Crystec Technology Trading GmbH

In the semiconductor industry it is necessary to work under very clean conditions. Therefore production takes place in a cleanroom. Silicon wafers are handled in special plastic cassettes. However, people are still required for manufacturing and they introduce particles into the cleanroom despite appropriate cleanroom garments. To increase the cleanliness of the production environment a so-called "mini-environment", a small encapsulated cleanroom within the cleanroom, was introduced. The semiconductor wafers are no longer transported in open cassettes but in closed, clean containers that are only opened within the corresponding process equipment, such as a vertical furnace, a horizontal furnace, or an RTP system. Only a few examples are listed.

For 200 mm wafers either open cassettes or SMIF containers were used. SMIF stands for Standard Mechanical InterFace. The boxes contain an open cassette that is removed from the bottom. For 300 mm silicon wafers the container design was changed and so-called FOUP (Front Opening Unified Pod) boxes are now state of the art. These containers are opened from the front and the tool robot removes the wafers directly from the FOUP. For transport purposes a simple version of a wafer container called FOSB (Front Opening Shipping Box) is available.

All these cassettes, SMIF, FOSB and FOUP containers must be kept very clean. Therefore they are stored in appropriate stockers.