摘要:
Traditionally, hydrofluoric acid (HF) or buffered bydrofluoric acid (NH.sub.4 F) is mixed with water to form a etching solution for cleaning silicon dioxide from semiconductor wafer surfaces. An etching solution formed by mixing ammonium hydrogen bifluoride ((NH.sub.4)HF.sub.2) with water provides a benign alternative for cleaning silicon dioxide.
摘要:
This invention is for an improved slurry for shallow trench isolation processing in chemical mechanical polishing of semiconductor devices. The oxide/nitride selectivity is enhanced by increasing the pH of the slurry, increasing the solids content of the slurry and/or by adding a fluoride salt to the slurry. With these modifications, selectivity of greater than 10:1 can be attained.
摘要:
Chemical mechanical polishing slurry with functionalized silica abrasive particles, the functionalization permits high pH slurry without rapid degradation of silica particles and also permits the modification of surface properties of abrasive particles to modify slurry behavior. One example of modified behavior would be to enhance selectivity by controlling particle interaction with different surfaces on the wafer.
摘要:
A method of formulating a strong oxidizing solution comprising formulating a strong oxidizing solution having from about 2 to about 5 percent PDSA with concentrated sulfuric acid in the ratio of from about 1:8 to about 1:20 parts by volume and storing the strong oxidizing solution in a container having a space over the solution containing one of a vacuum or a non-oxidizing atmosphere inert to the oxidizing solution. The amount of PDSA is preferably about 4 percent by volume and the ratio is preferably about 1:10 parts by volume. The space over the strong oxidizing solution is preferably a vacuum or substantially all nitrogen. Hydrogen peroxide can be substituted for the PDSA in which case the method comprises formulating a strong oxidizing solution having from about 40 to about 60 percent hydrogen peroxide with concentrated sulfuric acid in the ratio of from about 1:8 to about 1:20 parts by volume and storing the strong oxidizing solution in a container having a space over the solution containing one of a vacuum or a non-oxidizing atmosphere inert to the oxidizing solution.