Method for forming a structure having holes

Abstract

To provide a method for forming a structure with a hole on a substrate.SOLUTION: A method may include: depositing a first structure on a substrate; etching a first part of a hole in the first structure; depositing a plug fill in the first part of the hole; depositing a second structure on the top of the first structure; etching a second part of the hole substantially aligned with the first part of the hole in the second structure; and etching the plug fill of the first part of the hole and thereby opening up the hole by dry etching. In this way a 3-D NAND device may be provided.SELECTED DRAWING: Figure 2-1

Description

Technical Field

[0001] The present disclosure generally relates to a method of forming a structure having holes on a substrate. The method can include depositing a sacrificial material and etching the material to achieve proper formation of a device structure for a 3-D NAND device.

Background Art

[0002] A NAND device is a logic gate that can be used in applications such as flash memory. The manufacture of a 3D NAND device can include forming holes in a structure disposed on a substrate. The holes can be manufactured by creating a first portion of the holes in a first structure, and the first portion of the holes can be filled with a sacrificial material. A second structure can be provided on top of the first structure, and a second portion of the holes aligned with the first portion of the holes can be provided. Thereafter, the holes can be formed by removing the sacrificial material from the first portion of the holes through the second portion of the holes.

[0003] An example of such a process for manufacturing a 3D NAND device can be illustrated in FIGS. 1A-1D. An intermediate product 100 for a 3D NAND device can be manufactured by using a substrate 110 having two layers including a structure, for example, a nitride layer 120 and an oxide layer 130. The deposition of the nitride layer 120 and the oxide layer 130 may be repeated as necessary to form the structure. As shown in FIG. 1A, a first structure, for example, a first stack 140 including alternating nitride 120 and oxide layers 130, may be provided. A second structure, for example, a second stack 150 including alternating nitride 120 and oxide layers 130, may be provided.

[0004] As shown in FIG. 1B, the nitride layer 120 and the oxide layer 130 undergo an etching process to form a first portion of the holes within the structure. FIG. 1C shows an intermediate product 100 for a NAND device after dry etching and after undergoing a first process to form a liner, a second process to form plug implants, and a third process to polish the surface. Next, the first portion of the holes 100 comprises a liner 160 and plug implants 170. The liner 160 may comprise, for example, silicon oxide (SiO x ). After the third polishing process, another oxynitride layer stack may be added on top of the stack 150, the liner 160, and the plug implants 170.

[0005] However, it may come to a point where after the first portion of the holes are filled with the liner 160 and the plug implants 170, the liner 160 and the plug implants 170 must be removed. The plug implants 170 may be removed by a wet etching process. A wet cleaning process may follow to remove the liner (160). Due to the capillary effect of the holes, good wet etching of the plug implants may be difficult.

[0006] FIG. 1D illustrates the intermediate product 100 after the removal has been performed. However, the chemicals may leave a residue 180 and cause damage 190 to either the nitride layer 120 and / or the oxide layer 130 by the chemicals used for the removal of the liner 160 or the plug implants 170. The residue 180 and the damage 190 may render the NAND device inoperable. In the next technology node, the holes may be deeper and narrower, so the capillary effect of the wet etching solution within the holes increases and thus it may become more difficult to achieve high-quality etching. Furthermore, the removal of the liner 160 and the plug implants 170 may be performed at a slow etching rate, which means that the time to remove the liner 160 and the plug implants 170 is unnecessarily long.

[0007] As a result, it is desirable to obtain an improved apparatus and method for forming a structure having holes on a substrate. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0008] The summary of the present invention is provided to introduce the selected concepts in a simplified form. These concepts will be described in more detail in the "DETAILED DESCRIPTION OF THE INVENTION" of the exemplary embodiments of the present disclosure below. The summary of the present invention is not intended to identify the main features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0009] According to at least one embodiment of the present invention, a method is disclosed. An exemplary method includes a method for forming a structure having holes on a substrate. The method may be for forming a 3-D NAND device. The method for forming a structure having holes on a substrate can include depositing a first structure on the substrate, etching a first portion of the holes in the first structure, and depositing plug implants in the first portion of the holes. Subsequently, the method can continue by depositing a second structure on top of the first structure, etching a second portion of the holes substantially aligned with the first portion of the holes in the second structure. And it can continue by etching the plug implants in the first portion of the holes, thereby opening the holes. Etching the plug implants can include dry etching.

[0010] These and other embodiments will be readily apparent to those skilled in the art from the following detailed description of specific embodiments with reference to the accompanying drawings. The present invention is not limited to the specific embodiments disclosed.

[0011] These and other features, aspects, and advantages of the invention disclosed herein are described below with reference to the drawings of certain embodiments, which are intended to be illustrative and not intended to limit the invention.

Brief Description of the Drawings

[0012]

Fig. 1-1

Fig. 1-2

Fig. 2-1

Fig. 2-2

Fig. 2-3

Fig. 2-4

Fig. 2-5

Fig. 3

Fig. 4

Best Mode for Carrying Out the Invention

[0013] Of course, the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, some of the dimensions of the elements in the figures may be exaggerated relative to other elements to assist in understanding the illustrated embodiments of the present disclosure.

[0014] Certain embodiments and examples are disclosed below, but it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, as well as its obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specific disclosed embodiments described below.

[0015] The figures shown in this specification do not mean the actual figures of any specific material, structure or device, but are merely idealized representations used to illustrate the embodiments of the present disclosure.

[0016] Three-dimensional (3-D) Not-AND (NAND) devices can be utilized for memory applications. The fabrication of 3-D NAND devices can include an intermediate product structure having two-layer stacks disposed on top of each other. The two layers can include, for example, an oxide and a nitride. When arranging a plurality of two-layer stacks in another stack, alignment and stress on the layers, as well as different characteristics, may be important.

[0017] FIG. 2A illustrates an intermediate product 200 for a 3-D NAND device according to at least one embodiment. The intermediate product 200 may include a substrate 210 and a first two-layer stack including a first structure, such as a nitride layer 220 and an oxide layer 230. The substrate 210 may include silicon, silicon oxide, or a metal oxide. The nitride layer 220 may include at least one of silicon nitride, germanium nitride, silicon germanium nitride (SiGeN), silicon oxynitride (SiON), germanium oxynitride (GeON), or a combination thereof. The oxide layer 230 may include at least one of silicon oxide, germanium oxide, silicon germanium oxide (SiGeOx), germanium oxynitride (GeON), silicon oxynitride (SiON), or a combination thereof. The deposition of the nitride layer 220 and the oxide layer 230 can be performed in batches within a reaction chamber of a vertical furnace. Thus, the method can include loading the substrate into a boat and moving the boat having the substrate into the reaction chamber of a batch reactor of a vertical furnace for processing.

[0018] And, as shown in FIG. 2B, the intermediate product 200 can undergo a dry etching process to form a first portion of the holes within the first structure of the product 200. The dry etching process may be anisotropic. The etching process can be performed, for example, using an etching mask formed by lithography. The dry etching process may utilize a halide agent using fluorine, such as NF3, CHF3, SF6, CF4, C2F2, and mixtures thereof. The dry etching process can include, for example, plasma. The dry etching agent can optionally include oxygen or ozone.

[0019] Optionally, as shown in FIG. 2C, the first liner 240 may be added to the intermediate product 200 later. The first liner 240 can include at least one of silicon, germanium, nitride, and / or oxide. For example, the first liner can include silicon, silicon oxide, germanium oxide, germanium oxide, germanium, silicon germanium (SiGe), or germanium nitride (GeN). Depositing the first liner 240 can include supplying a germanium precursor. The germanium precursor may be selected, for example, from germanium, digermanium, dichlorogermanium, trichlorogermanium, tetrachlorogermanium, germanium alkoxide, or combinations thereof. Depositing the first liner 240 can include a flow of a silicon precursor. The silicon precursor can be selected, for example, from silane, disilane, trisilane, chlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, or combinations of the above.

[0020] The first liner 240 is illustrated to cover the top and sides of the oxide layer 230 and nitride layer 220 of the first two-layer stack (in the first portion of the holes). The liner 240 may also extend to cover the exposed portion of the substrate 210 at the bottom of the holes. The liner 240 can be deposited, for example, by an atomic layer deposition (ALD) process, a chemical vapor deposition (CVD) process, or an epitaxial process. The first liner can have a thickness of 10, preferably less than 5 nanometers.

[0021] The first liner 240 can also function as a seed layer for subsequent layers. For example, the seed layer can be deposited by supplying trisilane. The seed layer can help improve nucleation, quality, and the deposition of subsequent plug fillings. The seed layer can, for example, reduce roughness.

[0022] Figure 2D illustrates the result after the generation of 3-D plug fillings. The intermediate product 200 includes a plug filling 250 within the first portion of the holes in the structure. There may be voids 260 remaining within the plug filling 250. The voids may not exist, or may be closed in another process step, for example, a heating step involving reflow of the plug filling material.

[0023] The plug filling 250 may include silicon germanium (SiGe). The plug filling 250 can include graded germanium. The concentration of germanium in the SiGe plug filling 250 can range from 1% to 100%. The germanium content can be adjusted to obtain the desired material properties required in subsequent process steps, such as etching processes and removal rates in thermal stability. By increasing the supply of the germanium precursor, the concentration of germanium in the plug filling 250 can be increased from the first layer at the bottom and sides of the plug towards the center and top of the plug.

[0024] The deposition of the liner 240 and / or the plug implant 250 can be carried out in batches within the reaction chamber of a vertical furnace. Thus, this method can include loading the substrate into a boat and moving the boat with the substrate into the reaction chamber of a batch reactor of a vertical furnace for processing. The temperature window of the deposition process can be, for example, 450 - 550 °C when the Ge content of the plug implant 250 is 10 - 60 at%, and the deposition rate can be 5 - 20 nm / min. The deposition of the liner 240 and the plug implant 250 can be carried out in situ within the same reactor to minimize the risk that the liner 240 may oxidize.

[0025] The shape of the plug implant 250 may vary, similar to the size of the void 260, depending on the process used for the 3-D plug implant. As a result of forming the void 260, the plug implant 250 may not completely fill the holes. The voids can result in more rapid removal during the removal of the plug implant 250 in the latter part of the process, thereby reducing device damage by the etchant and increasing throughput. On the other hand, voids or pinch-offs can make the implant unstable, and thus the quality of the implant may deteriorate, which may not be desirable. Thus, in some embodiments of the present invention, the void 260 may be substantially avoided.

[0026] The plug implant 250 may be formed by an in-situ process including a deposition process. The deposition process can occur by a thermal reaction, a plasma reaction, a plasma-enhanced reaction, or a high-density plasma (HDP) chemical vapor deposition (CVD) process. The deposition process includes, for example, an etch-back process including a halide agent, partially opens the upper part of the plug implant, and then deposition can continue. The etching process may be a wet etching process or a dry etching process. Examples of the halide agent involved in the etch-back process include hydrogen fluoride (HF), hydrochloric acid (HCl), hydrogen bromide (HBr), or a combination of the above. The dry etching process can include, for example, plasma.

[0027] The deposition process can include a flow of a silicon precursor, such as silane, disilane, trisilane, chlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, or a combination of the above. The deposition process can also include a flow of a germanium precursor, such as germane, digermane, dichlorogermane, trichlorogermane, tetrachlorogermane, germanium alkoxide, or a combination of the above. The ratio of the germanium precursor to the silicon precursor during the deposition of the silicon-germanium plug implant 250 can be increased. Thus, the concentration of germanium in the silicon-germanium plug implant 250 can be increased from the first layer of the plug deposited on the bottom and side surfaces of the first part of the hole towards the center and upper part of the first part of the hole. The deposition process can include in-situ doping of germanium. For example, by mixing germanium into the silicon precursor flow.

[0028] For the thermal deposition process, the pressure may be in the range of 10 mTorr to 800 Torr, and the temperature may be in the range of 50 °C to 800 °C. In the case of a plasma-enhanced reaction or an HDP CVD deposition process, the pressure may be in the range of 10 mTorr to 100 Torr, and the temperature may be in the range of 10 °C to 700 °C.

[0029] The excess material of the plug implant 250 may be polished and removed by a CMP process as shown in FIG. 2E. What remains forms the first stack 270 of the first structure. With a flat surface, the second stack of the second structure can be formed on the liner 240 and the plug implant 250.

[0030] A second structure, such as a two-layer stack 280, is shown in FIG. 2F. The second stack 280, similar to the first stack 270, can comprise an alternating arrangement of nitride layers 220 and oxide layers 230. The nitride layer 220 may include at least one of silicon nitride, germanium nitride, silicon nitride, germanium nitride, silicon germanium nitride (SiGeN), silicon oxynitride (SiON), germanium oxynitride (GeON), or a combination thereof. The oxide layer 230 may include at least one of silicon oxide, germanium oxide, silicon germanium oxide (SiGeOx), germanium oxynitride (GeON), silicon oxynitride (SiON), or a combination thereof. The deposition of the nitride layer 220 and the oxide layer 230 can be performed in batches within the reaction chamber of a vertical furnace. Thus, the method can include loading a substrate onto a boat and moving the boat with the substrate into the reaction chamber of a batch reactor of a vertical furnace for processing.

[0031] Next, the second portion of the hole may be formed within a second structure, such as stack 280, by a dry etching process. The dry etching process may be anisotropic. The etching process can be performed, for example, using an etching mask formed by lithography. The dry etching process may utilize a halide agent using fluorine, such as NF3, CHF3, SF6, CF4, C2F2, and mixtures thereof. The dry etching process can include, for example, plasma. The dry etching agent can optionally include oxygen or ozone. Liner 240 and plug implant 250 can function as an etch stop for the etching process. As shown in FIGS. 2G and 2H, liner 240 and plug implant 250 can remain after the etching process.

[0032] Optionally, as shown in FIG. 2H, a second liner 245 may be added to the second structure, such as stack 280. The second liner 245 can comprise a silicon, oxide, nitride, and / or carbide layer. The second liner can include, for example, silicon oxycarbide nitride (SiOCN), aluminum nitride, and / or boron carbide. Thus, depositing the second liner includes supplying nitrogen or oxide containing reactants.

[0033] The second liner 245 can cover the top and sides of a two-layer stack of an oxide layer 230 and a nitride layer 220 of the second structure (in the second portion of the hole). The second liner 245 can also extend to cover the exposed portion of the plug implant 250 (at the bottom of the second portion of the hole). The second liner can be deposited in batches within the reaction chamber of a vertical furnace. Thus, this method can include loading a substrate into a boat and moving the boat having the substrate into the reaction chamber of a batch reactor of a vertical furnace for processing. The second liner 245 can be deposited, for example, by an atomic layer deposition (ALD) process, a chemical vapor deposition (CVD) process, or an epitaxial process. The second liner can have a thickness less than 10, preferably less than 5 nanometers.

[0034] The second liner 245 can cover a portion of the plug implant 250 at the bottom of the second portion of the hole. A portion of the second liner 245 at the bottom of the second portion of the hole can be removed by anisotropic dry etching. For example, reactive ion etching (RIE) is used.

[0035] And the plug implant 250 can be removed by dry etching. The dry etching can be isotropic. The etching can be performed within the reaction chamber of a batch reactor of a vertical furnace or within the reaction chamber of a single-wafer reactor.

[0036] When a furnace is used, the substrate 210 may be supplied to a boat having space for accommodating 25 to 250 substrates. The boat having the substrate can be moved into the reaction chamber of the reactor.

[0037] Batch or single-sheet reactors can be configured and arranged to supply a gaseous etchant to the reaction chamber to isotropically etch the plug implant 250. For example, the reactor may be configured to supply one or more gaseous etchants containing a halide to the reaction chamber. The halide can be selected from chlorides and fluorides. For dry etching the plug implant 250, the halide can be selected from nitrogen trifluoride (NF3), chlorine (Cl2), hydrogen chloride (HCl), hydrogen fluoride (HF), hydrogen bromide (HBr), boron trichloride (BCl3), and fluorine (F2).

[0038] Dry etching may be thermally activated. The temperature inside the reactor can be kept below 500 °C so as not to damage structures sensitive to the temperature inside the intermediate product. The pressure inside the reactor can be kept below 1 Torr. The reaction chamber may be kept substantially free of radicals and / or ions. A suitable etchant at these temperatures may be chlorine (Cl2).

[0039] Dry etching using gaseous chlorine (Cl2) is not affected by the capillary effect of pores, similar to wet etching. Therefore, good etching of the plug implant can be achieved by dry etching using gaseous chlorine Cl2. Dry etching may leave no residue. Damage to either the nitride layer 220 and / or the oxide layer 230 due to dry etching used for removal can be avoided. The use of thermally activated dry etching can be scalable, and dry etching may provide the best etching even when the pores become deeper and narrower in the next technology node. Not only the reactivity and thus the etching rate, but also the potential for damage of thermally activated dry etching can be carefully adjusted by changing the temperature inside the reaction chamber.

[0040] The main time-limiting factor in dry etching can be attributed to the depth and width of the holes being formed. The diffusion rates of reactants and reaction by-products are determined by the depth and width of the holes being formed. This limiting factor can be substantially similar for single-wafer (substrate) reactors and for substrates processed within a batch reactor, and may become more pronounced in future technology nodes where the holes can be narrow and deep. Since a single-wafer tool can only process one substrate at a time, the overall disadvantage due to diffusion rates can be much greater for single-wafer tools compared to batch reactors that can process 25 - 175 substrates simultaneously. Therefore, a batch reactor may be preferred for dry etching narrow holes.

[0041] Dry etching can substantially remove the plug implant 250 containing germanium at a faster rate than it removes silicon. For example, within the plug implant 250, thermally-activated dry etching of SiGe (50%) using Cl2 can result in an etching rate that is more than 1000 times higher than the etching rate of SiO / SiN used in the two layers of the structure. Dry etching of SiGe (50%) using Cl2 within the plug implant 250 can result in an etching rate that is more than 200 times higher than the etching rate of Si used in the first or second liner 240, 245.

[0042] Dry etching of SiGe using Cl2 can be carried out at a temperature of 250 - 450 °C, preferably 300 - 400 °C. At 350 °C, for example, in the case of SiGe plug implant 250, a high etching rate of 10 - 200 or 75 - 100 nm / min may be obtained. Under the same circumstances, the etching rates of the first and second silicon liners can be 0.1 - 2 or about 0.4 nm / min. Therefore, the first and second silicon liners 240, 245 can protect the first and second structures while the SiGe plug implant 250 is removed. The Si liners remain conformal over the first and second structures after etching of the SiGe plug implant 250, minimizing the risk of attacking the underlying first and second structures.

[0043] The etching rate of the plug implant 250 can be in the range of 1 - 1000 nm / min, 10 - 100 nm / min, or 1 - 10 nm / min. The first and second liners 240, 245 can protect the two layers of the first and second structures during dry etching.

[0044] After the plug implant 250 is removed and the first and second liners are used as needed, the first and second liners 240, 245 can still remain (see Fig. 2I). Then, the first and second liners 240, 245 can be removed by another dry etching. The etching can also be carried out using, for example, a batch reactor or a single-wafer reactor in a vertical furnace. When a furnace is used, the substrate 210 may be supplied to a boat having a space for accommodating 25 - 250 substrates. The boat with the substrates can be moved into the reaction chamber of the reactor. This can be the same reactor used for etching the plug implant 250.

[0045] A batch or single-wafer reactor can be configured and arranged to supply a gaseous etchant to a reaction chamber to isotropically etch first and second liners 240, 245. For example, the reactor may be configured to supply one or more gaseous etchants containing a halide to the reaction chamber. To dry etch the first liner 240, the halide can be selected from nitrogen trifluoride (NF3), chlorine (Cl2), hydrogen chloride (HCl), hydrogen fluoride (HF), hydrogen bromide (HBr), boron trichloride (BCl3), fluorine (F2).

[0046] The temperature in the reactor can be maintained below 500°C, 350 - 500°C, preferably 375 - 450°C, and the pressure in the reactor can be maintained below 1 Torr. The reaction chamber may be maintained substantially free of radicals and / or ions. The removal of the plug implant 250 and the first and second liners can be performed in situ in the same reactor or the same tool, and oxidation can be avoided if the product is transported in an uncontrolled atmosphere (e.g., containing oxygen or water therein).

[0047] Dry etching of the first or second liner can be performed at a temperature of 350 to 500 °C, preferably 375 to 450 °C, using Cl2. For example, dry etching of Si using Cl2 in the first and second liners 240, 245 can result in an etching rate that is more than 10 times faster than the etching rate of SiO / SiN used in the two layers of the structure. When Si is used, the etching rate of the first and second liners is 0.1 to 10 or about 1 nm / min at 410 °C using Cl2. Thus, the plug implant 250 can be dry etched at 350 °C until it is completely removed, and then, by raising the temperature to 410 or 420 °C, the first and second liners 240, 245 can be dry etched. Thus, the plug implant 250 and the first and second liners 240, 245 can be dry etched within the same reaction chamber, thereby improving the efficiency and cleanliness of the etching process.

[0048] What remains is, as shown in FIG. 2J, a combination of the first and second structures having holes formed by the first and second holes, and a structure forming the intermediate product 200. At this point, the manufacture of the intermediate product 200 may be completed, or the process may be repeated to form a stack on top of the intermediate product 200, for example, another structure.

[0049] Figure 3 illustrates a method 300 for manufacturing a 3-D NAND device according to at least one embodiment of the present invention. Method 300 begins after a first structure is deposited on a substrate to form an intermediate product. The intermediate product is then processed by an anisotropic etching process 310, such as dry etching using plasma, to form a first portion of the holes, a first liner deposition process 320, a plug embedding process 330, a polishing process 340, a second structure deposition process 350, a second dry etching process 360, such as using plasma, to form a second portion of the holes, an optional second liner deposition process (not shown), a plug implant dry etching process 370 (removal) using a gaseous etchant for isotropic etching, and optional first and second liner dry etching processes using a gaseous etchant for isotropic etching (not shown). If the plug implant dry etching 370 also removes the first and / or second liners, or if neither the first nor the second liner is used, the first and second liner dry etching processes may be unnecessary. As illustrated by loop 380, processes 310 - 370 can be repeated.

[0050] The method of forming a 3-D NAND device may be performed, for example, in an ALD reaction chamber, a chemical vapor deposition (CVD) chamber, an epitaxial reaction chamber, an etching reactor, a batch reaction chamber, a mini-batch reaction chamber, or a single-wafer reaction chamber. A suitable reaction chamber can enable most of these processes to be performed as in-situ processes.

[0051] Figure 4 illustrates a 3-D NAND device 400 made according to at least one embodiment of the present invention. The 3-D NAND device 400 includes a substrate 410, an oxide-nitride layer stack section 420, a source line 430, and a bit line electrode section 440. The oxide-nitride layer stack section 420 may also include a plurality of channel holes.

[0052] The specific embodiments shown and described are illustrative examples of the invention and its best mode, and are not intended to limit the scope of aspects and embodiments in any way. Indeed, for the sake of brevity, conventional manufacturing, related, preparation, and other functional aspects of the system may not be described in detail. Further, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may exist in the actual system and / or may not exist in some embodiments.

[0053] The configurations and / or methods described herein are exemplary in nature, and these specific embodiments or examples should not be construed in a limiting sense as numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Accordingly, the various operations illustrated may be performed in the illustrated order, in other orders, or in some cases may be omitted.

[0054] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various processes, systems, and configurations, as well as other features, functions, operations, and / or characteristics disclosed herein, and any and all equivalents thereof.

Description of Reference Numerals

[0055] Intermediate product for 200 3-D NAND devices 210 Substrate 220 Nitride layer 230 Oxide layer 240 First liner 245 Second liner 250 Plug implant 260 Void 270 First stack 280 Second stack 300 Method for manufacturing a 3-D NAND device 310 Dry etching process 320 First liner deposition process 330 Plug embedding process 340 Polishing process 350 Second structure deposition process 360 Second dry etching process 370 Plug implant dry etching process 380 Loop 400 3-D NAND device 410 Substrate 420 Oxide-nitride layer stack section 430 Source line 440 Bit line electrode section

Claims

1. A method of forming a structure having holes on a substrate, the method comprising: depositing a first structure on the substrate; etching a first portion of the holes in the first structure; depositing a first liner on top of the first structure and within the first portion of the holes; depositing a plug implant in the first portion of the holes; depositing a second structure on the first structure; etching a second portion of the holes substantially aligned with the first portion of the holes in the second structure; etching the plug implant in the first portion of the holes, thereby opening the holes, wherein etching the plug implant includes dry etching; depositing a second liner on top of the second structure and within the second portion of the holes; etching the bottom of the second portion of the holes and etching the plug implant in the first portion of the holes; removing the second liner by isotropic dry etching; removing the first liner by isotropic dry etching; A method comprising the above steps.

2. The method according to claim 1, wherein etching the plug implant includes supplying the substrate to a reaction chamber configured and arranged to supply a gaseous etchant for isotropically etching the plug implant in the reaction chamber.

3. The method according to claim 2, wherein etching the plug implant includes supplying one or more of the gaseous etchants containing halides to the reaction chamber.

4. The halide is nitrogen trifluoride (NF ３ ), and chlorine (Cl ２ ), and the method according to claim 3, which is selected from the group consisting of

5. The method according to claim 2, wherein during the etching of the plug implant, the temperature in the reaction chamber is less than 500 °C, the pressure in the reactor is less than 1 Torr, and the reaction chamber is substantially free of radicals and / or ions.

6. The halide in the reaction chamber for dry etching the plug insert is nitrogen trifluoride (NF ３ ), chlorine (Cl ２ ), hydrogen chloride (HCl), hydrogen fluoride (HF), hydrogen bromide (HBr), boron chloride (BCl ３ ), fluorine (F ２ ), and the method according to claim 2, which is selected from the group consisting of

7. The method according to claim 1, further comprising loading the substrate onto a boat and moving the boat having the substrate into a batch reactor of a vertical furnace for processing.

8. The method according to claim 1, wherein depositing the plug implant includes supplying a germanium precursor.

9. The method according to claim 8, wherein the germanium precursor is germanium, digermanium, dichlorogermanium, trichlorogermanium, tetrachlorogermanium, germanium alkoxide, or a combination thereof.

10. The method according to claim 8, wherein depositing the plug implant includes providing a silicon precursor, and the plug implant includes silicon germanium (SiGe) having a germanium content of 1% or more and less than 100%.

11. The method according to claim 10, wherein the silicon precursor is silane, disilane, trisilane, chlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, or a combination thereof.

12. The method according to claim 10, wherein during the deposition of silicon germanium, the ratio of germanium to silicon is increased, and the germanium content of silicon germanium is increased from the first layer of the plug implant toward the center and top of the plug implant.

13. The method according to claim 1, wherein depositing the plug implant includes a deposition process involving at least one etching process.

14. The method according to claim 1, wherein the first liner includes silicon, silicon oxide, and / or germanium oxide.

15. The method according to claim 1, wherein depositing the first liner includes supplying a germanium precursor, and the germanium precursor is selected from germanium, digermanium, dichlorogermanium, trichlorogermanium, tetrachlorogermanium, germanium alkoxide, or a combination thereof.

16. The method according to claim 1, wherein depositing the first liner includes supplying a silicon precursor, and the silicon precursor is silane, disilane, trisilane, chlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, or a combination thereof.

17. The method according to claim 1, wherein the second liner includes silicon, oxide, nitride, and / or carbide.

18. The method according to claim 17, wherein the second liner comprises silicon oxycarbide nitride (SiOCN), aluminum nitride, and / or boron carbide.

19. The method according to claim 18, wherein depositing the second liner comprises supplying nitrogen or an oxide containing a reactant.

20. The method according to claim 1, wherein depositing the first or second liner comprises depositing a liner having a thickness less than 10 nanometers.

21. The method according to claim 1, comprising supplying a substrate to a reaction chamber configured and arranged to supply a gaseous etchant for anisotropically etching the first and / or second liner.

22. The method according to claim 21, comprising supplying to the reaction chamber one or more of the gaseous etchants containing a halide.

23. To dry-etch the plug implant in the reaction chamber, the halide is nitrogen trifluoride NF ３ and chlorine Cl ２ The method according to claim 22, selected from.

24. The method according to claim 21, wherein the temperature in the reaction chamber is less than 500 °C, the pressure in the reaction chamber is less than 1 Torr, and the reaction chamber is substantially free of radicals and / or ions.

25. The method according to claim 1, wherein etching the first or second portion of the holes of the first or second structure comprises anisotropic etching.

26. The method according to claim 1, comprising polishing the plug implant before depositing the second structure on top of the first structure.

27. The method according to claim 1, wherein any of the above steps is repeated to form a 3-D NAND device.

28. The method according to claim 1, wherein depositing the first or second structure on the substrate comprises depositing a two-layer structure on the substrate, the two-layer structure comprising alternating layers of a silicon oxide layer and a silicon nitride layer.

Images