KR20110009834A - Etching formulations for isotropic copper etching - Google Patents

Abstract

PURPOSE: A wet etching composition for isotropic copper etching is provided to avoid surface roughening of a copper layer and to remove copper at a very high etch rate. CONSTITUTION: A wet etching composition for isotropic copper etching comprises (a) a complexing agent selected from the group consisting of dimaines, triamines, and tetraamines, and (b) an aqueous solution including an oxidizing agent. The etching composition has pH of 5-12 and can etch copper. A method for etching a copper-containing part of a semiconductor substrate comprises the steps of: accommodating a semiconductor substrate including exposed copper region which is partly manufactured; and etching copper on the substrate by contacting the wet etching solution and the substrate.

Description

Etching composition for isotropic copper etching {ETCHING FORMULATIONS FOR ISOTROPIC COPPER ETCHING}

Field of invention

The present invention relates to a method of etching copper. More particularly, the present invention relates to a method for isotropic etching of copper on a semiconductor substrate.

Background

Copper and copper alloys are widely used as conductive materials in the field of semiconductor fabrication. Copper is often preferred as a conductor over other metals such as aluminum because of its high electrical conductivity and good electrophoretic resistance. Because of these advantages, copper-filled lines and vias are now found everywhere, for example as conducting paths connecting semiconductor device elements in an integrated circuit.

However, the processing of copper during the fabrication of semiconductor devices presents a series of problems. Since copper is not easy to plasma etch, copper-containing devices typically need to be fabricated using damascene processing. In a damascene process, copper is deposited on the substrate as an inlay with a pattern of pre-formed and recessed damascene features, such as vias and trenches. The pattern of recessed features is typically formed by photolithography techniques. After the recessed features are formed, copper is deposited entirely so that the copper fills the recessed features and also forms an overburdenlayer over the field region, where the field region deposits copper. It means the upper plane of the board | substrate before following. Subsequently, the overlaid is removed by a planarization technique such as chemical mechanical polishing (CMP), resulting in a planarized substrate having a pattern of conductive paths filled with copper.

While effective copper removal methods are needed in various semiconductor device fabrication steps, conventional wet copper etching techniques have not been widely introduced because they generally cannot be successfully integrated into semiconductor device fabrication processes. One of the major drawbacks of conventional etching chemistry includes the anisotropy of etching. Anisotropic etching selectively etches copper in one particular direction, or selectively etches in one type of grain orientation, resulting in uniform copper along roughening, pitting, and grain boundaries of the copper surface. To get rid of it. In many cases, this drawback is typically unacceptable in semiconductor fabrication requiring removal of clean, smooth and isotropic copper.

summary

The present invention solves these problems by providing a composition for isotropic copper etching, and a method for isotropically removing copper using an isotropic etching composition. These compositions can be used to remove copper at very high etching rates (eg, rates of about 1,000 m 3 / min or more) without causing substantial surface roughness. For example, in some embodiments, a solution is provided that can remove 1,000 kPa of copper without increasing the surface roughness of the etched copper surface (determined by a deficiency due to a decrease in surface reflectivity during etching). do. In other embodiments, the surface roughness is only increased to a slight extent (eg, to reduce surface reflectance less than about 20% initially when 1,000 kPa of copper is etched).

In one aspect, provided etching compositions comprise (a) a bidentate, tridentate, or tetradentate complexing agent selected from the group consisting of diamines, triamines, and tetraamines; And (b) an aqueous solution comprising an oxidizing agent. The solution has a pH of about 5-12, more typically about 6-10. In some embodiments the aqueous solution may comprise other components, such as, for example, a pH adjustor.

Suitable oxidants include, but are not limited to, peroxides, permanganate, persulfate and ozone solutions. In many embodiments hydrogen peroxide (H ₂ O ₂ ) is the preferred oxidant.

In some embodiments, the complexing agent used in the composition is diamine. Examples of suitable bidentate diamines include ethylenediamine (EDA, H ₂ NCH ₂ CH ₂ NH ₂ ) and N-methylethylenediamine (H ₃ CNHCH ₂ CH ₂ NH ₂ ).

In some embodiments, the complexing agent is a triamine, such as tridentate triamine, diethylenetriamine (H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NH ₂ ).

In another embodiment, the complexing agent is tetraamine, such as tris (2-aminoethyl) amine (N (CH ₂ CH ₂ NH ₂ ) ₃ ). In some embodiments the etching solution may comprise a mixture of polyamines selected from the group consisting of diamines, triamines, and tetraamines.

In one particular embodiment, the etching composition comprises ethylenediamine, hydrogen peroxide, and, optionally, a pH adjuster (eg, sulfuric acid) and has a pH of about 6-10.

In another aspect, a method of etching a portion containing copper in a partially fabricated semiconductor substrate is provided. This method can be used in a variety of processes. For example, this method can be used in etching-and-capping processes, etc., to etch overloaded copper, to create recesses in the copper filled vias. The method includes (a) receiving a partially fabricated semiconductor substrate comprising exposed copper regions; And (b) etching the copper on the substrate by contacting the substrate with a wet etching solution at a pH in the range of about 5 to 12, wherein the etching solution comprises (i) diamine, triamine and Bidentate, tridentate, or tetradentate complexing agents selected from the group consisting of tetraamines; And (ii) an oxidizing agent. The etching solution may have the above composition, and preferably copper isotropically etched at a high rate.

The etching solution can be delivered on the substrate using a number of methods, including deposition, spraying, spin on contact, and the like. In some embodiments, it is desirable to spray the solution onto the substrate.

The above and other features, and advantages of the present invention will be described in more detail below with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As mentioned above, the present invention provides compositions and methods for isotropic etching of copper. The provided compositions are particularly useful for etching copper on partially fabricated semiconductor substrates, such as etching overloaded copper, making recesses in copper filled vias, and the like.

As used herein, "copper" refers to copper metals deposited with copper metals and alloys thereof, and with organic compounds (such as planarizers, accelerators, and moderators commonly used during copper plating). It is to be noted that the provided compositions can also etch other copper-containing materials, such as oxidized copper species, including copper oxides and copper hydroxides.

As used herein, "semiconductor substrate" means substrates in any stage of processing substrates containing semiconductor material (eg, Si wafer or die). The semiconductor substrate can include various materials (eg, dielectrics and conductors) deposited over the substrate.

"Isotropic etching" means removing copper at substantially similar rates in all directions and / or removing copper at substantially similar rates in all particle orientations. In some embodiments, isotropic etching is characterized by little or no surface roughening of copper during etching. Surface roughness can be measured by measuring the surface reflectivity before etching and after a certain amount of copper (eg, 1,000 kPa) has been removed. In some embodiments, provided etching compositions are characterized by an initial reduction in reflectivity to less than about 20% when copper is etched 1,000 ns. In some embodiments, the initial decrease in reflectivity is less than about 15%, such as less than about 10%, such as 5% or less.

The etching of copper can be made isotropic using certain compositions containing oxidizing agents and complexing agents. Unexpectedly, the properties of the complexing agent have been found to be particularly important when significant fitting or unbalanced isotropic uniform etching is required. Etch compositions have been developed that provide high etch rates (eg, at least about 1,000 kPa / min, preferably at least about 2,000 kPa / min) in the pH range of about 5-12, preferably about 6-10. In particular, in some embodiments the etching occurs at substantially the same rate inside recessed features (or copper filled lines) of different sizes. Moreover, different surfaces within the recessed features are etched at substantially the same speed, for example, etching at the corners of the formed recessed features occurs at the same speed as etching at the feature bottoms. In some embodiments, etching using the compositions also occurs uniformly throughout the wafer, with little change in etching rate between the center and edge portions of the wafer.

In contrast, conventional copper etching compositions, such as those having low pH of less than about 5, typically exhibit anisotropic behavior, and the etch rate inside smaller features is greater than the etch rate inside larger features. Substantially larger than. In addition, using a conventional etching composition, high fitting and surface roughness are observed.

Unusual isotropic etching behavior described in this application is responsible for the rate-limiting reactions occurring at the copper surface. Without wishing to be bound by any theory, it is possible that in the pH range of about 6-12, copper oxide is formed on the copper surface and immediately dissolved and removed by the complexing agent of the copper etching composition. Advantageously, in some embodiments, the etching compositions described herein do not form a copper oxide layer present on the copper surface, but instead have a high reflectivity (eg, relative to Si surface) 120% after etching of 5,000 kPa. It should be noted that it provides a smooth, oxide-free copper surface with greater reflectivity, with the reflectivity reduced to less than about 10% when copper is etched 1,000 Å. Therefore, when oxides are formed during the etching reaction, these oxides are immediately removed in place, eliminating the need for additional oxide removal work.

Etching is usually non-particle specific, for example, etching does not occur at a substantially high rate at only one particular particle orientation or only at a particular particle boundary and therefore does not produce undesirable facets. . Etch rate is independent of feature size and pitch. Moreover, the etching compositions can reduce the fitting and surface roughness and provide a smooth, oxide free surface with high reflectivity.

According to one embodiment, the composition comprises an oxidizing agent (eg, peroxide, persulfate, permanganate, ozone solution, etc.) and a bidentate, tridentate or tetradentate complexing agent which is diamine, triamine, or tetraamine. In some embodiments, hydrogen peroxide is a preferred oxidant because of its high solubility and low cost.

The nature of the complexing agent has been found to be particularly important. For example, it has been found that simple monodentate ligands such as ammonia and large multidentate ligands rich in carboxylates such as ethylene diamine tetraacetic acid (EDTA) provide low etching rates and form surface oxides. In some embodiments, the wet etch solutions provided are substantially free of ligands having a density greater than 4 (eg, EDTA), and ammonia and salts thereof.

Unexpectedly, two, three and four digit diamines, triamines, and tetraamines have been found to provide excellent etching rates, isotropic behavior, low surface roughness, and no residual surface oxides. Various bidentate, tridentate and tetradental amines can be used. These amines may be derivatized at nitrogen (eg may be N-alkyl substituted) or at other positions or may not be derivatized. Examples include ethylenediamine (EDA, H ₂ NCH ₂ CH ₂ NH ₂ ), N-methylethylenediamine (CH ₃ NHCH ₂ CH ₂ NH ₂ ), diethylenetriamine (H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NH ₂ ), And tris (2-aminoethyl) amine (N (CH ₂ CH ₂ NH ₂ ) ₃ ). Mixtures of bidentate, tridentate and tetradentary amines may also be used in the etching composition.

Advantageously, the etching compositions provided provide very high etching rates and produce smooth metal surfaces with very high reflectivity. In addition, in some embodiments, the polyamines do not require any or significant amounts of expensive basic pH adjusters to produce the desired pH. Examples of typical etching compositions comprising polyamines include compositions having a pH of about 6-10, polyamines (eg, EDA), and H ₂ O ₂ . In other embodiments, basic pH adjusters such as tetraalkylammonium hydroxides can be added to the composition. In some embodiments, the etching compositions include an acidic pH adjuster such as sulfuric acid (H ₂ SO ₄ ) to lower the pH. It should be understood that above pH 5 (where the provided composition acts), the acidic pH adjuster will be present primarily as a salt in the etching solution. Thus, for example, the term “etch solution comprising sulfuric acid” should be interpreted as a solution containing an appropriate base base for the required pH. One representative etching composition includes ethylenediamine, hydrogen peroxide and, optionally, sulfuric acid. Wherein the pH of the composition is about 6-10. The etching solutions may generally contain various additive ingredients (eg, surfactants, inhibitors, etc.), but in some embodiments the etching solutions are essentially selected from the group consisting of water, diamines, triamines, and tetraamines. Double, three or four-digit complexing agents; Oxidizing agent, and optionally pH adjusting agent.

Another advantageous feature of the compositions of the invention is that the etching can be rapidly quenched (ie, the etching rate is reduced) at high pH. For example, if the etching needs to be quenched at a certain time in the process, a basic pH adjuster may be supplied to the system to increase the pH of the etchant, eg, greater than about 10-12. The etching rate for the etching composition decreases at high pH and the etching can be quenched at high pH by introducing an appropriate pH adjuster (eg, OH-containing adjuster). Suitable basic pH adjusters include tetraalkylammonium hydroxides such as tetramethylammonium hydroxide (TMAH).

The etch compositions provided are aqueous solutions which distinguish themselves from chemical mechanical polishing solutions or slurries in that they do not contain abrasive particles at all and do not rely on mechanical surface polishing with a pad during metal removal. Therefore, in the etching methods provided, for example, pads (with the polishing agent present in the solution, the abrasive supported or fixed to the pad, or not in the pad or in the solution), can be used to spray the etching solution onto the substrate. It can be done simply by In many embodiments, spraying is the preferred method of delivering the etching composition onto the substrate. In one exemplary embodiment, the etching solution is injected onto a rotating substrate that is rotated (eg, at a speed of about 20-200 rpm) from a nozzle (so-called "fan-nozzle") that produces a spray line across the surface at ambient temperature. All. In general, higher temperatures may be used to increase the etching rate. In some instances, the device for applying the etching solution includes devices used in many EBRs (bevel removal) or SRD (spin rinse dryer). Examples of suitable devices and methods of using the devices are described in detail in US Pat. No. 6,309,981 to Mayer et al., Published October 30, 2001, and US Pat. No. 6,586,342 to Mayer et al., Published 1 July 2003. have.

The etching compositions can be used in a variety of environments during semiconductor processing. For example, the compositions can be used to form recesses in copper lines in the presence of an exposed dielectric. Moreover, the compositions can be used to selectively etch copper in the presence of diffusion barrier materials (eg tantalum and / or tantalum nitride). In another example, the etching compositions are transferred onto a substrate comprising overloaded copper to partially or completely remove the overload.

It is to be understood that the use of the composition for isotropic etching described in the present application is not limited to the above-mentioned applications, and can be used in any field where isotropic etching of copper is required. The compositions and methods are particularly advantageous for use during the fabrication of semiconductor devices with copper filled features having a thickness of less than about 400 nm, but can be widely used in a variety of fields besides integrated circuit (IC) fabrication.

When a copper etching method is used in semiconductor processing, the method includes (a) providing a semiconductor substrate comprising a copper region and (b) contacting the copper region with the etching composition described in the present application. In some embodiments, after the initial etching cycle, the etching reaction is quenched by increasing the pH of the etching solution (eg, by adding a basic pH adjuster) (ie, the etching rate is reduced or the reaction is stopped).

1A-1C provide representative cross-sectional views of damascene structures in which the etching methods provided above can be used. 1A shows a structure (eg, a dielectric) comprising a substrate 101 having embedded and copper filled recessed features 111. An overloaded copper layer 109 is present over the field region of the substrate. A thin conformal diffusion barrier layer 105 (eg, at least one of tantalum and tantalum nitride) is present between the copper regions 109 and 111 and the substrate region 101. In one embodiment, the overlaid copper layer 109 may be fully or partially etched by contacting the substrate with the isotropic wet etching solution provided in this application. In some embodiments, planarization operations, such as CMP or electroplanarization operations, are performed before or after wet etching.

1B shows the substrate obtained after removing the deposited copper. The diffusion barrier layer 105 is exposed to the field region and the copper layer 111 is exposed on top of the recessed features filled with copper. In some embodiments, the isotropic etching solutions provided herein are transferred over the substrate (without etching the diffusion barrier layer), optionally in the presence of the diffusion barrier layer 105 to form a recess inside the copper layer 111. And the structure shown in FIG. 1C, which shows that a recess is formed in the upper portion of the copper-filled layer 111. Next, in some embodiments such recesses may be filled using, for example, a cap (eg, a cobalt-containing cap) by electroless deposition. In some embodiments, these captured copper interconnects are needed because these interconnects improve the electrophoretic properties of the interconnects.

It is to be understood that the isotropic etching compositions provided herein are not limited to those used in the examples discussed above (eg, etch-and-capping). The isotropic compositions provided may be used in a variety of environments (eg, copper etched in most environments) in damascene process flows and in other processes. For example, provided etchantes can be used to remove unwanted copper from the edge region of the semiconductor substrate or from the backside of the substrate.

Experiments with the provided etching compositions and methods are described in detail below.

Experiment

Copper Etching  In the composition Ligands  compare

A blanket coated copper film layer was first deposited and then etched using various wet etching compositions. The reflectivity of the copper surface was measured before and after etching at a wavelength of 480 nm, giving a percentage of the silicon surface. The following aqueous solutions were tested for the ability to isotropically etch copper:

(a) ethylenediamine (0.066M), H ₂ O ₂ (1.06 M), pH 8.9, 20 ° C.

The solution showed a very high etch rate of 4600 mm 3 / min and also showed excellent isotropic behavior. When 6900Å of copper was removed after etching, the reflectivity of the copper surface was 131% (134% before etching).

(b) glycine (0.066 M), H ₂ O ₂ (1.06 M), pH 8.9, 20 ° C.

This solution shows an etch rate and isotropic behavior of 1580 kPa / min. The etching rate is low compared to EDA. When 1053 μs of copper was removed after etching, the reflectivity of the copper surface was 140% (134% before etching).

(c) ammonium persulfate (0.066M), no hydrogen peroxide, pH 2.6, 20 ° C.

This etching solution of low pH (acidic) showed an etching rate of 1849 dl / min, but a high roughness copper surface was obtained after etching. When 1849Å of copper was removed after etching, the reflectivity of the copper surface was only 61% (134% before etching). Matt finish was not observed.

(d) ammonium acetate (0.066 M), H ₂ O ₂ (1.06 M), pH 3.6, 20 ° C.

This low pH etching solution showed an etch rate of 1163 dl / min, but a red / brown copper oxide surface film was obtained during and after etching. When 1163Å of copper was removed after etching, the reflectivity of the copper surface was only 8.8% (134% before etching).

(e) Ammonium persulfate (0.066M), no hydrogen peroxide, pH 8.9, 20 ° C.

This etching solution showed an etching rate of 613 kPa / min, but after etching, a copper surface with reddish brown oxide was obtained. When 429 kV of copper was removed after etching, the reflectivity of the copper surface was 52% (134% before etching).

(f) ammonium hydroxide (0.066 M), H ₂ O ₂ (1.06 M), pH 8.9, 20 ° C.

This etching solution showed an etching rate of only 53 kW / min, but a copper surface with reddish brown oxide was obtained after etching. When 53 구리 of copper was removed after etching, the reflectivity of the copper surface was 68% (134% before etching).

(g) EDTA (0.066 M), H ₂ O ₂ (1.06 M), pH 8.9, 20 ° C.

This etching solution containing ethylenediaminetetraacetic acid (EDTA) showed an etching rate of only 5 kPa / min. When 5 μs of copper was removed after etching, the reflectivity of the copper surface was 135% (134% before etching), indicating little interaction with the surface (ie, little metal removal or film formation).

(h) citric acid (0.066 M), H ₂ O ₂ (1.06 M), pH 8.9, 20 ° C.

This etching solution shows no obvious etching at all.

(i) Oxalic acid (0.066 M), H ₂ O ₂ (1.06 M), pH 8.9, 20 ° C.

This etching solution also shows no obvious etching at all.

(j) ammonium acetate (0.066 M), H ₂ O ₂ (1.06 M), pH 9.6, 20 ° C.

This etching solution showed an etching rate of 429 dl / min, but after etching, a copper surface with reddish brown oxide was obtained. When 429 μs of copper was removed after etching, the reflectivity of the copper surface was 13% (134% before etching).

A bar graph showing the dependence of the etching rate on the etching chemicals is shown in FIG. 2.

From the above experiments, it can be seen that only EDA and glycine provide high etching rate and isotropic behavior. Ammonium hydroxide and ammonium salts form oxide deposits on the copper surface or result in high surface roughness. EDTA, citric acid and oxalic acid do not show distinct etch rates. EDA is superior to glycine because it provides a significantly higher etch rate than glycine.

EDA Wow H ₂ O ₂ Containing Etching  Solutions

Cu film was etched by spraying onto the substrate to the etching solution containing EDA (4 g / L, 0.067 M), and _{H 2 O 2 (120 g /} L 30% H 2 O 2, in, or about 1.9 M) . The pH of the solution was 8.9; The temperature was 20 ° C. An etching rate of about 4,600 mA / min was observed. After 7,000 kPa of copper was removed, the reflectivity was 122% (compared to 125% reflectivity before etching).

3 shows the dependence of the amount of etched copper on the injection etch time. It can be seen that about 9,000 ms has been removed in about 120 seconds. The amount of etched copper is linearly dependent on the spray etch time.

In another experiment, the pH dependence of the copper etch rate was studied. Plots for etch rate versus pH dependence are shown in FIG. 4. An etching solution containing 2 g / L (0.033 M) of EDA and 30 g / L of 30% H ₂ O ₂ (9 g / L, or 0.47 M) was used. The pH was adjusted using H ₂ SO ₄ or TMAH as needed to increase or decrease the pH from the pH value of the unmodified EDA / peroxide mixture. At pH values below 7, it has been observed that the copper surface has a rough, matte surface reflection, has streaks or swirls, and is generally not uniform in appearance. The etching rate attenuated through the surface at high pH (above 11) appeared to be relatively unchanged (reflective / smooth). It was found that the preferred pH for EDA etching was about 7 to about 10.5, more typically about 8.5 to 10.

5 is H ₂ O ₂ with respect to the solution containing the EDA (0.067M) and H ₂ O ₂ (10-40 g / L) at a fixed pH of 8.9 Etch rate dependence on concentration is shown. The etching rate gradually increases as the amount of H ₂ O ₂ increases.

FIG. 6 shows the etching rate dependence on the concentration of EDA with respect to a solution containing EDA (0-8 g / L) and H ₂ O ₂ (1 M) at pH 8.9. It can be seen that the etching rate is highly dependent on the EDA concentration and increases in a nearly linear manner as the concentration increases.

Table 2 shows the change in reflectivity (measurement of isotropic behavior) for etching solutions containing EDA and hydrogen peroxide, where the EDA concentration ranges from 1 to 8 g / L, and the hydrogen peroxide concentration is about 10 to about 40 g. / L and the pH value is 7 to 11.6. It can be seen that in all cases the reflectivity value did not decrease by more than 15%.

Table 2. Copper surface roughness obtained after etching with different solutions including EDA.

EDA concentration (g / L) H2O2 concentration (g / L) pH % Reflectivity change / (1000Hz) One 39.6 8.9 11.1 2 9.9 7 5.4 2 9.9 8.1 3.9 2 9.9 8.9 2.8 2 9.9 10.3 14.4 2 9.9 11.6 14.2 4 9.9 8.9 1.4 4 19.8 8.9 0.67 4 39.6 8.9 0.34 8 39.6 8.9 2.8

Other containing amino groups Complexing agents  Branch Etching  Solutions

Many solutions containing different complexing agents have been tested. pH was adjusted to 8.9 or 8.8 using TMAH or H ₂ SO ₄ .

(a) N-methylethylenediamine (0.066M), H ₂ O ₂ (1.00 M), pH 8.9, 20 ° C.

This solution shows a significant etch rate and isotropic behavior of 1575 dl / min. When 1575 구리 of copper was removed after etching, the reflectivity of the copper surface was 127% (134% before etching).

(b) sarcosine (0.066M), H ₂ O ₂ (1.00 M), pH 8.9, 20 ° C.

This solution has an etch rate of 11.5 dl / min.

(c) taurine (0.066M), H ₂ O ₂ (1.00 M), pH 8.9, 20 ° C.

This solution shows an etching rate of 12 mW / min.

(d) ethanolamine (0.066M), H ₂ O ₂ (1.00 M), pH 8.9, 20 ° C.

This solution shows no obvious etching.

1A-1C show a schematic representation of a cross-sectional view of a portion of a damascene structure and illustrate representative processes in which isotropic copper etching may be used.

2 is an experimental bar graph showing copper etch rates for different etch chemistries.

FIG. 3 is an experimental plot showing the dependence of the amount of etched copper on spray etch time with respect to an etching solution containing EDA and hydrogen peroxide.

FIG. 4 is an experimental plot showing the pH dependence of the copper etch rate for etching solutions containing EDA and hydrogen peroxide.

5 is an experimental plot showing the dependence of the copper etch rate on the hydrogen peroxide concentration in the etching solution containing EDA and hydrogen peroxide.

FIG. 6 is an experimental plot illustrating the dependence of the copper etch rate on the concentration of EDA in an etching solution containing EDA and hydrogen peroxide.

Claims (27)

(a) a bidentate, tridentate, or tetradentate complexing agent selected from the group consisting of diamines, triamines, and tetraamines; And (b) oxidizing agent As a wet etching formulation comprising an aqueous solution comprising a, The etching composition has a pH of 5 to 12 and can etch copper Wet etching composition. The wet etching composition of claim 1, wherein the composition further comprises a pH adjustor. The wet etching composition of claim 1, wherein the composition is capable of etching copper at an etching rate of 1,000 Pa / min or more. The wet etching composition of claim 1, wherein the composition is capable of removing at least 1,000 μs of copper from the substrate without increasing the surface roughness of the etched copper regions. The wet etching composition of claim 1, wherein the oxidant comprises hydrogen peroxide (H ₂ O ₂ ). The wet etching composition of claim 1, wherein the complexing agent comprises diamine. The wet etching composition of claim 6, wherein the diamine is at least one of ethylenediamine (H ₂ NCH ₂ CH ₂ NH ₂ ) and N-methylethylenediamine (H ₃ CNHCH ₂ CH ₂ NH ₂ ). The wet etching composition of claim 1, wherein the complexing agent comprises triamine. The wet etching composition of claim 8, wherein the triamine is diethylenetriamine ((H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NH ₂ ). The wet etching composition of claim 1, wherein the complexing agent comprises tetraamine. The wet etching composition of claim 10, wherein the tetraamine is tris (2-aminoethyl) amine (N (CH ₂ CH ₂ NH ₂ ) ₃ ). The wet etching composition of claim 1, wherein the aqueous solution comprises ethylenediamine and hydrogen peroxide. 13. The wet etching composition of claim 12, wherein the aqueous solution has a pH of 6 to 10. 13. The wet etching composition of claim 12, wherein the aqueous solution further comprises a pH adjuster. A method of etching a copper-containing portion of a partially fabricated semiconductor substrate containing a copper region, comprising the following steps: (a) receiving a partially fabricated semiconductor substrate comprising exposed copper regions; And (b) etching the copper on the substrate by contacting the substrate with a wet etching solution having a pH in the range of 5 to 12, wherein the etching solution comprises (i) a bidentate selected from the group consisting of diamines, triamines and tetraamines, Tridentate or tetradentate complexing agents; And (ii) an oxidizing agent. The method of claim 15, wherein the wet etching solution further comprises a pH adjuster. The method of claim 15, wherein the complexing agent comprises a diamine. The method of claim 15, wherein the diamine is selected from the group consisting of ethylene diamine or N-methylethylenediamine. The method of claim 15, wherein the wet etching solution comprises ethylenediamine and hydrogen peroxide. 20. The method of claim 19, wherein the wet etching solution further comprises a pH adjuster. The method of claim 20, wherein the wet etching solution has a pH of 6 to 10. The method of claim 15, wherein the complexing agent is selected from the group consisting of triamines and tetraamines. The method of claim 15, wherein the etched copper region comprises overloaded copper. The method of claim 15, wherein the copper is etched at a rate of at least 1,000 kW / min. The method of claim 15, wherein the etching is substantially isotropic. The method of claim 15, further comprising quenching the etching process by increasing the pH of the wet etching solution. 27. The method of claim 26, wherein increasing the pH of the wet etching solution comprises adding a basic pH-adjusting agent to the wet etching solution.

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