Have anyone worked on building an integrated circuit or a MEMS without using a complete clean room for all processes (just a clean process in a filtered air positive pressure room)? Of course the yield may be very low since many dust particles will drop into wafer's surface but I wonder if it will remain high enough to allow process technology test and development (not production). The porpouse of this question is to build argumentation in a discussion regarding potential positive results when building a very low cost facility for first steps in microelectronics' process technology development and training. Thanks in advance, Augusto Einsfeldt