Method and apparatus for semiconductor wafer cleaning with reuse of chemicals

Abstract

An apparatus and method for cleaning and rinsing of disk-shaped objects, such as silicon wafers, high precision lenses and the like. The cleaning and rinsing may take place in a single chamber, that is sequentially filled with cleaning solution, rinsing solution, and the like. In an important aspect of the invention, chemical cleaning solutions are dumped to containers and recycled for the use. Moreover, a cleaning solution composition may be monitored, and the concentration of solution can be adjusted automatically, or make-up chemicals may be added, as necessary. The apparatus has a relatively small footprint and maybe surrounded with an enclosure that may be kept at lower than atmosphere pressure to prevent escape of potentially hazardous contaminants into the environment. In preferred embodiments of the invention, the handling of wafers to be cleaned is carried out robotically, most preferably using a robot with at least two end-effectors, each adapted for a specific function. The apparatus of the invention provides the advantage of permitting the recycling of cleaning solutions, thereby reducing the amount of hazardous waste generated for disposal, while at the same time reducing the cost of cleaning and rinsing wafers.