Theoretical and experimental investigation of chemical pattern etching

The processes occurring during wet chemical etching of partially masked copper surfaces for pattern definition were investigated. Chemical dissolution of rectangular cavities with active copper base and inert photoresist sidewalls was carried out in the presence of flowing acidic cupric chloride solutions. It was found that for a 3.5M CuCl$\sb2$ + 0.5M HCl + 0.5M KCl etching solution a salt film precipitated on the entire metal surface and dissolution was controlled by mass transfer of the products. The presence of recirculating eddies at the corners added extra resistance to mass transfer there, such that undercutting was suppressed and anisotropic profiles were obtained. For a 0.5M CuCl$\sb2$ + 0.5M HCl + 0.5M KCl etching solution the solubility of the film is higher since the ratio of Cu$\sp{+2}$ to Cl$\sp-$ concentration is lower; the film precipitated preferentially at the corners of a 5:1 cavity, whereas the rest of the surface dissolved film-free. Anisotropic profiles were also obtained. For the same solution and 1:1 cavities, dissolution proceeded under film precipitation on the entire surface.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Georgiadou, Maria

Contributors dc:contributor

• Alkire, Richard C.

• Engineering, Chemical

Statement dc:rights

• Copyright 1990 Georgiadou, Maria

Language dc:language

eng

Identifier

AAI9125968
(UMI)AAI9125968

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21828