| 摘要 |
Aqueous etching soluton consists of 13.5-45 wt.% NH4F, 1-11 wt.% HF and 2.5-20,000 ppm of a fluoroalkyl sulphonate surfactant formula XC- (CFX)n-CX (I). In (I) n= no. up to 6; C chain is branched; X= F, H, Cl, OH, SO3A; Y= F, H, OH, R; A= H+, NH+, Na+, K+, Li+, R+, NR4+; R= C1-C4 alkyl. The solution are useful for etching SiO2, when they show desirable etching rates and improved wetting over known solutions. In addition, the solutions are free of metal ions after 0.2 micron filtration, and do not leave residues or adversely affect photoresist adhesion.
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