Why Use Amorphous Silicon?

university wafer substrates

Amorphous Silicon Thin Films on Substrates

A scientist on a master level requested a quote for the following:

For one of our experiments we are looking for thin films of amorphous
silicon on a substrate. The Substrate need to be transparent between
600nm-2000nm. While the film need to be absorbing at around 775nm and transparent above ~1300nm. It should not be thicker then one mum but still absorb most of a light beam at 775nm.

The carrier recombination times need to be fast, below a hundred
piecosecond would be good.

Reference #90835 for specs and pricing.

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Amorphous Silicon on Fused Silicon

A researcher asked for a quote on the following:

I am looking to buy one 4" Si on Fused quartz double polished wafer with an amorphous Si layer of 50 nm thick. These are the important specs for me and am more curious of how much and the lead time for this wafer.

Please reference #267283 for pricing.

What Techniques Can Fabricate Amorphous SIlicon Solar Cells?

Although different techniques can be used, a route for producing an amorphous silicon solar cell in a thin film starts from the substrate. Hydrogenated layers of amorphous silicon are used to make very efficient heterojunction solar cells, but when used for amorphous silicon solar cells, it results in a cell efficiency of only 7 percent. All of these factors combine to give for amorphous silicon solar cells, a reasonable efficiencies at cell level of around 9-10%, while for traditional Pn-structures, such as the ones used for all other types of solar cells, you will not get above 1%, in the case of amorphous silicon. Amorphous silicon solar cells exhibit an initial degradation, and their efficiency stabilises after approximately two years of a regular exposure to sunlight, besides, the efficiency decline observed in amorphous silicon is completely reversible: the initial condition can be restored by annealing at around 200C. Furthermore, the instability observed in amorphous silicon depends on the operating temperature: the degradation is far less marked, as is typically encountered in tropical countries. 

Important Amorphous Silicon Terms

  • silicon solar 
  • amorphous silicon
  • dielectric strengths
  • solar cells
  • hydrogenated silicon
  • polycrystalline silicon
  • nanorod structures
  • etched silicon
  • type silicon
  • silicon dioxide
  • quantum efficiency
  • cell efficiency
  • amorphous silica
  • tandem solar
  • film solar    

Can You Deposit Single Crystal Silicon on Glass Substrates?

A researcher who requested a quote on Silicon-on-Sapphier (SoS) wafer.

 4" SOS substrates with 1 micron thick Si R-plane+/-0.2° 460+/-20um DSP Prime Si p/N (100) thicknes 1 micron

Do you have the Silicon on Glass substrate: Same Si  single crystal layer: Si (100) n/P thickness 1 micron over a borosilicate or over fused silica?

UniversityWafer, Inc. Replied:

Silicon on Glass substrate:borosilicate or over fused silica can only be amorphous,Not single crystal,thickness 1 micron easily cracked,and much higher cost than Si on Sapphire.

Thin Fused Silica to Construct a Filter for X-Ray Application

A corporate scientist requested the following quote:

I’m looking to construct a filter for an X-ray application. It is important that the material be amorphous, pure, and of a very well characterized thickness. Roughness down to about a 1/2 micron level is best.

I can model such a filter like this using pure SiO2 which is 100 um thick:

This is about right. So what I think I would like is a fused silica wafer which is 100 microns thick (+/- some small amount). I can make several of these filters by chopping up the wafer.

I’m also open to other materials if you wish to suggest them. What would you have available?

Reference #195918 for specs and pricing.

Amorphous Silicon on Quartz Wafers

A researcher ased for the following quote:

I was wondering if University Wafers makes amorphous Si on Quartz wafers are something similar? We are planning on using lithographic techniques to etch out nanostructures and then test the optical properties of the structures.

Reference#267283 for pricing.


Why Use Amorphous Silicon?

Amorphous silicon wafers have several cost advantages over single-crystal silicon wafers, primarily due to differences in their manufacturing processes and material properties:

  1. Lower Production Costs: Manufacturing amorphous silicon involves simpler and less expensive processes than producing single-crystal silicon. Single-crystal silicon requires a high-purity silicon source and a complex process like the Czochralski method to grow single crystals, which is energy-intensive and costly. In contrast, amorphous silicon can be deposited in thin films directly onto a substrate through techniques like Plasma-Enhanced Chemical Vapor Deposition (PECVD), which is more economical.
  2. Less Material Usage: Amorphous silicon can be deposited as a thin film, which means it uses significantly less silicon material than the thick wafers needed for single-crystal silicon. This reduction in material usage leads to lower costs.
  3. Lower Energy Consumption: The processes used to create amorphous silicon typically operate at lower temperatures than those required for single-crystal silicon production. This results in lower energy consumption and, consequently, reduced manufacturing costs.
  4. Flexibility in Substrate Choice: Amorphous silicon can be deposited on various substrates, including glass, plastic, and metal, often cheaper than the high-quality silicon substrates required for single-crystal silicon. This flexibility can further reduce the overall cost.
  5. Simplified Processing for Certain Applications: For some applications, particularly thin-film solar cells, amorphous silicon can be used directly without the need for additional processing steps required for single-crystal silicon, such as wafer slicing and polishing, thus reducing processing time and costs.

However, while amorphous silicon is less expensive, it generally has lower efficiency and stability compared to single-crystal silicon, especially in applications like solar cells. This trade-off between cost and performance is a key consideration when choosing between these materials for specific applications.

Advantages and Disadvantages of Amorphous Silicon

Amorphous Silicon is an important element in many different applications, including Solar cells, Thin-film amorphous silicon explainedtransistors, and X-ray imagers. This article will discuss the advantages and disadvantages of amorphous silicon and how it can be used for a variety of applications. The following are some examples of Amorphous Silicon products. Listed below are a few:

What are Amorphous Silicon Solar cells?

Amorphous Silicon is a highly flexible material that has the potential to be used in solar cells. Its high refractoriness and excellent transmission characteristics make it an ideal material for solar cells. Amorphous silicon can be used in solar cells at a high efficiency rate, and the main component of a p-i-n cell is three layers of p-doped material. Other materials for solar cells include amorphous silicon and n-doped silicon.

Amorphous silicon is a good material for solar cells because it can be shaped to meet the needs of the module. The crystalline silicon is more stable at lower temperatures, while amorphous silicon is more malleable at higher temperatures. However, this material is limited in use in solar cells. The use of Amorphous Silicon in solar cells is becoming more popular. In recent years, more manufacturers are embracing the material as a viable alternative.

The prototype Solar cell (of my propietary design) can be based on an existing thin-film photovoltaic materiel such as amorphous Silicon or CdTe.  If you can manufacture thin film Solar cells on a flexible substrate then you may well have capability of building my prototype. My prototype wil not be based upon a Crystalline Silicon type Solar cell so that type of manufacturing will not work.

In the past few years, researchers have been investigating amorphous silicon for solar cells. They have developed a shunt-free contacting method on non-planar fabrics. Although transmission losses in a 10 nm titanium layer limit the short-circuit current density to 3.7 mA/cm, this material offers a high fill factor, and achieved efficiencies of 1.4%. The use of a transparent conductive oxide in the p-type layer will enable the material to achieve a higher efficiency.

Researchers at Heriot Watt University are also working on amorphous silicon for solar cells. They are developing thin film solar cells on textile substrates, where they can benefit from the scattering properties of the material. Ultimately, these solar cells can be used in disaster relief shelters, agriculture and architecture. For the time being, however, they are only being tested in laboratories. Further research will need to be conducted in this area.

Amorphous Silicon Deposited onto Borofloat 33 Substrate

A research scientist requested a quote for the following:


Can you quote the guy below for Pyrex with 1.5 microns of amorphous silicon on each side.

We’d like to order quantity 12 of: 4” BF33, prefer wafer w/ major flat with 1.5 microns of amorphous silicon on each side.

LPCVD or PECVD deposition would be fine; we're just looking or a wet etch mask and sputtering is too expensive.


It would be a lot better to do this by low-temperature LPCVD since the a-Si would grow on both sides simultaneously, but I don't know if you can get it thicker than 0.5µm by this technique.

We can sputter Si, but we have no data on how amorphous it is.  It may have some polycrystalline aspects to it, but this is just speculation.

The sputtered route is expensive, as a two sided process will take 2 days of machine time.  Here's our quote:  our lot charge for in-situ sputter etch followed by sputter deposition of 1.5µm Si is $.  Lot size: 12-4"
wafers.  Coating both sides doubles the price to $.

Reference #91258 for specs and pricing.

What are Amorphous SiliconThin-Film Transistors?

Amorphous silicon thin-film transistors can be fabricated on polyimide foil, which is 25 mm thick and flexible. It is capable of being bent at radii of curvature as small as 0.5 mm without changing its electrical properties. The best performing thin-film transistors are those made of amorphous silicon. Here is a description of how amorphous silicon thin-film transistors work.

Amorphous silicon has many benefits over crystalline silicon. It is cheaper and has more crystalline grains, which make them good candidates for flexible image sensors and flat panel displays. Amorphous silicon can also detect individual X-rays or neutrons. The amorphous nature of amorphous silicon makes it ideal for thin-film transistor elements in LCDs. The deposition process of amorphous silicon makes it possible to fabricate image sensor arrays on plastic substrates.

While amorphous silicon thin-film transistors are a popular choice for liquid-crystal displays and other large-area electronics, they have a number of fundamental limitations associated with their performance. Using plasma-enhanced chemical vapor deposition, for example, is a good way to create large displays. Using this method allows for exceptional reproducibility and uniformity. In addition, engineering solutions are also available to mitigate amorphous silicon's limitations.

In 1979, the RCA group led by Weimer reported the first pixel switching devices. This breakthrough was not used until material was available for the fabrication of large-area flat panel displays. LeComber and Spear's experiments were cited as the most important breakthrough in flat panel technology. However, the invention of the amorphous silicon TFT is credited to another RCA group.

What is Amorphous Silicon X-ray Imagers?

Compared to conventional X-ray imagers, amorphous silicon arrays exhibit improved pixel design. They are composed of a continuous layer above the readout structures, and their geometry extends beyond the mesa isolated structure. When used with conversion phosphor, these new imagers offer better sensitivity to X-ray illumination and visible light. However, the current technology has certain drawbacks.

The technology behind X-ray imagers for spherical amorphous silicon is relatively new, but the underlying physics is very similar. Amorphous silicon is an analog of CCD detectors and does not degrade under x-ray exposure. Thus, it is suitable for a wide range of applications, including medical imaging. The advantage of using amorphous silicon is that it is inexpensive, and there are many applications for this material.

Amorphous silicon imagers have improved low-contrast performance compared with amorphous selenium detectors for doses up to 135 uGy. For higher-dose phantoms, the amorphous silicon detector was superior. However, the difference between the two systems was not statistically significant. If you're looking for an amorphous silicon imager for use in radiology, you've come to the right place.

Amorphous silicon imagers are becoming increasingly popular, and this technology is ready for mass production. X-ray imagers for amorphous silicon will enable large-area detectors and be more flexible. Unlike conventional detectors, amorphous silicon is cheaper than crystalline silicon. Its larger size makes it a more cost-effective option in the long run.

The main objective of this study was to compare the image quality of both systems in chest radiography. It aimed to evaluate the differences in contrast detail and image quality among the detectors at different dose settings. Table 1 provides the technical characteristics of both detectors. Each photodiode converts light into an electric charge. The resulting digital signal is a 14,-bit digital signal with a 3,001 x 3,001-pixel matrix.

What Amorphous Silicon is used in Liquid Crystal Displays (LCD)?

Amorphous Silicon liquid crystal displays have several advantages over their glassy counterparts. The lack of crossovers in the array reduces the overall capacitance of the display, making them faster to address. The top and bottom transparent plates are polarized. This polarization is in line with the type of liquid crystal display material 120. This method also improves the overall structure of the display. The result is a more compact display.

The display of the present invention includes an insulative substrate, a first electrode, and a second electrode formed on the insulative substrate. The pixel electrodes are separated by a first isolation device, which is insulated from the first electrode, and are electrically connected to a second electrode formed on the first pixel electrode. The electrodes are in a row and column arrangement, with the second pixel being spaced apart and substantially parallel to the first one. The light-influencing material is disposed between these two electrodes.

In the 1980s, a group of researchers at Dundee University demonstrated the use of amorphous silicon field-effect transistors to switch liquid crystal arrays. They did so while other semiconductor thin film materials were deemed unsuitable for large-area substrates. These results laid the groundwork for the commercial development of flat-panel television displays. The displays will be mounted on an outside wall of the building. A plaque commemorating the development of amorphous silicon liquid crystal displays will be erected on the wall, making it visible to visitors to the campus.

Despite the advantages of Amorphous Silicon liquid crystal displays, they do not have the same drawbacks as the traditional polycrystalline counterparts. Their high sensitivity and low energy consumption make them suitable for most applications. Amorphous silicon is ideal for LCDs and thin-film transistors for the LCD. Amorphous silicon displays have the potential to be more powerful than polycrystalline ones, and are expected to become the most widely used flat-panel displays.

What is Amorphous Silicon TFT-LCDs?

In the past few years, TFT-LCDs made of amorphous silicon have been the focus of research and development. These displays can be extremely thin, which is an excellent fit for mobile phones. Amorphous silicon can be made into thin, flexible panels with an extremely high resolution. However, this technology may not be appropriate for all mobile devices. Some applications are more suitable for thinner displays than others, so a hybrid solution may be the best option.

Amorphous silicon TFT-LCDs operate by controlling the brightness of RGB sub-pixels. Because these pixels do not produce light, they require LED backlights for illumination. Unlike conventional LCDs, TFT screens can be adjusted for nighttime or sunlight readability. In addition, all TFTs are active matrix displays, which means that the individual pixels do not fade while waiting for the next cycle.

Low-temperature Poly-silicon TFT-LCDs have the advantage of being less susceptible to degradation. Moreover, the LTPS technology can reduce the number of components and connections in the LCD by more than half. This technology fosters greater reliability and flexibility. It can also be fabricated on glass substrates, making it an excellent choice for mobile devices. LTPS technology also offers higher resolution and picture quality, as well as lower power consumption and fewer connections.

Amorphous silicon has the same advantages as crystalline-silicon, including low cost and plentiful supply. However, its low electron mobility makes it incompatible for high refresh rates. Currently, new materials, including metal oxide and low-temperature polysilicon, are replacing amorphous silicon for LCDs and OLEDs. Despite its limitations, amorphous silicon remains an excellent option for liquid-crystal displays.