TWI554171B - Method for fabricating buried-type conductive wiring - Google Patents

Description

Buried conductive wiring manufacturing method

The invention relates to a method for manufacturing a conductive wiring, in particular to a method for manufacturing a thick film conductive wiring.

In recent years, with the advancement of electronic technology, wiring boards for mounting semiconductor devices, integrated circuits, and electronic components have been rapidly integrated, high-output, and high-speed, in addition to miniaturization. progress. In particular, the above-described wiring board process has also been developed to miniaturize metal wiring. For example, when a metal wiring such as copper is formed on a substrate, a process such as sputtering film formation and electrolytic plating can be generally employed.

When a thick film metal wiring is formed on a substrate by a conventional technique, the thickness of the metal wiring affects the etching ability, and the etching yield is often affected by the uncleanness of the product, and it is impossible to produce a product having an expected copper thickness and wiring pitch.

Embodiments of the present invention provide a method of fabricating a thick film conductive wiring.

A method of fabricating a buried conductive wiring according to an embodiment of the present invention. Includes the following steps. First, a substrate is provided. Next, the substrate is patterned to form a first recessed region on the upper surface of the substrate. And forming a conductive layer on the upper surface of the substrate, wherein the conductive layer comprises a conductive pattern, the conductive pattern is at least filled in the first recessed region, and the conductive pattern is convex in a thickness direction The sidewall of the conductive pattern forms a second recessed region for the upper surface of the substrate, and the second recessed region has a partial thickness of the conductive layer. And forming a first sacrificial pattern on the conductive layer, The first sacrificial pattern is filled in at least the second recessed region, the first sacrificial pattern protrudes from an upper surface of the conductive pattern in a thickness direction, and sidewalls of the first sacrificial pattern form a a third recessed area, and the third recessed area exposes a portion of the conductive pattern. Then, the conductive layer is subjected to a plating treatment to thicken the conductive pattern exposed by the third recess region. Finally, the first sacrificial pattern is removed, and the conductive layer in the second recessed region is removed.

According to the method for fabricating the buried conductive wiring according to the embodiment of the present invention, a thick film conductive wiring having a high wiring density and a narrow wiring width can be produced without being limited to the etching ability.

For a better understanding of the features and technical aspects of the present invention, reference should be made to the accompanying drawings.

1‧‧‧Substrate

101‧‧‧ Upper surface of the substrate

2‧‧‧First groove area

3"‧‧‧ initial conductive layer

3, 3'‧‧‧ conductive layer

31, 31'‧‧‧ conductive patterns

301, 301’‧‧‧ upper surface

4, 4'‧‧‧ second groove area

5‧‧‧First Sacrifice Pattern

501‧‧‧ upper surface

6‧‧‧ Third groove area

7‧‧‧Second sacrificial pattern

8‧‧‧etching barrier

H1, H2‧‧‧ thickness

H3‧‧‧ Height

S1~S7‧‧‧ steps

1A to 1J are flowcharts showing the steps of a method of fabricating a buried conductive wiring according to an embodiment of the present invention.

2 is a flow chart showing the steps of a method for fabricating a buried conductive wiring according to another embodiment of the present invention.

1A to FIG. 1J, FIG. 1A to FIG. 1J are schematic side views of a substrate having a buried conductive wiring in a manufacturing process according to an embodiment of the present invention, and FIGS. 1A to 1J show an embodiment of the present invention. The flow of steps in the method of manufacturing the buried conductive wiring.

Referring to FIG. 1A, first, a substrate 1 is provided. The type of the substrate 1 can be selected according to actual needs. For example, when the manufacturing method of the conductive wiring is applied to the semiconductor field, the substrate 1 may be a germanium-containing semiconductor wafer; in other applications, the substrate 1 may be a circuit substrate, and the material of the substrate 1 may be Polycarbonate (PC), polycarbonate and acrylonitrile butadiene-styrene (ABS) or glass fiber-containing materials. The substrate 1 may also be a glass substrate.

Next, referring to FIG. 1B, the substrate 1 is patterned to form a first recessed region 2 on the upper surface 101 of the substrate 1. Regarding the embodiment of the step of patterning the substrate 1, the substrate 1 may be ablated with a laser to groove the upper surface 101 of the substrate 1. As shown in FIG. 1B, the first groove region 2 has a predetermined depth.

Next, referring to FIG. 1C, in order to form the conductive layer 3 (FIG. 1D) on the upper surface 101 of the substrate 1, the initial conductive layer 3" may be formed over the entire surface of the upper surface 101 of the substrate 1, wherein the initial conductive layer Layer 3" is filled with the first recessed area 2. The manner in which the initial conductive layer 3" is formed may be, for example, a common conductive material coating process such as printing a conductive paste, a spray coating, an electroless plating, or a sputtering process.

Then, the initial conductive layer 3" is patterned to form the initial conductive layer 3" to form the conductive layer 3 on the upper surface 101 of the substrate 1. Regarding the embodiment of the step of patterning the initial conductive layer 3", the initial conductive layer 3" can be subjected to the first etching treatment. The etching process can be performed by wet etching. In detail, referring to FIG. 1D, a sacrificial pattern may be formed on the initial conductive layer 3", such as the second sacrificial pattern 7 shown in FIG. 1D. The second sacrificial pattern 7 may use a dry ink to form a second sacrificial pattern. The method of 7 includes, for example, exposure and development, etc. Next, the initial conductive layer 3" is etched through the second sacrificial pattern 7, that is, the portion where the initial conductive layer 3" is not covered by the second sacrificial pattern 7 and is exposed. Etching (eg, a copper bite process) to pattern the initial conductive layer 3". In the above-described process of etching the initial conductive layer 3", only a portion of the thickness of the exposed initial conductive layer 3" is etched. Finally, the second sacrificial pattern 7 is removed again, as shown in FIG. 1E.

In summary, the conductive layer 3 can be formed on the upper surface 101 of the substrate 1. Referring to FIG. 1E, the conductive layer 3 includes a conductive pattern 31 which is filled at least into the first recessed region 2 of the substrate 1, and the conductive pattern 31 protrudes from the substrate 1 in the thickness direction. Surface 101. That is, the upper surface 301 of the conductive pattern 31 and the upper surface 101 of the substrate 1 have a predetermined distance in the thickness direction. In addition, conductive The sidewall of the pattern 31 forms a second recessed region 4 having a portion of the thickness H2 of the conductive layer 3 therein. The conductive layer 3 formed on the upper surface 101 of the substrate 1 can be fully turned on by the thickness H2 in the second recessed region 4 for subsequent plating treatment.

It is worth mentioning that the thickness H1 of the initial conductive layer 3" as shown in FIG. 1C (that is, the vertical distance from the upper surface of the initial conductive layer 3" to the upper surface 101 of the substrate 1) may be based on the first concave The pitch of the groove region 2, the expected line pitch of the conductive wiring, and the expected line width of the conductive wiring are adjusted to facilitate the implementation of the etching of the initial conductive layer 3".

In another embodiment of the present invention, with respect to an embodiment of the step of patterning the initial conductive layer 3", the etching process may be dry etched to ablate the initial conductive layer 3". Specifically, depending on actual needs, for example, depending on the material of the initial conductive layer 3", the thickness H1 of the initial conductive layer 3", or the residual thickness H2 of the conductive layer 3 in the second recessed region 4, etc., The scanning time of the laser is adjusted to avoid excessive laser ablation to expose the second recessed region 4 to the upper surface 101 of the substrate 1, or to avoid insufficient laser energy to cause the second recessed region 4 did not reach the expected depth.

It should be noted that, as shown in FIG. 1E , in the specific embodiment, the conductive pattern 31 is corresponding to the first recessed region 2 of the substrate 1 . Further, the sidewall of the conductive pattern 31 may be adjacent to the first recessed region. 2 side walls.

Next, referring to FIG. 1F, a first sacrificial pattern 5 is formed on the conductive layer 3, the first sacrificial pattern 5 is filled in at least the second recess region 4, and the first sacrificial pattern 5 is convex in the thickness direction. On the upper surface 301 of the conductive pattern 31. That is, the height H3 of the first sacrificial pattern 5 in the thickness direction is greater than the height of the conductive pattern 31 in the thickness direction. The height H3 of the first sacrificial pattern 5 in the thickness direction is also the vertical distance from the upper surface 501 of the first sacrificial pattern 5 to the upper surface 101 of the substrate 1, and the height of the conductive pattern 31 in the thickness direction is also the conductive pattern 31. The vertical distance from the upper surface 301 to the upper surface 101 of the substrate 1. Furthermore, the sidewall of the first sacrificial pattern 5 forms a third recessed region 6, which may expose at least A portion of the conductive pattern 31.

An embodiment in which the first sacrificial pattern 5 is formed on the conductive layer 3 will be described in detail below. For example, a first sacrificial layer (not shown) may be formed on the conductive layer 3 in a full-surface manner, wherein the first sacrificial layer may fill the second recess region 4. Then, the first sacrificial layer is patterned to form the first sacrificial layer to form the first sacrificial pattern 5. The first sacrificial layer may use dry ink, and the manner of patterning the first sacrificial pattern 5 includes, for example, exposure and development processes.

Thereby, the first sacrificial pattern 5 can be formed on the conductive layer 3 remaining in the second recessed region 4 corresponding to the second recessed region 4. As shown in FIG. 1F, in the embodiment, the first sacrificial pattern 5 can fill the second recessed region 4, and the sidewall of the first sacrificial pattern 5 and the sidewall of the conductive pattern 31 can be partially aligned, in other words, the third recess. The groove region 6 may expose all of the conductive patterns 31. On the other hand, the first sacrificial pattern 5 and the conductive pattern 31 are positive and negative complementary, but the invention is not limited thereto.

Next, referring to FIG. 1F to FIG. 1G, the conductive layer 3 is subjected to a plating treatment to thicken the conductive pattern 31 exposed by the third recess region 6. In the present embodiment, the conductive pattern 31 is thickened to a height H3 of the first sacrificial pattern 5 in the thickness direction. In other words, the height of the thickened conductive pattern 31' in the thickness direction may be the same as the height H3 of the first sacrificial pattern 5 in the thickness direction.

Then, in order to remove the first sacrificial pattern 5 and remove the conductive layer 3' remaining in the second recessed region 4', an etch stop layer 8 may be formed on the conductive pattern 31' to protect the conductive pattern 31'. The material of the etching stopper layer 8 includes, for example, tin and lead. Next, under the protection of the etch barrier layer 8, the first sacrificial pattern 5 is removed by deinking, as shown in FIG. 1H. The deinking method is, for example, immersing the first sacrificial pattern 5 with a solvent or stripping the first sacrificial pattern 5 with a plasma.

Next, referring to FIG. 1I, in order to remove the conductive layer 3' remaining in the first recess region 2, the conductive layer 3' may be subjected to a second etching treatment under the protection of the etching stopper layer 8. Similar to the first etching process, the second etching process can also be a wet copper bite or a dry laser ablation. Second groove area The conductive layer 3' in 4' has only a partial thickness, and the thickness of the portion of the conductive layer 3' may be, for example, less than 5 microns, and therefore, whether by wet etching or dry etching, the second groove The conductive layer 3' in the region 4' can be easily removed.

Finally, as shown in FIG. 1J, as long as the etching stopper layer 8 is removed, fabrication of the conductive wiring can be completed, and thick film conductive wiring such as thick copper wiring can be obtained. In an embodiment of the invention, the thickness of the thick copper wiring (i.e., the thickness of the conductive pattern 31') may be greater than 50 micrometers, and the wiring pitch of the thick copper wiring may be less than 50 micrometers. In the embodiment shown in Figs. 1A to 1H, the wiring pitch of the thick copper wiring is also the width of the second recessed regions 4, 4'.

The above embodiment can be summarized as a method for fabricating the buried conductive wiring according to another embodiment of the present invention. Please refer to the flowchart of FIG. First, a substrate is provided (step S1); then, the substrate is patterned to form a first groove region on the upper surface of the substrate (step S2); then, at the base Forming a conductive layer on the upper surface of the material, wherein the conductive layer includes a conductive pattern, the conductive pattern is at least filled in the first recessed region, and the conductive pattern protrudes from the substrate in a thickness direction The upper surface of the conductive pattern forms a second recessed region, and the second recessed region has a partial thickness of the conductive layer (step S3); then, a conductive layer is formed on the conductive layer a first sacrificial pattern, wherein the first sacrificial pattern is filled in at least the second recessed region, the first sacrificial pattern protrudes from an upper surface of the conductive pattern in a thickness direction, the first sacrifice a sidewall of the pattern forms a third recessed region, and the third recessed region exposes a portion of the conductive pattern (step S4); then, the conductive layer is subjected to a plating process to cause the third recessed region The exposed conductive pattern is thickened (step S5) Secondly, the first sacrificial pattern is removed (step S6); and the conductive layer in the second recessed region is removed (step S7).

In summary, the embodiments of the present invention provide a method for fabricating a buried conductive wiring, which uses a first etching process to pattern the initial conductive layer 3", and then uses a second etching process to remove the second The thickness of the conductive layer remaining in the recessed area. In the method for fabricating the buried conductive wiring, the conductive wiring is formed by the two-stage etching method, and the etching capability is not limited, thereby avoiding the problem of poor conductivity due to incomplete etching.

In addition, the method for fabricating the buried conductive wiring utilizes the first recessed region 2 formed by the upper surface 101 of the substrate 1 to establish a buried depth of the thick film conductive wiring (eg, thick copper wiring); The conductive pattern 31 formed by the upper surface 101 can establish a first-stage height of the thick film conductive wiring (for example, thick copper wiring), and can be established by using the first sacrificial pattern 5 protruding from the upper surface 301 of the conductive pattern 31. The second stage height of thick film conductive wiring (such as thick copper wiring). In the method of manufacturing the conductive wiring, wiring having a high wiring density and a narrow wiring width can be produced.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, equivalent technical changes made by using the present specification and the contents of the drawings are included in the protection scope of the present invention. .

S1~S7‧‧‧ steps

Claims (10)

A method for fabricating a buried conductive wiring, comprising: providing a substrate; patterning the substrate to form a first recessed region on an upper surface of the substrate; Forming a conductive layer on the upper surface, wherein the conductive layer comprises a conductive pattern, the conductive pattern is at least filled in the first recessed region, and the conductive pattern protrudes from the substrate in a thickness direction a surface, a sidewall of the conductive pattern forms a second recess region, and the second recess region has a partial thickness of the conductive layer; a first sacrificial pattern is formed on the conductive layer, wherein a first sacrificial pattern is filled in at least the second recessed region, the first sacrificial pattern protrudes from an upper surface of the conductive pattern in a thickness direction, and a sidewall of the first sacrificial pattern forms a third a recessed area, wherein the third recessed area exposes a portion of the conductive pattern; and the conductive layer is subjected to a plating process to thicken the conductive pattern exposed by the third recessed area; First sacrificial pattern; The conductive layer is removed in the region of the second groove. The method of manufacturing the buried conductive wiring of claim 1, wherein the step of forming the conductive layer on the upper surface of the substrate further comprises: forming an initial conductive layer over the entire surface An upper surface of the substrate, wherein the initial conductive layer fills the first recess region; and the initial conductive layer is patterned. The method for fabricating a buried conductive wiring according to claim 2, wherein The step of performing the patterning process on the initial conductive layer further includes: forming a second sacrificial pattern on the initial conductive layer; etching the initial conductive layer through the second sacrificial pattern; and removing the first Two sacrificial patterns. The method for fabricating a buried conductive wiring according to claim 1, wherein the step of patterning the initial conductive layer further comprises: ablation of the initial conductive layer by laser. The method for fabricating a buried conductive wiring according to claim 1, wherein the step of performing the plating treatment on the conductive layer and the step of removing the first sacrificial pattern further comprises: An etch stop layer is formed on the conductive layer. The method of fabricating the buried conductive wiring of claim 5, wherein the step of removing the conductive layer in the second recessed region further comprises: removing the etch stop layer. The method of fabricating a buried conductive wiring according to claim 1, wherein the conductive pattern is thickened to a height of the first sacrificial pattern in a thickness direction. The method of fabricating a buried conductive wiring according to claim 1, wherein a sidewall of the first recessed region is adjacent to a sidewall of the conductive pattern. The method of fabricating a buried conductive wiring according to claim 1, wherein a sidewall of the conductive pattern is aligned with a sidewall portion of the first sacrificial pattern. The method for fabricating a buried conductive wiring according to claim 1, wherein the method A method of forming a conductive layer includes printing a conductive paste.