TWI489623B - Semiconductor structure and manufacturing method of the same - Google Patents

Description

Semiconductor structure and method of manufacturing same

The present invention relates to a semiconductor structure and a method of fabricating the same, and more particularly to a semiconductor structure for a three-dimensional memory device and a method of fabricating the same.

In recent years, the structure of semiconductor elements has been constantly changing, and the memory storage capacity of the elements has also been increasing. Memory devices are used in many products, such as MP3 players, digital cameras, computer files, and the like. As applications increase, so does the demand for memory devices toward smaller sizes and larger memory capacities.

Designers have developed a way to increase the density of memory devices by using a three-dimensional stacked memory device to achieve higher memory capacity while reducing the cost per bit. However, when making such a memory device, it is necessary to separately make contact points for each bit layer located in different layers in the stacked structure, and also need to make contact points for different components, such as string selection line, ground selection line and source connection. The complex structure of such a memory device also complicates the manufacturing method.

The present invention relates to a semiconductor structure and a method of fabricating the same, which can be applied to a memory device. According to an embodiment of the present disclosure, a plurality of contact structures of a semiconductor structure are formed in a two-stage manner, and a plurality of contact structures having different heights can be fabricated in the same process, which has a simplified process step, And the effect of reducing process time and cost.

According to an aspect of the invention, a semiconductor structure is proposed. The semiconductor structure includes a plurality of stacked structures and a plurality of contact structures, wherein each of the stacked structures includes a plurality of conductive strips and a plurality of insulating strips, and the conductive strips and the insulating strips are interlaced, and the contact structures are electrically connected to the stacks respectively. structure. The contact structure includes a first conductive pillar, a dielectric material layer, a metal telluride layer, and a second conductive pillar. The dielectric material layer surrounds the side of the first conductive pillar, the metal telluride layer is formed on the upper surface of the first conductive pillar, and the second conductive pillar is formed on the metal telluride layer, and the upper surface of the first conductive pillar is Same plane.

According to another aspect of the present invention, a method of fabricating a semiconductor structure is proposed. The manufacturing method of the semiconductor structure comprises the steps of: forming a plurality of stacked structures, comprising forming a plurality of conductive strips and a plurality of insulating strips, the conductive strips and the insulating strips are interlaced; and forming a plurality of contact structures, each of the contact structures They are electrically connected to each stack structure. Forming each contact structure includes the steps of: forming a first conductive pillar; forming a layer of dielectric material surrounding the side of the first conductive pillar; forming a metal telluride layer on the upper surface of the first conductive pillar; And forming a second conductive pillar on the metal telluride layer, wherein the heights of the second conductive pillars are the same.

According to still another aspect of the present invention, a method of fabricating a semiconductor structure is proposed. The manufacturing method of the semiconductor structure comprises the steps of: forming a plurality of stacked structures, comprising forming a plurality of conductive strips and a plurality of insulating strips, the conductive strips and the insulating strips are staggered; forming an insulating material layer, and the insulating material layer is coated and stacked Structure; forming a plurality of recessed holes in the layer of insulating material a recessed hole exposes a portion of each of the stacked structures; a plurality of dielectric material layers are formed on the sidewalls of the recessed holes; a conductive material is filled in the recessed holes to form a plurality of first conductive pillars; and a plurality of metals are formed The telluride layer is on the upper surface of the first conductive pillar; and a plurality of second conductive pillars are formed on the metal telluride layer, wherein the heights of the second conductive pillars are the same.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

In the embodiments disclosed herein, a semiconductor structure and a method of fabricating the same are presented. According to an embodiment of the present disclosure, a plurality of contact structures of a semiconductor structure are formed in a two-stage manner, and a plurality of contact structures having different heights can be fabricated in the same process, which has a simplified process step, and reduces process time and cost. Effect. It is to be noted that the drawings have been simplified to clearly illustrate the contents of the embodiments, and the dimensional ratios in the drawings are not drawn to the scale of the actual products, and thus are not intended to limit the scope of the present invention. Further, the detailed structure and process steps set forth in the embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Those having ordinary knowledge may modify or change the steps as needed according to the actual implementation.

1 is a top plan view of a semiconductor structure in accordance with an embodiment of the present invention, FIG. 2A is a cross-sectional view taken along line 2A-2A' of FIG. 1, and FIG. 2B is a cross-sectional view along FIG. Section of line 2B-2B' Fig. 2C is a schematic cross-sectional view taken along line 2C-2C' of Fig. 1.

Please refer to Figures 1 and 2A~2C. The semiconductor structure 100 includes a plurality of stacked structures 110 and a plurality of contact structures 120. Each of the stacked structures 110 includes a plurality of conductive strips 111 and a plurality of insulating strips 113, and the conductive strips 111 and the insulating strips 113 are interlaced. Each of the contact structures 120 is electrically connected to the first end 110a of each of the stacked structures 110. Each contact structure 120 includes a first conductive pillar 121, a dielectric material layer 123, a metal telluride layer 125, and a second conductive pillar 127. The dielectric material layer 123 surrounds the side of the first conductive pillar 121, the metal telluride layer 125 is formed on the upper surface 121a of the first conductive pillar 121, and the second conductive pillar 127 is formed on the metal halide layer 125. The upper surface 121a of the first conductive pillar 121 of the plurality of contact structures 120 is in the same plane. In an embodiment, the material of the conductive strips 111 includes a germanium-containing material, such as polysilicon, and the material of the insulating strips 113 includes an oxide, such as cerium oxide. However, in practical applications, the materials are also appropriately selected depending on the application. Not limited to the aforementioned materials.

In the embodiment, as shown in FIG. 2B (please refer to FIG. 1 at the same time), in the contact region BLP, the heights 127H of the plurality of second conductive pillars 127 are, for example, the same, and the heights of the plurality of first conductive pillars 121 are 121H1~ 121H8 is different, for example, the height 121H1 of the first conductive pillar 121 is different from the heights 121H2 to 121H8 of the remaining first conductive pillars 121. As such, as shown in FIG. 2B, the plurality of contact structures 120 in the contact region BLP form a stepped overall structure.

In the embodiment, the material of the first conductive pillar 121 is different from the material of the second conductive pillar 127, for example. The material of the first conductive pillar 121 is, for example, polycrystalline Polysilicon, the material of the second conductive pillar 127 is, for example, tungsten. The material of the metal telluride layer 125 is, for example, nickel telluride or cobalt telluride, and has an effect of lowering the impedance of the first conductive pillar 121. However, in actual application, the materials are also appropriately selected depending on the application conditions, and are not limited to the aforementioned materials.

In the embodiment, as shown in FIG. 2A, the dielectric material layer 123 is also formed on the two sidewalls 110s of the stacked structure 110. The dielectric material layer 123 includes a charge trapping material, for example, may have a multilayer structure such as an ONO composite layer or an ONONO composite layer or a BE-SONOS composite layer, or may include, for example, a stack of yttrium oxide and tantalum nitride. The formed ONO structure.

In the embodiment, as shown in FIG. 2A to FIG. 2B , each contact structure 120 is electrically connected to one of the plurality of conductive strips 111 of each stacked structure 110 via each of the first conductive pillars 121 .

In one embodiment, as shown in FIGS. 1 and 2A, the semiconductor structure 100 may further include a plurality of strip-shaped conductive structures 130 and 130' formed on the stacked structure 110 and a plurality of Between the stacked structures 110, and the extending direction D1 of the strip-shaped conductive structures 130 and 130' is perpendicular to the extending direction D2 of the stacked structure 110.

In an embodiment, the semiconductor structure 100 may further include an insulating structure 140. As shown in Fig. 1, an insulating structure 140 is formed between the plurality of strip-shaped conductive structures 130/130'. As shown in FIG. 2B, the insulating structure 140 is also formed between the plurality of contact structures 120, and the contact structures 120 are separated from each other by the insulating structure 140. In the embodiment, the material of the insulating structure 140 includes, for example, an oxide.

In one embodiment, as shown in FIG. 2C, the semiconductor structure 100 can be further A plurality of conductive blocks 150 are included, and the conductive blocks 150 are electrically connected to the stacked structure 110. In an embodiment, each of the conductive bumps 150 is formed on each of the stacked structures 110 relative to the second end 110b of the first end 110a. As shown in FIG. 2C, the contact structure 120 can be formed on the conductive block 150.

In an embodiment, as shown in FIG. 2B , the semiconductor structure 100 may further include a barrier layer 160 , and the barrier layer 160 is disposed between the contact structures 120 , for example. In the embodiment, the material of the barrier layer 160 includes, for example, a metal nitride. However, in actual application, the materials are also appropriately selected depending on the application conditions, and are not limited to the foregoing materials.

In one embodiment, as shown in FIG. 1 , the semiconductor structure 100 may further include a plurality of conductive blocks 170 electrically connected to the stacked structure 110 . In the embodiment, each of the conductive blocks 170 is electrically connected to the corresponding respective contact structures 120.

In one embodiment, the semiconductor structure 100 is a 3D memory device. As shown in FIGS. 1~2C, the stacked structure 110 is, for example, a bit line (BL), above the contact area BLP. The contact structure 120 is, for example, a bit line pad (BLP), the strip conductive structure 130 is, for example, a word line (WL), and the strip conductive structure 130' is, for example, a ground selection line (ground select line) Line, GSL), the conductive block 150 is, for example, a source contact (SC), and the conductive block 170 is, for example, a string select line SSL, and a plurality of contacts arranged in a stepped manner in the contact region BLP. The structure 120 is capable of leading to the conductive strips 111 of different layers in the stacked structure 110.

Generally, a three-dimensional memory device is fabricated by first forming a stepped structure at the end of the stacked structure 110, and then etching the oxide layer above the stepped structure to form an oxide layer. A plurality of contact holes are then filled with tungsten metal to form a plurality of tungsten plugs having different heights. However, the different tungsten inserts connected to the different conductive strips 111 have different heights, so the etch depth required for each plug must be different, which can result in increased process steps, time, and cost. Moreover, there are other contacts in the memory device that need to make contact plugs, such as source contacts and tandem select lines. For similar reasons, it is even more impossible to do the memory device in one step at the same time. All contact plugs needed. In contrast, in the embodiment of the disclosure, the upper surface 121a of the first conductive pillar 121 of the plurality of contact structures 120 is in the same plane, and then a plurality of second conductive pillars 127 may be formed in one process (contact plug, For example, tungsten plugging), therefore, the steps, time and cost of the process of the memory device can be effectively reduced.

The following is a method of fabricating a semiconductor structure of the embodiments, which are for illustrative purposes only and are not intended to limit the invention. Those having ordinary knowledge may modify or change the steps as needed according to the actual implementation. Please refer to Figures 3 to 23C. 3 to 23C are schematic views showing a method of fabricating a semiconductor structure in accordance with an embodiment of the present invention. It is to be noted that the drawings have been simplified to clearly illustrate the contents of the embodiments, and the dimensional ratios in the drawings are not drawn to the scale of the actual products, and thus are not intended to limit the scope of the present invention.

First, referring to FIGS. 3-7C, a plurality of stacked structures 110 are formed, including forming a plurality of conductive strips 111 and a plurality of insulating strips 113, and the conductive strips 111 and the insulating strips 113 are interlaced. Also, a contact region BLP having a stepped structure is formed at one end of the stacked structure 110. Moreover, a plurality of conductive blocks 150 are formed on the other end of the plurality of stacked structures 110 with respect to the end of the contact region BLP, and the conductive blocks 150 are electrically connected to the stacked structure 110.

The manufacturing method of forming the stacked structure 110, the contact region BLP, and the conductive bump 150 includes, for example, the following steps.

As shown in Figures 3 and 4A-4B (Fig. 4A is a cross-sectional view taken along line 3A-3A' of Fig. 3, and Fig. 4B is a cross-sectional view taken along line 3B-3B' of Fig. 3. a plurality of conductive layers 111a and a plurality of insulating layers 113a are formed. The conductive layer 111a and the insulating layer 113a are interlaced, and a plurality of conductive blocks 150 are formed on the composite layer composed of the conductive layer 111a and the insulating layer 113a. in. Then, a portion of the conductive layer 111a and a portion of the insulating layer 113a are removed from the selected contact region BLP to form a step structure as shown in FIG. 4B, for example, by mask etching using a hard mask HM1. Part of the conductive layer 111a and a portion of the insulating layer 113a.

As shown in Figures 5A-5B (Fig. 5A shows a cross-sectional view along section line 3A-3A' of Fig. 3, and Fig. 5B shows a cross-sectional view along section line 3B-3B' of Fig. 3) After the hard mask HM1 is removed, the barrier material layer 160a is formed on the conductive layer 111a, the insulating layer 113a and the conductive block 150, and the barrier material layer 160a can serve as an etching barrier layer in a subsequent process. Next, a hard mask HM2 is disposed to cover the barrier material layer 160a, and a patterned photoresist layer PR1 is disposed on the hard mask HM2.

As shown in Figures 6-7C (Fig. 7A is a cross-sectional view taken along line 6A-6A' of Fig. 6, and Fig. 7B is a cross-sectional view taken along line 6B-6B' of Fig. 6, Figure 7C shows the section line along Figure 6. A cross-sectional view of 6C-6C'), for example, etching the conductive layer 111a and the insulating layer 113a according to the patterned photoresist layer PR1 in a mask etching manner to form a plurality of stacked structures 110. At the same time, after the etching process, the barrier material layer 160a is also etched to form the barrier layer 160 on the stacked structure 110, the conductive block 150 and the contact region BLP.

Next, referring to FIGS. 8A to 23C , a plurality of contact structures 120 are formed. Each of the contact structures 120 is electrically connected to each of the stacked structures 110 , for example, electrically connected to the first ends 110 a of the stacked structures 110 . Contact structure 120 may also be formed on conductive bumps 150 and 170. The manufacturing method for forming a contact structure 120 includes: forming a first conductive pillar 121; forming a dielectric material layer 123, the dielectric material layer 123 surrounding the side of the first conductive pillar 121; forming a metal telluride layer 125 on the first conductive pillar 121 On the upper surface 121a; and forming a second conductive pillar 127 on the metal telluride layer 125, wherein the heights 127H of the plurality of second conductive pillars 127 are the same.

The manufacturing method of forming the plurality of first conductive pillars 121 and the corresponding plurality of dielectric material layers 123 includes, for example, the following steps.

As shown in Figs. 8A-8C (Fig. 8A is a cross-sectional view taken along line 6A-6A' of Fig. 6, and Fig. 8B is a cross-sectional view taken along line 6B-6B' of Fig. 6, 8C is a cross-sectional view taken along line 6C-6C' of FIG. 6 to form an insulating material layer 140a on the surface of the entire structure. The insulating material layer 140a covers the stacked structure 110, the conductive bumps 150, and the contact regions BLP. In the embodiment, the insulating material layer 140a is, for example, a metal oxide.

As shown in Figures 9 to 10C (Fig. 10A shows a cross-sectional view along section line 9A-9A' of Fig. 9, and Fig. 10B shows a section line along Fig. 9. 9B-9B' is a schematic cross-sectional view, and FIG. 10C is a cross-sectional view taken along line 9C-9C' of FIG. 9 to form a plurality of holes 121h in the insulating material layer 140a, and the recessed holes 121h is located above stacking structure 110 connected to one end 110a of contact area BLP. As shown in FIGS. 9-10C, a plurality of recessed holes 150h and 170h and a plurality of trenches 130t and 130t' are formed in the insulating material layer 140a, and the extending directions D1 of the recesses 130t and 130t' are perpendicular to The extending direction D2 of the stacked structure 110. In the embodiment, the grooves 130t and 130t' are formed simultaneously with the recessed holes 121h, 150h and 170h. In an embodiment, the recessed holes and the recesses are formed, for example, by etching, and the barrier layer 160 can serve as an etch barrier layer, so that the insulating material layer 140a between the stacked structures 110 is completely removed, and the stacked structure 110 is protected. Etching, and the barrier layer 160 at the bottom of the recesses 121h, 150h, and 170h is thinned without being completely removed, so that the conductive strips 111 under the recesses 121h, 150h, and 170h are not damaged by etching, and are also clear A stacked structure 110 is defined.

In the embodiment, the semiconductor structure 100 is a three-dimensional memory device, and the recessed holes and the recesses are respectively used to define subsequently formed word lines, ground selection lines, serial selection lines, source contacts, and bit lines. The shape, position and extent of the contact plug of the pad. Therefore, in the embodiment of the disclosure, the position of the contact plug of the plurality of components can be defined together in one process, which has the advantages of simplifying the processing steps of the memory device and reducing the processing time and cost.

As shown in FIG. 11A to FIG. 11C (FIG. 11A is a cross-sectional view taken along line 9A-9A′ of FIG. 9 , and FIG. 11B is a cross-sectional view taken along line 9B-9B′ of FIG. 9 . Figure 11C shows the section line along Figure 9. A cross-sectional view of the 9C-9C' is formed to form a dielectric material coating layer 123a on the stacked structure 110 and in the recess 121h. In the embodiment, the dielectric material coating layer 123a completely covers the barrier layer 160, the stacked structure 110, the grooves 130t and 130t', and the recessed holes 121h, 150h, and 170h.

As shown in Figures 12A-12C (Fig. 12A is a cross-sectional view taken along line 9A-9A' of Fig. 9, and Fig. 12B is a cross-sectional view taken along line 9B-9B' of Fig. 9, 12C is a cross-sectional view of the cross-sectional line 9C-9C' along the ninth drawing, etching the dielectric material coating layer 123a and the barrier layer 160, and the recess 121h exposes a part of each of the stacked structures 110, for example, The first end 110a of each of the stacked structures 110 (the conductive strips 111 at one end of the contact regions BLP) forms a dielectric material layer 123 on the sidewalls of the recessed holes 121h. In the embodiment, a dielectric material layer 123 is also formed on the sidewalls of the recesses 150h and 170h, between the sidewalls of the recesses 130t and 130t' and between the stacked structures 110, and the recess 150h exposes the respective conductive bumps 150. In the examples, for example, a comprehensive etching is performed by an anisotropic etching method.

As shown in Figs. 13A-13C (Fig. 13A is a cross-sectional view taken along line 9A-9A' of Fig. 9 and Fig. 13B is a cross-sectional view taken along line 9B-9B' of Fig. 9, 13C is a cross-sectional view taken along line 9C-9C' of FIG. 9 and filled with a conductive material in the recess 121h to form a conductive material layer 1320. In the embodiment, a conductive material is also filled in the recesses 150h and 170h, in the recesses 130t and 130t', and between the stacked structures 110. In the embodiment, the filling of the conductive material in the grooves 130t and 130t' is performed simultaneously with filling the conductive material in the recesses 121h, 150h and 170h, for example. In an embodiment, the conductive material layer 1320 completely covers the stacked structure 110 and the contact region BLP. The conductive material layer 1320 is, for example, an undoped polysilicon (undoped polysilicon).

As shown in Figures 14 to 15C (Fig. 15A is a cross-sectional view taken along line 14A-14A' of Fig. 14, and Fig. 15B is a cross-sectional view taken along line 14B-14B' of Fig. 14, 15C is a cross-sectional view of the section line 14C-14C' taken along line 14 of FIG. 14 and a portion of the conductive material layer 1320 is removed to expose the upper surface 140a1 of the insulating material layer 140a, thereby forming a plurality of first conductive pillars 121. In an embodiment, the plurality of first conductive pillars 121 are formed over the stepped structure of the contact region BLP and over the conductive bumps 150, for example. In an embodiment, a portion of the conductive material layer 1320 is removed, for example, by chemical mechanical polishing (CMP) to form a plurality of first conductive pillars 121. In the embodiment, the upper surface 121a of the first conductive pillar 121 formed after planarization is substantially in the same plane as the upper surface 140a1 of the insulating material layer 140a.

In an embodiment, removing a portion of the conductive material layer 1320 to expose the upper surface 140a1 of the insulating material layer 140a also forms a plurality of strip-shaped conductive structures 130 and 130' in the recesses 130t and 130t', and the strip-shaped conductive structures 130 and 130 The extending direction D1 of ' is perpendicular to the extending direction D2 of the stacked structure 110. In the embodiment, forming the strip-shaped conductive structures 130 and 130 is performed simultaneously with forming the first conductive pillars 121, for example. In an embodiment, removing a portion of the conductive material layer 1320 to expose the upper surface 140a1 of the insulating material layer 140a also forms a plurality of conductive bumps 170 in the recess 170h.

In one embodiment, the semiconductor structure 100 is a three-dimensional memory device. The strip-shaped conductive structure 130 is, for example, a word line. The strip-shaped conductive structures 130 ′ on both sides of the strip-shaped conductive structure 130 are, for example, ground selection lines. The first conductive pillar 121 on the block 150 is, for example, a contact plug of a source contact, and the conductive block 170 is, for example, a tandem selection line, and the conductive block 170 is via the conductive strip 111. Electrically connected to the contact structure 120. In the embodiment, the strip-shaped conductive structures 130 are formed in the spaced apart grooves 130t, so that the strip-shaped conductive structures 130 have good insulation between them. That is to say, the strip-shaped conductive structures 130 are independently embedded in the spaced apart recesses 130t and spaced apart from each other, so that there is no residual conductive material between the strip-shaped conductive structures 130, and can have good The insulation improves the reliability of the subsequently completed memory device.

The manufacturing method of forming the metal telluride layer 125 includes, for example, the following steps. However, it is not limited thereto, and the metal halide layer 125 may be deposited directly on selected regions.

As shown in Figs. 16A to 16C (Fig. 16A is a cross-sectional view taken along line 14A-14A' of Fig. 14, and Fig. 16B is a cross-sectional view taken along line 14B-14B' of Fig. 14, 16C is a cross-sectional view taken along line 14C-14C' of FIG. 14 to form a metal layer 1620 on the first conductive pillar 121. The metal layer 1620 directly contacts the upper surface 121a of the first conductive pillar 121. Metal layer 1620 is, for example, cobalt or nickel. In an embodiment, the metal layer 1620 is formed substantially on the surface of the entire structure, covering the stacked structure 110, the strip-shaped conductive structures 130 and 130' and the contact region BLP, and the metal layer 1620 directly contacts the strip-shaped conductive structures 130 and 130' Upper surface.

As shown in Figs. 17 to 18C (Fig. 18A is a cross-sectional view taken along line 17A-17A' of Fig. 17, and Fig. 18B is a cross-sectional view taken along line 17B-17B' of Fig. 17, 18C is a cross-sectional view of the section line 17C-17C' along the 17th drawing. The first conductive pillar 121 and the strip-shaped conductive structures 130 and 130' are, for example, germanium-containing materials. After the metal layer 1620 is heat-treated, the metal is deuterated. The layer 125 is formed on the first conductive pillar 121 And on the upper surface of the strip-shaped conductive structures 130 and 130'. The metal halide layer 125 formed is, for example, nickel telluride or cobalt telluride.

The method of forming the second conductive pillar 127 on the metal telluride layer 125 includes, for example, the following steps.

19A to 19C (Fig. 19A is a cross-sectional view taken along line 17A-17A' of Fig. 17, and Fig. 19B is a cross-sectional view taken along line 17B-17B' of Fig. 17, 19C is a cross-sectional view taken along line 17C-17C' of FIG. 17 to form an insulating material layer 140b on the surface of the entire structure. In other words, the insulating material layer 140b covers the stacked structure 110 and the contact region BLP. In an embodiment, the insulating material layer 140b covers all of the metal telluride layers 125. In an embodiment, the insulating material layer 140b comprises a metal oxide, such as an interlayer dielectric.

20A-20B (Fig. 20A is a cross-sectional view taken along line 17A-17A' of Fig. 17, and Fig. 20B is a cross-sectional view taken along line 17B-17B' of Fig. 17) A hard mask HM3 is disposed to cover the insulating material layer 140b, and a patterned photoresist layer PR2 is disposed on the hard mask HM3. In an embodiment, the pattern of the patterned photoresist layer PR2 corresponds to a plurality of second conductive pillars 127 that are formed in advance.

21A to 21C (FIG. 21A is a cross-sectional view taken along line 17A-17A' of FIG. 17, and FIG. 21B is a cross-sectional view taken along line 17B-17B' of FIG. 21C is a cross-sectional view taken along line 17C-17C' of FIG. 17, and a plurality of recessed holes 127h are formed in the insulating material layer 140b, and the recessed holes 127h expose the metal on the first conductive pillar 121. Telluride layer 125. In the embodiment, a plurality of recessed holes 150h' are also formed in the insulating material layer 140b above the conductive block 150, And forming a plurality of recesses in the insulating material layer 140b over the conductive bumps 170, and exposing the metal telluride layer 125 over the conductive bumps 150 and 170. In an embodiment, the insulating material layer 140b is etched according to the patterned photoresist layer PR2, for example, in a mask etching manner to form recessed holes.

As shown in Fig. 22~23C (Fig. 23A shows a cross-sectional view along section line 22A-22A' of Fig. 22, and Fig. 23B shows a cross-sectional view along section line 22B-22B' of Fig. 22, 23C is a cross-sectional view taken along line 22C-22C' of FIG. 22, and a conductive material is filled in the recess 127h to form a second conductive pillar 127. In an embodiment, the second conductive pillars 127 are also formed in the recesses above the conductive bumps 150 and 170. In the embodiment, the surface of the insulating material layer 140b and the plurality of second conductive pillars 127 are further planarized, and the heights of the plurality of second conductive pillars 127 are the same. So far, the semiconductor structure 100 is formed.

As shown in FIGS. 22 to 23C, the insulating material layers 140a and 140b form an insulating structure 140, the insulating structure 140 is located between the contact structures 120, and the contact structures 120 are separated from each other by the insulating structure 140. Further, the strip-shaped conductive structures 130 and 130' are separated from each other by an insulating structure 140 (insulating material layer 140a).

In one embodiment, taking the semiconductor structure 100 as a three-dimensional memory device as an example, the contact structure 120 above the conductive block 150 is, for example, a contact plug of the source contact, and the contact structure above the conductive block 170 is, for example, a tandem selection line. The contact structure 120 above the contact region BLP is, for example, a bit line liner. The plurality of contact structures 120 arranged in a stepped manner in the contact region BLP can be electrically connected to and select different layers in the stacked structure 110. Conductive strip 111.

Generally, a contact plug of a plurality of components is formed by first etching an oxide layer above the step structure to form a plurality of contact holes. The etching depth of the plurality of contact holes is determined according to the height of the tungsten plug, and then filled with tungsten metal. A plurality of tungsten inserts having different heights. However, as the etching depth is deeper, it is less likely that the tungsten metal is densely filled in the etching hole, and if the inside of the tungsten intercalation is filled with voids, there is a possibility that contact failure may occur. Moreover, in order to etch a deep etching hole, a problem that subsequent polishing is difficult is also caused, and the difficulty of the process is improved. In contrast, in the embodiment of the present disclosure, the contact structure is formed in a two-stage manner, that is, one contact plug is divided into two steps to etch and fill the conductive material, so that the formed contact structure can be ensured. With high density, voids are not easily generated inside the contact structure, and a plurality of contact structures having different heights can be fabricated in the same process, thereby simplifying the process steps and reducing the process time and cost.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧Semiconductor structure

110‧‧‧Stack structure

110a‧‧‧ first end

110b‧‧‧second end

110s‧‧‧ side wall

111‧‧‧ Conductive strip

111a‧‧‧ Conductive layer

113‧‧‧Insulation strip

113a‧‧‧Insulation

120‧‧‧Contact structure

121‧‧‧First conductive column

121a, 140a1‧‧‧ upper surface

121H1~121H8, 127H‧‧‧ height

121h, 127h, 150h, 150h', 170h‧‧‧ recessed holes

123‧‧‧ dielectric material layer

123a‧‧‧Dielectric material coating layer

125‧‧‧metal telluride layer

127‧‧‧second conductive column

130, 130'‧‧‧ strip-shaped conductive structure

130t, 130t’‧‧‧ grooves

140‧‧‧Insulation structure

140a, 140b‧‧‧ insulating material layer

150, 170‧‧‧ conductive blocks

160‧‧‧Barrier layer

160a‧‧‧layer of barrier material

1320‧‧‧ Conductive material layer

1620‧‧‧metal layer

2A-2A'2B-2B', 2C-2C', 3A-3A', 3B-3B', 6A-6A', 6B-6B', 6C-6C', 9A-9A', 9B-9B', 9C -9C', 14A-14A', 14B-14B', 14C-14C', 17A-17A', 17B-17B', 17C-17C', 22A-22A', 22B-22B', 22C-22C'‧ ‧ section line

BLP‧‧‧Contact Zone

D1, D2‧‧‧ extending direction

HM1, HM2, HM3‧‧‧ hard mask

PR1, PR2‧‧‧ photoresist layer

1 is a top plan view of a semiconductor structure in accordance with an embodiment of the present invention.

Fig. 2A is a schematic cross-sectional view taken along line 2A-2A' of Fig. 1 Figure.

Fig. 2B is a schematic cross-sectional view taken along line 2B-2B' of Fig. 1.

Fig. 2C is a schematic cross-sectional view taken along line 2C-2C' of Fig. 1.

3 to 23C are schematic views showing a method of fabricating a semiconductor structure in accordance with an embodiment of the present invention.

100‧‧‧Semiconductor structure

110a‧‧‧ first end

111‧‧‧ Conductive strip

120‧‧‧Contact structure

121‧‧‧First conductive column

121a‧‧‧ upper surface

121H1~121H8, 127H‧‧‧ height

123‧‧‧ dielectric material layer

125‧‧‧metal telluride layer

127‧‧‧second conductive column

140‧‧‧Insulation structure

160‧‧‧Barrier layer

Claims (9)

A semiconductor structure includes: a plurality of stacked structures, wherein each of the stacked structures includes a plurality of conductive strips and a plurality of insulating strips, the conductive strips are interlaced with the insulating strips; and a plurality of contact structures, each The contact structure includes: a first conductive pillar; a dielectric material layer surrounding the side of the first conductive pillar; a metal telluride layer formed on the upper surface of the first conductive pillar; a second conductive pillar is formed on the metal telluride layer; wherein the upper surfaces of the first conductive pillars are in the same plane, and each of the contact structures is directly in contact with each of the stacked structures via each of the first conductive pillars One of the conductive strips is electrically connected to each of the stacked structures. The semiconductor structure of claim 1, wherein the heights of the second conductive pillars are the same. The semiconductor structure of claim 1, wherein a height of at least one of the first conductive pillars is different from a height of the remaining ones of the first conductive pillars. The semiconductor structure of claim 1, wherein the materials of the first conductive pillars are different from the materials of the second conductive pillars. A method of fabricating a semiconductor structure, comprising: forming a plurality of stacked structures, including forming a plurality of conductive strips and a plurality of insulating strips, wherein the conductive strips are interlaced with the insulating strips And forming a plurality of contact structures, wherein forming each of the contact structures comprises: forming a first conductive pillar; forming a layer of dielectric material surrounding the side of the first conductive pillar; forming a metal bismuth The layer is on the upper surface of the first conductive pillar; and a second conductive pillar is formed on the metal halide layer; wherein the heights of the second conductive pillars are the same, and each of the contact structures is via the first A conductive pillar is directly in contact with one of the conductive strips of each of the stacked structures to electrically connect to each of the stacked structures. The method for fabricating a semiconductor structure according to claim 5, wherein the forming the first conductive pillars and the dielectric material layers comprises: forming an insulating material layer; forming a plurality of holes In the insulating material layer, the recessed holes expose a portion of each of the stacked structures; the dielectric material layer is formed on sidewalls of the recessed holes; and a conductive material is filled in the recessed holes to form the recessed hole Some first conductive columns. The method for fabricating a semiconductor structure according to claim 5, further comprising: forming a plurality of strip-shaped conductive structures on the stacked structures and between the stacked structures, wherein extending directions of the strip-shaped conductive structures It is perpendicular to the extending direction of the stacked structures. Manufacturing of a semiconductor structure as described in claim 7 The method wherein the strip-shaped conductive structures are formed simultaneously with forming the first conductive pillars. The method for fabricating a semiconductor structure according to claim 5, further comprising: forming an insulating structure between the strips of conductive structures.