CN-121985806-A - Metal wire manufacturing method and semiconductor structure

CN121985806ACN 121985806 ACN121985806 ACN 121985806ACN-121985806-A

Abstract

The embodiment of the application discloses a metal wire manufacturing method and a semiconductor structure, which comprise the steps of forming a metal layer of ruthenium material on a substrate, performing first etching on the metal layer to form a groove intermediate structure, depositing a carbon-based protective layer on the inner wall of the groove intermediate structure, performing second etching on the carbon-based protective layer on the bottom of the groove intermediate structure to remove the carbon-based protective layer, oxidizing the surface of the exposed ruthenium material to form a ruthenium dioxide surface layer, performing third etching on the ruthenium dioxide surface layer to remove the ruthenium dioxide surface layer to expose the surface of the lower ruthenium material to perform first etching again, and sequentially repeating the processes of the first etching, the carbon-based protective layer deposition, the second etching and the third etching until the groove is formed and the divided metal wire is formed, and cleaning the side wall of the groove. The embodiment of the application can improve the problem of poor roughness of the side wall from the source in the etching process, reduce the risk of short circuit or disconnection, and realize lower resistance and interconnection stability.

Inventors

WANG SHIJING
WANG ZHAOXIANG
FANG WENQIANG
CHEN GANG
LIU HU

Assignees

上海邦芯半导体科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A method of manufacturing a metal wire, comprising: Providing a substrate; Forming a metal layer on the surface of the substrate, wherein the material of the metal layer is ruthenium; performing first etching on the surface of the metal layer by using oxygen-containing gas and chlorine-containing gas, and forming a groove intermediate structure on the metal layer; Depositing a carbon-based protective layer on the inner wall of the trench intermediate structure using a carbon-hydrogen containing gas; performing second etching on the carbon-based protective layer on the bottom of the trench intermediate structure by using oxygen-containing gas to remove the carbon-based protective layer, and oxidizing the surface of the ruthenium material exposed on the bottom to form a ruthenium dioxide surface layer; performing a third etching on the ruthenium dioxide surface layer formed on the bottom using an oxygen-containing gas and a chlorine-containing gas to remove, exposing the surface of the ruthenium material below, to perform the first etching again; Sequentially repeating the processes of performing the first etching, depositing the carbon-based protective layer, the second etching and the third etching until a through trench completion structure which is changed from the trench intermediate structure is formed on the metal layer, so as to form a plurality of metal lines which are divided by the trench completion structure on the surface of the substrate; and cleaning the side wall of the groove by using hydrogen-containing gas.
2. The method of claim 1, wherein the cleaning the trench sidewall using a hydrogen-containing gas comprises a first cleaning the trench-completed sidewall using a hydrogen-containing gas to remove the carbon-based protective layer and the oxide layer present on the sidewall.
3. The method of claim 1, wherein the cleaning the trench sidewall with a hydrogen-containing gas comprises performing a second cleaning of the trench intermediate sidewall with a hydrogen-containing gas after each of the predetermined number of the third etches to reduce the residual product.
4. The method according to claim 1, wherein the third etching is performed by adding a chlorine-containing gas to an oxygen-containing gas and reacting with the ruthenium dioxide surface layer to form a volatile RuO x Cl y compound, thereby removing the ruthenium dioxide surface layer.
5. The method of manufacturing a metal line according to claim 1, wherein when the first etching is performed, a chlorine-containing gas flow rate is equal to or less than 20w to 100w for 0.1s to 15s, and/or a first diluent gas is added to a hydrocarbon-containing gas, wherein the carbon-containing gas flow rate is equal to or less than 1:4 to 1:6, the total flow rate of the hydrocarbon-containing gas and the first diluent gas is equal to or less than 50sccm to 300sccm, the temperature is equal to or less than 20 ℃ to 60 ℃, the source power is equal to or less than 100mtorr to or less than 5mtorr, the source power is equal to 300w to 800w, the bias power is equal to or less than 10w to 100w, the time is equal to or less than 0.1s to 15s, and/or the carbon-containing protective layer is deposited, the total flow rate of the carbon-containing gas is equal to or less than 1:4 to 1:6, the total flow rate of the carbon-containing gas and the chlorine-containing gas is equal to or less than 50sccm to 300sccm, the temperature is equal to or less than 20 ℃ to or less than 60 ℃, the source power is equal to or less than 100mtorr to 100mtorr, the bias power is equal to 100w to or less than 300w, the bias power is equal to 300w to or less than 300w, and 60 ℃ is equal to 60 ℃ when the second diluent gas flow rate is equal to or less than 200sccm, the total flow rate of the carbon-containing gas is equal to or less than 50sccm to 50sccm, and 60 ℃ is equal to or 60 ℃ to or less than 50 sccm.
6. The method according to claim 2, wherein a second diluent gas is added to the hydrogen-containing gas during the first cleaning, the flow rate of the hydrogen-containing gas is equal to or less than 1:4-1:6, the total flow rate of the hydrogen-containing gas and the second diluent gas is equal to or less than 200 sccm-1000 sccm, the temperature is equal to or less than 20 ℃ to 60 ℃, the pressure is equal to or less than 50 mtorr-500 mtorr, the source power is equal to or less than 200 w-600 w, and the bias power is equal to or less than 10 w-30 w, and the time is equal to or longer than 5 s-15 s.
7. The method according to claim 3, wherein a third diluent gas is further added to the hydrogen-containing gas during the second cleaning, the flow rate of the hydrogen-containing gas is such that the third diluent gas flow rate=1:4 to 1:6, the total flow rate of the hydrogen-containing gas and the third diluent gas is 100sccm to 300sccm, the temperature is 20 ℃ to 60 ℃, the pressure is 20mtorr to 100mtorr, the source power is 100W to 500W, the bias power is 0W, and the time is 0.1s to 5s.
8. The method of manufacturing a metal wire according to claim 1, wherein the oxygen-containing gas comprises O 2 or O 3 , and/or the chlorine-containing gas comprises Cl 2 , and/or the carbon-containing hydrogen gas comprises at least one of CH 4 、C 2 H 4 and C 3 H 6 , and/or the hydrogen-containing gas comprises H 2 .
9. The method of manufacturing a metal wire according to claim 3, wherein the predetermined number of times is 5 to 10 times.
10. A semiconductor structure obtained using the metal line manufacturing method according to any one of claims 1 to 9.

Description

Metal wire manufacturing method and semiconductor structure Technical Field The present application relates to the field of semiconductor processing technology, and in particular, to a method for manufacturing a metal wire and a semiconductor structure. Background Under advanced nodes, when forming metal interconnection layers on a substrate, the industry is exploring to use a "subtractive" patterning process (depositing metal first and then etching the pattern) to make the most critical and densely patterned bottom metal layers (e.g., M1 and M2). Currently, ruthenium (Ru) is one of the preferred materials for the underlying metal layer for the "subtractive" process. When patterning metal Ru, a single-step etching method is generally adopted, but the product is easy to deposit on the side wall in the etching process to generate residues (RuO x/RuCly), so that the roughness of the side wall of the Ru metal wire etched downwards can be affected, the risk of short circuit or open circuit of the Ru metal wire is easy to be caused by uneven line width, the overlay accuracy can be affected, and the connection quality between the Ru metal wire and an upper metal through hole is deteriorated. In addition, the existence of the problems also affects the manufacture of the Ru metal wire with high aspect ratio, so that the resistance is difficult to reduce. Therefore, there is a need to develop a process that significantly ameliorates the above-mentioned problems. Disclosure of Invention The present application is directed to a method for manufacturing a metal line and a semiconductor structure, which overcome the above problems of the prior art. In order to achieve the above purpose, the technical scheme of the application is as follows: According to a first aspect of the present application, an embodiment of the present application provides a metal line manufacturing method, including: Providing a substrate; Forming a metal layer on the surface of the substrate, wherein the material of the metal layer is ruthenium; performing first etching on the surface of the metal layer by using oxygen-containing gas and chlorine-containing gas, and forming a groove intermediate structure on the metal layer; Depositing a carbon-based protective layer on the inner wall of the trench intermediate structure using a carbon-hydrogen containing gas; performing second etching on the carbon-based protective layer on the bottom of the trench intermediate structure by using oxygen-containing gas to remove the carbon-based protective layer, and oxidizing the surface of the ruthenium material exposed on the bottom to form a ruthenium dioxide surface layer; performing a third etching on the ruthenium dioxide surface layer formed on the bottom using an oxygen-containing gas and a chlorine-containing gas to remove, exposing the surface of the ruthenium material below, to perform the first etching again; Sequentially repeating the processes of performing the first etching, depositing the carbon-based protective layer, the second etching and the third etching until a through trench completion structure which is changed from the trench intermediate structure is formed on the metal layer, so as to form a plurality of metal lines which are divided by the trench completion structure on the surface of the substrate; and cleaning the side wall of the groove by using hydrogen-containing gas. In some embodiments, the cleaning of the side wall of the trench by using the hydrogen-containing gas specifically comprises the step of performing a first cleaning on the side wall of the trench completion structure by using the hydrogen-containing gas to remove the carbon-based protective layer and the oxide layer on the side wall. In some embodiments, the cleaning of the side wall of the trench by using the hydrogen-containing gas specifically includes performing a second cleaning of the side wall of the trench intermediate structure by using the hydrogen-containing gas after each preset number of times of the third etching is completed, so as to reduce the residual product. In some embodiments, the third etch is performed by adding a chlorine-containing gas to the oxygen-containing gas to react with the ruthenium dioxide surface layer to form a volatile RuO xCly complex to remove the ruthenium dioxide surface layer. In some embodiments, the first etching is performed at a chlorine-containing gas flow rate of oxygen-containing gas flow rate=1:10 to 3:10, a total flow rate of oxygen-containing gas and chlorine-containing gas is 50sccm to 300sccm, a temperature is 20 ℃ to 60 ℃, a pressure is 5mTorr to 50mTorr, a source power is 300W to 800W, a bias power is 10W to 100W, and a time is 0.1s to 15s. In some embodiments, when the carbon-based protective layer is deposited, a first diluent gas is further added into the hydrocarbon-containing gas, wherein the flow of the hydrocarbon-containing gas is that the flow of the first diluent gas is=1:4-1:6, the total flow of the