JPH10180619A - Grinding agent, grinding method and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve grinding selectivity for a metallic film against an insulated film by including N(CH2 , CH2 , OH)3 in an additive for grinding agents using MnO2 as grinding particles. SOLUTION: During the manufacturing process of an MOS transistor, a layer insulated film 3 made of SiO2 is deposited, its surface is ground by a normal method and a contact hole 3a is formed in the insulated film 3. Further, a conductor layer 4 made of metal such as W or Al or an alloy is deposited. Then, since the conductor layer 4 buries the contact hole 3a, a recessed part 4a is correspondingly formed on the surface of the conductor layer 4 and recessed and projecting parts are formed on the surface. By dispersing MnO2 grinding particles in pure water and using grinding agents added with N (CH2 , CH2 OH)3 as an additive, the conductor layer 4 is uniformly ground and thereby a structure where the surface of the insulated film 3 is flat is obtained. These grinding agents selectively act for a W layer constituting the conductor layer 4 and grinding spontaneously stops when the upper main surface of the insulated film 3 is exposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to semiconductor device manufacturing, and more particularly to a semiconductor device manufacturing method including a polishing step. Further, the present invention relates to a polishing method and an abrasive. 2. Description of the Related Art In a semiconductor device, especially a semiconductor integrated circuit, a multilayer wiring structure in which a wiring structure in which a wiring pattern is embedded on an insulating layer formed on a substrate is multilayered has been partially adopted. In such a multilayer wiring structure, since another wiring structure is formed on the first lower wiring structure, each wiring structure is required to have a flat surface.

[0002]

Therefore, conventionally, when a multilayer wiring structure is formed, a contact hole or a wiring groove is formed on an insulating layer, and a metal is formed on the insulating layer so as to fill the contact hole or the wiring groove. Depositing a layer, and then removing the metal layer until the surface of the insulating layer is exposed.
Removal is performed by P (chemical mechanical polishing) to form a flat wiring structure. Since the upper main surface of such a wiring structure is flat, the next wiring structure can be easily formed thereon.

In such a conventional semiconductor device manufacturing process, a metal layer such as W for filling a contact hole or a wiring groove is formed by using abrasive grains made of α-alumina (Al ₂ O ₃ ) and liquid made of H ₂ O ₂ or the like. Using an abrasive made of a mixture with an oxidizing agent, polishing on a polishing cloth such as urethane resin,
Flattened.

However, when an abrasive containing such an oxidizing agent is used for polishing a conductor layer such as W, the oxidizing agent in the abrasive is applied to the surface of the conductor layer, for example, in correspondence with contact holes or wiring grooves. Along the seam or seam of the formed concave portion, it penetrates into the conductor layer, and as a result,
The polishing process performed in the presence of such an oxidizing agent causes a problem that the seam is enlarged. That is,
As a result of the CMP of the conductor layer, a large and deep recess corresponding to the seam is formed at the center of the conductor plug formed to fill the contact hole, and the electrical connection in the contact hole becomes uncertain. The problem arises. The recesses formed during polishing of the conductor plug cause a particularly serious reduction in reliability particularly in semiconductor devices and integrated circuits having a high integration density of 0.5 μm or less in the size of contact holes.

In order to solve this problem, the applicant of the present invention has previously disclosed in Japanese Patent Application No. 7-169057 an abrasive having MnO ₂ acting as a solid oxidant as abrasive grains, and such an abrasive. A method of manufacturing the used semiconductor device was proposed. In such an abrasive using MnO ₂ , H ₂
Since a liquid oxidizing agent such as O ₂ is not used, the seam in the contact hole is not oxidized, and therefore the seam is not eroded even if polishing is performed.

On the other hand, with such an abrasive using MnO ₂ , in particular, when polishing a conductor layer such as W or TiN deposited on a SiO ₂ film, the selectivity of the polishing of the conductor layer with respect to the underlying SiO _{2 is} increased. , in other words, since the ratio of the polishing rate for the conductive layer to the polishing rate of SiO ₂ is about two times, SiO ₂
However, there is a problem in that it does not act as an effective polishing stopper.

For this reason, the applicant of the present invention has proposed that MnO _{2 is} used as a polishing agent which can prevent erosion of a metal material to be polished by a liquid oxidizing agent and has high selectivity to an insulating film.
In the abrasive comprising the abrasive grains, the solvent, and the additive, as the additive, a compound containing a benzene ring, or using lactic acid, or lactose,
It was proposed in Japanese Patent Application No. 7-169048. It has been discovered that the use of such an additive can achieve a selectivity of 20 or more between the polishing rate of W and the polishing rate of SiO ₂ . In other words, in such a case, SiO ₂
Acts as an effective polishing stopper.

On the other hand, in the manufacture of such a semiconductor integrated circuit, it is often necessary to polish an insulating layer such as an interlayer insulating film. For example, in a semiconductor integrated circuit, an element isolation structure is generally formed to electrically isolate adjacent semiconductor devices from each other. In particular, in a recent miniaturized semiconductor integrated circuit, a field oxide film formed by a conventional LOCOS method is used. Instead, a so-called shallow trench structure in which a groove (shallow trench) is formed between adjacent elements has been used. In such a shallow trench method, a desired element isolation effect is obtained by filling a groove formed between elements with an insulating layer. However, in such a conventional shallow trench method, since a groove is formed on the substrate surface, irregularities are inevitably generated, and therefore, a semiconductor device or a multilayer wiring structure is formed on the substrate surface on which such an isolation structure is formed. Therefore, it is necessary to planarize the interlayer insulating film covering the substrate.

In response to such a request, the applicant of the present invention disclosed in Japanese Patent Application No. 8-167621, Mn ₂ O ₃
Alternatively, an abrasive using Mn ₃ O ₄ as abrasive grains has been proposed. By using Mn ₂ O ₃ or Mn ₃ O ₄ ,
The SiO ₂ layer can be polished at a polishing rate substantially equal to or higher than the conventional colloidal silica abrasive. Furthermore, it was confirmed that similar results were obtained when MnO ₂ abrasive grains were used during polishing and the surface was treated under conditions such that Mn ₂ O ₃ or Mn ₃ O ₄ was formed. .

[0010]

However, when an additive such as a compound having a benzene ring is added to the above-described MnO ₂ abrasive, a large amount of additive is required to obtain desired polishing selectivity. Typically needed to be added in the order of 10% by weight. However, when using a large amount of additives,
Problems such as the necessity of performing cleaning after polishing for a long time occur, and the throughput is reduced particularly in the manufacture of semiconductor devices.

When polishing an insulating layer such as a SiO ₂ layer using Mn ₂ O ₃ or Mn ₃ O ₄ as abrasive grains, a polishing rate comparable to that of a silica-based abrasive such as colloidal silica can be obtained. Is inferior when polishing glass such as SiO ₂ using ceria (CeO ₂ ).

Accordingly, the present invention provides a polishing agent using MnO ₂ as abrasive grains, by adding a small amount of an additive when polishing a metal layer, thereby improving the polishing selectivity for a metal film relative to an insulating film. It is a first object to provide a polishing agent and a polishing method which can be greatly improved by using the method, and a method for manufacturing a semiconductor device.

The present invention further provides MnO ₂ , Mn ₂ O ₃
And a polishing method for improving the polishing efficiency for an insulating layer by adding an additive to a polishing agent using Mn oxides containing Mn and Mn ₃ O ₄ as abrasive grains, and a semiconductor using the polishing agent A second object is to provide a method for manufacturing the device.

[0014]

According to the present invention, there is provided an abrasive comprising an abrasive made of MnO ₂ , a solvent, and an additive. Is a polishing agent characterized in that it contains N (CH ₂ CH ₂ OH) ₃ , or as defined in claim 2, M
An abrasive comprising nO ₂ , a solvent, and an additive, wherein the additive is an abrasive containing an organosilane, or as described in claim 3, a Mn oxide. In an abrasive comprising abrasive grains, a solvent, and an additive, the additive is selected from the group consisting of silica, alumina, and zirconia. As described above, the Mn oxide contains MnO ₂ , Mn ₂ O ₃ and Mn.
An abrasive made of MnO ₂ , a solvent, and N (CH ₂ ), selected from the group consisting of n ₃ O ₄ and the abrasive according to claim 3 or as described in claim 5.
7. A polishing method characterized by polishing a metal using an abrasive comprising an additive containing CH ₂ OH) ₃ or an organosilane, or as described in claim 6,
Using an abrasive selected from the group consisting of nO ₂ , Mn ₂ O ₃ , and Mn ₃ O ₄ , a solvent, and an abrasive comprising an additive selected from the group consisting of silica, alumina, and zirconia, By a polishing method comprising a step of polishing M, or as described in claim 7,
An abrasive made of nO ₂ , a solvent, and N (CH ₂ CH ₂ O
H) a method for manufacturing a semiconductor device, comprising a step of polishing a conductor layer using an abrasive comprising an additive containing ₃ or an organosilane; or as described in claim 8, MnO _2. , Mn ₂ O ₃ , Mn ₃ O ₄ , the abrasive layer selected from the group consisting of a solvent, an additive selected from the group consisting of silica, alumina, and zirconia; The problem is solved by a method for manufacturing a semiconductor device, which includes a step of polishing.

According to the present invention, the polishing characteristics are changed by adding an additive to a polishing slurry containing Mn oxide as abrasive grains. In particular, the present inventor has used MnO ₂ as abrasive grains and prepared N (CH ₂ C
By adding a small amount of an organosilane containing a silane coupling agent soluble in H ₂ OH) ₃ or water as an additive, it is possible to obtain a polishing agent that can selectively polish a conductor and can stop polishing with an insulator. Was found.

FIGS. 1 and 2 show the polishing rate when polishing a SiO ₂ film using MnO ₂ as a polishing agent as a function of the amounts of N (CH ₂ CH ₂ OH) ₃ and organosilane added. . However, H ₂ NC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ was used as the organosilane, and the polishing was performed on a turntable in which a polishing cloth IC400 made by RODEL was further covered on a polishing cloth SUBA400 made by RODEL. Was carried out at a polishing pressure of 350 g / cm ² , while rotating the polishing head carrying the and the turntable in the same direction at a rotation speed of 70 rpm. At that time, the abrasive was supplied at a rate of 100 cc / min. The polishing agent is obtained by converting MnO ₂ into H ₂ O as abrasive grains.
About 10 wt% is used therein, and additives are added thereto in various ratios.

As can be seen from FIGS. 1 and 2, N (C
When H ₂ CH ₂ OH) ₃ or organosilane was not added, the polishing rate of the SiO ₂ film was about 0.2 μm / min, but only 1 wt% of N (CH ₂ CH ₂ OH) ₃ or organosilane was used. Only by adding
It can be seen that the polishing rate of the iO ₂ film drops to almost zero. On the other hand, as shown in FIG. 3, even if the abrasive is added with the additive, as shown in FIG.
It shows a sufficient polishing rate of about 14 μm / min. However, FIG. 3 shows the polishing rate when W is polished under the same polishing conditions as a function of the added amount of N (CH ₂ CH ₂ OH) ₃ and organosilane.

Further, according to the present invention, as described in claims 3 to 4, silica,
By adding an additive selected from alumina and zirconia, a polishing agent capable of efficiently polishing the insulating layer can be obtained. FIG. 4 shows MnO ₂ , Mn ₂ O ₃ and Mn.
_This shows the polishing rate obtained when the SiO ₂ film is polished with an abrasive using ₃ O ₄ as abrasive grains. However, the result of FIG. 4 shows that the turntable was covered with the SUBA400 and IC1000 polishing cloth as before, and the table and the polishing head were rotated in the same direction at a speed of 20 rpm.
This is for the case where polishing is performed at a polishing rate of 420 g / cm ² . As can be seen from FIG. 4, MnO ₂ , M
Using any of n ₂ O ₃ and Mn ₃ O ₄ as abrasive grains, a polishing rate of more than 0.15 μm / min can be obtained,
Moreover, the polishing rates are MnO ₂ , Mn ₂ O ₃ and Mn ₃ O
_Increase in order of ₄ . However, in the experiment of FIG. 4, the ratio of Mn oxide abrasive grains in the abrasive was set to 10 wt%. H ₂ O is used as the solvent.

In FIG. 4, when MnO ₂ is used as abrasive grains, the polishing rate is 0.18 μm / min and Mn ₂ O ₃
When Mn is used, 0.27 μm / min and Mn ₃
When O ₄ is used, a polishing rate of 0.30 μm / min can be obtained. FIGS. 5, 6, and 7 show the powder X-ray diffraction patterns of MnO ₂ , Mn ₂ O ₃ and Mn ₃ O ₄ used in the experiment of FIG. 4, respectively. Among them, MnO ₂ abrasive grains are MnO ₂ abrasive grains.
M formed on the anode by electrolysis of the salt electrolyte solution
Mn ₂ O ₃ abrasive grains are produced by crushing nO ₂ agglomerates until the average particle size is 1 μm or less, while MnO ₂ thus formed is heated in air at 900 ° C. For 10 minutes followed by rapid cooling. Further, Mn ₃ O ₄ can be obtained by performing the heat treatment of MnO ₂ in air at 1000 ° C. for 10 minutes. As can be seen from FIG. 5, the MnO ₂ abrasive grains are mainly composed of γ-phase MnO ₂ , while the Mn ₃ O ₄ abrasive grains contain a small amount of Mn ₂ O ₃ as can be seen from FIGS. .

As shown in FIG. 8, the inventor of the present invention
In a polishing agent using nO ₂ , Mn ₂ O ₃ , and Mn ₃ O ₄ as abrasive grains, silica, alumina or zirconia is added as an additive to greatly increase the polishing rate when polishing an oxide film. I found that I can do it.

More specifically, MnO ₂ abrasive grains are added in an amount of 10 wt.
% Of the polishing agent, the polishing rate of the SiO ₂ film is reduced to 0.18 μm by adding 3 wt% of silica.
/ Min was found to increase from 0.28 μm / min. When alumina was added instead of silica, the polishing rate increased from 0.18 μm / min to 0.291 μm / min when the SiO ₂ film was polished. Further, when zirconia is added instead of silica, the polishing rate is from 0.18 μm / min to 0.285 μm / m when the SiO ₂ film is polished.
in. However, the polishing conditions were the same as above, and the polishing pressure was 420 g / cm while rotating the turntable and the polishing head in the same direction at a speed of 20 rpm on a turntable covered with a SUBA400 polishing cloth and an IC1000 polishing cloth. I set it to ² .
At that time, the abrasive is supplied onto the polishing cloth at a rate of 100 cc / min.

Further, instead of MnO ₂ abrasive grains, Mn ₂ O
_{3 For} abrasives containing 10 wt% abrasive, silica is 3 wt%
The addition increased the polishing rate of the SiO ₂ film from the initial 0.27 μm / min to 0.388 μm. When alumina was added instead of silica, the polishing rate increased from the initial 0.27 μm to 0.291 μm when polishing the SiO ₂ film. Furthermore, when zirconia is added instead of silica,
The polishing rate increased from the initial 0.27 μm to 0.285 μm when the SiO ₂ film was polished. However, the polishing conditions were the same as in the previous case. On a polishing turntable covered with a SUBA400 polishing cloth and an IC1000 polishing cloth, the polishing pressure was increased by 4 while rotating the turntable and the polishing head in the same direction at a speed of 20 rpm.
The setting was performed at 20 g / cm ² . At that time, the abrasive,
It is supplied on the polishing cloth at a rate of 100 cc / min.

The silica particles to be added must be smaller than the Mn oxide particles in order to avoid scratches. Therefore, the particle size is 0.5 μm or less, preferably 0.1 μm or less. Such fine particles can be obtained by finely pulverizing fused silica, but fumed silica obtained by spraying a gas such as silicon tetrachloride in a park or colloidal silica obtained by precipitation from water glass may be used. The dry powder may be added to the slurry, but if the aggregated particles are not unraveled, it may cause scratches, so it is better to add the powder dispersed in water. Further, the Mn oxide may be added and mixed after the pulverization is completed, but may be added before or during the pulverization.

The amount of addition is effective in the range of 0.1 to 15%. If it is less than 0.1%, no effect is exhibited by adding it. If it is more than 15%, the additive starts to hinder the polishing action of the Mn oxide, so that the polishing rate is rather reduced.
Particularly, a range of 1 to 5% is desirable.

In an abrasive containing 10 wt% of Mn ₃ O ₄ abrasive grains instead of MnO ₂ abrasive grains, the addition of 3 wt% of silica reduces the polishing rate of the SiO ₂ film to the initial 0.30%.
It increased from μm / min to 0.407 μm. Also,
When alumina was added instead of silica, the polishing rate was 0.30 μm when the SiO ₂ film was polished.
To 0.399 μm. Further, when zirconia is added instead of silica, the polishing rate is S
When the iO ₂ film was polished, it increased from the initial value of 0.30 μm to 0.405 μm. However, the polishing conditions were the same as in the previous case, namely, the SUBA400 polishing cloth and IC100.
A polishing pressure was set to 420 g / cm ² while rotating the turntable and the polishing head in the same direction at a speed of 20 rpm on a polishing turntable covered with a polishing cloth. At this time, the polishing agent was supplied at 100 cc / min.
Is supplied onto the polishing cloth at a rate of

As described above, according to the present invention, the Mn oxide
SiO 2 _TwoPolishing insulating film etc.
, Add silica, alumina or zirconia
The polishing rate is greatly increased by adding
Can improve the efficiency of the polishing operation.
Wear.

Table 1 below summarizes the experimental results of the SiO ₂ film polishing.

[0028]

[Table 1]

Further, the inventors of the present invention have found that the polishing rate of a conductive film such as W or TiN can be increased by adding silica, alumina or zirconia as an additive in an abrasive using MnO ₂ as abrasive grains. Found to improve. More specifically, 10 wt the MnO ₂ abrasives
% Of the W film, the polishing rate of the W film is reduced to 0.15 μm / mi by adding 3 wt% of silica.
It was found to increase from n to 0.34 μm / min. When alumina was added instead of silica, the polishing rate was changed from 0.15 μm / min to 0.35 μm / min.
increased to μm / min. Further, when zirconia was added instead of silica, the polishing rate was 0.1%.
It increased from 5 μm / min to 0.36 μm / min. However, polishing was performed using SUBA400 polishing cloth and IC1.
On a polishing turntable covered with a 000 polishing cloth,
Turntable and polishing head in the same direction at 70 rpm
m while rotating at a speed of 250 g / cm ^2.
I went to set. At that time, the polishing agent was changed to 100 cc / m
The powder was supplied onto the polishing cloth at a rate of in.

As described above, according to the present invention, silica, alumina or zirconia is added as an additive even when a conductive film such as W or TiN is polished with an abrasive having MnO ₂ as abrasive grains. Accordingly, the polishing rate can be greatly increased, and the efficiency of the polishing operation can be improved.

Table 2 below summarizes the experimental results of the W film polishing.

[0032]

[Table 2]

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described for a case where the present invention is applied to the manufacture of a semiconductor device. [Embodiment 1] Next, a process of manufacturing a semiconductor device according to a first embodiment of the present invention using the polishing slurry of the present invention will be described with reference to an example of a process of manufacturing a MOS transistor.

Referring to FIG. 9A, a MOS transistor corresponds to an active region 1A defined by a field oxide film 1a formed on a p-type doped Si substrate 1, for example. Formed. More specifically,
The MOS transistor includes an n ⁺ -type diffusion region 1b formed on the surface of the active region 1A and a MOS transistor formed on the surface of the active region 1A.
Another diffusion region 1c formed separated from the diffusion region 1b by a channel region 1d of a MOS transistor.
And a gate electrode 2 formed on the channel region 1d with a gate oxide film (not shown) interposed therebetween.
Sidewall insulating films 2a and 2b are formed on side walls of the gate electrode 2. The diffusion regions 1b and 1c function as a source region and a drain region of a MOS transistor, respectively.

In the step shown in FIG.
Embedded in the transistor _TwoInterlayer insulation consisting of
The film 3 has a thickness of typically 50 nm by a CVD method or the like.
Deposited to a thickness of the order of magnitude. As a result, the gate electrode and
And the diffusion regions 1b and 1c are covered with the insulating film 3.
You. However, as shown in FIG.
Have irregularities corresponding to the gate electrode 2.

Next, in the step of FIG.
Is uniformly polished, and as a result, the surface of the insulating film 3 is flattened. In this step, a known appropriate abrasive may be used. Further, in the step of FIG.
Is patterned by photolithography using a resist (not shown). As a result, in the insulating film 3,
A contact hole 3a exposing the surface of the region 1b is formed corresponding to the diffusion region 1b. Further, in the step of FIG. 10D, on the structure of FIG.
Conductive layer 4 made of metal or alloy such as W, Al, Cu, etc.
Is deposited to a uniform thickness, for example, by a CVD method. As a result, the conductor layer 4 fills the contact hole 3a and makes electrical contact with the diffusion region 1b in the contact hole. In the structure of FIG. 10D, the conductor layer 4 fills the contact hole 3a.
A concave portion 4 corresponding to the contact hole 3a is formed on the surface.
a appears. In other words, the surface of the conductor layer 4 has irregularities.

Therefore, in this embodiment, FIG.
In the step (E), the conductor layer 4 is uniformly formed by using an abrasive containing MnO ₂ as abrasive grains and further adding N (CH ₂ CH ₂ OH) ₃ or an organosilane as an additive. Polishing is performed to obtain a structure in which the surface of the insulating film 3 illustrated in FIG. The abrasive according to the present invention selectively acts on the W layer constituting the conductor layer 4, and the polishing stops spontaneously when the upper main surface of the insulating film 3 is exposed. As a result, a conductor plug 4b that contacts the diffusion region 1b is formed so as to fill the contact hole 3a. As a result of the planarization by such polishing, the upper main surface of the conductor plug 4b coincides with the upper main surface of the insulating film 3.
In the abrasive of the present invention, since MnO ₂ contained as abrasive grains acts as a solid oxidizing agent, polishing is limited to the surface of the conductor plug 4b on which the abrasive grains actually act.
The inner seam is not eroded during polishing.

Next, in the step of FIG. 11F, another insulating film 5 made of SiO ₂ or the like is deposited on the planarized structure of FIG. In the process, a groove 5a exposing the conductor plug 4b is formed by patterning by photolithography. Further, FIG.
In the step 2 (H), another conductor layer 6 made of a metal or an alloy such as W, Al, Cu or the like is deposited on the structure of FIG. 12 (G). A concave portion 6a is formed in the layer 6 as shown in FIG.

Further, in the step of FIG. 13 (I), the conductor layer 6 is made of MnO ₂ , similarly to the step of FIG. 11 (E).
Is used as abrasive grains, and polished with an abrasive to which N (CH ₂ CH ₂ OH) ₃ or organosilane is added as an additive, to obtain a flattened structure shown in FIG. FIG.
In the structure of (I), the groove in the insulating film 5 is
Is filled with the conductor patterning 6b forming a part of the pattern. further,
On this structure, another insulating layer 7 is deposited in the step of FIG. 13J, and various wiring patterns are formed on the insulating layer 7 as necessary.

In such a method of manufacturing a semiconductor device,
A structure with excellent flatness can be obtained in the polishing step of FIG. 11E or FIG. 13I, and the conductive plug extending in the insulating layer is not eroded by the abrasive, so that the multilayer wiring structure can be easily formed. And can be formed reliably.

The abrasive used in the step of FIG. 11E or FIG. 13I has, for example, an average particle diameter of 0.1 to 0.1%.
About 10 wt% of 1 μm MnO ₂ abrasive grains in pure water (H ₂ O)
% And further dispersed in N (CH ₂ CH ₂ OH) ₃ or H ₂ NC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ ,

[0042]

Embedded image

The above organosilane is added to pure water by 1 to 2 times.
It is preferable to use a material to which about% by weight is added. In this case, polishing is performed, for example, on a turntable on which SUBA400 and IC1000 polishing cloths are overlapped and covered with each other.
It is preferred that the polishing be performed at a pressure of about 0 g / cm ² while rotating the turntable and the polishing head at 70 rpm. At that time, the abrasive is supplied at a rate of, for example, about 100 cc / min.

Although the above embodiment has described in detail the polishing of W on SiO ₂ , the present invention is also effective for polishing a metal on another insulating film. As another insulating film, PS
G, BPSG, SiN and the like are included, and the metal to which the present invention can be applied further includes a high melting point metal such as Al, Cu, and Ti, or a high melting point metal compound such as TiN. [Embodiment 2] FIGS. 14A to 14C are views showing a manufacturing process of a semiconductor device according to a second embodiment of the present invention, in particular, a process of forming an element isolation structure using shallow trenches.

Referring to FIG. 14A, the Si substrate 11
Above the device isolation groove 11A, a depth of, for example, about 400 nm is formed.
Then, in step (B), the structure of step (A) is formed.
SiO on the structure_TwoThe layer 14 fills the groove 11A.
Is deposited by a CVD method. Further, in step (C)
In the above, the SiO_TwoLayer 14 is made of MnO as described in Table 1.
_Two, Mn_TwoO_ThreeOr Mn_ThreeO_FourWith abrasive grains
Use abrasives to which mosquito, alumina or zirconia are added.
Is polished.

As described above, the polishing of the SiO ₂ layer 14 is performed by turning the turntable and the polishing head on the turntable covered with the SUBA400 and IC1000 polishing cloth at a pressure of about 420 g / cm ² and 20 rpm.
It is performed using H ₂ O as solvent while rotating in the same direction at a speed of m. At that time, the polishing is automatically stopped when the surface of the Si substrate 11 is exposed, due to the selectivity of the polishing rate of SiO ₂ with respect to Si.

MnO ₂ , Mn ₂ O ₃ or Mn ₃ O ₄
By adding an additive such as silica, alumina or zirconia to the abrasive grains such as above, the polishing efficiency in the step (B) becomes extremely high, and the production throughput of the semiconductor device is improved. In the steps shown in FIGS. 14A to 14C, the surface itself of the Si substrate 11 acts as a polishing stopper, and as a result, a polishing stopper layer is separately provided as in the related art.
Further, an extra step of removing it can be omitted.

In this embodiment, Mn is used during polishing.
Using O ₂ as abrasive grains, oxidation-reduction potential of solvent and pH
By adjusting the, Mn ₂ O to MnO ₂ abrasive surface
₃ or Mn ₃ O ₄ may be formed. In this case, M
The same S as when using n ₂ O ₃ or Mn ₃ O ₄ abrasive grains
Efficient polishing of iO ₂ layer 4 and SiO to Si
The automatic stopping effect of polishing by the selectivity of ₂ can be obtained. According to this method, the same polishing agent as the MnO ₂ polishing agent used for polishing the conductor layer such as W in another polishing step is used, and only the composition of the solvent is changed.
The polishing process becomes very simple. For example, the oxidation-reduction potential E
Is set to 0 V and pH to 12 or more, Mn ₂
O ₃ can be formed on the surface of MnO ₂ abrasive grains.

[0049] Although the present invention has been described for the preparation of semiconductor device, the present invention is capable polished at a polishing rate comparable insulating layer such as a glass CeO _2, polishing conventional lens CeO ₂ was used It is also effective. Moreover, Mn
Because oxides are much cheaper than CeO ₂ , the present invention can reduce the cost of manufactured lenses.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the appended claims.

[0051]

The features of the present invention described in claims 1, 2, 5, and 7 are as follows.
According to the remarks, MnO_TwoAbrasive, solvent and additive
And N (CH
_TwoCH _TwoOH)_ThreeOr use organosilane
Therefore, only the conductor layer is used without substantially polishing the insulating layer.
Can be efficiently polished, and the necessary additives
A small amount of addition is required.

According to a feature of the present invention, in the abrasive comprising an Mn oxide, a solvent and an additive, silica is used as the additive.
By selecting from the group consisting of alumina and zirconia, the speed of polishing an insulating layer of glass or the like is increased, and the process of manufacturing a semiconductor device including such a polishing process or the process of manufacturing a lens or the like can be made more efficient.

[Brief description of the drawings]

FIG. 1 is a diagram (part 1) illustrating the principle of the present invention.

FIG. 2 is a diagram (part 2) for explaining the principle of the present invention;

FIG. 3 is a diagram (part 3) for explaining the principle of the present invention;

FIG. 4 SiO ₂ by an abrasive having Mn oxide as abrasive grains
FIG. 3 is a diagram showing polishing characteristics of a film.

FIG. 5 is a view showing a powder X-ray diffraction pattern of MnO ₂ abrasive grains according to the present invention.

FIG. 6 is a view showing a powder X diffraction pattern of Mn ₂ O ₃ abrasive grains according to the present invention.

FIG. 7 is a view showing a powder X diffraction pattern of Mn ₃ O ₄ abrasive grains according to the present invention.

FIG. 8 is a diagram (part 4) explaining the principle of the present invention.

FIGS. 9A and 9B are diagrams (part 1) illustrating the steps of manufacturing the semiconductor device according to the first embodiment of the present invention; FIGS.

FIGS. 10 (C) and 10 (D) are views (No. 2) showing the steps of manufacturing the semiconductor device according to the first embodiment of the present invention; FIGS.

FIGS. 11E and 11F are diagrams (part 3) illustrating a process for manufacturing the semiconductor device according to the first embodiment of the present invention; FIGS.

FIGS. 12G and 12H are views (No. 4) showing the steps of manufacturing the semiconductor device according to the first embodiment of the present invention; FIGS.

FIGS. 13 (I) and (J) are views (No. 5) showing the steps of manufacturing the semiconductor device according to the first embodiment of the present invention.

FIG. 14 is a view illustrating a manufacturing process of a semiconductor device according to a second embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 1,11 Substrate 1a Field oxide film 1b, 1c Diffusion region 1d Channel region 2 Gate electrode 2a, 2b Gate sidewall insulating film 3,5,7 Insulating film 3a Contact hole 4,6 Conductive layer 4a Depression 4b Conductive plug 4c Seam 5a Groove 6a recess 6b conductor pattern 11A separation groove 14 oxide film 14A recess

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Wataru Nakamura 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Akira Hatada, Inventor 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa No. 1 Inside Fujitsu Limited (72) Inventor Yoshihiro Arimoto 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Within Fujitsu Limited (72) Inventor Shisei Ueda 4 Fujimi, Fukiage-cho, Kita-Adachi-gun, Saitama −12−25 (72) Inventor Kenzo Hanawa 1380-1 Hara-shi, Ageo-shi, Saitama

Claims (8)

[Claims] 1. An abrasive comprising an abrasive made of MnO ₂ , a solvent and an additive, wherein the additive is N (CH ₂
An abrasive comprising CH ₂ OH) ₃ . 2. A polishing agent comprising an abrasive made of MnO ₂ , a solvent and an additive, wherein the additive contains an organosilane. 3. An abrasive comprising an abrasive made of Mn oxide, a solvent and an additive, wherein the additive is silica,
An abrasive selected from the group consisting of alumina and zirconia. 4. The Mn oxide comprises MnO ₂ , Mn ₂ O
Abrasive according to claim 3, characterized in that it is selected from ₃ and Mn ₃ O ₄ group consisting. 5. MnO_TwoAbrasive, solvent and N
(CH_TwoCH_TwoOH) _ThreeOr an additive containing organosilane
Special feature is to polish metal using an abrasive consisting of additives.
Characteristic polishing method. 6. An abrasive comprising abrasive grains selected from the group consisting of MnO ₂ , Mn ₂ O ₃ and Mn ₃ O ₄ , a solvent, and an additive selected from the group consisting of silica, alumina and zirconia. A polishing method comprising the step of polishing a glass using the method. 7. MnO_TwoAbrasive, solvent and N
(CH_TwoCH_TwoOH) _ThreeOr an additive containing organosilane
Polishing the conductor layer using a polishing agent consisting of an additive
A method for manufacturing a semiconductor device, comprising: 8. An abrasive comprising abrasive grains selected from the group consisting of MnO ₂ , Mn ₂ O ₃ and Mn ₃ O ₄ , a solvent, and an additive selected from the group consisting of silica, alumina and zirconia. A method for manufacturing a semiconductor device, comprising: polishing an insulating layer using the method.