Test key structure
A test key structure includes a substrate; a first metal pad disposed on the substrate; a second metal pad disposed in proximity to the first metal pad on the substrate; a gap between the first metal pad and the second metal pad; a first contact disposed on the first metal pad; and a second contact disposed on the second metal pad.
1 . A test key structure configured to detect a short circuit caused by metal residues, comprising:
a substrate;
a first metal pad disposed on the substrate;
a second metal pad disposed in proximity to the first metal pad on the substrate, wherein the first metal pad and the second metal pad have a dimension of equal to or greater than 1 μm×1 μm;
a gap between the first metal pad and the second metal pad, wherein the gap has width of equal to or less than 0.15 μm;
a first contact disposed on the first metal pad, wherein the first contact is electrically connected to a first voltage; and
a second contact disposed on the second metal pad, wherein the second contact is electrically connected to a second voltage that is different from the first voltage to detect the short circuit across the gap.
2 . The test key structure according to claim 1 , wherein the first metal pad comprises aluminum, titanium nitride or tantalum nitride.
3 . The test key structure according to claim 1 , wherein the second metal pad comprises aluminum, titanium nitride or tantalum nitride.
4 . A test key structure configured to detect a short circuit caused by metal residues, comprising:
a substrate;
an array of metal pads disposed on the substrate, wherein each of the array of metal pads has a dimension of equal to or greater than 1 μm×1 μm;
a gap between the array of metal pads, wherein the gap has width of equal to or less than 0.15 μm; and
an array of contacts disposed on the array of metal pads, respectively, wherein the array of contacts comprises first contacts electrically connected to a first voltage and second contacts electrically connected to a second voltage that is different from the first voltage to detect the short circuit across the gap.
5 . The test key structure according to claim 4 , wherein the first contacts and the second contacts are arranged in a staggered manner.
6 . The test key structure according to claim 5 , wherein the first contacts are electrically connected to a first interconnect line and the second contacts are electrically connected to a second interconnect line, wherein the first interconnect line and the second interconnect line are in different metal levels.
7 . The test key structure according to claim 4 , wherein each of the array of metal pads comprises aluminum, titanium nitride or tantalum nitride.