Patent ID: 7638027
Filing Date: 2009-12-29
Classification: B32B,C23C,C25D,G02B,Y10T

Abstract:
1. A method comprising the steps of: (a) forming a plurality of thermoplastic microstructures at common intervals on a wafer after processing a surface of the wafer to become a water-repellant surface using a silane coupling agent having a functional group containing fluorine; (b) causing the plurality of thermoplastic microstructures to undergo reflow to form an array of microstructures with a curved profile separated by flat portions, wherein each of the plurality of thermoplastic microstructures are never brought into contact at the time of reflow; and (c) forming a continuous layer of an approximately uniform thickness on the microstructures with a curved profile and on the flat portions until the flat portions between the microstructures disappear, wherein each of the microstructures with the curved profile is formed by controlling temperature and duration of heating during reflow such that an angle θ, on the microstructure side, between the surface of the wafer and a tangential plane of the microstructure at a location where the microstructure is in contact with the surface of the wafer is greater than 90 degrees, wherein the continuous layer is formed in a thickness that is equal to the height of the center of each of the microstructures with the curved profile from the surface of the flat portions, wherein each of the microstructures with the curved profile has a single flat surface as its entire bottom surface contacting the wafer, and wherein the microstructures with the curved profile comprise, at the same time, a first plurality of microstructures with a first curved profile having a first spacing between microstructures and a second plurality of microstructures with a second curved profile different from the first curved profile having a second spacing between microstructures different from the first spacing.