The split-gate flash memory is widely used in the market, and the dry etching process has an important effect on the parameters and performance of the Floating gate. The plasmas containing Cl₂ and CF₄ were used to etch the top half of polycrystalline gate, and the HBr/He-O₂ gases with a high selectivity to oxide were adopted to etch the bottom half. The orthogonal tests were made upon the process parameters and the optimal process parameters of the main etch step were finally determined, and then the final morphology and uniformity of the Floating gate were obtainedwhen adding a proper over etch step.

中文翻译：

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干法刻蚀浮栅工艺研究与优化

分裂栅闪存在市场上应用广泛，干法刻蚀工艺对浮栅的参数和性能有重要影响。采用含Cl ₂和CF ₄的等离子体刻蚀多晶栅的上半部，采用对氧化物具有高选择性的HBr/He-O ₂气体刻蚀下半部。对工艺参数进行正交试验，最终确定主要蚀刻步骤的最佳工艺参数，然后在加入适当的过蚀刻步骤后得到浮栅的最终形貌和均匀性。