Semiconductors have a wide range of uses in computing of all kinds and new machines are being developed every day. This means that the manufacture of silicon wafers has had to keep up with all of the advances. Or, one could say that the advances have kept up with the development of the wafers. Either way you look at it, you will want to find the best silicon wafers available.
Look for a silicon wafer manufacturer with the highest standards in production. Silicon Valley is home to many such companies and you will know which one to look for if you have just a bit of information. The manufacturer should operate out of a large facility, preferably larger than most. It should be able to claim many class 10 clean rooms for development and manufacture.
Silicon and sapphire wafers are not cheap so they must be made to exacting standards. Whether you are looking for small wafers of 1/16th of an inch or as large as 400 mm, you should be able to find what is needed from the same supplier. Ask about the polishing methods as well. The very flattest of wafers are now made using a wax-free polishing method.
If the methods are clearly detailed and you find the selection of wafers you need, then ask about how you can have wafers made specifically for your needs. The better companies will be able to take your orders and produce what is needed in a timely fashion. They will have a good reputation with a solid history in the industry. Check out the clients they have had in the past and find reviews.
Much of this is easy to understand. You want to go with the best quality and price along with real guarantees so that your budget is maintained but there is no shortage of quality and integrity.