Disclosure of Invention
The invention aims to provide a polishing device, and a semiconductor device obtained by polishing by using the polishing device has low surface roughness, high flatness, low TTV value and concentrated TTV value.
The present invention provides a polishing device comprising:
a polishing head;
a polishing pad disposed on a surface of the polishing head;
the polishing pad is annular, the annular width of the polishing pad is 10-80mm, and the thickness of the polishing pad is 0.5-6 mm;
preferably, the ring width of the polishing pad is 40-60mm, and the thickness of the polishing pad is 1.8-2.5 mm.
Further, the polishing pad has a hardness of 60 to 90 HB;
preferably, the material of the polishing pad includes at least one of rubber, non-woven fabric and composite type.
Further, in a direction in which the polishing pad is away from the polishing head, a center of the polishing pad is in line with a center of the polishing head;
preferably, the polishing pad is circular in shape;
preferably, the polishing head has a circular cross-sectional shape.
Further, the width of the polishing pad is 40-100 mm.
Further, still include: a ceramic disk disposed between the polishing head and the polishing pad;
preferably, the center of the ceramic disk, the center of the polishing pad, and the center of the polishing head are on a straight line in a direction in which the polishing pad is away from the polishing head.
A method of preparing a polishing device as set forth above, comprising: and arranging a polishing pad on the surface of the polishing head to obtain the polishing device.
Further, disposing the polishing pad on the surface of the polishing head at a temperature within ± 2 ℃ of room temperature;
preferably, the polishing pad is disposed on the surface of the polishing head in such a manner as to be attached.
A method of polishing comprising: contacting the polishing pad of the polishing device with an object to be polished for polishing, and delivering a polishing solution to the polishing pad and the surface of the object to be polished during polishing;
preferably, the object to be polished is placed on the surface of a polishing disk, and then the polishing pad is brought into contact with the object to be polished to perform the polishing, wherein the object to be polished is located between the polishing disk and the polishing pad.
Further, the polishing satisfies at least one of the following conditions:
the pressure of the polishing head is 0.3-0.5kg/cm2;
The rotating speed of the polishing head is 40-60 rpm;
the rotating speed of the polishing disc is 50-70 rpm;
the flow rate of the polishing solution is 90-110 ml/min; and the number of the first and second groups,
the polishing temperature is 40-45 ℃.
A semiconductor device, at least a part of the surface of which is polished by the aforementioned polishing method;
preferably, the semiconductor device includes at least one of a SiC substrate wafer, a silicon substrate wafer, and a sapphire substrate wafer.
Compared with the prior art, the invention can at least obtain the following beneficial effects:
the polishing pad is arranged on the surface of the polishing head, and can bear the pressure applied by the polishing head; the polishing pad is annular, so that the pressure applied by the polishing head can be effectively dispersed, and the TTV quality of a product obtained by polishing can be effectively prevented from being lower due to the fact that the pressure applied by the polishing head is concentrated in a certain area.
The polishing pad can ensure that the polishing solution is uniformly distributed on the surface of the object to be polished, the contact amount and the contact time distribution of the polishing solution and the object to be polished are uniform during polishing, the removal amount of the surface of the object to be polished is more uniform and more appropriate, and the TTV quality of a polished product is further improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the term "disposed" is to be interpreted broadly, e.g., as being fixedly attached, detachably attached, or integrally attached; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In one aspect of the present invention, the present invention provides a polishing device, referring to fig. 1 and 2, comprising: a polishing head 100; a polishing pad 200, the polishing pad 200 being disposed on a surface of the polishing head 100; wherein the polishing pad 200 is ring-shaped, the ring width W of the polishing pad 200 is 10-80mm (e.g., 10mm, 30mm, 50mm, 70mm, or 80mm, etc.), and the thickness H of the polishing pad is 0.5-6mm (e.g., 0.5mm, 1mm, 3mm, 5mm, or 6mm, etc.).
The polishing pad is arranged on the surface of the polishing head, and can bear the pressure applied by the polishing head; the polishing pad is annular, so that the pressure applied by the polishing head can be effectively dispersed, and the TTV quality of a product obtained by polishing can be effectively prevented from being lower due to the fact that the pressure applied by the polishing head is concentrated in a certain area, therefore, the polishing device can uniformly and effectively polish an object to be polished, reduce the pressure difference of each position of the object to be polished during polishing, and effectively reduce the roughness of the surface of the polished object to be polished (for example, the surface roughness can be less than 0.2 nanometer), and the TTV value of the polished object to be polished is lower (for example, the TTV value can be less than 3 micrometers), more concentrated and higher in flatness, so that the TTV quality of the polished product is improved.
When the ring width of the polishing pad is too wide or when the ring width of the polishing pad is too narrow, the TTV variation is not significantly different from the effect of not using the pad ring; when the thickness of the polishing pad is too thick, there is a risk that the ceramic disk is thrown out, and when the thickness of the polishing pad is too thin, the TTV change is not significantly different from the effect of non-use.
In some embodiments of the invention, the polishing pad is circular in shape; the cross section of the polishing head is circular.
It should be noted that, the ring width refers to, when the ring is a circular ring formed by two concentric circles, the ring width refers to a difference value of radii of the two concentric circles; when two circles surrounding a circular ring are not concentric circles, the ring width refers to the maximum value of the distance between a connecting line (an extension line of the connecting line passes through the center of the circular ring) between any point on the inner circle and any point on the outer circle in the circular ring region.
In some preferred embodiments of the present invention, the ring width of the polishing pad is 40 to 60mm, and the thickness of the polishing pad is 1.8 to 2.5 mm.
In some embodiments of the invention, the width of the polishing pad is 40-100mm (e.g., can be 40mm, 60mm, 80mm, or 100mm, etc.).
It should be noted that the width of the polishing pad refers to the maximum distance of the line between any two points on the outer peripheral wall of the annular polishing pad; the width of the polishing pad, which refers to the diameter of the outer circle, is explained by taking a circular ring as an example.
In some embodiments of the invention, the polishing pad has a hardness of 60 to 90 HB. Therefore, the polishing pad has stronger pressure resistance, better effect of buffering the pressure of the polishing head and more benefit for uniformly dispersing the pressure applied by the polishing head.
In some embodiments of the present invention, the material of the polishing pad includes at least one of rubber, non-woven fabric, and composite type. Therefore, the material has wide sources, low price and proper hardness.
In some embodiments of the present invention, the center of the polishing pad is aligned with the center of the polishing head in a direction in which the polishing pad is away from the polishing head. Therefore, the polishing pad and the polishing head can stably run, the pressure in the polishing head can be uniformly dispersed, and the TTV quality of a product obtained by polishing can be improved.
It should be noted that the center of the polishing pad can be the center of gravity of the polishing pad, and the center of the polishing pad is explained by taking the polishing pad as a concentric circular ring, which refers to the center of the concentric circular ring; the center of the polishing head may be the center of gravity of the polishing head, and the center of the polishing head is explained by taking the polishing head as a circle, which refers to the center of the circle of the circular polishing head.
In some embodiments of the present invention, referring to fig. 3, the polishing device further comprises: a ceramic disk 300, the ceramic disk 300 being disposed between the polishing head 100 and the polishing pad 200.
In some embodiments of the present invention, the center of the ceramic disk, the center of the polishing pad, and the center of the polishing head are on a straight line in a direction in which the polishing pad is away from the polishing head. Therefore, the stable operation of the polishing device is facilitated, the uniform dispersion of the pressure in the polishing head is facilitated, and the TTV quality of a product obtained by polishing is further facilitated to be improved.
It should be noted that, the center of the ceramic disc is explained by taking the ceramic disc as a circle, which refers to the center of the circle of the circular ceramic disc.
It is understood that the polishing device may include the polishing pad, the polishing head, and the ceramic disk, and the polishing disk, the power supply, and so on, which are not described in detail herein.
In another aspect of the present invention, there is provided a method for producing the aforementioned polishing device, the method comprising: and arranging a polishing pad on the surface of the polishing head to obtain the polishing device.
In some embodiments of the invention, the polishing pad is disposed on the surface of the polishing head at a temperature within ± 2 ℃ of room temperature.
In some embodiments of the present invention, the polishing pad is disposed on the surface of the polishing head in an attaching manner. In some embodiments of the present invention, in order to firmly attach the polishing pad to the surface of the polishing head, the polishing pad may be reinforced by static pressure, and the pressure of the static pressure used may be flexibly selected according to actual needs, which is not described herein in detail.
In another aspect of the present invention, the present invention provides a polishing method comprising: and (3) contacting the polishing pad of the polishing device with an object to be polished for polishing, and delivering polishing liquid to the polishing pad and the surface of the object to be polished during polishing. Therefore, the polished object to be polished has low surface roughness and high surface smoothness, and the polished product has excellent TTV quality.
In some embodiments of the present invention, the polishing is performed by placing the object to be polished on the surface of a polishing platen and then contacting the polishing pad with the object to be polished, wherein the object to be polished is located between the polishing platen and the polishing pad.
In some embodiments of the invention, the polishing satisfies at least one of the following conditions: the pressure of the polishing head is 0.3-0.5kg/cm2(for example, it may be 0.3kg/cm2、0.4kg/cm2Or 0.5kg/cm2Etc.); the rotating speed of the polishing head is 40-60rpm (for example, 40rpm, 50rpm or 60rpm and the like can be achieved); the rotation speed of the polishing disk is 50-70rpm (for example, 50rpm, 60rpm or 70rpm and the like can be achieved); the flow rate of the polishing solution is 90-110ml/min (for example, 90ml/min, 100ml/min or 110 ml/min); and the polishing temperature is 40-45 deg.C (such as 40 deg.C, 42 deg.C, 44 deg.C or 45 deg.C). Therefore, the TTV quality of the product obtained by polishing is more favorably improved.
In another aspect of the present invention, there is provided a semiconductor device having at least a part of a surface thereof polished by the polishing method described above. Therefore, the surface of the semiconductor device is smooth and flat, and the quality is high.
In some embodiments of the present invention, the semiconductor device includes at least one of a SiC substrate wafer, a silicon substrate wafer, and a sapphire substrate wafer.
The invention is further explained below with reference to specific examples.
Examples
Example 1
The structure of the polishing device is as follows:
a polishing head;
a polishing pad disposed on a surface of the polishing head;
the polishing pad is in a concentric ring shape, the polishing pad is made of rubber, the polishing head is in a circular shape, and the circle center of the polishing head is overlapped with that of the polishing pad;
the outer diameter of the ring is 360mm, the ring width is 15mm, and the thickness of the polishing pad is 1.5 mm.
Example 2
The polishing device was constructed as in example 1 except that the ring width was 35mm and the thickness of the polishing pad was 2 mm.
Example 3
The structure of the polishing device was the same as that of example 1 except that the ring width was 80 mm.
Example 4
The structure of the polishing device was the same as that of example 1 except that the ring width was 10 mm.
Example 5
The polishing device was constructed as in example 1, except that the thickness of the polishing pad was 0.5 mm.
Example 6
The polishing device was constructed as in example 1 except that the thickness of the polishing pad was 6 mm.
Comparative example 1
The structure of the polishing device was the same as that of example 1 except that the ring width was 5 mm.
Comparative example 2
The polishing device was constructed as in example 1 except that the ring width was 85 mm.
Comparative example 3
The polishing device was constructed as in example 1, except that the thickness of the polishing pad was 0.2 mm.
Comparative example 4
The polishing device was constructed as in example 1 except that the thickness of the polishing pad was 5 mm.
Comparative example 5
The structure of the polishing device was the same as that of example 1 except that the polishing pad was not included.
2-inch 4H-SiC substrate wafers were polished using the polishing devices of examples 1 to 6 and comparative examples 1 to 5, and the 2-inch 4H-SiC substrate wafers were placed between the polishing device and the polishing platen, and polished while being in contact with each other, with the polishing satisfying the following conditions: polishing ofHead pressure of 0.4kg/cm2(ii) a The rotating speed of the polishing disk is 60 rpm; the rotating speed of the polishing head is 50 rpm; the flow rate of the polishing solution is 100 ml/min; the polishing temperature was 43 ℃, and after polishing 2 inch substrate wafers of 10 cycles (10run) of 4H-SiC, the roughness and TTV value of the substrate wafers were measured (wherein the roughness was measured using AFM equipment and the TTV value was measured using FRT equipment), and the results after polishing the substrate wafers using the polishing devices corresponding to each of the examples and comparative examples are shown in table 1 below:
TABLE 1
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.