US 5,472,774 A · Photolithography test structure

Abstract

A photolithography test structure is provided for measuring the amount of notching associated with photolithography processing. The test structure includes a curved insulating structure placed in close spaced proximity with a conductive, interconnect structure. A pair of conductive pads are deposited at opposite ends of the interconnect structure for measuring the resistance through the interconnect. Depending upon the amount of notching associated with the interconnect, resistance readings will vary. Test areas containing notched interconnect can be compared with controlled areas specifically designed not to have notching in order to determine relative changes in resistance, and to correlate that resistance with notching magnitude. The insulating structure, interconnect structure and conductive pads are processed upon the same substrate material containing the resulting product requiring testing.

Claims11

Dependent claims

A photolithography test structure comprising:

a substrate;
a serpentine shaped first insulating structure deposited upon said substrate, said insulating structure having a sidewall extending in a sloping path from a peak of said insulating structure to an outer periphery at a base of said insulating structure;
an interconnect structure deposited in an elongated straight line upon said substrate a spaced distance less than 1.0 .mu.m from the base of a plurality of select portions of said insulating structure;
a pair of conductive pads deposited upon said substrate and connected at opposite ends of said interconnect structure;
a current producing device coupled to said pads for producing current between said pads;
and
a voltage sensor coupled to said pads for measuring a resulting voltage between said pads.

4 more elements

An integrated circuit photolithography test structure formed by a method comprising the steps of:

providing a first insulating film deposited across a silicon substrate;
selectively etching away said first insulating film to produce a first surface topography, wherein said first topography includes a serpentine shaped first insulating structure extending laterally across said substrate about an insulating structure central axis, said insulating structure includes a plurality of sloped sidewalls spaced at a distal location from said insulating structure central axis;
depositing a conductive film across said first topography to form a second surface topography;
placing a photoresist across said second surface topography;
placing a mask proximate to said second surface topography;
generating light beams comprising transmitted light beams and reflected light beams, said transmitted light beams include light beams transmitted through said mask and upon said second topography, said reflected light beams include light beams reflected from said first topography;
solubilizing said photoresist in areas receiving transmitted and reflected said light beams;
and
etching away said conductive film in areas underlying the solubilized resist to produce a third surface topography, wherein said third topography includes an elongated interconnect structure having an interconnect central axis along which said interconnect extends a spaced distance less than 1.0 .mu.m from said plurality of sloped sidewalls.

6 more elements

Dependencies are inferred from the claim text.

Photolithography test structure

Life of this patent

Photolithography test structure

Life of this patent

Abstract

Claims11