Silicon Valley Microelectronics carries a wide selection of glass wafers designed to meet the unique specifications of each customer. There are glass wafers available in our inventory, and if we are unable to meet any requirements, we will custom manufacture wafers to fit the end user’s specifications.
Borofloat 33 is a clear, colorless floated borosilicate glass produced by Schott. It is produced via the float method, where molten glass (~1,000°C) is poured across molten tin or another low melting point metal. The molten glass floats on top of the tin and distributes itself uniformly across the surface.
Once the wafer is solidified and cooled, the resulting sheet of glass is very flat with minimal contamination. The properties of this glass are very close to silicon, so it is common to use them together.
- High chemical resistance – more than most metals and other glass substrates.
- Great mechanical strength.
- Low thermal expansion – same as silicon.
- Near parallel flatness.
- Good homogeneity.
- High resistance to abrasives.
- High ultraviolet (UV) transmission.
Due to its similarities to silicon, Borofloat® 33 has many uses in a variety of industries. Some of the most common uses are for anodic bonding, electrical insulators, telescope mirrors and display glass and sensors for electronics, as well as various uses within the precision engineering, optical (LED), nuclear energy and microelectromechanical systems (MEMS) industries.
This glass works interchangeably with Corning 7740 for most applications.
Fused silica wafers are the most simple chemical composition of non-crystalline silica glass. The glass consists of amorphous silicon dioxide that is formed into wafers in a chemical vapor deposition chamber. Silicon precursors are burned with oxygen in order to form nano particles of SiO2, which are then melted and deposited in a thin film on a rotating plate. The heat source in the CVD system can be either an open flame, a furnace, or plasma flame in order to fabricate these wafers.
- High chemical purity.
- Great resistance to thermal expansion and thermal shock.
- High radiation resistance.
- Transparent to light wavelengths from ultraviolet to infrared.
Due to the high optical qualities and chemical purity, there are a range of uses for these wafers. Most commonly they are found in microlithography, and heat and light sensing or measurement tools. The highest quality fused silica is used in MEMS devices and for lasers.
Corning® 7740 is a clear, colorless borosilicate glass by Corning with very similar properties to Borofloat® 33. To produce this glass, particles of silica sand, boric acid, fluxes and stabilizers mix together. Next, a furnace heats the mixture at 1600°C for up to 24 hours to remove any bubbles and imperfections. The glass is formed in blocks, as opposed to sheets, so they must be sliced, ground, lapped, and polished before being used.
- Good thermal shock resistance
- high temperature resistance
- low thermal expansion – same as silicon
- high acid resistance
- great optical transmission over a wide range of wavelengths, from ultraviolet to infrared.
Due to their similarities, these wafers have many of the same applications and are interchangeable with Borofloat® substrates. Some common uses for these substrates are LCD displays, dielectric coating, sensor substrates, neutron absorber, and in high temperature environments.
SVM does NOT keep stock of Corning 7740 and recommends the more commonly found and cost effective Borofloat 33 for most applications. If you absolutely require Corning 7740, please contact us and we will work with you to procure this material.
Quartz – Fused Silica
Quartz, often used interchangeably with fused silica, is a high purity and low contamination crystallized silicon dioxide that is commonly used in high temperature and particle sensitive applications. Single crystal quartz differs slightly from fused silica, but is not commonly used in the semiconductor industry. To produce single crystal quartz, quartz chips mix with sodium hydroxide (NaOH) and heat to 400°C in a furnace. The pressure in the system must also be high, between 1,000 – 1,500 bar (1019.72 kg/cm² – 1529.574 kg/cm²), to maintain its high purity.
- Excellent chemical resistance
- High heat resistance
- Low thermal expansion across a wide temperature range.
- Excellent optical transmission at a wide range of wavelengths, from ultraviolet to infrared. It also transmits ultraviolet rays better than other glass.
- Photomask in lithography
- Optics (LEDs)
- Laser optics
- as furnace chambers for chemical vapor deposition.
Soda lime glass accounts for 90% of glass used in the world, making up most bottles, windows, glassware, etc. It is a combination of crystalline silicon dioxide, sodium oxide (soda) and calcium oxide (lime).
This glass is not as chemically or heat resistant as borosilicate glass. It also has a much higher rate of thermal expansion.
These make soda lime glass a great alternative for low temperature and low cost applications.
Silicon Valley Microelectronics carries both stock glass wafers, and will custom manufacture substrates to your exact specifications. Please CONTACT SVM today to request a quote or discuss your current requirements.