SEMICONDUCTOR STRUCTURE & FABRICATION

1. (a) Name the three major groups of contamination and briefly describe their physical characteristics.

    (b) Where do the above contamination types come from? Give one example of each.

2. Name two processes metrics which would be worsened by poor cleanroom practices in a semiconductor cleanroom. Describe briefly what is meant by each term.

3. (a) What sizes of particles would cause problems for the following processes: • 5 ?m bipolar • 4.5 ?m NMOS • 1.1 ?m CMOS • 0.9 ?m BICMOS • 0.3 ?m CMOS?

(b) What effect is illustrated by the above?

(c) What additional particle related issue affects smaller feature size processes?