Quantitative Examination of Photofabricated
Profiles. Measurement of Etch Factor
Etch factor in this series of papers is defined as the depth
of etch divided by the undercut' (Fig. I). From this figure
it can be seen that evaluation of etch factor requires the
measurement of three quantities:
(I) The width of the line (or slot) in the developed photoresist
(2) The width of the slot at the metal surface after etching.
(3) The depth of etching measured when etching is stopped
before break-through of the metal sheet.
D.M. Allen, D.F. Horne and G.W.W. Stevens, Cranfield Institute of Technology