TWI744933B - Conductive wire structrue and manufacturing method thereof - Google Patents

Abstract

A method of manufacturing a conductive wire structure including the following steps is provided. A substrate is provided. A conductive layer is formed on the substrate. A rectangular ring spacer is formed on the conductive layer by a self-alignment double patterning (SADP) process. A patterned photoresist layer is formed. The patterned photoresist layer exposes a first portion and a second portion of the rectangular ring spacer. The first portion and the second portion are located at two corners on the diagonal of the rectangular ring spacer. The first portion and the second portion are removed by using the patterned photoresist layer as a mask to form a first spacer and a second spacer. The first spacer and the second spacer are L-shape. The patterned photoresist layer is removed. A pattern of the first spacer and a pattern of the second spacer are transferred to the conductive layer to form a first conductive wire having L-shape and a second conductive wire having L-shape.

Description

Wire structure and manufacturing method thereof

The present invention relates to a semiconductor element and its manufacturing method, and more particularly to a wire structure and its manufacturing method.

With the advancement of semiconductor technology, the size of components is also continuously shrinking. When the integration degree of the integrated circuit increases, the critical dimension of the wire and the distance between the wire and the wire will decrease. When the critical size of the wire is reduced, it will be difficult to align the subsequently formed contact window with the wire, and the alignment margin between the contact window and the wire will be reduced. In addition, when the distance between the wire and the wire is reduced, the contact window is likely to be connected to two adjacent wires at the same time, resulting in a short circuit problem.

The present invention provides a wire structure and a manufacturing method thereof, which can improve the alignment margin between a contact window and the wire, and can prevent the problem of a short circuit between two adjacent wires.

The present invention provides a method for manufacturing a wire structure, which includes the following steps. Provide a base. A conductor layer is formed on the substrate. A rectangular ring-shaped spacer is formed on the conductor layer by a self-alignment double patterning (SADP) process. A patterned photoresist layer is formed. The patterned photoresist layer exposes the first part and the second part of the rectangular ring-shaped spacer. The first part and the second part are located at two corners on the diagonal of the rectangular ring-shaped spacer. The patterned photoresist layer is used as a mask, and the first part and the second part are removed to form a first gap wall and a second gap wall. The first spacer and the second spacer are L-shaped. Remove the patterned photoresist layer. The pattern of the first spacer and the pattern of the second spacer are transferred to the conductor layer to form an L-shaped first wire and an L-shaped second wire.

The present invention provides a wire structure including a first wire and a second wire. The second wire is located on one side of the first wire. The first wire includes a first wire portion and a first pad portion. The first wire portion extends in the first direction and has a first end and a second end. The first pad part is connected to the first end of the first wire part. The second wire includes a second wire portion and a second pad portion. The second wire portion extends in the second direction and has a third end and a fourth end. The third end is adjacent to the first end, and the fourth end is adjacent to the second end. The second direction is the opposite direction of the first direction. The second pad part is connected to the fourth end of the second wire part. The first imaginary extension portion extends from the second end of the first wire portion in a first direction away from the first end of the first wire portion. The second imaginary extension portion extends in the second direction from the third end of the second wire portion so as to be away from the fourth end of the second wire portion. The first pad portion extends toward the second imaginary extension portion but does not intersect the second imaginary extension portion. The second pad portion extends toward the first imaginary extension portion but does not intersect the first imaginary extension portion.

Based on the above, in the manufacturing method of the wire structure proposed in the present invention, the L-shaped first wire and the L-shaped second wire are formed by a self-aligned double patterning process, a patterning process, and a pattern transfer process. Effectively simplify the process to reduce the complexity of the process. In addition, the L-shaped first wire and the L-shaped second wire produced by the above method can increase the area for electrical connection with the contact window formed later, so that the contact window and the first wire can be effectively increased. And the alignment margin between the contact window and the second wire. In addition, the distance between the first wire and the second wire can be flexibly adjusted by the above method, so that the short circuit problem caused by the contact window being connected to the first wire and the second wire at the same time can be prevented.

In addition, in the wire structure proposed by the present invention, since the first wire and the second wire respectively have a first pad portion and a second pad portion, the alignment between the contact window and the first wire can be effectively improved. The margin and the alignment margin between the contact window and the second wire. In addition, since the first pad portion extends toward the second imaginary extension portion but does not intersect the second imaginary extension portion, and the second pad portion extends toward the first imaginary extension portion but does not intersect the first imaginary extension portion, it can be Prevent the short circuit caused by the contact window being connected to the first wire and the second wire at the same time.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

1A and 2A, a substrate 100 is provided. The substrate 100 may be a semiconductor substrate, such as a silicon substrate. In addition, those skilled in the art can form semiconductor elements (eg, transistors) and dielectric layers (not shown) on the substrate 100 according to product requirements, and the descriptions are omitted here.

Next, a conductive layer 102 is formed on the substrate 100. The conductor layer 102 may be a single-layer structure or a multi-layer structure. For example, the conductive layer 102 may be a multilayer structure including the conductive layer 104 and the conductive layer 106, but the invention is not limited thereto. The conductive layer 104 is, for example, doped polysilicon. The conductive layer 106 is, for example, a metal or a metal compound, such as tungsten, tungsten nitride, aluminum, titanium nitride, or copper.

Then, a hard mask layer 108 may be formed on the conductor layer 102. The hard mask layer 108 is, for example, silicon nitride or silicon oxide.

Next, referring to FIGS. 1A to 1D and FIGS. 2A to 2D, a rectangular ring-shaped spacer 112a can be formed on the conductor layer 102 by a self-aligned double patterning (SADP) process (please refer to FIGS. 1D and 2D). ). For example, the rectangular ring-shaped spacer 112a can be formed on the hard mask layer 108 by self-aligned double patterning, as described below.

1A and 2A, a rectangular core pattern 110 may be formed on the conductor layer 102. The material of the core pattern 110 is, for example, carbon, polysilicon, silicon oxide, or silicon nitride. The core pattern 110 can be formed by a deposition process, a lithography process, and an etching process.

Referring to FIGS. 1B and 2B, a spacer material layer 112 may be conformally formed on the core pattern 110. The material of the spacer material layer 112 is, for example, silicon oxide or silicon nitride. The formation method of the spacer material layer 112 is, for example, a chemical vapor deposition method or an atomic layer deposition method.

1C and 2C, the spacer material layer 112 can be etched to form a rectangular ring-shaped spacer 112a surrounding the sidewall of the core pattern 110. The rectangular ring-shaped spacer 112a may include a long side portion LP1, a long side portion LP2, a short side portion SP1, and a short side portion SP2. The short side part SP1 is connected to one end of the long side part LP1 and one end of the long side part LP2. The short side part SP2 is connected to the other end of the long side part LP1 and the other end of the long side part LP2. The above-mentioned etching process is, for example, a dry etching process.

Please refer to FIG. 1D and FIG. 2D, the core pattern 110 can be removed. When the material of the core pattern 110 is carbon, the removal method of the core pattern 110 is, for example, ashing. When the material of the core pattern 110 is polysilicon, silicon oxide or silicon nitride, the method for removing the core pattern 110 is, for example, a wet etching method.

In addition, although the self-aligned double patterning process is described using the above-mentioned method as an example, the present invention does not take this as a line.

Please refer to FIG. 1E and FIG. 2E to form a patterned photoresist layer 114. The patterned photoresist layer 114 can be formed by a photolithography process. The patterned photoresist layer 114 exposes the first portion P1 and the second portion P2 of the rectangular ring-shaped spacer 112a. The first part P1 and the second part P2 are located at two corners on the diagonal of the rectangular ring-shaped spacer 112a. The first part P1 may include a part of the short side part SP1, and the second part P2 may include a part of the short side part SP2. The length of part of the short side part SP1 in the first part P1 may be one-third to two-thirds of the total length of the short side part SP1, and the length of the part of the short side part SP2 in the second part P2 may be the short side One-third to two-thirds of the total length of SP2. That is, the patterned photoresist layer 114 may expose part of the short side portion SP1 and part of the short side portion SP2, but the invention is not limited to this. In other embodiments, the first part P1 may further include a part of the long side LP1, and the second part P2 may further include a part of the long side LP2. That is, the patterned photoresist layer 114 can further expose part of the long side portion LP1 and part of the long side portion LP2.

1F and FIG. 2F, using the patterned photoresist layer 114 as a mask, the first part P1 and the second part P2 are removed to form a spacer S1 and a spacer S2. The spacer S1 and the spacer S2 are L-shaped. The method for removing the first part P1 and the second part P2 is, for example, a dry etching method. In some embodiments, since the thickness of the patterned photoresist layer 114 located above the rectangular ring-shaped spacer 112a is relatively thin, in the process of removing the first portion P1 and the second portion P2, the patterned photoresist layer 114 is located in the rectangular ring-shaped gap. The patterned photoresist layer 114 above the wall 112a may be removed to expose the rectangular ring-shaped spacer 112a. In this way, in the process of removing the first part P1 and the second part P2, part of the rectangular ring-shaped spacer 112a originally located under the patterned photoresist layer 114 may be removed at the same time, so that the height of the spacer S1 The height of the spacer S2 is lower than the height of the rectangular annular spacer 112a (please refer to FIGS. 2E and 2F), but the present invention is not limited to this. In other embodiments, in the process of removing the first portion P1 and the second portion P2, if the patterned photoresist layer 114 located above the rectangular ring-shaped spacer 112a is not removed, the height of the spacer S1 The height with the spacer S2 may be approximately equal to the height of the rectangular ring-shaped spacer 112a.

Next, the patterned photoresist layer 114 is removed. The removal method of the patterned photoresist layer 114 is, for example, dry stripping or wet stripping.

1G and 2G, the pattern of the spacer S1 and the pattern of the spacer S2 are transferred to the hard mask layer 108 and the conductor layer 102 to form an L-shaped hard mask layer 108a and an L-shaped hard mask layer 108b. L-shaped wire W1 and L-shaped wire W2. The wire W1 may include a conductive layer 104a and a conductive layer 106a. The wire W2 may include a conductive layer 104b and a conductive layer 106b. The method of transferring the pattern of the spacer S1 and the pattern of the spacer S2 to the hard mask layer 108 and the conductor layer 102 is, for example, to use the spacer S1 and the spacer S2 as a mask to remove part of the hard mask layer 108 and part of the conductor.层102。 Layer 102. The method for removing part of the hard mask layer 108 and part of the conductor layer 102 is, for example, a dry etching method.

Then, the spacer S1 and the spacer S2 can be removed. In some embodiments, in the process of transferring the pattern of the spacer S1 and the pattern of the spacer S2 to the hard mask layer 108 and the conductor layer 102, the spacer S1 and the spacer S2 can be gradually consumed and removed, but The present invention is not unlimited by this. In this case, the hard mask layer 108a and the hard mask layer 108b may be partially removed as an etching mask, so that the height of the hard mask layer 108a and the height of the hard mask layer 108b are lower than that of the hard mask. The height of the curtain layer 108. For example, the height of the hard mask layer 108a and the height of the hard mask layer 108b may be lower than the height of the hard mask layer 108 by 20% or less. In other embodiments, after transferring the pattern of the spacer S1 and the pattern of the spacer S2 to the hard mask layer 108 and the conductor layer 102, if the spacer S1 and the spacer S2 are still left, it can be wetted The etching method removes the spacer S1 and the spacer S2. In this case, the height of the hard mask layer 108 a and the height of the hard mask layer 108 b may be approximately equal to the height of the hard mask layer 108.

1H and FIG. 2H, a dielectric layer 116 may be formed on the substrate 100 between the wire W1 and the wire W2. The material of the dielectric layer 116 is silicon oxide, for example. The method for forming the dielectric layer 116 is, for example, to first form a dielectric material layer (not shown) covering the hard mask layer 108a and the hard mask layer 108b, and then perform a chemical mechanical polishing process on the dielectric material layer to expose the hard mask layer 108a and 108b. The mask layer 108a and the hard mask layer 108b.

Referring to FIG. 1I and FIG. 2I, a plurality of contact windows 118 are formed. The contact window 118 is electrically connected to the wire W1 and the wire W2, respectively. The material of the contact window 118 is, for example, a metal material, such as tungsten, aluminum, and copper. The contact window 118 can be formed by an interconnection process. In some embodiments, barrier layers (not shown) may be formed between the contact window 118 and the wire W1 and between the contact window 118 and the wire W2, respectively.

Based on the above embodiment, it can be seen that in the manufacturing method of the wire structure 10 (please refer to FIGS. 1G and 2G), L-shaped wires W1 and L-shaped wires are formed by a self-aligned double patterning process, a patterning process, and a pattern transfer process. The wire W2 can effectively simplify the process to reduce the complexity of the process. In addition, the L-shaped wire W1 and the L-shaped wire W2 produced by the above method can increase the area for electrical connection with the contact window 118 formed subsequently, and thus can effectively increase the distance between the contact window 118 and the wire W1. And the alignment margin between the contact window 118 and the wire W2. In addition, the distance between the wire W1 and the wire W2 can be flexibly adjusted by the above method, so that the short circuit problem caused by the contact window 118 being connected to the wire W1 and the wire W2 at the same time can be prevented.

Hereinafter, the wire structure 10 of this embodiment will be described with reference to FIGS. 1G and 2G. In this embodiment, although the method for forming the wire structure 10 is described by taking the above-mentioned method as an example, the present invention is not limited to this.

1G and 2G, the wire structure 10 includes a wire W1 and a wire W2. In this embodiment, the wire structure 10 includes multiple pairs of wires W1 and W2 as an example, but the present invention is not limited to this. As long as the wire structure 10 includes at least a pair of wires W1 and W2, it falls within the scope of the present invention. The wire W2 is located on one side of the wire W1. The shape of the wire W1 and the wire W2 may be L-shaped. The wire W1 and the wire W2 may have a single-layer structure or a multi-layer structure. The wire W1 may include a conductive layer 104a and a conductive layer 106a. The wire W2 may include a conductive layer 104b and a conductive layer 106b.

The wire W1 includes a wire portion WP1 and a pad portion EP1. The wire portion WP1 extends in the first direction D1 and has a first end T1 and a second end T2. The pad portion EP1 is connected to the first end T1 of the wire portion WP1. The pad portion EP1 may be perpendicular to the wire portion WP1.

The wire W2 includes a wire portion WP2 and a pad portion EP2. The wire portion WP2 extends in the second direction D2 and has a third end T3 and a fourth end T4. The third end T3 is adjacent to the first end T1, and the fourth end T4 is adjacent to the second end T2. The second direction D2 is the opposite direction of the first direction D1. The pad portion EP2 is connected to the fourth end T4 of the wire portion WP2. The pad part EP2 may be perpendicular to the wire part WP2. The pad portion EP1 may be parallel to the pad portion EP2.

The imaginary extension portion IE1 extends in the first direction D1 from the second end T2 of the wire portion WP1 so as to be away from the first end T1 of the wire portion WP1. The imaginary extension portion IE2 extends in the second direction D2 from the third end T3 of the wire portion WP2 so as to be away from the fourth end T4 of the wire portion WP2. The pad portion EP1 extends toward the imaginary extension portion IE2 but does not intersect the imaginary extension portion IE2. The pad portion EP2 extends toward the imaginary extension portion IE1 but does not intersect the imaginary extension portion IE1. The imaginary extension portion IE1 and the wire portion WP1 may have the same width. The imaginary extension portion IE2 and the wire portion WP2 may have the same width. In addition, the imaginary extension portion IE1 and the imaginary extension portion IE2 are imaginary members and do not actually exist. The purpose of the imaginary extension IE1 is to describe the configuration relationship between the pad EP1 and the wire W2, and the purpose of the imaginary extension IE2 is to describe the configuration relationship between the pad EP2 and the wire W1.

In addition, the materials, forming methods, and configuration methods of the components of the wire structure 10 have been described in detail in the above-mentioned embodiments, and the description will not be repeated here.

Based on the above embodiment, it can be seen that in the wire structure 10, since the wire W1 and the wire W2 have the pad portion EP1 and the pad portion EP2, respectively, the alignment margin and contact between the contact window 118 and the wire W1 can be effectively improved. Alignment margin between window 118 and wire W2. In addition, since the pad portion EP1 extends toward the imaginary extension portion IE2 but does not intersect with the imaginary extension portion IE2, and the pad portion EP2 extends toward the imaginary extension portion IE1 but does not intersect with the imaginary extension portion IE1, it can prevent the contact window 118 from being caused at the same time. Connected to the wire W1 and wire W2 caused by the short-circuit problem.

In summary, with the wire structure and manufacturing method of the above embodiment, the alignment margin between the contact window and the wire can be improved, and the problem of short circuit between two adjacent wires can be prevented.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be subject to those defined by the attached patent application scope.

10: Wire structure 100: base 102, 104, 104a, 104b, 106, 106a, 106b: conductor layer 108, 108a, 108b: hard mask layer 110: core pattern 112: spacer material layer 112a: Rectangular annular spacer 114: Patterned photoresist layer 116: Dielectric layer 118: contact window D1: First direction D2: second direction EP1, EP2: Pad part IE1, IE2: imaginary extension LP1, LP2: Long side P1: Part One P2: Part Two S1, S2: Clearance wall SP1, SP2: short side T1: first end T2: second end T3: third end T4: Fourth end W1, W2: Wire WP1, WP2: Lead wire part

1A to 1G are top views of a manufacturing process of a wire structure according to an embodiment of the present invention. 1H to FIG. 1I are top views of a manufacturing process of a contact window according to an embodiment of the present invention. 2A to 2I are cross-sectional views taken along the I-I' section line and the II-II' section line in FIGS. 1A to 1I.

10: Wire structure

100: base

108a, 108b: hard mask layer

D1: First direction

D2: second direction

EP1, EP2: Pad part

IE1, IE2: imaginary extension

T1: first end

T2: second end

T3: third end

T4: Fourth end

W1, W2: Wire

WP1, WP2: Lead wire part

Claims (10)

A method for manufacturing a wire structure includes: Provide a base; Forming a conductor layer on the substrate; Forming a rectangular ring-shaped spacer on the conductor layer by a self-aligned double patterning process; A patterned photoresist layer is formed, wherein the patterned photoresist layer exposes the first part and the second part of the rectangular ring-shaped spacer, and the first part and the second part are located in the rectangular ring shape Two corners on the diagonal of the gap wall; Using the patterned photoresist layer as a mask, removing the first part and the second part to form a first spacer and a second spacer, wherein the first spacer and the second spacer The wall is L-shaped; Removing the patterned photoresist layer; and The pattern of the first spacer and the pattern of the second spacer are transferred to the conductor layer to form an L-shaped first wire and an L-shaped second wire. The manufacturing method of the wire structure according to claim 1, wherein the self-aligned double patterning process includes: Forming a rectangular core pattern on the conductor layer; Forming a spacer material layer conformally on the core pattern; Performing an etching process on the spacer material layer to form the rectangular ring-shaped spacer surrounding the sidewall of the core pattern; and Remove the core pattern. The method for manufacturing a wire structure according to claim 1, wherein the rectangular ring-shaped spacer includes: The first long side portion, the second long side portion, the first short side portion, and the second short side portion, wherein the first short side portion is connected to one end of the first long side portion and the second long side The second short side portion is connected to the other end of the first long side portion and the other end of the second long side portion. The manufacturing method of the wire structure according to claim 3, wherein the first portion includes a part of the first short side portion, and the second portion includes a portion of the second short side portion. The manufacturing method of the wire structure according to claim 4, wherein the length of a part of the first short side portion in the first portion is one-third to one-third of the total length of the first short side portion 2. The length of part of the second short side portion in the second part is one-third to two-thirds of the total length of the second short side portion. The manufacturing method of the wire structure as described in claim 1, further including: Before forming the rectangular annular spacer, forming a hard mask layer on the conductor layer; and The pattern of the first spacer and the pattern of the second spacer are transferred to the hard mask layer. A wire structure, including: The first wire; and The second wire is located on one side of the first wire, where The first wire includes: The first wire part extends in the first direction and has a first end and a second end; and The first pad part is connected to the first end of the first wire part, and The second wire includes: The second wire portion extends in the second direction and has a third end and a fourth end, wherein the third end is adjacent to the first end, and the fourth end is adjacent to the second end, and The second direction is the opposite direction of the first direction; and The second pad part is connected to the fourth end of the second wire part, wherein A first imaginary extension portion extends in the first direction from the second end of the first wire portion away from the first end of the first wire portion, A second imaginary extension portion extends in the second direction from the third end of the second wire portion away from the fourth end of the second wire portion, The first pad portion extends toward the second imaginary extension portion but does not intersect the second imaginary extension portion, and The second pad portion extends toward the first imaginary extension portion but does not intersect with the first imaginary extension portion. The wire structure according to claim 7, wherein the shape of the first wire and the second wire includes an L shape. The wire structure according to claim 7, wherein the first pad portion is perpendicular to the first wire portion, and the second pad portion is perpendicular to the second wire portion. The wire structure according to claim 7, wherein the first pad portion is parallel to the second pad portion.

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