TW594918B - A method for fabricating a wet barrier layer - Google Patents

Abstract

A method for fabricating a wet barrier layer for a plug fabricating process is provided. A titanium layer is formed in an opening, which is located in a dielectric layer on a substrate. The titanium layer is treated through an in-situ plasma treatment process. A titanium nitride layer is formed on the titanium layer to form a wet barrier layer. The method disclosed in the present invention is adapted for lowing the resistance of the plug.

Description

594918 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a wet barrier layer suitable for a plug process. [Previous technology] One of the main reasons for the advancement of electronic technology today is the use of semiconductor technology to implement various electronic components such as transistors, capacitors, and resistors in a high-density manner. Body Circuit (Integrated Circuit). In semiconductor devices, these different electronic components are connected through conductive interconnects. Each state area of each electronic component, such as the source and drain of the transistor, is connected to the conductive interconnect via a vertical wire, a so-called plug. Please refer to FIG. 1. FIG. 1 illustrates a conventional contact plug structure. There is a doped region 102 on the substrate 100. This doped region 1 0 2 may be, for example, a drain or a source of a transistor. There is a dielectric layer 103 on the substrate 100. The material of the dielectric layer 103 can be borophospho glass or a low dielectric material. On the dielectric layer 103, there are conductive interconnects 106. In order to transmit the signal of the doped region 102 to the conductive interconnect 106, a vertical conductor is required, that is, the metal plug 105. However, since the material of the metal plug 105 is diffused into the substrate 100 and the dielectric layer 103, a wet barrier layer 104 is added to form the substrate 100 and the dielectric layer 1. Between 0 3 and plug 1 0 5. Wet barrier layer 1 0 4 example pack

Page 6 594918 V. Description of the Invention (2) Includes thin films made of titanium / titanium nitride. At present, the manufacturing method of the wet barrier layer is based on an I on Metal Plasma (IMP) process or a collimator deposition process. A titanium metal layer is first deposited on the bottom and side walls of the contact window, and then Then, a titanium nitride layer is formed on the titanium metal layer by a chemical vapor deposition process. It is known that the titanium metal deposited using the collimated tube deposition process has a lower resistance value than the titanium metal formed by the ion metal plasma process for the entire wafer. However, the openings suitable for the collimated tube deposition process are suitable. The aspect ratio cannot be too large, and is generally only applicable to the process of the via window plug. As for the process of contact window plugs, because of the aspect ratio of the contact window, the process of collimating tube deposition is not applicable. Instead, an ion metal plasma process must be used to deposit the titanium metal layer. However, the use of an ionic metal plasma process to deposit a titanium metal layer to produce a contact window plug sheet with high sheet resistance (Rs) does not meet requirements. »In the case of narrower semiconductor process line widths, how to reduce the sheet resistance of the wires and the impedance of the circuit becomes more and more important. Especially in the semiconductor peripheral area, when the vertical height of the plug is larger than other places, the contact resistance becomes a serious problem, and the high contact resistance will also greatly increase the resistance of the entire circuit. Therefore, how to solve the contact resistance of the plugs in the semiconductor manufacturing process, especially the contact resistance of the plugs in the peripheral area, will be an important key that affects whether the semiconductor as a whole can advance to a higher concentration and a smaller line width. The barriers made by the barriers are wet and wet seeds. 1 The supply and release are in the contents of § 3, which is hereby issued.

Page 7 594918 V. Description of the invention Applicable to the manufacture of low film Another purpose of the present invention to form a plug may be five. The purpose of the present invention is to provide a resistor according to the present invention that is suitable for use in a plug such as a transistor resistance value. The purpose of providing a plug is to provide a resistance of a contact plug circuit. The base or source of the doped region. A domain is formed by a photolithography process at least within the material of the drain layer of each element including the boron-phosphorus glass (3) and the aspect ratio. An ion metal plasma process is performed on a titanium metal layer. Next, a formed titanium metal layer is processed, and the material layer is completed on the titanium metal layer. The material layer used to form the material layer is a selected metal / titanium tungsten alloy composite layer which is a nitride group. Finally, the contact window is filled with the material of the conductor located on the dielectric layer, and the method disclosed in the present invention is also applicable to the Dual Damascene process. According to the present invention, in a preferred embodiment, a method for manufacturing a wet barrier layer uses a sheet resistor to reduce at least 21% of a method for manufacturing a wet barrier layer. In a suitable process, by reducing the chip resistance of a plug The value decreases. A manufacturing method of a moisture barrier layer is formed on the bottom. This doped region can be taken as an example. The substrate additionally has a dielectric layer, a glass or a low dielectric material. An in-situ plasma process is formed at the opening of the dielectric layer contact window to expose the bottom and sidewalls of the doped region contact window opening. The process of forming a dielectric barrier wet barrier layer by the chemical vapor deposition process It is suitable for metal nitride, titanium crane alloy and nitrogen, and the metal nitride can be titanium nitride or material, and the contact plug is completed by a flattening process. Of course, based on the interposer plug process and bimetal damascene as an example, a contact window plug

Page 8 594918 V. Description of the invention (4) Manufacturing method, and measuring the resistance of the sheet and comparing it with the conventional one to prove the efficacy of the plugging process provided by the present invention. [Embodiment]

Figures 2 to 5 are schematic cross-sectional views of a contact window plug process according to a preferred embodiment of the present invention. Referring to FIG. 2, there is a conductive layer 202 on a substrate 200. The conductive layer 202 can be a doped region or a conductive line. If the conductive layer 2 0 2 is a doped region, it may be, for example, a drain or a source of a transistor, and a plug to be formed is a contact plug. If the conductive layer 2 0 2 is a wire, the plug to be formed is a via plug. There is a dielectric layer 204 on the substrate 200, and the material of the dielectric layer 204 can be borophospho glass or low-dielectric material. A contact window 206 is formed in the dielectric layer 204. The method for forming the contact window 206 includes spin-coating a photoresist layer (not shown) on the dielectric layer 204, patterning the photoresist layer by a lithography process, and using the patterned photoresist layer as The mask is etched to expose the exposed dielectric layer 204 to form a contact window 206, wherein the contact window 206 exposes a partially doped region 202. Finally, the photoresist layer is removed.

Referring to FIG. 3, a titanium metal layer 208 is formed on the dielectric layer 204 and the dielectric window 206. The method for forming the Chin metal layer 20 8 is through an ion metal plasma process. Next, an in-situ plasma 2 10 is used to perform a post-treatment on the titanium metal layer 208. The reaction gas used in the in-situ plasma 2 10 may be nitrogen, hydrogen, or a mixed gas of nitrogen and hydrogen. Referring to FIG. 4, a titanium nitride layer 2 1 2 is formed on the titanium metal layer 208. 594918 V. Description of the invention (5) The method for forming the titanium nitride layer 2 1 2 includes a chemical vapor deposition method The titanium nitride layer 2 12 and the titanium metal layer 208 are used as a wet barrier layer to prevent the material of the subsequent conductor layer from penetrating into the dielectric layer 204. Next, a conductor layer 2 1 4 is deposited on the titanium nitride layer 2 1 2 and fills the interstitial window 2 06. The material for forming the conductor layer 2 1 4 can be a metal material, such as tungsten metal or a tungsten alloy. The method of the conductive layer 21 4 includes a chemical vapor deposition method. Finally, referring to FIG. 5, a planarization process is used to remove the titanium metal layer, the titanium nitride layer, and the conductor layer higher than the dielectric layer 204, and a contact plug 2 is formed within the dielectric window 206. 1 6. The planarization process may be a chemical mechanical polishing process. Subsequent processes are not shown on the diagram, but are simply explained below. A wet barrier layer is formed according to the aforementioned process in this embodiment during the subsequent process of plugging the interlayer window for electrically connecting different layers of wires or the subsequent bimetal inlay process. The comparison is made with several different line width processes. In a 0.15 micron process, the thickness of the titanium metal layer formed by the ion metal plasma process is 100 angstroms and the thickness of the titanium nitride layer is 50 angstroms before the titanium nitride layer is formed. Compared with the case where the in-situ plasma treatment is not performed on the titanium metal layer, the former is 35.5% less than the latter. In a 0.18 micron process, the thickness of the titanium metal layer formed by the ion metal plasma process is 160 angstroms and the thickness of the titanium nitride layer is 70 angstroms before the titanium nitride layer is formed. Compared with the example where the in-situ plasma treatment is performed on the titanium metal layer, the former is 36.6% less than the latter. In a 0.2 2 / 0.25 micron process, the thickness of the titanium metal layer formed by the ion metal plasma process is 100 angstroms and the titanium nitride layer is

Page 10 594918 V. Description of the invention (6) In the case of a thickness of 100 angstroms, the titanium metal layer is subjected to an in-situ plasma treatment before the titanium nitride layer is formed and the in-situ plasma treatment is not performed. Compared to the example, the former is 29.7% less than the latter. From the above experimental results, even if the most conservative estimation is made, the method for manufacturing the wet barrier layer disclosed in the present invention can reduce the sheet resistance by at least 25%. -As can be seen from the above-mentioned preferred embodiments of the present invention, the application of the present invention has the following advantages. The invention provides a method for manufacturing a plug, which can reduce the sheet resistance of the plug interface by 25%. In addition, the process disclosed in the present invention does not need to move the wafer between different machines, and an in-situ plasma is used to process the titanium metal layer formed in the 4 ion metal deposition process, which can make the plug's wet barrier. The sheet resistance of the layer is greatly reduced. In addition, the ionic metal deposition process is suitable for processes with a high aspect ratio structure. Therefore, the process of contact plugs can also be performed using the process disclosed in the present invention. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various changes and decorations without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application.

594918 Brief description of the drawings [Simplified description of the drawings] In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is described below in conjunction with the accompanying drawings for detailed description. As follows: FIG. 1 is a conventional contact plug structure shown in the drawing; and FIGS. 2 to 5 are schematic cross-sectional views showing a contact window plug manufacturing process according to a preferred embodiment of the present invention. [Simple description of element representative symbols] 4 100, 2 0 0: substrate 102: doped region 103, .2 0 4: dielectric layer 104 wet barrier layer 105 metal plug 106 conductive interconnect 202 conductive layer 206 contact window 208 Titanium metal layer 210 In-situ plasma 212 Titanium nitride layer 214 Conductor layer 216 Contact plug

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Claims (1)

594918 VI. Scope of patent application 1. A method for manufacturing a wet barrier layer is suitable for being formed in an opening in a dielectric layer on a substrate. The method includes at least: forming the barrier layer. Its quality, materials, and electricity are based on squares; The system is •, the top or bottom of the glass layer of the electrical layer is filled with the original gold; 1 boron '; the first titanium 1 includes the t Special metal. High-quality Titanium gold material, Shen Yiqin, D. The formation of the layered layer pair 2. Electricity 3. The manufacturing method as described in item 1 of the scope of patent application, wherein the titanium metal layer and the material Layer to form the wet barrier layer. 4. The manufacturing method according to item 1 of the scope of the patent application, wherein the material forming the material layer may be titanium nitride, a nitride button, a titanium tungsten alloy, or a composite layer of a metal nitride / titanium tungsten alloy. 5. The manufacturing method according to item 1 of the scope of the patent application, wherein the reaction gas used in the in-situ plasma can be hydrogen, nitrogen, or a nitrogen-hydrogen mixed gas. 6. The manufacturing method according to item 1 of the scope of patent application, wherein the method for forming the titanium metal layer is an ionic metal deposition process. 7. —A method for manufacturing a plug, suitable for a substrate having a dielectric layer Page 13 594918 6. Above the scope of applying for a patent, the method includes at least: forming an opening in the dielectric layer, wherein the opening exposes a conductive layer below the dielectric layer; forming a titanium metal layer on the dielectric layer; Inside the opening and above the dielectric layer; performing an in-situ plasma treatment on the titanium metal layer; forming a material layer on the titanium metal layer; forming a conductor layer to fill the opening; and flattening the opening The process removes the conductor layer, the material layer, and the titanium metal layer higher than the surface of the dielectric layer. 8. The manufacturing method according to item 7 of the scope of patent application, wherein the method of forming the opening further comprises: forming a photoresist layer on the dielectric layer; patterning the photoresist layer; and patterning the photoresist layer. The photoresist layer is a mask, and the dielectric layer is etched until the conductive layer is exposed. 9. The manufacturing method as described in item 7 of the scope of patent application, wherein the material forming the dielectric layer includes at least borophospho glass or a low dielectric material. 10. The manufacturing method as described in item 7 of the scope of the patent application, wherein the titanium metal layer and the material layer form a wet barrier layer. 1 1. The manufacturing method as described in item 7 of the scope of patent application, wherein Page 14 594918 6. Scope of patent application The material of the material layer can be titanium nitride, nitride group, titanium hafnium alloy, or a composite layer of metal nitride / titanium tungsten alloy. 1 2. The manufacturing method as described in item 7 of the scope of patent application, wherein the reaction gas used in the in-situ plasma includes at least hydrogen, nitrogen and a mixed gas of nitrogen and hydrogen. -1 3. The manufacturing method according to item 7 of the scope of patent application, wherein the material for forming the conductor layer may be tungsten metal or tungsten alloy. 1 4. The manufacturing method as described in item 7 of the scope of patent application, wherein the planarization process is a chemical mechanical polishing process. 1 5. The manufacturing method as described in item 7 of the scope of patent application, wherein the method for forming the titanium metal layer is an ionic metal deposition process. Page 15