Megasonic cleaning with controlled boundary layer thickness and associated systems and methods

摘要

Megasonic cleaning systems and methods of using megasonic pressure waves to impart cavitation energy proximate a surface of a microelectronic substrate are disclosed herein. In one embodiment, a megasonic cleaning system includes a process tank for containing a liquid, a support element for carrying a substrate submerged in the liquid, and first and second transducers positioned in the tank. The first transducer is further positioned and/or operated to initiate cavitation events in a bulk portion of the liquid proximate a surface of the substrate. The second transducer is further positioned and/or operated to control an interface of fluid friction between the substrate and the bulk portion of the liquid.

主权项

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 transducers are disposed within the process tank, and the first and second wave approach angles have a difference of 180 degrees.