CN102832167B - Metal hard mask layer preparation method and semiconductor making method - Google Patents

Abstract

The invention provides a method for preparing a metal hard mask layer and a method for manufacturing a semiconductor. The copper interconnection forming method according to the present invention includes: providing a base; depositing a barrier film on the base; depositing a dielectric film on the barrier film; depositing a metal hard mask layer on the dielectric film; UV irradiation treatment; depositing a hard mask cover layer on the metal hard mask layer; performing a single damascene etch process and/or a double damascene etch process to etch the dielectric film, the hard mask and the hard mask cover layer, Thereby exposing at least a portion of the pores of the porous media film. According to the present invention, after ultraviolet light irradiation treatment, the weaker chemical bonds inside the metal hard mask layer film will be removed, which improves the quality of the metal hard mask layer film; the metal hard mask layer film shrinks, making the metal hard mask layer The shrinkage of the film of the layer produces stress tending to stretch, so that the larger compressive stress in the film of the part of the metal hard mask layer can be offset.

Description

Metal hard mask layer preparation method and semiconductor manufacturing method

technical field

The invention relates to the field of semiconductor manufacturing, more specifically, the invention relates to a method for preparing a metal hard mask layer, a method for forming copper interconnections and a semiconductor manufacturing method using the method for preparing the metal hard mask layer.

Background technique

In 0.13um and more advanced back-end processes, copper interconnects are widely replaced by aluminum interconnects due to lower resistivity and better anti-electromigration performance. The completion of the copper interconnection process can be realized by the method of metal hard mask layer. The use of this process can reduce the damage caused by the low dielectric constant interlayer dielectric during the dry process, reduce the amount of photoresist, and the film is a sacrificial layer and will not remain in the final product, thus This process is widely used in copper interconnection below 65nm.

PVD (Physical Vapor Deposition) is usually used as the preparation method of the titanium nitride thin film of the metal hard mask layer.

However, in the actual production process, it is found that the stress of the titanium nitride film is very high, about -1.4GPa, and the titanium nitride film with a higher stress will have a certain effect on the low dielectric constant film below it, causing it to occur. Deformation, thus affecting the yield of the product.

The current method to solve this problem is to change the stress of the film by adjusting the parameters of the deposited titanium nitride film, thereby reducing the effect of the film on the force of the low dielectric constant film below it, and improving the product yield.

Although the adjustment of the deposition parameters of the titanium nitride film reduces the stress of the film, it affects the resistivity uniformity of the film, which in turn affects its subsequent etching and other processes. Therefore, there is a need for a method that can not only reduce the stress of the film, but also make other properties of the film not be greatly affected.

Contents of the invention

The technical problem to be solved by the present invention is to provide a metal hard mask layer preparation method that can not only reduce the stress of the film, but also prevent other properties of the film from being greatly affected by the above-mentioned defects in the prior art. And a semiconductor manufacturing method using the metal hard mask layer preparation method.

According to a first aspect of the present invention, a method for preparing a metal hard mask layer is provided, which includes: providing a substrate; forming a metal hard mask layer on the substrate; and performing ultraviolet light irradiation treatment on the metal hard mask layer .

Preferably, in the method for preparing the metal hard mask layer, the metal hard mask layer is a titanium nitride layer.

According to the second aspect of the present invention, there is provided a copper interconnection forming method, which includes: providing a substrate; depositing a barrier film on the substrate; depositing a dielectric film on the barrier film; depositing a dielectric film on the dielectric film depositing a metal hard mask layer; performing ultraviolet light irradiation treatment on the metal hard mask layer; depositing a hard mask cover layer on the metal hard mask layer; performing a single damascene etching process and/or a double damascene etching process an etching process to etch the dielectric thin film, the hard mask and the hard mask covering layer, thereby exposing at least a portion of pores of the porous dielectric thin film.

Preferably, in the copper interconnection forming method, the metal hard mask layer is a titanium nitride film layer.

Preferably, in the copper interconnection forming method, in the step of depositing a metal hard mask layer on the dielectric thin film, the metal hard mask layer is formed by chemical vapor deposition of a metal organic compound.

Preferably, in the method for forming copper interconnection, the thickness of the metal hard mask layer is in the range of 100-1000 Å.

Preferably, in the method for forming copper interconnection, in the step of irradiating the metal hard mask layer with ultraviolet light,

Preferably, in the copper interconnection forming method, the wavelength range of the ultraviolet light irradiation used in the ultraviolet light irradiation treatment is 320-400nm, the irradiation temperature range is 300-500C, and the irradiation time is 2-7 minutes.

Preferably, the copper interconnection forming method includes: performing deposition of a Cu barrier layer and/or a seed layer in the multilayer metal interconnection; and forming a copper layer.

According to a third aspect of the present invention, there is provided a semiconductor device manufacturing method using the metal hard mask layer preparation method according to the first aspect of the present invention.

The present invention proposes a method for preparing a metal hard mask layer especially suitable for copper interconnection. The preparation method of the metal hard mask layer is to irradiate the film with ultraviolet light after the deposition of the commonly used metal hard mask layer is completed. Since the ultraviolet light irradiation can improve the quality of the film, the film shrinks and produces stress tending to stretch. Thereby, the relatively high compressive stress in the partial film can be counteracted. The method can reduce the stress of the titanium nitride film, thereby reducing the possibility of deformation of the underlying film due to the high stress of the titanium nitride film.

Description of drawings

A more complete understanding of the invention, and its accompanying advantages and features, will be more readily understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:

1 to 3 are schematic diagrams of a copper interconnection process according to the prior art.

FIG. 4 is a method for preparing a metal hard mask layer according to an embodiment of the present invention.

It should be noted that the accompanying drawings are used to illustrate the present invention, but not to limit the present invention. Note that drawings showing structures may not be drawn to scale. And, in the drawings, the same or similar elements are marked with the same or similar symbols.

detailed description

In order to make the content of the present invention clearer and easier to understand, the content of the present invention will be described in detail below in conjunction with specific embodiments and accompanying drawings.

Before describing the embodiments of the present invention in detail, the currently used Cu metal interconnection process will be introduced first. Specifically, the Cu metal interconnection process steps are usually as follows:

1) First deposit the low-K barrier film 3 in the multilayer metal interconnection on the substrate (such as the substrate containing the porous low-K dielectric film 1 shown in Figure 1);

2) After that, low-K dielectric film 4 deposition in multilayer metal interconnection is carried out: SiOC dielectric film (such as SiHCON) is usually used below 45nm process;

3) Deposition of a metal hard mask layer 5 (such as a titanium nitride layer) and a hard mask covering layer 6 (such as a silicon dioxide layer) in a multilayer metal interconnection; after that, a photoresist 7 is deposited, and the resulting The structure is shown in Figure 1;

4) Double damascene etching process; the resulting structure is shown in Figure 2;

5) Deposition of the Cu barrier layer/seed layer 8 in the multilayer metal interconnection; the resulting structure is shown in Figure 3;

6) Thereafter, a copper metal layer (not shown) is formed on the structure shown in FIG. 3 .

<First embodiment>

Different from the above-mentioned prior art, as shown in FIG. 4 , in the metal hard mask layer preparation method of the embodiment of the present invention, after the metal hard mask layer 5 is formed on the substrate, the metal hard mask layer 5 is UV light treatment. Thereafter, for the Cu metal interconnection process according to the embodiment of the present invention, subsequent steps may be performed as in the prior art.

Therefore, compared with the original method, the weaker chemical bonds inside the metal hard mask layer film will be removed after ultraviolet light irradiation treatment, which improves the quality of the metal hard mask layer film; the metal hard mask layer film shrinks , so that the metal hard mask layer thin film shrinks to produce stress tending to stretch, so as to offset the larger compressive stress in part of the metal hard mask layer thin film.

Using this method can reduce the stress of the metal hard mask layer (titanium nitride film) without affecting the resistivity uniformity of the metal hard mask layer (such as titanium nitride film), and reduce the stress of the underlying film due to the metal hard mask layer (titanium nitride film). The high stress of the mask layer (titanium nitride film) may cause deformation.

According to another preferred embodiment of the present invention, the present invention also provides a semiconductor device manufacturing method using the above-mentioned method for preparing the metal hard mask layer.

<Second Embodiment>

The copper interconnection forming method according to the embodiment of the present invention will be specifically described below.

Specifically, the copper interconnection forming method according to the embodiment of the present invention may include the following steps:

First, a barrier film is deposited on a substrate, for example, the substrate is a porous dielectric film substrate.

Thereafter, a dielectric film is deposited on the barrier film.

Subsequently, a metal hard mask layer is deposited on the dielectric film, wherein, preferably, the metal hard mask layer is a titanium nitride film layer, and further preferably, the nitrogen used as the metal hard mask layer The preparation method of titanium oxide film is usually PVD (Physical Vapor Deposition, PhysicalVaporDeposition), but MOCVD (Metal-organic Chemical VaporDeposition, Metal-organicChemicalVaporDeposition) and ALD (Atomic Layer Deposition) can be used as alternate methods; in addition, preferably, The metal hard mask layer has a thickness in the range of 100-1000A.

Then, the metal hard mask layer is subjected to ultraviolet light irradiation treatment, wherein preferably, the ultraviolet light irradiation wavelength range used in the ultraviolet light irradiation treatment is 320-400nm, the irradiation temperature range is 300-500°C, and the irradiation time is 2 -7 minutes.

Subsequently, depositing a hard mask capping layer on the metal hard mask layer;

Subsequently, a single damascene etching process and/or a dual damascene etching process are performed to etch the dielectric film, the hard mask and the hard mask covering layer, thereby exposing at least a portion of pores of the porous dielectric film.

Thereafter, deposition of a Cu barrier layer and/or a seed layer in the multilayer metal interconnect may be performed.

Finally, a copper layer is formed.

Therefore, compared with the original method, the weaker chemical bonds inside the metal hard mask layer film will be removed after ultraviolet light irradiation treatment, which improves the quality of the metal hard mask layer film; the metal hard mask layer film shrinks , so that the metal hard mask layer thin film shrinks to produce stress tending to stretch, so as to offset the larger compressive stress in part of the metal hard mask layer thin film.

Using this method can reduce the stress of the metal hard mask layer (titanium nitride film) without affecting the resistivity uniformity of the metal hard mask layer (such as titanium nitride film), and reduce the stress of the underlying film due to the metal hard mask layer (titanium nitride film). The high stress of the mask layer (titanium nitride film) may cause deformation.

According to another preferred embodiment of the present invention, the present invention also provides a semiconductor device manufacturing method using the above method for forming copper interconnections.

It can be understood that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or be modified to be equivalent to equivalent changes. Example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the technical solution of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. a metal hard mask layer preparation method, is characterized in that comprising:

Substrate is provided;

Substrate forms metal hard mask layer;

UV-irradiation process is carried out to described metal hard mask layer; And

Carry out graphically carrying out the described metal hard mask layer after UV-irradiation process.

2. metal hard mask layer preparation method according to claim 1, is characterized in that, described metal hard mask layer is titanium nitride layer.

3. a copper-connection formation method, is characterized in that comprising:

There is provided substrate, described substrate comprises porous media film;

Deposition preventing film in substrate;

Deposit dielectric film on described block film;

Depositing metal hard mask layer on described dielectric film;

UV-irradiation process is carried out to described metal hard mask layer;

The hard mask cover layer of deposit on described metal hard mask layer;

Fill order Damascus etching technics and/or dual damascene etching technics to etch described dielectric film, to carry out the described metal hard mask layer after UV-irradiation process and described hard mask cover layer, thus expose the hole at least partially of porous media film.

4. copper-connection formation method according to claim 3, is characterized in that, described metal hard mask layer is titanium nitride film.

5. the copper-connection formation method according to claim 3 or 4, is characterized in that, on described dielectric film depositing metal hard mask layer step in, adopt metallorganic chemical vapor deposition form described metal hard mask layer.

6. the copper-connection formation method according to claim 3 or 4, is characterized in that, the thickness range of described metal hard mask layer is

7. the copper-connection formation method according to claim 3 or 4, is characterized in that, the wave-length coverage of the UV-irradiation adopted in UV-irradiation process is 320-400nm, and irradiation temperature scope is 300-500 DEG C, and irradiation time is 2-7 minute.

8. the copper-connection formation method according to claim 3 or 4, characterized by further comprising: the Cu barrier layer during execution multiple layer metal is interconnected and/or the deposit of crystal seed layer; And

Form layers of copper.

9. one kind have employed the method, semi-conductor device manufacturing method according to the metal hard mask layer preparation method one of claim 1 or 2 Suo Shu.