Super Low Stress Silicon Nitride up to 4µm All Diameters

university wafer substrates

Why use Super Low Stress Nitride on Silicon Wafers?

A Phd requested a quote on the following:

"I want to purchase 25 4 inch diameter Silicon Wafers with Super Low Stress Nitride Here are the requirements:

  1. wafer thickness: 400-500 microns
  2. silicon nitride (on both sides) thickness: 200-300 nm
  3. wafer should be both-side polished with surface roughness less than 1nm
  4. Do you have characterization for the surface roughness?
  5. Do you have the tensile residual stress level for them? 

We quoted the following:

2,000 angstroms Super Low Stress LPCVD Nitride (<100 MPa Tensile) on 25 pieces of 100mm (525um).

Reference #218255 for spec and pricing.

The semiconductor industry is constantly looking for ways to improve the performance of their products. One way to do this is by increasing the thickness of the nitride layer that is deposited on the silicon wafer.

The problem is that most nitrides are very thin and cannot deposit more than a few microns of nitride on a semiconductor. This can lead to poor performance and low yields in manufacturing.

UniversityWaferr, Inc.'s Super Low Stress Nitride (SLSN) solves this problem by being able to deposit up to 4 microns of nitride on a silicon wafer without the nitride cracking! This makes it possible to produce high quality, high performance semiconductors in large quantities.

When you need the thickest nitride Super Low Stress Nitride is the nitride to use. We can deposit up to 4 micron of nitride using this method of nitride deposition. Get Your Quote FAST!

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What are Super Low Stress Nitride Applications

A university researchers requested for a quote to fabricate Silicon Membranes:

"I’d like to get a quote for the quantity= 5 of the wafer with the following specification:

4 inches intrinsic, prime grade silicon wafer with the thickness of 300 um covered from both sides by 500 nm super low stress SLS silicon nitride. One more thing that I forgot to mention is since I want to make some SiN membrane and wet etch through the whole Si wafer, I prefer to have double-sided polished Si wafer in addition to the other specifications I mentioned in my previous email. I am wondering if I can have 1 wafer as a sample to make sure this kind of wafer works for our experiments before purchasing 25 wafers. If it is not possible, then give me 2 weeks to decide since we have some of your heavily doped Si covered by 300 nm thermal oxide and I need to see if I can do deep RIE to make a through substrate holes."

Please reference #240367 for specs and pricing.

Super Low Stress Nitride Coated Silicon Wafers for Nanopore Fabrication

 A university scientist requested the following quote:

"Hello, Im getting started in doing solid state nanopore fabrication. I tried doing the quote form but received "couldnt execute sql query" so I apologize if this is the fourth time youve received this message. Low Stress Nitride Silicon Wafers 20 nm thickness Wafer size 150 mm Wafer thickness 500 um Wafer material Silicon I would like to know the 10/25/50 unit prices Super Low Stress Silicon Nitride same specs as above and same inquiry If you have any other suggestions for materials for this application, please let me know. I am just getting started in this and it seems like silicon nitride on silicon is the common choice of material for nanopore fabrication based on what I've read so far. I was just wondering if you happen to know if any of your customers do solid state nanopore work and, if so, what they usually order."

Please reference #240813 for specs/pricing.

Super Low Stress Nitride for Fabricating Waveguides

Regarding silicon nitride waveguides. We are interested in stoichiometric Silicon Nitride on oxide. What is the standard silicon substrate height for a 4 inch wafer? We want to get quotes for 2 micron and 3 micron buried oxide. How much would 400 nm thick stoichiometric silicon nitride? I am new to fabrication so I apologize if I am wording this poorly. 

UniversityWafer, Inc Quoted:

This requirement is a problem.  400nm is the maximum of Stoichiometric Nitride we will deposit on a bare wafer.  On thick oxide we highly recommend no more than 300nm due to the high probability of cracking and delamination of the nitride film.  Another way around it is to use 400nm of Super Low Stress Nitride.  Please review this with the customer and I will quote whichever they select. 

The following answers your specific questions:

  1. We can deposit Si3N4 on Silicon wafers with a Thermal Oxide layer, that is Si3N4/SiO2/Si.
  2. Standard thickness of 4"Ø SIlicon wafers is 525±25µm.
  3. Thermal Oxide up to 2.4µm is relatively inexpensive, thicknesses above that are significantly more expensive.
  4. Stoichiometric Silicon Nitride (Si3N4) grown on Silicon or Thermal Silicon Oxide is significantly stressed (~1,000 MPa}. It is normally grown no thicker than 300nm. Above that, the layer is very likely to crack. We would not undertake to produce Si3N4 layer 400nm thick. Refractive Index of Si3N4 is 2.0559 @ 532nm.
  5. We can also grow Low Stress Silicon Nitride (SixNy) films. Such Low-Stress Silicon Nitride can be tailored to a specific stress eg <250 MPa in tension or even <100 MPa in tension or compression. Such films have lower refractive Indexes, at least as low as 1.9 @ 532nm. We can offer such films tailored to a specific refractive index, but not above 2.0559.
  6. Silicon Nitride made by PECVD grows quicker and is less precise than that grown by LPCVD. PECVD grows Silicon Nitride on one-side of the wafer whereas LPCVD grows it on both sides. PECVD is less expensive than LPCVD for thick layers (such as 2µm of Low Stress Silicon Nitride) but it is more expensive for very thin Nitride layers.

I hope that above answers your questions and lets you formulate your requirement such that we can quote a price for what you need.

Please reference #252132 for specs/pricing.

Super Low Stress Nitride For Optical Waveguides

A Phd student requested the following quote:

"We would like to have information on the optical quality of the low-stress (or super low stress) SiN, and of the stoichiometric nitride, since we are going to use them for optical waveguides at wavelengths around 750 and 1550 nm. Could you provide us with that information? Otherwise, are there photonic groups using them for the same application, and can we get information or papers mentioning optical losses?"

Please reference #241480  for specs/pricing.

Super Low Stress Nitride for MEMS Research

I am looking to purchase some SiN coated Si wafers with 1-10um of SiN. What kinds of options do you have?

Diameter 100mm
SiN Thickness: 500nm
Resistivity: Any
Dopant: Any
Type: Any
Polish: Any
Super Low Stress
Grade: Prime

We are essentially looking to use this as a substrate for MEMS purposes and outside of the stress, size, and thickness we don't have any specific requirements.

Please reference #249245 for specs/pricing.

Super Low Stress Nitride (SLSN) is a nitride that can be deposited on a silicon wafer. It is the thickest type of nitride. It can deposit up to 4 microns of nitride on a semiconductor. The process is effective in producing a wide range of LSSNs, from thin films to thick layers.

This low-stress material is deposited by a process that involves the deposition of a thin film. It is formed at a high DCS to NH3 ratio, and has low tensile stress. This type of nitride is produced in a variety of processes, including chemical vapor deposition, vacuum sputtering, and surface micromachining. It is an excellent material for use in electronic devices, ion implantation masks, and antioxidation.

High-stress silicon nitride microresonators show a remarkable Q factor at room temperature. This is significantly higher than that of single-crystal silicon, although the difference is small. At lower temperatures, Q-1 decreases, but the thin film is featureless. The thin film is suitable for coating both sides of a wafer, and is also a good material for hard masks.

During deposition, the low-stress silicon-rich nitride is characterized by its stoichimetric composition and extremely low mechanical stress. Besides, its excellent dielectric properties and high Young's modulus make it a useful material for MEMS devices and surface micromachining. The layered structure of the material makes it an excellent material for MEMS fabrication. However, if you are planning to use it for a commercial product, it is best to consult a reputable company for your specific needs.

Low-stress silicon nitride is an insulator that is highly resistant to mechanical stress. In addition, it has high thermal conductivity. In contrast to silicon, it is also transparent. Its internal stress is 135 MPa. It has been successfully used in high-tech applications, such as the construction of transistors and photodetectors. In general, this type of insulator is more flexible than its crystalline counterparts.

High-stress stoichiometric silicon nitride is the most common insulator. This material is more expensive than poly-Si, but it is a promising alternative. Its low-stress silicon nitride resonator is significantly less brittle than poly-Si, which is a more versatile material. This property makes it a great option for various industries.

In this study, super-low-stress silicon nitride was deposited on a commercially purchased 4'' silicon wafer using LPCVD. The resulting film was patterned by a standard UV photolithography process. The substrate was then etched by reactive ion etching using sulfur hexafluoride and Helium at a voltage of 110 w for 6 minutes.

Another advantage of LS SiN is its low etching rate. When exposed to KOH, it etching resistance is high and LS SiN is an excellent etching resistant barrier. In contrast, it is sensitive to oxygen residue in the film. This means that the film's sensitivity to oxygen is very high. A film containing LS SiN is susceptible to abrasion.

In this process, a conventional 4'' Si wafer is patterned with open windows. The wafer is then placed in a vacuum chamber under a house vacuum. Then, a 25% KOH solution is used to etch through the wafer, releasing a thin layer of metal. The photoresist is then removed and the metal pattern is revealed. The present disclosure relates to a method for deposition of LS SiN on a silicon-based substrate.

The new method enables a new approach to nanoindentation. The new technique combines two different types of indenters: a Berkovich indenter with a radius of 100 nm and a LS SiN film with a thickness of 1.2 m. The resulting nanoindented sample is shown in Figure 2. During this process, the LS SiN film undergoes significant deformation and a large amount of stress.

The technique is also suitable for the fabrication of conductive structures on silk matrices. The resulting conductive structures can be patterned using a range of analytical tools, such as SEM and IR spectroscopy. The exemplary pressure used during the process is 760 mTorr. The research has several applications in various fields. The technology is an excellent alternative to silicon-based sputtering and photolithography.

What are Super Low Stress Silicon Nitride Wafers used For?

This paper focuses on low stress silicon nitride films (LS - SiN) and investigates the effects of high temperature and low voltage deposition conditions on the characterization of residual stresses reported in this paper. The experiments were conducted to investigate the effect of the deposition of polysilicon (silicon nitrite) under a variety of process conditions. For example, residual stresses vary considerably between the different deposition conditions. At these two temperatures, the tension is always tensile, but at 850C we observe a significant increase in the residual pressure (RI) of the film. We found that the RI increases with temperature, with an increase of up to 1,000 degrees Celsius (2,500 degrees F), and we found an increased RI of 3,200 degrees C (4,600 degrees F). [Sources: 0, 2]

The emerging semiconductor devices with large band gaps, such as those built from the SiN system, are significant because they have the potential to revolutionize the power electronics industry. As MEMS devices become smaller, a reduced residual voltage level will improve the performance and reliability of the devices. The high-temperature return loosens the load and causes the material to settle at the grain boundary, where defects and voids occur at the grain boundaries and cause a return flow. [Sources: 2, 3]

The main objective of this invention is to create the ability to produce a silicon membrane by using a selective doping scheme to define a low stress structure. The aim of the invention was to provide a method for producing high-temperature reflux silicon nitride wafers and manufactured silicon diodes with controlled thickness and low voltage. [Sources: 5]

In the plasma deposition of silicon nitride, the hydrogen is simply integrated into the silicon wafer and a thin layer is formed without tensile stress. The wafers are then etched to a nitride membrane, which serves as a supporting membrane to increase its rigidity. [Sources: 1, 5]

In this experiment, the residual stress of the polysilicon is closely related to the membrane, which is stoichiometric and not low loaded. This microstructure is highly dependent on the deposition conditions, but since the stress is so low, it does not matter. [Sources: 2, 7]

The silicon membrane thickness is 28 micrometers, which makes it possible to integrate an integrated circuit on a wafer. The resulting thickness is difficult to control and it is not easy to dilute the entire wafer by 5 - 10 microns. The stress of the deposited layer is caused by stacking errors in the crystal structure and needle holes. [Sources: 1, 5]

This method also affects residual stress and is not a good choice if a higher thickness is required for a particular application. For this application, the thin film used must be stress-free or stress-compensated. The work will be presented at the annual meeting of the American Society of Materials Science and Engineering (ASSE) in San Francisco. [Sources: 0, 2]

WO 00 - 70630) shows a powerful MEMS electret Microphone with a layer of extremely low-load silicon nitride wafers (ST). Microphone microphone describes a method of making a microphone from epitaxial silicon substrates without forming holes. The membrane itself is a low-stress ST - silicon - nitrite, in contrast to the stoichiometric ST - nitride layer, which originates from an earlier technology window in which significant stresses occur. Remember that pressure is applied to push the membrane against the silicon substrate (e.g. peel off). [Sources: 4, 5]

The tensions are inherently tensile, since the kinetic energy of the silicon atoms is low and causes nucleation at small fine grain boundaries. [Sources: 2]

The type of deposited film is either amorphous or crystalline, and the deposition rate is slow - beeswax, but the tensile stress values are significantly lower. This often leads to stress in the compression film at deposit temperatures, which cannot be explained by a relaxation of tension alone. The weak binding force of the carrier material on the film causes very little stress than the tensile stresses. If we reverse the flow ratio to 10: 1, the silicon-rich nitride layers are deposited at a very low flow rate of 1: 10,000, which affects the residual voltage shown in Figures 8 and 9 [15-19]. [Sources: 0, 2]

The values of n-2 in wafer # 01 are consistent with the data already mentioned in the literature on silicon nitride waveguides 30,31. [Sources: 6]

A three-dimensional structure whose functionality typically requires functionality that should be freed from the planar substrate. The film pattern on the surface of the micromachining process has proven to be a high quality image of a silicon nitride waveguide with a thickness of less than 1 mm. Originally used in integrated circuits, films made of thin layers of silicon oxide and a thin layer of copper oxide were deposited or removed and deposited on silicon wafers. In the LPCVD system, the thin layer on the side of each silicon wafer is deposited, and etching this layer on the back requires extremely low pressure, high temperatures and low pressure. This provides a new approach to manufacturing silicon baking plates for a wide range of applications, such as microfluidic devices and microelectronics. [Sources: 0, 2, 5]

 

 

Sources:

[0]: https://www.hindawi.com/journals/amse/2013/835942/

[2]: https://www.hindawi.com/journals/jma/2014/954618/

[3]: https://jsmimmobilier.ma/kq1zq/semiconductor-device-simulation.html

[4]: https://www.2spi.com/item/4128sn-ba/

[5]: https://patents.google.com/patent/US20040253760A1/en

[6]: https://www.nature.com/articles/s41598-017-00062-6

[7]: https://www.2spi.com/item/4112sn-ba/