Patent ID: 6087266
Filing Date: 2000-07-11
Classification: H01J,H01L

Abstract:
A method for improving microloading of a substrate to be etched in a plasma processing chamber, said substrate being etched with a first etchant to form trenches having a given trench width, the plasma processing chamber having a first power supply configured to energize a first electrode of said chamber and a second power supply configured to energize a second electrode of said chamber, said method comprising:obtaining a first data set among a plurality of data sets that correlate power ratios of said first power supply and said second power supply with microloading percentages for said first etchant for different trench widths, said first data set correlating said power ratios with said microloading percentages for a first trench width, said first trench width approximating said given trench width as closely as possible;ascertaining a power ratio of settings to be applied to said first and second power supplies that yields a desired level of microloading;determining if said ascertained power ratio is in said first data set;if said power ratio is in said first data set, applying a first setting from said first data set to said first power supply and said second power supply in accordance with said ascertained power ratio to achieve said desired level of microloading in etching said substrate with said first etchant; andif said power ratio is not in said first data set, employing a second etchant different from said first etchant to etch said substrate, said second etchant having a greater inhibiting characteristic than said first etchant.