, this report focuses on the use of silicon wafers in the production of high-performance electronics, medical devices and other applications. A large stock of silicon wafers, which are available as P-type boron-doped wafers with primary flat-cut technology, is maintained as they are frequently used. This provides a good basis for research and development of the Float Zone (FZ), a test wafer that is available on request. [Sources: 0, 7, 9]

Doped silicon wafers, which are produced by adding certain impurities or doping to the silicon crystals of a manufactured prime wafer, are considered to be the highest possible silicon wafer quality. However, there are a number of prime quot wafers and the concentration and size of oxide clusters and nuclei in a given silicon wafer depends on the proportion of ingot the silicon wafer takes up. [Sources: 6, 9]

In this embodiment, the silicon wafer may be rectangular and possibly flaked off, but the excited beam may also flake off and move relative to the surface of the wafer. In addition, a silicon workpiece with a float zone can comprise a square silicon wafer with a thickness of 2 - 70 microns, which can form a floating zone with a diameter of 1.5 microns and a surface area of about 1,000 microns with a thickness of 160 - 600 microns. [Sources: 4]

What is Floating Silicon Method?

Developed by developed by Henry Theuerer, the floating-zone (FZ) technique produces high-purity, crystallized silicon. The float zone method is the best-and-final solution to this technique, where the wafer requires crystalline silicon that is pure, and has almost no impurities. Together with a requirement of reasonable prices and uniform distribution of resistivity, not just on the individual wafer, but on the entire boule, Float Zone silicon is the best choice of materials, and is thus used today solely in detector applications.

A scientist requested the following quote:

"I am looking to purchase 25 4" Si wafers with a thickness of 250um. Could you send me a price list for the products you offer, please?

The previous batch of wafers we ordered from University Wafers were "4 inch wafers of intrinsic Silicon, double side polished, orientation <100>, high-resistivity (? > 15 kO cm), floating zone and thickness of 250um". Would it be possible to order wafers of the same type?"

Please reference #265563 for specs and pricing.

Applications That Benefit from High Purity Silicon Wafers

The float zone method is the be-all and end-all for the technology when a wafer requires high-purity silicon with little or no impurities. When it comes to growing silicon crystals on silicon wafers, the FZ method can be used in a variety of applications such as microfibers and microfluidic devices, but is typically limited to about 150 mm and can have a thickness of between 2 and 70 micrometers (ki / c cm).

If you contact UniversityWafer, Inc. today, you can learn more and purchase your float zone silicon wafers from the best floating zone wafer vendors. UniversityWafer, Inc. is one of the leading suppliers of high-quality float zone silicon wafers and makes you your silicon wafer supplier. True - premium wafers are the product of UniversityWafer, Inc., a leading supplier of silicon wafers. The manufacturing company with over 30 years of experience in the semiconductor manufacturing sector offers all services for silicone wafer recovery and polishing for 100 - 300 mm silicon wafers. [Sources: 1, 9]


[0]: https://www.qyresearch.com/index/detail/1887399/global-float-zone-silicon-wafers-industry

[3]: https://scientect.com/news/1480032/semiconductor-silicon-wafer-market-segmental-highlights-and-table-of-content-2018-2023/

[4]: https://www.google.com/patents/WO2015126980A1?cl=en

[5]: https://bulletinline.com/2020/08/28/float-zone-silicon-wafers-market-analysis-by-trends-types-applications-manufactures-regions-market-size-and-forecast-up-to-2023/

[6]: http://www.google.com/patents/US9293329

[7]: https://www.aeresearch.net/float-zone-silicon-wafers-market-246214

[9]: https://directadmissionbanglore.com/tdtl7s/silicon-wafer.html

[10]: https://patents.justia.com/patent/20140096822