TWI410527B - Electroplating apparatus and method for plating conducting layer on substrate - Google Patents

Abstract

According to an embodiment of the present invention, an electroplating apparatus is provided, which includes a holder used to support a carrier substrate and a to-be-plated substrate disposed on the carrier substrate, wherein the to-be-plated substrate has a patterned material layer thereon, and the patterned material layer has at least an opening exposing a to-be-plated region on the to-be-plated substrate, and a seal ring used to be disposed on the to-be-plated substrate to confine an electroplating solution on the to-be-plated region, wherein the seal ring includes at least a protruding portion used to contact with the carrier substrate to block the electroplating solution from passing to the holder.

Description

Plating auxiliary device and method for plating conductive layer on substrate

This invention relates to electroplating apparatus, and in particular to sealing rings in electroplating apparatus.

In the fabrication of semiconductor integrated circuits, metal wire layers are used to form interconnects between various components in a semiconductor wafer. The electroplating process is one of the methods for forming a metal wiring layer. For example, a desired conductive pattern can be formed on a semiconductor wafer through an electroplating process, such as a patterned copper layer.

In order to improve the reliability and yield of semiconductor components, it has become an important issue to improve the plating apparatus to reduce the risk of damage to semiconductor components during the plating process.

An embodiment of the present invention provides a plating apparatus including a susceptor for carrying a carrier substrate and a substrate to be plated disposed on the carrier substrate, wherein the substrate to be plated has a patterned material layer, and the patterned material layer has at least one opening. Exposing a region to be plated on the substrate to be plated, and a sealing ring for being disposed on the substrate to be plated to limit the plating solution to the region to be plated, wherein the sealing ring includes at least one protruding portion for contacting the carrier substrate Block the plating solution from overflowing onto the pedestal.

An embodiment of the present invention provides a method for plating a conductive layer on a substrate, comprising: providing a substrate to be plated, forming a patterned material layer on the substrate to be plated, the patterned material layer having at least one opening to expose a substrate to be plated to be plated a mounting substrate is provided, and the substrate to be plated is disposed on the carrier substrate, the carrier substrate and the substrate to be plated are disposed on the base, and the sealing ring is disposed on the substrate to be plated, wherein the sealing ring includes at least one protruding portion. The protruding portion is brought into contact with the carrier substrate, and a plating solution is provided on the region to be plated, wherein the sealing ring limits the plating solution to the upper portion to be plated, and the protruding portion blocks the plating solution from overflowing onto the pedestal, and the plating region is applied The voltage forms a conductive layer on the region to be plated.

Hereinafter, the formation and use of the embodiments of the present invention will be discussed in detail. It should be noted, however, that the embodiments provide a number of inventive features that can be applied to a wide range of applications. The specific embodiments discussed are merely illustrative of specific ways to make and use the embodiments of the invention, and are not intended to limit the scope of the embodiments.

Moreover, repeated numbers or labels may be used in different embodiments. These repetitions are merely for the purpose of simplicity and clarity of the invention and are not necessarily to be construed as a limitation of the various embodiments and/or structures discussed. Furthermore, when a first material layer is referred to or on a second material layer, the first material layer is in direct contact with or separated from the second material layer by one or more other material layers. In the drawings, the shape or thickness of the embodiment may be expanded to simplify or facilitate the marking. Furthermore, elements not shown or described in the figures are in the form known to those of ordinary skill in the art.

Figure 1 shows a schematic cross-sectional view of a plating apparatus known to the inventors. However, it should be noted that it is not a conventional technique for determining the patentability of the present invention, but merely to show the problems discovered by the inventors.

As shown in FIG. 1, the plating apparatus 10 includes a susceptor 104 for carrying a substrate 100 to be plated. The substrate to be plated 100 is, for example, a germanium wafer, and may have a thickness between about 1 micrometer and about 800 micrometers. When the thickness of the substrate to be plated 100 is thin, it can be carried on the carrier substrate 102 to facilitate the subsequent process.

As shown in FIG. 1, a patterned material layer 106, which is, for example, a photoresist layer, may be formed on the substrate 100 to be plated. The patterned material layer 106 can have an opening (not shown) that exposes a region to be plated (not shown) of the substrate 100 to be plated.

In order to plate the conductive layer required for plating on the substrate 100 to be plated, a sealing ring 110 may be disposed on the substrate 100 to be plated. In the embodiment of Fig. 1, the sealing ring 110 is disposed around the region to be plated of the substrate 100 to be plated, and the plating solution 108 required for electroplating can be limited to the region to be plated. The seal ring 110 includes projections 110a and 110b for respectively resisting the patterned material layer 106 and the substrate 100 to be plated, and avoiding the plating solution 108 from overflowing to the susceptor 104. Additionally, electroplating apparatus 10 can also include a conductive electrode 112, such as a conductive probe. The conductive electrode 112 is electrically connected to the region to be plated on the substrate 100 to be plated, and can be used to apply a voltage to the plated region, and the conductive ions in the plating solution 108 are reduced and deposited on the region to be plated to form a desired conductive layer. .

However, the inventors of the present invention have found that after a period of plating, the plating solution 108 may overflow through the seal ring 110 and overflow to the susceptor 104. As shown in Fig. 1, a portion of the plating solution 108a overflows onto the susceptor 104. Wherein, part of the plating solution 108a may penetrate into the interface between the carrier substrate 102 and the susceptor 104 to increase the adhesion between the carrier substrate 102 and the susceptor 104. When the plating process is completed and the carrier substrate 102 and the substrate 100 to be plated thereon are removed from the susceptor 104, a large force is required to increase the adhesion between the carrier substrate 102 and the susceptor 104. The substrate 102 is separated from the susceptor 104. In this case, the substrate 100 to be plated is liable to be damaged by external force and the internal wiring and/or components are damaged.

In order to avoid the situation as described in the embodiment of FIG. 1 , an embodiment of the present invention provides a plating apparatus having a specially designed sealing ring, which can effectively avoid and/or reduce various problems caused by overflow of the plating solution to the susceptor. . Hereinafter, a plating apparatus according to an embodiment of the present invention will be described with reference to the drawings.

Fig. 2 is a cross-sectional view showing a plating apparatus according to an embodiment of the present invention. As shown in FIG. 2, the plating apparatus 20 includes a susceptor 204 for carrying a substrate 200 to be plated. The substrate to be plated 200 can be a semiconductor wafer (eg, a germanium wafer) having a thickness between about 1 micrometer and about 800 micrometers. When the thickness of the substrate to be plated 200 is relatively thin (for example, about 1 micrometer to about 100 micrometers), it can be carried on the carrier substrate 202 to facilitate the subsequent process.

The carrier substrate 202 can include, but is not limited to, a semiconductor material or an insulating material. In an embodiment, the size of the carrier substrate 202 is larger than the substrate 200 to be plated. For example, when the substrate to be plated 200 is a wafer, the carrier substrate 202 may be a wafer having a larger diameter or a glass substrate or the like.

As shown in FIG. 2, a patterned material layer 206, which is, for example, a photoresist layer, may be formed on the substrate 200 to be plated. The patterned material layer 206 can have an opening (not shown) that exposes a region to be plated (not shown) of the substrate 200 to be plated. It should be noted that the patterned material layer 206 is not limited to being a photoresist layer. In other embodiments, the patterned material layer 206 can be a dielectric layer, a conductive layer, or other material layer.

In order to plate the conductive layer required for plating on the substrate 200 to be plated, a sealing ring 210 may be disposed on the substrate 200 to be plated. The material of the seal ring 210 includes, for example, but not limited to, an insulating material. In an embodiment, the material of the sealing ring 210 may include an elastic material resistant to acid and alkali corrosion, such as Nitrile Butadiene Rubber (NBR), hydrogenated nitrile rubber (HNBR), and fluorocarbon rubber (FKM). ), or perfluorinated rubber (FFKM). In the embodiment of Fig. 2, the sealing ring 210 is disposed around the area to be plated of the substrate 200 to be plated, and the plating solution 208 required for electroplating can be limited to the area to be plated. In the embodiment of Fig. 2, the seal ring 210 is specifically designed to include at least one projection 210c. The protrusion 210c is used to contact and abut the carrier substrate 202 to prevent the plating solution 208 from overflowing to the susceptor 204.

In addition, the sealing ring 210 may further include at least one protruding portion 210a and at least one protruding portion 210b for respectively contacting and abutting the patterned material layer 206 and the substrate 200 to be plated, thereby further preventing the plating solution 208 from overflowing. To the pedestal 204. In the embodiment of FIG. 2, since the projection 210c of the seal ring 210 contacts and abuts the carrier substrate 202, even if a portion of the plating solution 208a overflows over the carrier substrate 202, it contacts and abuts against the projection of the carrier substrate 202. The outlet portion 210c can effectively block the overflow plating solution 208a, and the plating solution 208a can be prevented from overflowing to the susceptor 204. Therefore, when the plating process is completed and the carrier substrate 202 and the substrate 200 to be plated thereon are removed from the susceptor 204, the interface between the carrier substrate 202 and the susceptor 204 does not penetrate into the plating solution 208a, in which case The carrier substrate 202 and the substrate to be plated 200 can be easily removed, and the substrate 100 to be plated is prevented from being bent by an external force to damage the internal wiring and/or components.

Additionally, plating apparatus 20 can also include a conductive electrode 212, such as a conductive probe. The conductive electrode 212 is electrically connected to the region to be plated on the substrate 200 to be plated, and can be used to apply a voltage to the plated region, and the conductive ions in the plating solution 208 are reduced and deposited on the region to be plated to form a desired conductive layer. . For example, in one embodiment, the conductive electrode 212 is electrically connected to a seed layer previously formed on the region to be plated. In an embodiment, the conductive electrode 212 can be part of the seal ring 210. In another embodiment, the conductive electrode 212 is not part of the seal ring 210 and is not connected to the seal ring 210.

3A-3F are schematic cross-sectional views showing a series of processes for electroplating a conductive layer on a substrate in accordance with an embodiment of the present invention, which is performed using a plating apparatus according to an embodiment of the present invention.

As shown in FIG. 3A, a substrate 300 to be plated is provided, which may be, for example, a semiconductor wafer. In an embodiment, a hole 324 is defined in the substrate to be plated 300, which extends from the surface 300a of the substrate 300 to be plated toward the other surface 300b. An insulating layer 322 is also formed on the substrate to be plated 300, which is formed on the surface 300a and extends on the sidewalls and the bottom of the hole 324. A conductive plug 326 is also filled in the hole 324. After the subsequent polishing process, the conductive plug 326 will become a through-substrate via (TSV) in the substrate 300 to be plated. The material of the insulating layer 322 includes, for example, but not limited to, cerium oxide, cerium nitride, cerium oxynitride, or a combination thereof. The material of the conductive plug 326 includes, for example, but not limited to, copper, aluminum, gold, platinum, tungsten, or a combination thereof.

Next, as shown in FIG. 3B, a carrier substrate 302 is provided, and the substrate 300 to be plated is placed thereon. For example, an adhesive layer (not shown) may be applied between the surface 300a of the substrate 300 to be plated and the carrier substrate 302 to fix the substrate 300 to be plated on the carrier substrate 302. The carrier substrate 302 can include, but is not limited to, a semiconductor material or an insulating material.

As shown in FIG. 3C, a thinning process is then started from the surface 300b of the substrate 300 to be plated to thin the substrate 300 to be plated to expose the conductive plug 326. Suitable thinning processes are, for example, mechanical or chemical mechanical polishing. In one embodiment, after the substrate 300 to be plated is thinned, one end of the conductive plug 326 protrudes from the surface 300b of the substrate 300 to be plated. In addition, after the substrate 300 to be plated is thinned, the holes 324 originally formed in the substrate 300 to be plated are now passed through the substrate 300 to be plated to become the through holes 324'.

Next, as shown in FIG. 3D, a seed layer 328 is formed on the surface 300 and the exposed conductive plugs 326 to facilitate subsequent plating processes. The seed layer 328 can be formed, for example, by physical vapor deposition, and the material thereof is, for example, copper. In addition, a diffusion barrier layer (not shown) is preferably formed between the seed layer 328 and the substrate 300 to be plated, and the material thereof is, for example, Ti or TiN, to prevent the conductive material (for example, copper) from diffusing into the substrate 300 to be plated. The adhesion between the seed layer 328 and the substrate 300 to be plated can be increased.

As shown in FIG. 3D, after the seed layer 328 is formed, a patterned material layer 306 is formed on the substrate 300 to be plated. The patterned material layer 306 can include a dielectric layer, a conductive layer, an insulating layer, a photoresist layer, or other material layers. In one embodiment, the patterned material layer 306 is a photoresist layer and has at least one opening 307. The opening 307 exposes a region to be plated (i.e., a region occupied by the seed layer 328 exposed in the opening 307) on the substrate 300 to be plated. The patterned material layer 306 can prevent the conductive material from being electroplated on the substrate to be plated 300 without forming a conductive layer during the electroplating process.

Next, as shown in FIG. 3E, the carrier substrate 302 and the substrate 300 to be plated are placed on the susceptor 304. Next, the sealing ring 310 is placed on the substrate 300 to be plated. In the embodiment of FIG. 3E, the sealing ring 310 is disposed around the region to be plated of the substrate 300 to be plated, and the plating solution 308 required for electroplating can be limited to the region to be plated. The seal ring 310 is specifically designed to include at least one projection 310c. The protrusion 310c is used to contact and abut the carrier substrate 302 to prevent the plating solution 308 from overflowing to the susceptor 304.

In addition, the sealing ring 310 can further include at least one protruding portion 310a and at least one protruding portion 310b for respectively contacting and abutting the patterned material layer 306 and the substrate to be plated 300, thereby further preventing the plating solution 308 from overflowing. To the pedestal 304. In the embodiment of FIG. 3E, since the projection 310c of the seal ring 310 contacts and abuts the carrier substrate 302, even if a portion of the plating solution 308a overflows onto the carrier substrate 302, it contacts and abuts against the projection of the carrier substrate 302. The outlet portion 310c can effectively block the overflow plating solution 308a, and the plating solution 308a can be prevented from overflowing to the susceptor 304.

Next, a power source can be applied through the region to be plated (i.e., above the seed layer 328 at the bottom of the opening 307) of the substrate 300 to be plated to reduce metal ion deposition in the plating solution over the seed layer 328. For example, a power source required for electroplating can be applied to the seed layer 328 through the conductive electrode 312.

Therefore, as shown in FIG. 3F, the conductive layer 330 can be formed on the region to be plated through the above-described plating process. Next, the layer of patterned material and the seed layer directly beneath it can be selectively removed. When the plating process is completed and the carrier substrate 302 and the substrate to be plated 300 to be plated are removed from the susceptor 304, the interface between the carrier substrate 302 and the susceptor 304 does not penetrate into the plating solution 308a. In this case, the carrier substrate 302 and the substrate to be plated 300 can be easily removed, and the substrate to be plated 300 is prevented from being bent by an external force to damage the internal wiring and/or components.

In one embodiment, the seal ring of the embodiment of the present invention includes a plurality of projections that respectively contact surfaces of different heights to block overflow of the plating solution. It should be noted that the seal ring of the embodiment of the present invention is not limited thereto. For example, the projection of the seal ring can be an integrally formed continuous structure. 4A-4C are cross-sectional views showing plating apparatus according to several embodiments of the present invention, each having a different seal ring design.

In the embodiment of FIG. 4A, the plating apparatus 40 includes a base 404 and a seal ring 410. The susceptor 404 is configured to carry the carrier substrate 402 and the substrate to be plated 400 disposed thereon. The substrate to be plated 400 is formed with a patterned material layer 406 whose opening exposes a region to be plated on the substrate 400 to be plated. The plating apparatus 40 also includes a conductive electrode 412 for providing a power source required to plate the conductive layer. The sealing ring 410 of the electroplating device 40 is specially designed. The protruding portion 410a contacts the substrate to be plated 400 and the patterned material layer 406 in addition to the carrier substrate 402, thereby effectively preventing the plating solution 408 from overflowing to the susceptor 404. on.

Fig. 4B shows a plating apparatus 50 of another embodiment, the structure of which is similar to that of the embodiment of Fig. 4A, and therefore the same or similar elements will be designated by the same or like numerals. The main difference between electroplating devices 50 and 40 is the design of the seal ring. In the plating apparatus 50, the seal ring 410 includes a projection 410a and a projection 410c, wherein the projection 410a contacts the substrate 400 to be plated and the patterned material layer 406, and the other projection 410c contacts the carrier substrate 402. Similarly, the seal ring 410 of the plating apparatus 50 can effectively prevent the plating solution 408 from overflowing onto the susceptor 404.

4C shows a plating apparatus 60 of another embodiment, the structure of which is similar to that of the embodiment of FIG. 4A, and therefore the same or similar elements will be designated by the same or similar reference numerals. The main difference between electroplating devices 60 and 40 is the design of the seal ring. In the plating apparatus 60, the seal ring 410 includes a projection 410a and a projection 410c, wherein the projection 410a contacts the patterned material layer 406, and the other projection 410c contacts the substrate to be plated and the carrier substrate 402. Similarly, the seal ring 410 of the plating apparatus 60 can effectively prevent the plating solution 408 from overflowing onto the susceptor 404.

As described above, in the plating apparatus of the embodiment of the present invention, the projection on the seal ring is pressed against and contacts the carrier substrate through the arrangement of the seal ring, so that the overflow of the plating solution can be effectively blocked. In particular, when the substrate to be plated provided on the carrier substrate is thinned by the formation of the through-substrate conductive structure, it is more important to effectively and effectively prevent the plating solution used in the electroplating process from penetrating into the pedestal. The electroplating device of the embodiment of the present invention is used to form a conductive layer on a substrate to be plated (for example, a thinned wafer), so that the yield and reliability of the formed device can be improved.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the scope of the present invention, and any one of ordinary skill in the art can make any changes without departing from the spirit and scope of the invention. And the scope of the present invention is defined by the scope of the appended claims.

10, 20, 40, 50, 60. . . Plating device

100, 200, 300, 400. . . Substrate to be plated

102, 202, 302, 402. . . Carrier substrate

104, 204, 304, 404. . . Pedestal

106, 206, 306, 406. . . Material layer

108, 108a, 208, 208a, 308, 308a, 408. . . Plating solution

110, 210, 310, 410. . . Sealing ring

110a, 110b, 210a, 210b, 210c, 310a, 310b, 310c, 410a, 410c. . . Protrusion

112, 212, 312, 412. . . Conductive electrode

300a, 300b. . . surface

307. . . Opening

322. . . Insulation

324. . . Hole

324’. . . perforation

326. . . Conductive plug

328. . . Seed layer

330. . . Conductive layer

Figure 1 shows a schematic cross-sectional view of a plating apparatus known to the inventors.

Fig. 2 is a cross-sectional view showing a plating apparatus according to an embodiment of the present invention.

3A-3F are schematic cross-sectional views showing a series of processes for plating a conductive layer on a substrate in accordance with an embodiment of the present invention.

4A-4C are cross-sectional views showing a plating apparatus according to several embodiments of the present invention.

300. . . Substrate to be plated

302. . . Carrier substrate

304. . . Pedestal

306. . . Material layer

308, 308a. . . Plating solution

310. . . Sealing ring

310a, 310b, 310c. . . Protrusion

312. . . Conductive electrode

300a, 300b. . . surface

307. . . Opening

322. . . Insulation

324’. . . perforation

326. . . Conductive plug

328. . . Seed layer

330. . . Conductive layer

Claims (14)

An electroplating auxiliary device includes: a pedestal for carrying a carrier substrate and a substrate to be plated disposed on the carrier substrate, wherein the substrate to be plated has a patterned material layer, the patterned material layer having at least An opening to expose a region to be plated on the substrate to be plated; and a sealing ring for being disposed on the substrate to be plated to limit a plating solution to the region to be plated, wherein the sealing ring includes at least one And a protruding portion for contacting the carrier substrate to block the plating solution from overflowing onto the base. The electroplating auxiliary device according to claim 1, wherein the at least one protruding portion contacts the substrate to be plated and/or the patterned material layer to block the plating solution from overflowing onto the susceptor. The electroplating auxiliary device of claim 1, wherein the sealing ring further comprises at least one second protrusion for contacting the substrate to be plated to block the plating solution from overflowing onto the base. The plating auxiliary device of claim 1 or 2, wherein the sealing ring further comprises at least one third protruding portion for contacting the patterned material layer to block the plating solution from overflowing onto the base . The electroplating aid device of claim 1, wherein the patterned material layer comprises a photoresist layer. The electroplating auxiliary device according to claim 1, wherein the substrate to be plated comprises a semiconductor wafer. The electroplating aid of claim 6, wherein the semiconductor wafer has a thickness of between about 1 micrometer and about 800 micrometers. The electroplating auxiliary device according to claim 1, further comprising a conductive electrode electrically connected to the region to be plated on the substrate to be plated. The electroplating auxiliary device according to claim 1, wherein the substrate to be plated comprises a through-substrate conductive structure. A method for plating a conductive layer on a substrate, comprising: providing a substrate to be plated; forming a patterned material layer on the substrate to be plated, the patterned material layer having at least one opening to expose one of the substrates to be plated a plating substrate; a carrier substrate is disposed, and the substrate to be plated is disposed on the carrier substrate; the carrier substrate and the substrate to be plated are disposed on a base; and a sealing ring is disposed on the substrate to be plated, wherein The sealing ring includes at least one protruding portion, the at least one protruding portion contacting the carrier substrate; a plating solution is provided on the region to be plated, wherein the sealing ring limits the plating solution to the region to be plated, And the at least one protruding portion blocks the plating solution from overflowing onto the base; and applying a voltage to the region to be plated to form a conductive layer on the region to be plated. The method of electroplating a conductive layer on a substrate according to claim 10, wherein the sealing ring further comprises at least one second protrusion, the at least one protruding portion contacting the carrier substrate, the at least one The second protrusion contacts the substrate to be plated to block the plating solution from overflowing onto the base. The method of electroplating a conductive layer on a substrate according to claim 10 or 11, wherein the sealing ring further comprises at least one third protrusion, when the at least one protruding portion is brought into contact with the carrier substrate, At least one third protrusion contacts the layer of patterned material to block the plating solution from overflowing onto the susceptor. The method of electroplating a conductive layer on a substrate according to claim 10, wherein when the at least one protruding portion of the sealing ring contacts the carrier substrate, the at least one protruding portion contacts the substrate to be plated and / or the patterned material layer to block the plating solution from overflowing onto the susceptor. A method of plating a conductive layer on a substrate as described in claim 10, wherein the substrate to be plated comprises a through-substrate conductive structure.