Liquid solvent spray brush station for surface cleaning in nano-microtronics …

Description (excerpt)

RELATED APPLICATIONS The instant U.S. patent application claims the benefit of domestic priority from and is related to U.S. Provisional Patent Application No. 61/880,942; LIQUID SOLVENT SPRAY BRUSH STATION SURFACE CLEANING IN NANO-MICROTRONICS PROCESSING; Docket Number 102623; filed on Sep. 22, 2013; whose inventors are Adam L. Friedman and David W. Zapotok; and where said U.S. Provisional Patent Application is herein incorporated by reference in its entirety. FIELD OF THE INVENTION The present invention is generally related to nanotechnology and microtechnology fabrication and processing. In particular the present invention comprises a medium strength, liquid solvent, air/gas-brush spray station used for cleaning electronic devices, components, circuit elements, or surfaces during nanotechnology and microtechnology (hereafter nanotronics and microtronics) device processing. This medium strength, liquid solvent, air/gas-brush spray station includes intermediate strength, yet effective surface cleaning with minimal damage to the subject nanotronics and microtronics components; and the cleaning station is inexpensive to assemble and it is also compatible with a clean room facility. BACKGROUND OF THE INVENTION Nanotronics and microtronics components are composed of nanoscale and microscale elements, not visible to the human eye, where nanoscale is smaller than a micron, while microscale is smaller than 1 milimeter, still too small for the human eye to see without a compound light microscope (see FIG. 5B including thumbnail inset); in other words, nanoscale electronics are electronics on the order of nanometers (1-1000 nm), while microscale electronics are on the order of microns (1-1000 microns). When fabricating samples and devices for nanotronics and microtronics elements, it is necessary to clean the surfaces between steps and before mechanical or electronic testing of the devices. Nano- and microtronics device/component surface cleaning falls in at least two categories: (I) gentle methods and (II) strong methods. For gentle methods, cleaning is usually accomplished by slightly agitating a sample immersed in a solvent bath, or by gently rinsing a sample in solvent. Gentle methods are not effective at removing strongly adhering particles and impurities. For strong methods, immersion in ultrasonic baths is one widely adopted method. Ultrasonic baths where a sample is cleaned by high frequency sound waves distributed in a liquid bath, are readily available in the marketplace from a variety of vendors. However, ultrasonic baths often unintentionally damage wanted surface features. Mechanical cleaning is another strong cleaning method, whereby the surface is wiped using a specially designed cloth or similar tool. Mechanical cleaning is quite effective at removing surface impurities. However, it will damage more delicate surface features. Acid baths are commonly used for surface cleaning. However, the impurities must be susceptible to dissolution in acid for this method to be effective. Acid baths often leave unintended damage to surfaces, thus acid baths are incompatible or ineffective with a wide range of surfaces, and the acid bath surface cleaning methods present real danger of bodily harm to users. Nano- and microtronics device/component cleaning is usually accomplished using very gentle methods such as solvent rinses, or using very harsh methods such as immersion in an ultrasonic bath, acid bath or by mechanical cleaning, as discussed above. While gentle solvent rinses can be effective for impurities and dirt adhering weakly to surfaces, simple rinsing does not remove more stubborn particles. For instance, when conducting a metal/photoresist lift-off cleaning process, it can take hours of solvent baths and gentle rinsing to remove unwanted material. Oftentimes, one is unable to remove excess metals completely. Additionally, immersion in an ultrasonic bath, acid bath, or mechanical cleaning can effectively and quickly remove dirt and impurities from a surface. However, it often unintentionally damages nanoscale or microscale features on a surface. There currently are no medium-strength methods of surface cleaning for nano- and microtronics processing in the marketplace today. The features of such a method or instrument would include gentle, yet effective surface cleaning with minimal damage. Moreover, as the instrument must be compatible with a cleanroom environment, the peripheral mess and waste left by the process must be self-contained and easily managed. This invention disclosure describes an invention that accomplishes the above goals, and furthermore, this cleaning station is self-contained and small enough to fit on a desktop. SUMMARY OF THE INVENTION Exemplary embodiments describe an inexpensive, medium strength, liquid solvent, air/gas-brush spray station used in cleaning electronic devices, components, circuit elements, or surfaces during nano- and microtronics processing compatible with a clean room facility. This instrument includes gentle, yet effective surface cleaning with minimal damage to subject nano- and microtronics components. Moreover, as the