The name Reclaim sometimes strikes fear into the heart of semiconductor people and it really should not!
The name Reclaim sometimes strikes fear into the heart of semiconductor people and it really should not! Years ago some poor reclaim vendors used to turn out some pretty bad product that unfortunately gave reclaim wafers a bad name. Today there are many good reclaim vendors that turn out a very good product. Reclaim wafers are used prime and test wafers that have been stripped of thin films and re-polished to remove all patterns and scratches. Desert Silicon will sort your wafers for thickness and resistivity and in most cases reclaim wafers will perform as good as normal test wafers.
Of course the reclaim wafers will have the same limitations test wafers do when it comes to utilization for Thermal Oxidation and Photolithography. Remember reclaim wafers like test are not as flat and normally the resistivity spec they are sold under is very wide, generally 0-100 Ohm.cm. Reclaim wafers can be a little thinner but Desert Silicon will pull and dispose of the ones that are to thin and might cause you problems.
After the wafers arrive from the customer, our company records them by lot number.
Inspect all wafers visually, and separate them by type and film type. Only those wafers that can be reclaimed are selected.
Remove resist, oxide films, nitride film, polysilicon films and metal films using chemical solutions.
After removing the film(s), once again, only those wafers that can be reclaimed are selected.
Edge grinding is performed during reclaim.
If there are diffusion layers, they are lapped off.
Particles and surface damage from the lapping process are removed in the cleaning process.
Mirror polishing is performed next.
High purity chemicals and DI water are used to clean wafer surfaces of any particles and comtaminants. Special processing for removal of surface metal is performed if necessary.
Inspection of outer appearance
100% visual inspection under high-intesity light for haze, chips, scratches, and other surface defects and damage is performed.
Measurement inspection for thickness, particles, resistivity, bow, etc. (Randomized inspection).
All packing work is performed inside a Class 10 clean room environment.
Shipping or Film Depostion
Films are deposited as needed by the customer.