Methods for cleaning microelectronic substrates using ultradilute cleaning liquids

A method of cleaning a surface of a microelectronic device at a stage of manufacture, comprising the steps of:

• providing a cleaning liquid comprising solvent and ammonia, wherein the solvent and ammonia comprise a volume ratio of solvent to ammonia in the range from about 500:1 to about 500,000:1, and wherein the cleaning liquid does not include hydrogen peroxide;
• positioning the device in a vessel;
• introducing the cleaning liquid into the vessel under conditions effective to help clean the surface of the device, with the proviso that, if the surface of the device is subjected to an oxidizing treatment to facilitate said cleaning of the surface, the introduction of an oxidizing agent to carry out such oxidizing treatment occurs as a pre-treatment prior to the introduction of the cleaning liquid, wherein the cleaning liquid etches 10 angstroms or less of the surface of the device, and wherein the cleaning liquid is at a temperature in the range from about 0° C. to about 25° C. during at least a portion of the time that the cleaning liquid contacts the surface of the device;
• and
• applying acoustic energy to the cleaning liquid during at least a portion of the time that the cleaning liquid contacts the surface of the device.