Semiconductor device manufacturing method

Abstract

The semiconductor device manufacturing method includes: providing a substrate; forming an insulating layer on the substrate; etching the insulating layer to form an opening to expose the substrate; forming a contact plug in the opening and on the insulating layer; forming a metal layer on the contact plug; and irradiating the metal layer with laser.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor device. Background Art

[0002] Semiconductor devices can be divided into volatile memory devices and non-volatile memory devices. Typically, volatile memory devices include dynamic random access memory (DRAM) devices or static random access memory (SRAM) devices. Typically, non-volatile memory devices are flash memory devices.

[0003] On the other hand, as the electronic industry has rapidly developed, semiconductor devices have also become highly integrated. In the manufacturing process of semiconductor devices, contact plugs are formed for stable electrical connection between upper and lower patterns.

[0004] However, when a contact plug is formed according to a conventional method, a void is formed in the contact plug. This void is exposed to the outside in a subsequent process and forms a surface defect such as a seam, thereby causing a problem of deteriorating device characteristics such as increased wiring resistance.

[0005] Prior art document: Korean authorized patent No. 10-0465063. Summary of the invention

[0006] The present invention is intended to solve the above-mentioned problem, and an object of the present invention is to provide a method for manufacturing a semiconductor device, that is, a contact plug including removing a gap or a seam.

[0007] However, the technical problems to be solved by this embodiment are not limited to the technical problems described above, and other technical problems may exist.

[0008] Technical Solution

[0009] As a technical solution to the above-mentioned technical problems, one embodiment of the present invention can provide a semiconductor device manufacturing method, which includes: a step of providing a substrate; a step of forming an insulating layer on the above-mentioned substrate; a step of etching the above-mentioned insulating layer to form an opening portion exposing the above-mentioned substrate; a step of forming a contact plug in the above-mentioned opening portion and on the above-mentioned insulating layer; a step of forming a metal layer on the above-mentioned contact plug; and a step of irradiating the above-mentioned metal layer with a laser.

[0010] According to an embodiment, the method for manufacturing a semiconductor device may further include a step of removing the metal layer.

[0011] According to an embodiment, the step of irradiating the metal layer with laser light includes the step of indirectly heating the contact plug by directly heating the metal layer, thereby removing voids or seams in the contact plug.

[0012] According to an embodiment, the insulating layer may include at least one of oxide, nitride, and oxynitride.

[0013] According to an embodiment, the opening portion may include at least one of a dual damascene pattern, a via hole, and a trench.

[0014] According to an embodiment, the contact plug may be polysilicon or metal.

[0015] According to one embodiment, the metal layer may include at least one of titanium (Ti), titanium nitride (TiN), titanium silicide (TiSi), tantalum (Ta), tantalum nitride (TaN), cobalt (Co), cobalt silicide (CoSi), nickel (Ni), nickel silicide (NiSi), ruthenium (Ru), tungsten (W), tungsten silicide (WSi), copper (Cu), rhenium (Re), molybdenum (Mo), niobium (Nb), and chromium (Cr).

[0016] According to an embodiment, the contact plug may include a substance including an inorganic substance.

[0017] According to one embodiment, the laser may be a YAG laser, a diode laser, a carbon dioxide (CO2) laser or a fiber laser.

[0018] Effects of the Invention

[0019] According to one of the above technical solutions of the present invention, the present invention can provide a semiconductor device having a low resistance characteristic by removing the gap or seam in the contact plug. In addition, the present invention can provide a semiconductor device having a lower resistance characteristic by re-crystallizing the object during the melting and solidification process when the gap or seam is removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 1 is a diagram for explaining a method for manufacturing a semiconductor device according to an embodiment of the present invention.

[0021] Figure 2 A diagram for explaining irradiation of a contact plug with a laser beam.

[0022] Figure 3 The flowchart is a method for manufacturing a semiconductor device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that a person skilled in the art can easily implement the present invention. However, the present invention can be embodied in a variety of different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted in the accompanying drawings, and similar parts are given similar reference numerals throughout the specification.

[0024] Throughout the specification, when a part is "connected" to other parts, it includes not only the case of "direct connection" but also the case of "electrical connection" with other devices in between. Moreover, when a part "includes" a structural element, unless otherwise stated, it means that other structural elements may also be included, rather than excluding other structural elements, and does not preclude the existence or additional possibility of one or more different features or numbers, steps, actions, structural elements, components or their combinations.

[0025] In this specification, a "unit" includes a unit implemented by hardware, a unit implemented by software, and a unit implemented by using both. Furthermore, one unit may be implemented by using two or more hardwares, and two or more units may be implemented by one hardware.

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0027] Figure 1 FIG. 1 is a diagram for explaining a method for manufacturing a semiconductor device according to an embodiment of the present invention.

[0028] Reference Figure 1 The present invention provides a substrate 100 ( Figure 1 For example, the substrate 100 may include at least one selected from silicon (Si) or germanium (Ge).

[0029] Then, an insulating layer 110 ( Figure 1 (a) of FIG. 1 ). The insulating layer 110 may be formed by chemical vapor deposition (CVD: Chemical Vapor Deposition) or physical vapor deposition (PVD: Physical Vapor Deposition).

[0030] The insulating layer 110 may include at least one of oxide, nitride, or oxynitride.

[0031] Next, the insulating layer 110 is etched to form an opening 120 ( Figure 1 The opening 120 may be a dual damascene pattern, a through hole or a groove.

[0032] A resist pattern (not shown) may be formed on the insulating layer 110 , and the insulating layer 110 may be etched using the resist pattern as a mask, thereby forming the opening 120 .

[0033] In this case, the etching process may be performed by at least one selected from a chemical dry etching process or a wet etching process.

[0034] Then, a contact plug 130 is formed in the opening 120 and on the insulating layer 110 ( Figure 1 Part (c) of FIG. 1 ). The contact plug 130 may be formed by chemical vapor deposition or physical vapor deposition, and may be polysilicon (eg, amorphous silicon (Amorphous-Si)) or metal.

[0035] There may be voids or seams 10 in the contact plug 130. These voids or seams may reduce device characteristics by increasing wiring resistance.

[0036] In order to remove the void or the seam in the contact plug 130 , there is a method of irradiating laser to the contact plug 130 .

[0037] That is, when the contact plug 130 is irradiated with the laser 20 , the contact plug 130 is melted and then solidified again. In this case, the atoms are rearranged into a crystalline form with excellent crystallinity and the grain size increases accordingly, thereby removing the voids or seams in the contact plug 130 .

[0038] Relatedly, Figure 2 A diagram for explaining irradiation of a contact plug with a laser beam.

[0039] Reference Figure 2 When the laser 20 is directly irradiated to the contact plug 130, the contact plug 130 will be heated, causing a problem of protrusion 30 at the irradiation site of the laser 20. The reason for the protrusion is as follows: when the melted material solidifies, it will recrystallize again, in this case, forming grains. Since the impurity concentration of the grain boundary between the crystal and the crystal surface increases, the solidification time is slightly later than that of the grain center, in this case, the protrusion phenomenon occurs between the grain boundaries.

[0040] Therefore, in the present invention, the metal layer 140 is formed on the contact plug 130 , and the contact plug 130 is indirectly heated by directly heating the metal layer 140 , in order to solve the above-mentioned problem.

[0041] Also, since metals have relatively more free electrons, they can be heated to very high temperatures (e.g., 2000 to 3000 degrees) by laser. In contrast, it is difficult to heat materials containing inorganic substances (e.g., SiO2, Si, Si3N4) by laser.

[0042] The present invention can utilize these characteristics, and after arranging the metal layer 140 and the contact plug 130 adjacent to each other (for example, in contact with each other), directly irradiating the metal layer 140 with laser to indirectly heat the contact plug 130 , thereby effectively heating the contact plug 130 .

[0043] Specifically, a metal layer 140 ( Figure 1 Part (d) of the invention). The metal layer 140 may include at least one of titanium (Ti), titanium nitride (TiN), titanium silicide (TiSi), tantalum (Ta), tantalum nitride (TaN), cobalt (Co), cobalt silicide (CoSi), nickel (Ni), nickel silicide (NiSi), ruthenium (Ru), tungsten (W), tungsten silicide (WSi), copper (Cu), rhenium (Re), molybdenum (Mo), niobium (Nb), and chromium (Cr).

[0044] In this case, the materials of the contact plug 130 and the metal layer 140 can be selected so that the heat generated by irradiating the metal layer 140 with the laser 20 is greater than the heat generated by irradiating the contact plug 130 with the laser 20, thereby effectively indirectly heating the contact plug 130. For example, the contact plug 130 can be a material containing an inorganic substance (e.g., SiO2, Si, Si3N4).

[0045] Next, the metal layer 140 is irradiated with laser 20 ( Figure 1 The laser 20 may be a YAG laser, a diode laser, a carbon dioxide (CO2) laser or a fiber laser.

[0046] By irradiating the metal layer 140 with the laser 20 to directly heat the metal layer 140 , the contact plug 130 adjacent to the metal layer 140 is indirectly heated.

[0047] In this case, the contact plug 130 may be indirectly heated to undergo a recrystallization process, and the grain size may increase accordingly, thereby removing the void or seam within the contact plug 130 .

[0048] As described above, the void or seam 10 within the contact plug 130 is removed, and thus the semiconductor device has a low resistance characteristic.

[0049] In this case, a reaction or interdiffusion between the metal layer 140 and the contact plug 130 may occur due to high temperature heating, and a substance that can prevent the above situation may be included between the metal layer 140 and the contact plug 130. This is because if the reaction or interdiffusion occurs, it is difficult to remove the metal layer 140 in the step of removing the metal layer 140 described later.

[0050] For example, such a substance may include one of SiO2 film, Si3N4, polysilicon and amorphous-Si.

[0051] After removing the gap or seam 10 in the contact plug 130, the metal layer 140 ( Figure 1 (e) of the Regulations).

[0052] Figure 3 The flowchart is a method for manufacturing a semiconductor device according to an embodiment of the present invention.

[0053] Reference Figure 3 In step S300, a substrate is provided. In step S310, an insulating layer is formed on the substrate.

[0054] In step S320 , the insulating layer is etched to form an opening that exposes the substrate.

[0055] In step S330 , a contact plug is formed in the opening and on the insulating layer, and in step S340 , a metal layer is formed on the contact plug.

[0056] In step S350 , laser light is irradiated onto the metal layer.

[0057] The above description of the present invention is for illustration only, and a person skilled in the art of the present invention can easily change the present invention into other specific forms without changing the technical concept or basic features of the present invention. Therefore, the above-described embodiments are illustrative embodiments in all aspects and are not intended to limit the present invention. For example, each structural element described in a single type can be implemented in a dispersed manner, and similarly, dispersed structural elements can also be implemented in a combined form.

[0058] The scope of the present invention is presented by the protection scope of the claims rather than the above detailed description, and all changes or deformations derived from the meaning, scope and equivalent concepts of the protection scope of the invention are included in the scope of the present invention.

Claims

1. A method for manufacturing a semiconductor device, characterized in that: include: providing a substrate; forming an insulating layer on the substrate; The step of etching the insulating layer to form an opening portion exposing the substrate; forming a contact plug in the opening and on the insulating layer, wherein the contact plug is disposed in the opening and on the upper surface of the insulating layer; forming a metal layer on the contact plug so that the metal layer is disposed outside the opening; a step of irradiating the metal layer with laser light; and A step of removing the metal layer; The step of irradiating the metal layer with the laser includes indirectly heating the contact plug by directly heating the metal layer to remove the gap or seam in the contact plug. The method further comprises the step of forming an insertion layer between the contact plug and the metal layer to prevent the metal layer and the contact plug from reacting or mutually diffusing, and irradiating the metal layer with laser light while the insertion layer and the metal layer are disposed on the contact plug. Wherein, the contact plug comprises polysilicon. Wherein, the above-mentioned insertion layer comprises SiO2, The metal layer is heated to 2000°C to 3000°C by laser.

2. The method for manufacturing a semiconductor device according to claim 1, wherein: The heat generated by irradiating the metal layer with the laser is greater than the heat generated by irradiating the contact plug with the laser.

3. The method for manufacturing a semiconductor device according to claim 1, wherein: The insulating layer includes at least one of oxide, nitride and oxynitride.

4. The method for manufacturing a semiconductor device according to claim 1, wherein: The opening is a dual mosaic pattern, a through hole or a groove.

5. The method for manufacturing a semiconductor device according to claim 1, wherein: The metal layer includes at least one of titanium, titanium nitride, titanium silicide, tantalum, tantalum nitride, cobalt, cobalt silicide, nickel, nickel silicide, ruthenium, tungsten, tungsten silicide, copper, rhenium, molybdenum, niobium, and chromium.

6. The method for manufacturing a semiconductor device according to claim 5, wherein: The contact plug includes a material containing an inorganic substance.

7. The method for manufacturing a semiconductor device according to claim 1, wherein: The laser is YAG laser, diode laser, carbon dioxide laser or fiber laser.

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