(A) study on novel top surface imaging by selective adsorption of silicon-compounds

Abstract

Top surface imaging(TSI) has been utilized as a method for attaining high resolution with many advantages. TSI through gas phase silylation has been investigated by others but the ease by which liquid phase silylation can be carried out may make it an attractive alterative to gas phase silylation. The novel silicon incorporation process was studied for liquid phase process. This novel process to incorporate silicon component into resist polymer involves treatment of the resist-coated wafer with aqueous solution of silicone-oil/cationic surfactant prior to dry development by $O_2$ reactive ion etching($O_2$-RIE). The effectiveness of the silicone-oil/cationic surfactant aqueous solution(SSAS) treatment is dependent on a number of factors including structure and characteristics of resist polymer, concentration of surfactant and silicone-oil, mode and duration of SSAS treatment, and pH of the solution. The mechanism of the process has been investigated and the results suggest that the critical driving force of cationic surfactant adsorption is the coulombic force between cationic surfactant and carboxyl acid functional group in exposed area and then by hydrophobic effect, silicone-oil incorporates into inter-bilayer region.