Patent ID: 9373518
Filing Date: 2016-06-21
CPC Classification: H01L

Claim Text:
1. A method for processing a substrate, comprising: a. introducing a first etchant into a reactor cell, wherein the reactor cell isolates a region of a surface of a substrate; b. introducing a fluid into the reactor cell while the first etchant remains in the reactor cell; c. after initiating the introducing the fluid, removing contents of the reactor cell through a low-vacuum outlet and a mid-vacuum outlet, wherein the low-vacuum outlet extends further into the reactor cell than the mid-vacuum outlet; d. repeating steps b-c for a plurality of iterations while the reactor cell isolates the region of the surface of the substrate; e. maintaining a level of the contents of the reactor cell above an inlet to the low-vacuum outlet while removing the contents so that the isolated region of the surface of the substrate remains submerged by the contents of the reactor cell during the processing; f. introducing a second etchant into the reactor cell while removing the contents of the reactor cell through the low-vacuum outlet and the mid-vacuum outlet, wherein the first etchant is more acidic than the second etchant; and g. continuing the introducing of the second etchant until a concentration of the second etchant is at a desired level, wherein the isolated region of the surface of the substrate continues to remain submerged during the introducing of the second etchant.