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# Electrical Measurement of Resist And Etch Bias

IP.com Disclosure Number: IPCOM000102739D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 50K

IBM

## Related People

Bruce, JA: AUTHOR [+3]

## Abstract

A method is described whereby electrical measurement may be made of a) photoresist image width b) space between photoresist images, and c) width of a conductive line made using the measured photoresist image to define the conductive line during etching.

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Electrical Measurement of Resist And Etch Bias

A method is described whereby electrical measurement may be
made of a) photoresist image width b) space between photoresist
images, and c) width of a conductive line made using the measured
photoresist image to define the conductive line during etching.

Referring to the figure, line images 10 are developed in
photoresist on conductor layer 12 which is deposited over substrate
14.  Then, a thin layer of insulator 16 is conformally deposited over
the entire surface.  Next, a thin film 18 of a conductor is
anisotropically deposited normal to the surface.  The electrical
resistance RL of a set of conductive lines 18a on top of photoresist
images 10 and another set 18b between images 10 is measured.  Knowing
that the resistivity, length, and thickness of films 18a and 18b are
equal, the following equations can be written:

Resistance of a line R = PL/A = PL/w(t) = Pnw/wt = Pn/t, where
P = film resistivity, L = line length = number of line widths times
line width, and A = w(t) = cross sectional area perpendicular to
current flow = width of film times film thickness.  Sheet resistivity
Ps = P/t is measured at a large site (not shown).  Since R = nP/t
= nPs, n = R/Ps and since w = L/n, with L and n known,
line width w is found.

Thickness ti of insulator film 16 is measured accurately by
other means and 2ti is added to width of line 18b and subtracted from
width of line 18a to find actual...