In semiconductor processing it is necessary
to operate under very clean
conditions. Therefore, production is done in a clean room. Silicon
wafers are handled in special plastic cassettes. Still, people have to
work in the clean room and although they have to wear special clean
room clothes, they introduce particles in the clean room. In order to
improve the cleanliness of the semiconductor production, a so called
mini-environment has been introduced. This means that the wafers are no
longer handled in open cassettes, but in closed, clean boxes which are only
opened inside the processing equipment, e.g. a
vertical furnace, a
horizontal furnace, or an
RTP tool. These are just a few examples.
200mm open cassette
200mm SMIF box
300mm FOSB box
300mm FOUP box
For 200mm wafers, either open cassette or SMIF boxes have been used.
SMIF stands for Standard Mechanical InterFace and those boxes include an open
cassette which is unloaded through the
bottom of the SMIF pod. For 300mm silicon wafers, the design of the
mini environment boxes has been changed and so
called FOUP boxes (Front Opening Unified Pod) are now state of the art.
These boxes are opened from
the front side and the equipment robot unloads the wafers directly
from the FOUP. There are also more simple boxes available just for
transport, so called FOSB (Front Opening Shipping Box).
All these cassette, SMIF, FOSB and FOUP boxes have to be kept very clean. Therefore, they are stored in corresponding stockers.
FOUP Stocker are systems that store and manage FOUPs. To keep the air in the stocker clean, HEPA filters(High-Efficiency Particulate Air) are installed.
Delivery of FOUPs can be achieved by an operator, an AGV (Automatic Guided Vehicle) or OHT (Overhead Hoist Transport)
Crystec Technology is gladly helpful procuring corresponding machines.