Evaluation of organic monolayers formed on Si(111): Exploring the possibilities for application in electron beam nanoscale patterning

The methods of preparing organic monolayers on Si(111). the effects of elec tron-beam irradiation onto these monolayers. and the deposition of metal at oms over the irradiated areas have been investigated in order to develop a process of mass-scale production of nanometer-scale patterns on Si(111) waf er surfaces. The organic monolayers were fabricated on hydrogen-terminated Si(111) wafer surfaces using previously reported methods for the electrolys is of para-substituted benzenediazoniurn salts and the Grignard reaction wi th various alkyl moieties and reaction procedures. Using these electrolysis methods, partially well-defined two-dimensional monolayers were formed, wh ich were, however, obscured by precipitated by-products. The Grignard react ion deposited homogeneous monolayer moieties of alkyl groups which were ran domly arranged and are suitable for surface passivation. Electron-beam bomb ardment of the organic monolayers on Si(111) was performed in an atmosphere of O-2 or H2O. The bombarded area was effectively oxidized in a well-contr olled manner. By immersing the bombarded specimen into an aqueous NiSO4 + ( NH4)(2)SO4 solution, Ni was selectively impregnated only within the area of electron bombardment. Based on these results, application of organic monol ayers for fabricating nanometer-scale monolayer patterns is proposed.