Patent ID: 8951354
Filing Date: 2015-02-10
Classification: B08B,H01L

Abstract:
1. A cleaning method, comprising: immersing a substrate in a liquid contained in a process tank; operating a first transducer to communicate first sonic waves to a surface portion of the substrate, the first sonic waves having a first frequency and a first wave approach angle relative to the surface of the substrate, wherein the first sonic waves produce a boundary layer region in the liquid adjacent the surface portion of the substrate; and operating a second transducer to adjust a width of the boundary layer region by communicating second sonic waves to the surface portion of the substrate at a second wave approach angle relative to the surface of the substrate, the second sonic waves being concurrently communicated to the surface portion with the first sonic waves and having a second frequency that is greater than the first frequency of the first sonic waves, wherein the first and second wave approach angles have a difference of 180 degrees.