Use of acoustic waves for purging filters in semiconductor manufacturing equipment

#The disclosure is related to a method and system for using acoustic waves in the optimization of semiconductor manufacturing equipment, and more particularly to the use of acoustic waves to purge filters used in various coating operations associated with photolithography processes used in semiconductor manufacturing.

#Photolithography is a critical and frequently used operation in the manufacture of semiconductor devices. Each semiconductor device undergoes multiple photolithography operations which form the patterns that transform layers of material into interconnected circuits. Each photolithography operation includes an operation that coats the substrates with a photoresist material and a develop operation that develops the exposed and patterned photoresist layer by coating the substrate with a developer. Photolithography operations may also utilize additional coating operations such as operations that coat the substrates with anti-reflective coatings, ARC's, adhesion promoters, and various other coatings. Each photolithography operation therefore includes multiple coating operations that dispense a photolithography fluid onto a substrate that is rotated to produce a coating on the substrate surface.

#The manufacturing tools that are used to coat the substrates include a dispense port at which the fluid is introduced to the substrate, which is rotated to produce a very thin coating on the substrate. It is critical for the coating to include a thickness that is uniform and lies within a narrow range of acceptable thicknesses prescribed by the specification. It is also critical to obtain the desired thickness of the coated material from a corresponding amount of dispensed material because the fluids used in the various photolithography coating operations are very expensive and it would be cost prohibitive to dispense excess amounts of fluid that are simply expelled from the substrate when it is rotated, i.e. wasted. It is also important to assure that each coating operation results in a high quality coating. If there are voids in the layer coated on the substrate, if the coating is of non-uniform thickness, or if there are particles contaminating and distorting the coated film, the substrate must be reworked at considerable expense. The rework procedure is also time consuming and delays cycle time.

#The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not necessarily to scale. On the contrary, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. Like numerals denote like features throughout the specification and drawing.

#FIG. 1 is a side view showing a filter housing that contains a filter;

#FIG. 2 is a side view of a housing with a cut-away portion showing a filter inside the filter housing;

#The disclosure provides a method and apparatus that readies filters used in the semiconductor manufacturing industry, for use. In particular, the disclosure relates to filters used for filtering fluids such as liquids, gels or intermediates with various viscosities, particularly those fluids used in photolithography operations. The photolithography operations include the dispensing and coating of a photolithography fluid which may be a photoresist, a developer, an ARC (anti-reflective coating), various adhesion promoters, cleaning fluids or other photolithography fluids, i.e. fluids used for coating a substrate for a photolithography operation.

#According to other exemplary embodiments, the apparatus and method of the disclosure may find application in filters used in other coating operations, such as the coating of spin-on glass or other spin-on dielectrics also used in the semiconductor manufacturing industry. The apparatus and method of the disclosure may find application in any filter used to filter fluids.

#The disclosure provides a dispensing and coating apparatus that dispenses a fluid onto a substrate and rotates the substrate, such that the dispensed fluid becomes a thin coating spread across the substrate. The substrate may be a semiconductor wafer used in the semiconductor fabrication industry, in one exemplary embodiment. The apparatus dispenses the fluid at a dispense port and fluid is delivered to the dispense port through various delivery systems and lines within the apparatus. The fluid is filtered before it reaches the dispense port by a filter disposed within a filter housing and included within the dispensing/coating apparatus, although, in other exemplary embodiments, the filter and filter housing may be remote from the dispensing/coating apparatus. The apparatus further includes a fluid source, which may be a bottle or other reservoir, and a pump that pumps the fluid through the filter and to the dispense port. Many such coating apparatuses are known in the art and are not described further herein.