There are three major classifications of silicon wafer that manufacturers and industrial operations can choose from according to job application. These different wafer types vary in quality.

In order to minimize costs while still satisfying quality demands, you should consider which of the following three classifications of silicon wafer is best for your operation. The following is some basic information on the three grades: prime, monitor/test, and reclaimed wafers:

Prime wafers

If a maximum of quality is necessary for a silicon wafer application, prime grade wafers should be chosen. Another term for this type of silicon wafer is "device-quality."

A prime grade wafer can usually be easily recognized by its polished finish. Needless to say, this high quality type of wafer is the most expensive wafer type available. However, prime wafers are absolutely necessary for some applications.

A prime wafer is necessary for particle monitor applications or for photolithography. Any application requiring tighter resistivity specs or semiconductor manufacturing will usually require a prime grade wafer to get the job done right.

Monitor/test wafers

Monitor/test wafers are a lower grade silicon wafer, but they are acceptable for many different applications. In particular, monitor/test wafers are frequently used in applications like equipment testing or any type of application where large quantities are required.

In terms of quality, monitor/test wafers typically match the cleanliness and flatness standards of prime wafers. However, their production is more lax when it comes to some other qualities like resistivity. 

Because standards are less rigorous for producing monitor/test wafers, they tend to be more affordable. That's why this classification of wafer is ideal for marathon runs of manufactured product where enormous quantities are necessary. 

Reclaimed wafers

A reclaimed wafer can in fact be either a prime wafer or monitor/test wafer. However, reclaimed wafers have already been used and have completely lost their film so that re-polishing is necessary. 

The reclaiming process for silicon wafers involves removing any films, patterns, or surface irregularities on a used prime or monitor/test wafer. 

It's important to be aware of the availability of reclaimed wafers, because this type of wafer can be very affordable without lacking much in quality. After going through the process of reclaiming, prime and monitor/test wafers can meet many of the same performance standards that they met before being used.

Nevertheless, it's true that a reclaimed wafer inevitably loses some of its thickness after the first use, so certain performance standards won't be met. If you're using silicon wafers for an application where thickness is important, reclaimed wafers probably won't suffice. For more information, contact a company like Alsil Material.