Following on the earlier considerations of organic contaminants, let’s take a quick look at the ways they can interfere with semiconductor processing.

When allowed to agglomerate into particle-like colonies in the water delivery system, bacteria-based particles adsorbed on the exposed processed surfaces will have a harmful effect on the process just like any other particle in the semiconductor process environment.

Airborne volatile organics adsorbed on the processed surfaces in turn, if not removed prior to thin-film deposition on such surfaces, may lead to the major process malfunction. Prior to critical deposition steps such as for instance epitaxial deposition, organic contaminates will prevent high-quality film formation. Also, if not removed prior to the metal deposition, organic contaminants will results in the increased contact resistance.

Less obvious is a deleterious destabilizing effect of organic contaminants adsorbed on the wafers stored in between processing steps. What the terms “destabilizing effect” means, is that initially light organic compounds phsysisorbed of the surface are in the course of the prolonged exposure to the moisture containing ambient air chemically bonding to the surface changing its energy in the process. Such process is often referred to as “surface aging” and needs to be prevented, or strictly controlled in any semiconductor device manufacturing process.