Wiring structure to minimize stress induced void formation
First Claim
1. A wiring structure connecting a metal feature having a length, width, and thickness to a via for minimizing stress induced void formation, comprising:
- a plurality of “
n”
overlapping segments each comprised of two ends and having a width, a length, and a thickness wherein one end of a first segment is connected to the metal feature and one end of the nth segment is connected to the via and wherein an end of a segment and an end of an adjacent segment form a bend at an angle θ and
a plurality of segments form at least one bending portion.
1 Assignment
0 Petitions
Accused Products
Abstract
A wiring structure with improved resistance to void formation and a method of making the same are described. The wiring structure has a first conducting layer that includes a large area portion which is connected to an end of a protrusion with a plurality of “n” overlapping segments and at least one bending portion. The other end of the protrusion is connected to the bottom of a via which has an overlying second conducting layer. A bend is formed by overlapping the ends of two adjacent segments at an angle between 45° and 135°. The protrusion may also include at least one extension at a segment end beyond a bend. A bending portion and extension are used as bottlenecks to delay the diffusion of a vacancy from the large area portion to the vicinity of the via and is especially effective for copper interconnects or in a via test structure.
-
Citations
59 Claims
-
1. A wiring structure connecting a metal feature having a length, width, and thickness to a via for minimizing stress induced void formation, comprising:
a plurality of “
n”
overlapping segments each comprised of two ends and having a width, a length, and a thickness wherein one end of a first segment is connected to the metal feature and one end of the nth segment is connected to the via and wherein an end of a segment and an end of an adjacent segment form a bend at an angle θ and
a plurality of segments form at least one bending portion.- View Dependent Claims (2, 3, 4, 5, 6, 7)
-
8. A via test structure formed on a semiconductor substrate comprising:
-
(a) a first metal layer comprising a first metal line and second metal line which are each comprised of a first segment, a middle segment, and a third segment wherein the first and third segments have a length, width, and thickness and the middle segment has a plurality of “
n”
overlapping subsegments each having a width, length, thickness, and two ends, wherein one end of a first subsegment is connected to a first segment and one end of the nth subsegment is connected to a third segment and wherein an end of a subsegment and an end of an adjacent subsegment form a bend at an angle θ and
said middle segment is comprised of at least one bending portion;
(b) a second metal layer comprising a first metal line and second metal line which are each comprised of a first segment, a middle segment, and a third segment wherein the first and third segments have a length, width, and thickness and the middle segment has a plurality of “
n”
overlapping subsegments each having a width, length, two ends, and thickness wherein one end of a first subsegment connects to a first segment and one end of the nth subsegment connects to a third segment and wherein an end of a subsegment and an end of an adjacent subsegment form a bend at an angle θ and
said middle segment is comprised of at least one bending portion;
(c) a via formed between a first segment in the first metal layer and a first segment in the second metal layer;
(d) first and second bonding pads in the first metal layer that connect to a third segment in the first and second metal lines, respectively, in the first metal layer; and
(e) first and second bonding pads in the second metal layer that are connected to a third segment of the first and second metal lines, respectively, in the second metal layer. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. A method of determining via resistance during a reliability stress test in a test structure that includes a first metal layer connected to the bottom of a via and a second metal layer connected to the top of the via, comprising:
-
(a) applying a current to a first bonding pad in a first metal layer formed on a substrate, said first bonding pad being connected to the bottom of a via by a first metal line comprised of two ends and a segment that has a serpentine pattern;
(b) measuring the voltage at a second bonding pad in said first metal layer, said second bonding pad being connected to the bottom of said via by a second metal line comprised of two ends and a segment that has a serpentine pattern;
(c) measuring the voltage of a first bonding pad in a second metal layer formed above said first metal layer on said substrate, said first bonding pad in said second metal layer being connected to the top of said via by a first metal line comprised of a segment that has two ends and a serpentine pattern; and
(d) connecting a second bonding pad in said second metal layer to a predetermined voltage potential, said second bonding pad in said second metal layer being connected to the top of said via by a second metal line that has two ends and a segment with a serpentine pattern. - View Dependent Claims (22, 23, 24, 25, 26, 27)
-
-
28. An interconnect structure to reduce stress induced void formation, comprising:
-
(a) a first conducting layer including a large area portion having a first width, a first length, and a first thickness, an enlongated protrusion having a second width and length, first thickness, and two ends, wherein one end is connected to the large area portion and the other end is connected to a via and said protrusion is comprised of at least one bending portion;
(b) a via connected at a first end to the protrusion in the first conducting layer and at a second end to a second conducting layer. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
-
-
41. An interconnect structure to reduce stress induced void formation, comprising:
-
(a) a first conducting layer having a first width, a first length, a first thickness, and sides; and
(b) a protrusion on one side of the first conducting layer, said protrusion having a second width, a second length, a first thickness, and two ends formed along a first axis, wherein said protrusion has at least one bending portion comprised of a plurality of overlapping segments each with two ends that are not aligned along said first axis and wherein said bending portion includes at least one extension formed at the end of a segment. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49)
-
-
50. A method of forming an interconnect having increased resistance to void formation, said interconnect being formed on a substrate, comprising:
-
(a) providing a substrate with a first dielectric layer formed thereon;
(b) forming an opening in said first dielectric layer and depositing a first conducting layer that fills said opening, said first conducting layer being comprised of a large area portion having a first length, a first width, a first thickness, and sides, and a protrusion with a first thickness, a second length, and a second width, said protrusion having two ends wherein one end is connected to a side of the large area portion and the other end is connected to a via and wherein said protrusion has at least one bending portion and a plurality of “
n”
overlapping segments each with two ends;
(c) depositing a second dielectric layer over said first dielectric layer and said first conducting layer; and
(d) forming a second opening comprised of a via opening substantially aligned with the nth segment in said protrusion and an overlying trench opening in said second dielectric layer and depositing a second conducting layer that fills said second opening. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58, 59)
-
Specification