Sapphire wafers are used in multiple areas of the semiconductor industry. Each substrate is an individual and must be used for different purposes, due to the crystallized nature of it. The applications for sapphire wafers are huge, ranging from infrared detectors to silicon on sapphire techniques to polishing to dicing and many more. Sapphire needs to be kept of high purity so that it can function to the fullest, and are engineered rather than mined from nature. With a number of different industry uses, there are many possibilities for this substrate.

There are three different types of sapphire substrates. The A-Plane sapphire wafer, the first type of substrate, is commonly used in microelectronic applications. They are ideal for dielectric constant and insulating characteristics and must be ground on the edges. A smooth and polished surface finish must be made with no signs of scratches for the front surface, and the back surface can either be as smooth as the front or simply ground depending on whether it requires a single side polish or double side polish. It can also be used for epitaxial growth.

The second type of sapphire wafer, a C-Plane substrate, is more often used in III-V compounds like gallium nitride, as well as II-IV compounds like zinc selenide. These substrates are used in laser diodes and in LED in colors green and blue. They also are utilized in infrared detectors. The edges of this type of wafer should be the same as the A-Plane wafer. They can be diced into sizes as small as 4mm.

The third variety, the R-Plane substrate, is a wafer that is used in applications like silicon-on-sapphire growth for microelectronic IC uses. Of all the substrates, the R-Plane is the most versatile. This substrate is perfect for a high dielectric constant, as they can ensure no damage to the surface due to improvements in the industry. Once the deposition process has been finished, these sapphire wafers can be essentially useful for high-speed IC and pressure transducer applications.  It also has established a place in super conducting, gallium arsenic and thallium growth, and for bonding materials to each other.

Sapphire wafers are highly useful in the semiconductor industry, as they can fill many roles. The overall list for applications includes optical transmission from ultraviolet to infrared, radiation resistance, high temperature usage and edge polishing as well as the other processes previously mentioned. The three different types of sapphire wafers, A-Plane, C-Plane, and R-Plane, all have different purposes and must be developed in relation to the A, C, and R axis. Sapphire wafers are commonly used with gallium compounds, as well as other III-V compounds. This large array of applications makes them excellent for semiconductor assembly.