JP2002246340A - Planar polishing apparatus and planar polishing method - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a planar polishing apparatus using a completely new polishing method instead of chemical mechanical polishing (CMP) in precision polishing for which distortion-free planarization processing is required for semiconductor devices and the like. A planar polishing apparatus (A) includes a support means (12) for supporting a workpiece (2), a polishing tool (5) made of an elastic material relatively moving with respect to a plane to be polished of the workpiece (2), and a flat and polishing tool. And a slurry liquid supply means 1 for supplying a polishing slurry liquid between the polishing tool 5 and the polishing tool. The flat surface is polished by non-contact polishing utilizing an extremely small amount destruction phenomenon caused by colliding abrasive grains in a liquid with a flat surface at high speed and at an acute angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar polishing apparatus, and is particularly suitable for flattening the front or back surface of an intermediate structure or a semiconductor device obtained in a manufacturing process of a semiconductor wafer or a semiconductor device.

[0002]

2. Description of the Related Art With the trend toward miniaturization of structures and multi-layer wiring of semiconductor devices, the surface is flattened for each wiring layer in the manufacturing process in order to achieve high density, high integration and high functionality. After that, the next wiring layer is constructed. The planarization of the wafer surface in the device fabrication process solves the serious problem that the depth of focus becomes shallower as the optical scanning device lithography becomes finer. And it can greatly contribute to further miniaturizing the limit of optical lithography.

As a method of polishing the front or back surface of a semiconductor wafer, a semiconductor device, and an intermediate structure obtained in the above-described semiconductor device manufacturing process, a polishing method called chemical mechanical polishing (CMP) is used. The method has been widely adopted.

[0004] Chemical mechanical polishing (CMP) involves polishing abrasive grains,
Polishing the surface to be polished with a polishing pad (polishing pad) in a state in which a slurry liquid containing an etchant causing a chemical reaction on the surface to be polished is supplied to the surface to be polished, thereby causing a chemical reaction on the surface to be polished. This is a technique for polishing while raising, and is a technique for realizing mirror polishing. The abrasive grains and the etchant to be contained in the slurry liquid are variously selected in consideration of the material of the surface to be polished and the processing speed of the polishing process.

In the manufacture of semiconductor devices, CMP is generally applied to a polishing step of a SiO ₂ film, which is an oxide film of silicon as an insulating film, a polishing step of poly-Si, and a polishing step of a metal film.

The polishing process of the SiO ₂ film is roughly classified into a flattening process of an interlayer insulating film and a flattening process of isolation between elements.

As shown in FIG. 10, the step of flattening the interlayer insulating film is an intermediate step in which an SiO ₂ insulating film 73 is formed on wires or various elements 72 provided on the first interlayer insulating film 71. This is a step of flattening the insulating film 73 on the surface of the structure by CMP (up to the broken line a in the figure), and the next second and third layers are formed on this first layer.
This is a flattening step for sequentially constructing wiring patterns of layers, fourth layers,... The step of planarizing the interlayer insulating film is the most basic and important step in an LSI device aiming for multilayer wiring.

On the other hand, flattening of isolation between elements is a step for insulating and isolating elements between neighboring devices by an SiO ₂ film. As shown in FIG. 11, a trench 76 is formed on the Si wafer underlying to the intermediate structure obtained by depositing a SIO ₂ film 77 is formed thereon, the portion 77a embedded in the trench 76
The remaining SiO ₂ film 77b is removed by CMP (up to the broken line b in the figure). In this case, if a film 79 (for example, a silicon nitride film) having an extremely low processing speed by CMP is formed as a stopper on the upper surface of the Si substrate 78 after forming the trench groove, the erosion of the Si substrate by CMP is prevented. be able to.

[0009] CMP of poly-Si is performed by STI (Shallow Trench I).
solation)
Is a process in which the material to be deposited is poly-Si.
To leave poly Si only in the deep trench. Tre
This is for forming an inch-type capacitor. Si substrate surface
Since an oxide film is formed in the trench, SiO
_TwoThe membrane can be used as a stopper.

The CMP of the metal film includes Cu as well as Al and W as a metal film for wiring. Among them, Cu has advantages such as low resistance and high electromigration resistance, and is expected as a next-generation wiring material. The reason why CMP has begun to be applied to these wiring metals is that the yield of wiring is better when using CMP than when processing by etching.

As shown in FIGS. 12 (a) to 12 (c), a groove 83 (contact hole) for connecting the upper wiring and the lower wiring 82 of the insulating film 81 is formed (see FIG. 12 (a)). Then, the metal other than the groove 83 is removed by CMP from the intermediate structure (see FIG. 12 (b)) on which a metal film 84 as a wiring material is formed (see FIG. 12 (c)). This method is called a “damascene method”. In the case of this damascene method, the above-mentioned SiO ₂ film is
Unlike CMP, an insulating film (SiO ₂ film) serves as a stopper.

However, since the load (pressure) from the contacting polishing pad is shared by the projecting portions of the pattern, the progress of the processing cannot be stopped by the density and size of the wiring pattern. As a result, as shown in FIG. 13A, a portion where the wiring portion is over-processed occurs depending on the density and dimensions of the wiring pattern. The decrease in the thickness of the wiring metal caused by such a phenomenon is referred to as “thinning”.
g) ". Further, even in the over-processing of the wiring portion, as shown in FIG. 13 (b), the central portion of the wiring portion is rapidly processed and dents are generated mainly due to the elasticity of the polishing pad and the chemical effect of the slurry. This phenomenon of being processed into a dent is similar to that of a dish.
shing) ".

According to the damascene method, contact hole opening (SiO ₂ film), metal film formation (SiO ₂ film), CM of metal film
P, Insulation (SiO ₂ ) film formation, wiring groove opening (SiO
₂ ), metal film formation, and CMP of the metal film. In this damascene method, a contact hole is formed in the SiO ₂ film, and a wiring groove is formed in the SiO ₂ film to perform CMP only once.
ual Damascene) method.

In the dual damascene method, as shown in FIGS. 14A to 14C, an insulating film 92 on which a wiring or an element 91 is formed is formed.
A contact hole 93 and a wiring groove 94 are opened in the (SiO ₂ film) (FIG. 14A), and a metal 95 is formed on the intermediate structure (FIG. 14B). The CMP (Fig. 14 (c)) can be completed in less than half the number of steps of a normal damascene method. Because of this CMP, there is also a feature that the incidence of processing scratches and the like is reduced.

[0015] When performing the CMP of the metal film, processing scratches and pollution and foreign matter such as scratches, including SiO ₂ film it must be made under the condition that does not remain. If CMP is performed under processing conditions in which processing flaws remain in the SiO ₂ film, traces of wiring metal processing debris may enter the processing flaws. is there. In other words, in order to obtain good device characteristics by performing buried wiring by the damascene method, it is assumed that processing scratches such as scratches and foreign substances such as slurry do not remain on the surface of the insulating film (SiO ₂ ) or wiring metal film by CMP. It is extremely important.

[0016]

The flattening by chemical mechanical polishing (CMP) in the process of manufacturing a semiconductor device has the following problems.

1. SiO ₂ film CMP, poly Si CMP, metal film
In CMP, the material to be polished is different, so it is necessary to change the slurry liquid. For example, in polishing with a strongly alkaline colloidal silica polishing solution used for CMP of poly-Si, a workpiece other than silicon, for example, SiO ₂ ,
There is a problem that a metal film such as Si ₃ N ₄ , Cu or W cannot be polished with high efficiency, and since the polishing solution is strongly alkaline, the material to be polished or other members may be undesirably etched due to a chemical action. is there. For this reason, as the number of layers of the semiconductor device increases and the wiring structure becomes more complicated, the frequency of changing the slurry liquid increases, and the work load of the CMP process increases.

In the process of manufacturing a semiconductor device, when polishing an intermediate structure in which a different material such as an insulating film (for example, SiO ₂ ), poly-Si, or a metal material for wiring is exposed, the different material is polished under the same conditions. In other words, CMP involving chemical reactions
Then, there is a problem that it is difficult to set the processing conditions.

2. The issues for CMP of wiring metal films are high purity, high processing rate (metal film and barrier metal), high selectivity with underlying oxide film, improvement of surface condition, stability, development of circulating slurry and its system. . For example, conventional
In CMP, polishing with a strongly alkaline colloidal silica polishing solution has a problem that not only processing distortion due to pre-processing cannot be removed but also polishing distortion remains due to polishing pressure. In addition, since it involves chemical action,
Or "dishing" may occur and distortion-free flattening may not be realized.

3. In particular, for CMP of a Cu wiring metal film, although Cu is expected as an ideal wiring material, the development of a new slurry solution exclusively for Cu has not yet been developed. Also, CMP
Then, in the case of further material change in the future, it is necessary to develop a slurry liquid corresponding to the material.

4. In addition, since CMP uses PH10 and a strong alkaline solution as the polishing slurry, it is difficult to handle and waste liquid treatment of the polishing solution is also difficult, and the colloidal silica abrasive is fixed when dried and cannot be cleaned. there were.

5. It is difficult to make the chemical action uniform on the surface to be polished, and there is also a problem that distortion is easily generated on the polished surface.

As mentioned above, chemical mechanical polishing (CMP)
Is a processing method for realizing a high degree of mirror polishing. However, in the polishing of a semiconductor device or the like in which materials of different materials are incorporated in a complex manner, a problem occurs due to a chemical action.

Accordingly, an object of the present invention is to provide a plane polishing apparatus using a completely new polishing method instead of chemical mechanical polishing (CMP) in precision polishing such as a semiconductor device which requires flattening without distortion.

[0025]

According to a first aspect of the present invention, there is provided a planar polishing apparatus, comprising: a supporting means for supporting a workpiece; a polishing tool which moves relative to a plane of the workpiece to be polished; A slurry liquid supply means for supplying a polishing slurry liquid between the flat surface and the polishing tool, and polishing the flat surface in a non-contact state by a flow of the polishing slurry liquid formed between the flat surface and the polishing tool. It is characterized by doing.

The surface polishing apparatus of the present invention provides a polishing surface of a workpiece while supplying a polishing slurry liquid to a minute gap between a surface to be polished of the workpiece formed during polishing and a polishing tool. The polishing pad is relatively moved, and the non-contact polishing is performed by utilizing the micro-destruction phenomenon that occurs when the abrasive grains in the polishing slurry liquid collide with the polishing surface of the workpiece at high speed and at an acute angle. I do. According to the polishing technique utilizing this micro-destruction phenomenon, mechanical polishing is performed without a chemical action. Mirror polishing can be realized. Therefore, it is particularly suitable for precision polishing in which flattening without distortion is required.

[0027] The planar polishing apparatus according to claim 2 is characterized in that the polishing slurry liquid does not cause a chemical reaction with the flat surface.

[0028] According to a third aspect of the present invention, in the flat surface polishing apparatus, the workpiece is a semiconductor wafer.

According to a fourth aspect of the present invention, in the flat surface polishing apparatus, the workpiece is an intermediate structure obtained in a semiconductor device manufacturing process. Here, the “intermediate structure”
Intermediate obtained in the process of manufacturing a semiconductor device, for example, as described in the prior art FIG. 10, FIG. 11, FIG. 12 (b), FIG.
14 (b) and the state shown in FIG. 14 (b) are all included in the intermediate structure.

A flat polishing apparatus according to a fifth aspect is characterized in that the workpiece is a semiconductor device.

According to the planar polishing method of the present invention, a relative movement is provided between the polishing tool and the flat surface of the workpiece to be polished,
A polishing slurry liquid is supplied between the flat surface and the polishing tool, and the flat surface is polished in a non-contact state by a flow of the polishing slurry liquid formed between the flat surface and the polishing tool. .

[0032] A flat polishing method according to a seventh aspect is characterized in that the polishing slurry liquid does not cause a chemical reaction with the flat surface.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a polishing apparatus according to an embodiment of the present invention.

The flat-surface polishing apparatus according to the present invention employs the non-contact polishing method based on the above-described minute amount destruction phenomenon.

Planar polishing apparatus A according to the first embodiment of the present invention
Is for polishing an intermediate structure 2 obtained in a semiconductor device manufacturing process, and as shown in FIGS. 1 and 2, a polishing liquid tank 1 filled with a polishing slurry liquid and an intermediate liquid in the polishing liquid tank 1. A turntable 3 on which the structure 2 is mounted and rotated, a first drive unit 4 for reciprocating the turntable 3 in the X direction (indicated by an arrow X in the figure), and an intermediate structure 2 on the turntable 3 Polishing cylinder 5 as a polishing tool that rotates with respect to
And a second driving unit 6 for reciprocating the turntable 3 in the Y direction (indicated by the arrow Y in the figure).

As the polishing slurry liquid to be put into the polishing liquid tank 1, a neutral slurry liquid can be adopted in order to suppress a chemical reaction. For example, the viscosity is 100 cp to 200 cp and the particle size is 1 μm to 10 cp.
A neutral polishing slurry solution containing synthetic bentonite, glycols, an organic acid and an organic acid salt in addition to the abrasive grains can be used. As the abrasive grains, for example, those using abrasive grains of SiC, Al ₂ O ₃ , SiO ₂ , and SeO ₂ can be used. More preferably, the polishing slurry liquid has a chemically stable property that does not cause a chemical reaction with a plane of the intermediate structure 2 to be polished.

The turntable 3 is provided on a base portion 11 having a built-in turn mechanism. The mounting portion 12 can be placed horizontally at the center of the turntable 3 while holding the peripheral end of the intermediate structure 2 therebetween.
To rotate or swing the intermediate structure 2 in the circumferential direction.

The mounting portion 12 is, for example, a depression formed in accordance with the peripheral shape and thickness of the intermediate structure 2, and is provided with a non-slip material such as rubber and a chuck mechanism on the peripheral surface thereof, and is intended to be polished. The intermediate structure 2 may be fitted with the surface (polished surface 2a) facing upward. The turn mechanism incorporated in the base 11 rotates or swings the turntable 3 more slowly than the rotation speed of the polishing cylinder 5 by the power of a motor incorporated in the base 11, for example.

The turntable 3 is placed on a guide rail 14 laid on the bottom of the polishing liquid tank 1 and is movably arranged along the guide rail 14.

The first drive unit 4 has one end attached to the base 11 of the turntable 3, and a hole provided with a seal provided on the side surface of the polishing liquid tank 1 (not shown), and the other end is polished. An arm 16 extending outside the liquid tank 1 and a first drive mechanism 17 for linearly reciprocating the arm 16 in the axial direction outside the polishing liquid tank 1
And The first drive mechanism 17 linearly reciprocates the turntable 3 slowly by the power of a built-in motor, for example, in comparison with the rotation speed of the polishing cylinder 5.

The polishing cylinder 5 is obtained by winding a polishing pad 23 around an intermediate shaft portion 22 of a rotating shaft 21 which is horizontally supported in the polishing liquid tank 1. The rotating shaft 21 is supported at one end by a bearing 24 (see FIG. 2) disposed on the side surface of the polishing liquid tank 1, passes through a bearing 25 having a seal and a bearing on the side surface of the polishing liquid tank 1, Two
It is connected to the drive unit 6. The polishing pad 23 is a polishing pad made of an elastic material having a required rigidity. As the polishing pad, for example, a polishing pad made of a resin material such as polyurethane, a porous soft polishing pad material, or the like can be used.

The polishing cylinder 5 is mounted on the mounting portion 12 of the turntable 3.
The polishing pad 23 is placed at a height at which the outer peripheral surface of the polishing pad 23 abuts on the intermediate structure 2 placed on the intermediate structure 2. This height adjustment is performed, for example, by setting the mounting portion 12 of the turntable 3 to be a replaceable member and setting the thickness of the intermediate structure 2 so that the mounted intermediate structure 2 can abut the polishing pad 23 of the polishing cylinder 5. The mounting portion 12 may be replaceable according to the gap between the sheath cylinder 5 and the polishing pad 23. Further, the height of the polishing cylinder 5 may be adjusted according to the height of the polished surface 2a of the intermediate structure 2 mounted on the mounting portion 12 of the turntable 3. Further, the height of the polished surface 2a of the intermediate structure 2 mounted on the mounting portion 12 may be adjusted in accordance with the height of the peripheral surface of the turntable 3.

As shown in FIG. 2, the second drive unit 6 comprises a second drive mechanism 26 for linearly reciprocating the rotary shaft 21 in the axial direction outside the polishing liquid tank 1 via a motor, and a rotary shaft 21. Motor 2
7 and a third drive mechanism 29 rotated by a belt 28.

Hereinafter, the operation of the planar polishing apparatus A will be described.

When the intermediate structure 2 is polished by the flat-surface polishing apparatus A, the intermediate structure 2 is fitted into the mounting portion 12 of the turntable 3 with the surface to be polished facing up, and the polishing pad 23 of the polishing cylinder 5 is The polishing slurry liquid is poured into the polishing liquid tank 1 to a height at which the intermediate structure 2 is sufficiently immersed in a state where the polishing slurry is placed in a state of being pressed lightly against the structure 2.

In this state, the turntable 3 is rotated or oscillated in the circumferential direction, and the turntable 3 is linearly reciprocated in the X direction along the guide rail 14 by the first drive mechanism 17. The polishing cylinder 5 is reciprocated linearly in the axial direction (Y direction) by the
Rotates the polishing cylinder 5. The rotation or swing of the turntable 3, the linear reciprocating motion of the turntable 3, and the linear reciprocating motion of the polishing cylinder 5 in the axial direction are operations for gradually changing the polishing position. It moves at a speed that is slower than the rotation speed.

At this time, as the polishing cylinder 5 rotates, the polishing pad 23 of the polishing cylinder 5 and the surface to be polished of the intermediate structure 2 are formed.
The polishing slurry liquid is drawn in between 2a. At this time, the polishing pad 23 is elastically deformed by the pressure of the polishing slurry liquid drawn in, and a minute gap s1 is formed between the polishing pad 23 and the polished surface 2a of the intermediate structure 2.

In the minute gap s1, the flow path of the drawn-in polishing slurry liquid is narrowed, so that the flow velocity of the polishing slurry liquid is increased, and the abrasive grains contained in the polishing slurry liquid are rapidly and acutely sharpened in the intermediate structure 2. Collision occurs with the surface to be polished 2a, and the energy of this collision causes an extremely small amount of destruction on the surface to be polished 2a of the intermediate structure 2, thereby performing highly accurate polishing. According to this planar polishing apparatus A, the polishing is performed by contacting the polishing abrasive grains in the flow of the polishing slurry liquid flowing through the surface of the polished surface 2a of the intermediate structure 2 without contacting the polishing pad 23. Intermediate structure 2
The polished surface 2a can be uniformly polished.

In the turntable 3, the position at which the polishing cylinder 5 comes into contact with the polishing surface 2a of the intermediate structure 2 is gradually increased because the mounting portion 12 swings slowly and the turntable 3 reciprocates linearly slowly. Instead, the entire surface to be polished 2a can be polished.

This planar polishing apparatus is a mechanical polishing that does not involve a chemical action. Even when a different material is exposed on the surface 2a to be polished as in the intermediate structure 2, the chemical polishing of the different material is performed. Irrespective of the properties, the polishing can be performed mechanically and uniformly, and the polishing is performed by using the non-contact micro-destruction phenomenon, so that the mirror polishing with very little distortion can be realized. In other words, this planar polishing apparatus is suitable for precision polishing such as flattening of a semiconductor device in which a different material is exposed on a processing surface and an intermediate structure obtained in a manufacturing process of the semiconductor device.

This planar polishing apparatus can be applied not only to semiconductor devices but also to flattening of the front or back surface of a semiconductor wafer without distortion. A flat-surface polishing apparatus B shown in FIG. 3 is such that the mounting section 12 of the turntable 3 of the flat-surface polishing apparatus A is replaced with a mounting section 32 on which a disk-shaped semiconductor wafer 31 can be mounted. The semiconductor wafer 31 is placed on the mounting portion 32 with the surface to be polished (the surface to be polished 31a) facing up, and the semiconductor wafer 31 is immersed in a polishing slurry liquid in the same manner as in the polishing of the intermediate structure 2 by the above-mentioned planar polishing apparatus A. Non-contact polishing is performed in this state.

Also, in the field of precision optics, it is necessary to finish precision optics to a mirror surface with higher precision in order to perform higher precision optical processing in the future. Since this planar polishing apparatus can realize high-precision distortion-free flattening, it can also be applied to mirror polishing of precision optical components.

In the flat-surface polishing apparatus C shown in FIG. 4, the mounting portion 12 of the turntable 3 of the flat-surface polishing device A is replaced with a mounting portion 42 on which a plurality of square column-shaped precision optical components 41 can be arranged and fixed. As shown in the figure, a precision optical component 41 arranged with a predetermined end surface to be polished (the surface to be polished 41a) facing upward is fixed to a mounting portion 42 while being fixed by a fixing jig 43, and Similar to the polishing of the intermediate structure 2 by the plane polishing apparatus A, non-contact polishing is performed with the precision optical component 41 immersed in a polishing slurry liquid.

Next, another embodiment of the planar polishing apparatus according to the present invention will be described.

As shown in FIGS. 5 and 6, this planar polishing apparatus D includes a guide rail 52 laid on the bottom of a polishing liquid tank 51.
And a base 53 on a flat plate placed upright on the guide rail 52, a turntable 54 disposed on both sides of the base 53, and a workpiece 55 fixed on the surface of the turntable 54. Workpiece fixing part 56 and workpiece fixing parts 56 on both sides
And a polishing cylinder 57 disposed to face each other. As shown in FIG.
A polishing pad 59 is wound around the substrate.

This planar polishing apparatus D sets the polishing cylinder 57 in a state in which the polishing cylinder 57 is lightly abutted on the workpiece 55 fixed to the workpiece fixing portion 56, and the polishing liquid tank is brought to a height at which the workpiece 55 is completely immersed.
The polishing slurry liquid is poured into 51, the polishing cylinder 57 is rotated and linearly reciprocated slowly up and down, and the base 53 is linearly reciprocated slowly along the guide rail 52. When the polishing cylinder 57 is rotating, the polishing pad 59 receives the liquid pressure and elastically deforms between the polishing cylinder 57 and the workpiece 55, and a minute gap is formed between the polishing pad 59 and the workpiece 55.

Thus, similarly to the above-described polishing of the intermediate structure 2 by the plane polishing apparatus A, non-contact polishing is performed while the workpiece 55 is immersed in the polishing slurry liquid.

Although the embodiment of the planar polishing apparatus according to the present invention has been described above, the present invention is not limited to the above.

For example, a polishing pad wound around a polishing cylinder is formed into a shape having irregularities on the outer surface, and a dynamic pressure action is generated in the polishing slurry liquid between the polishing cylinder and the surface to be polished to more efficiently produce the polishing slurry liquid. May be drawn between the polishing cylinder and the surface to be polished. As a result, it is expected that the polishing slurry liquid is confined around the polishing cylinder and the polishing efficiency is improved. Incidentally, the unevenness formed on the polishing cylinder is, for example, FIG.
As shown in (b), a projection having a square cross section or a projection 62 having a trapezoidal or wedge-shaped cross section is conceivable. 7 (a) and 7 (b), reference numeral 60 denotes a polishing cylinder, 63 denotes a workpiece, and 64 denotes a support means for supporting the workpiece.

The planar polishing apparatus E shown in FIG. 8 is a belt-shaped polishing pad 68 in which a polishing pad is wound around two pulleys 66 and 67 disposed in a polishing liquid tank 65 with tension applied thereto. And the pulleys 66 and 67 are rotated to rotate the polishing pad 68. In this case, the work 69
Is a turntable that reciprocates linearly on a guide
It is desirable that it is mounted on 70 and rotates or swings while slowly reciprocating linearly.

Further, as shown in the flow chart of FIG. 9, the above-mentioned flat surface polishing apparatus carries out a first step s1 for loading a workpiece to be polished, and a process for polishing a surface to be processed on an installation portion of the flat surface polishing apparatus. Second step s to set the workpiece with the plane up
2 and a third step s3 of polishing a workpiece by a plane polishing device
And a fourth step s4 of shower-cleaning the workpiece polished by the plane polishing apparatus, a fifth step s5 of cleaning the workpiece by brush scrub, and a sixth step of drying the workpiece by a spin dryer. By configuring a system in which the robot sequentially performs s6 and the seventh step s7 of sending the dried workpiece to the unloading section, the polishing operation can be automated and the polishing time can be reduced.

In the fifth step s5, the step of cleaning with a brush scrub is desirably performed in two steps of rough cleaning and finish cleaning.

As described above, the planar polishing apparatus of the present invention
Non-contact polishing in a polishing slurry liquid is performed by a micro-destruction phenomenon, so that mirror polishing with very little distortion can be realized. Therefore, an intermediate structure obtained in a manufacturing process of a semiconductor wafer, a semiconductor device, and a semiconductor device In addition to the polishing of the front surface or the back surface and the polishing of a predetermined end surface of a precision optical component, the present invention can be applied to planar polishing that requires high-precision flattening without distortion.

[0064]

According to the present invention, there is provided a flat surface polishing apparatus comprising: a supporting means for supporting a workpiece; a polishing tool which moves relative to a flat surface of the workpiece to be polished; Slurry supply means for supplying a polishing slurry liquid to the polishing slurry, wherein a polishing pad formed during polishing draws a minute gap between the polishing surface and the polishing pad. Thus, the surface to be processed can be polished by non-contact polishing by utilizing an extremely small amount destruction phenomenon caused by causing the abrasive grains to collide with the surface to be polished at high speed and at an acute angle. According to the polishing technique utilizing this micro-destruction phenomenon, the workpiece can be mechanically and uniformly polished irrespective of the chemical properties of the workpiece, and flattening with very little distortion can be realized.

Therefore, the present invention is suitable for applications such as a semiconductor wafer, an intermediate structure obtained in a manufacturing process of a semiconductor device, and a strain-free flattening process of a semiconductor device.

According to the flat surface polishing method of the present invention, a relative movement is provided between the flat surface of the workpiece to be polished and the polishing tool, and a polishing slurry liquid is supplied between the flat surface and the polishing tool. The flat surface is polished in a non-contact state by the flow of the polishing slurry liquid formed between the polishing tool and the polishing tool. it can.

In the present invention, since the polishing slurry liquid that does not cause a chemical reaction with the flat surface can be used, it is possible to realize polishing in which the chemical properties of the flat surface of the workpiece to be polished are not affected at all. .

[Brief description of the drawings]

FIG. 1 is a perspective view of a planar polishing apparatus A according to the present invention.

FIG. 2 is a cross-sectional view of the flat-surface polishing apparatus A according to the present invention.

FIG. 3 is a perspective view of a planar polishing apparatus B for polishing a semiconductor wafer.

FIG. 4 is a perspective view of a plane polishing apparatus C for polishing a precision optical component.

FIG. 5 is a cross-sectional view of a flat-surface polishing apparatus D according to the present invention.

FIG. 6 is a plan view of a plane polishing apparatus D according to the present invention.

FIGS. 7A and 7B show another embodiment of the polishing pad of the planar polishing apparatus according to the present invention.

FIG. 8 is a perspective view of a planar polishing apparatus E according to the present invention.

FIG. 9 is a flowchart showing a procedure of a planar polishing step.

FIG. 10 is a cross-sectional view of an intermediate structure showing CMP in a step of flattening an interlayer insulating film.

FIG. 11 is a cross-sectional view of an intermediate structure showing a CMP in a planarization step of element isolation.

FIGS. 12A to 12C are cross-sectional views of an intermediate structure showing a processing procedure of a damascene method.

FIG. 13A is a cross-sectional view of an intermediate structure showing thinning.
(b) is a sectional view of the intermediate structure showing dishing.

14A to 14C are cross-sectional views of an intermediate structure showing a processing procedure of a dual damascene method.

[Explanation of symbols]

 A to E Planar polishing equipment 1 Polishing liquid tank 2 Semiconductor device 2a Polished surface 3 Turntable 5 Polishing cylinder 5 23 Polishing pad 31 Semiconductor wafer 41 Precision optical parts

【The invention's effect】

Continued on the front page (72) Inventor Hitoshi Tanbo 5 Asahioka, Kannabe-cho, Shenzhen-gun, Hiroshima Prefecture Inside Ishii Notation Co., Ltd. 3C058 AA07 AA09 AA11 CA01 CB01 CB03 CB04 DA02 DA17

Claims (7)

[Claims] 1. A support means for supporting a workpiece, a polishing tool which moves relative to a plane of the workpiece to be polished, and a slurry for supplying a polishing slurry liquid between the plane and the polishing tool. A flat-surface polishing apparatus comprising: a liquid supply unit; and polishing the flat surface in a non-contact state by a flow of the polishing slurry liquid formed between the flat surface and a polishing tool. 2. The apparatus according to claim 1, wherein the polishing slurry liquid does not cause a chemical reaction with the flat surface. 3. The apparatus according to claim 1, wherein said workpiece is a semiconductor wafer. 4. The apparatus according to claim 1, wherein the workpiece is an intermediate structure obtained in a semiconductor device manufacturing process. 5. The apparatus according to claim 1, wherein the workpiece is a semiconductor device. 6. A polishing tool is provided with a relative movement between a flat surface of a workpiece to be polished and a polishing tool to supply a polishing slurry liquid between the flat surface and the polishing tool. A flat surface polishing method, wherein the flat surface is polished in a non-contact state by a flow of the polishing slurry liquid to be formed. 7. The method according to claim 6, wherein the polishing slurry liquid does not cause a chemical reaction with the flat surface.