JP3494119B2 - Semiconductor wafer polishing method using a double-side polishing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polishing a semiconductor wafer using a double-sided polishing apparatus, and more specifically, a double-sided polishing apparatus having no sun gear incorporated therein to obtain semiconductor wafers having different polishing amounts on the front and back surfaces. The present invention relates to a semiconductor wafer polishing method using a polishing apparatus.

[0002]

2. Description of the Related Art In the production of a conventional double-sided polished wafer, after slicing a single crystal silicon ingot to produce a silicon wafer, chamfering, lapping, and acid etching are sequentially performed on the silicon wafer.
Then, double-side polishing is performed to make both front and back surfaces of the wafer mirror-finished. For this double-sided polishing, a double-sided polishing device having a planetary gear structure in which a sun gear is arranged in the center part and an internal gear is arranged in the outer peripheral part is usually used. This double-sided polishing machine inserts and holds silicon wafers inside a plurality of wafer holding holes formed in a carrier plate, and supplies slurry containing polishing abrasives to the silicon wafers from above, while polishing the opposite surfaces of the silicon wafers. The upper surface plate and the lower surface plate on which the cloth is stretched are pressed against the front and back surfaces of each wafer, and the carrier plate is revolved between the sun gear and the internal gear, whereby both surfaces of each silicon wafer are simultaneously polished.

By the way, in this planetary gear type double-side polishing apparatus, a sun gear is provided at the center of the apparatus. As a result, when manufacturing an apparatus for double-side polishing a large-diameter wafer such as a 300 mm wafer, which has been attracting attention as a next-generation silicon wafer, the carrier plate, and thus the entire double-side polishing apparatus, is provided as much as the sun gear is provided. However, there is a problem that the diameter of this device becomes 3 m or more.

Therefore, as a conventional technique for solving this,
For example, a "double-sided polishing device" described in JP-A-11-254302 is known. This double-sided polishing device is provided with a carrier plate having a plurality of wafer holding holes for holding silicon wafers, and arranged vertically in the carrier plate. An upper surface plate and a lower surface plate on which a polishing cloth for polishing both front and back surfaces at the same polishing rate is spread,
A carrier moving means for moving the carrier plate held between the upper platen and the lower platen in a plane parallel to the surface of the carrier plate is provided. The movement of the carrier plate here means a circular movement without rotation of the carrier plate, such that the silicon wafer held between the upper surface plate and the lower surface plate is swung in the corresponding wafer holding hole. means. Further, during polishing of both surfaces of the wafer, the upper platen and the lower platen are rotated in directions opposite to each other about each vertical rotation axis.

Therefore, at the time of polishing both sides of the wafer, the silicon wafer is inserted and held in each wafer holding hole of the carrier plate, and while the slurry containing the polishing abrasives is supplied to the silicon wafer, the upper surface plate and the lower surface plate are rotated. On the other hand, by causing the carrier plate to perform a circular motion without rotation, each silicon wafer is simultaneously polished on both sides. Since the sun gear is not incorporated in this double-sided polishing apparatus, the space for forming each wafer holding hole on the carrier plate is correspondingly expanded.
As a result, it is possible to increase the size of a silicon wafer that can be handled even with double-side polishing apparatuses of the same size (hereinafter, sometimes referred to as a sun gear type double-side polishing apparatus).

[0006]

However, the conventional double-sided polishing method for a silicon wafer using the conventional sun gear-type double-sided polishing apparatus has the following problems. That is, in the double-sided wafer polishing method using the conventional apparatus, both the front and back surfaces of the silicon wafer are finished with the same polishing amount and have the same glossiness. Therefore, the polishing cloths spread on the upper surface plate and the lower surface plate are of the same kind and of the same material. By the way, most of the widely used polishing cloths are 3
It is roughly divided into two different material types. The first is a urethane foam type made of a urethane foam sheet, the second is a nonwoven fabric type in which a nonwoven fabric such as polyester is impregnated with urethane resin, and the third is a suede type.

As described above, in the conventional double-sided wafer polishing method, since the front and back surfaces of the silicon wafer are finished with the same polishing amount, for example, it is desired to reduce the glossiness of the back surface of the wafer and make this surface a satin finish. In case, we could not respond.

[0008]

It is an object of the present invention to selectively polish one side of a semiconductor wafer so that the front and back surfaces of the wafer can be polished in different amounts, and thus a semiconductor wafer having different glossinesses on both the front and back sides can be obtained. It is an object of the present invention to provide a method for polishing a semiconductor wafer using a polishing apparatus. Another object of the present invention is to provide a method for polishing a semiconductor wafer using a double-sided polishing apparatus capable of increasing the flatness of the mirror surface of the semiconductor wafer. Furthermore, the present invention can be applied to almost the entire front and back surfaces of a wafer.
It is an object of the present invention to provide a method for polishing a semiconductor wafer using a double-sided polishing apparatus that can uniformly polish over the entire surface.

[0009]

According to a first aspect of the present invention, a semiconductor wafer is inserted and held in a wafer holding hole formed in a carrier plate, and a polishing agent is supplied to the semiconductor wafer so as to be opposed to each other. Between a pair of polishing members, by moving the carrier plate in a plane parallel to the surface of the carrier plate, a semiconductor wafer using a double-side polishing apparatus capable of simultaneously polishing both front and back surfaces of the semiconductor wafer. In the polishing method, one of the polishing members is a fixed abrasive having fixed abrasive grains having a particle size of 0.1 to 3.0 μm, and the other polishing member is provided on a surface facing the fixed abrasive. This is a method for polishing a semiconductor wafer using a double-sided polishing device that changes the amount of polishing of the front and back surfaces of a semiconductor wafer by using a polishing platen having a polishing cloth stretched.

Examples of the semiconductor wafer include a silicon wafer and a gallium arsenide wafer. The size of the semiconductor wafer is not limited, and is 300 mm, for example.
A large diameter wafer such as a wafer may be used. The semiconductor wafer may have one surface coated with an oxide film. In this case, the bare wafer surface opposite to the oxide film of the semiconductor wafer may be selectively polished. The double-sided polishing apparatus is not limited to a sun gear-type double-sided polishing apparatus that does not incorporate a sun gear and simultaneously polishes both front and back surfaces of a semiconductor wafer by moving a carrier plate between a pair of polishing members.

The number of wafer holding holes formed in the carrier plate may be one (single wafer type) or plural. The size of the wafer holding hole is arbitrarily changed according to the size of the semiconductor wafer to be polished. The movement of the carrier plate may be movement in a plane parallel to the front surface (or back surface) of the carrier plate, and the direction of movement is not limited. For example, the silicon wafer held between the pair of polishing members as in claim 4 may be circular motion without rotation of the carrier plate such that the silicon wafer is swung in the corresponding wafer holding hole. Other,
A circular motion centered on the center line of the carrier plate, a circular motion at an eccentric position, or a linear motion may be used. In the case of this linear movement, it is possible to uniformly polish both the front and back surfaces of the wafer by rotating the pair of polishing members about their respective axes.

The type of abrasive used is not limited. For example, only an alkaline solution that does not contain loose abrasive grains may be used. Further, a slurry in which colloidal silica particles (polishing abrasive particles) having an average particle diameter of about 0.1 to 0.02 μm are dispersed in this alkaline liquid may be used. However, since a fixed abrasive is used for one of the polishing members, an alkaline solution containing no free abrasive is preferable. The supply amount of this abrasive varies depending on the size of the carrier plate and is not limited. Normally, 1.0-
2.0 liters / minute. The polishing agent can be supplied to the semiconductor wafer on the mirror surface side of the semiconductor wafer. It should be noted that this polishing agent is preferably supplied within the movement range of the wafer.

The rotation speed of each polishing member is not limited. For example, they may be rotated at the same speed or different speeds. Also, each rotation direction is not limited. That is, they may be rotated in the same direction or may be rotated in opposite directions. However, it is not always necessary to rotate the pair of polishing members simultaneously. This is because the present invention adopts a configuration in which the carrier plate is moved while pressing the respective polishing members on both the front and back surfaces of the semiconductor wafer. The pressing force of each polishing member against the semiconductor wafer is not limited. However, usually 150-
It is 250 g / cm ² .

The surface of the semiconductor wafer to be selectively polished is not limited. Also, the amount of polishing on both front and back surfaces of the wafer is not limited. However, for example, in the case of a single-sided mirror-finished wafer whose back surface is a matte surface, the polishing amount on the mirror surface (wafer surface) side is usually 5 to 20 μm, and the polishing amount on the matte surface side is 1 μm or less. In this way, by performing selective polishing in which one surface of the wafer is polished more than the other surface, the glossiness of the front and back surfaces of the wafer can be made different. Here, “different in glossiness” means that one surface of the wafer (usually the front surface of the wafer) has a higher glossiness than the other surface of the wafer (usually the back surface of the wafer). A known measuring device (for example, a measuring device manufactured by Nippon Denshoku Co., Ltd.) can be used for measuring the glossiness.

The type of fixed abrasive is not limited. For example, a polishing grindstone in which fixed abrasive grains are hardened into a predetermined shape with a binder, for example, a thick disk shape, or a fixed abrasive is fixed on the front surface and / or the back surface of the tape base material with the binder material A tape may be used, or a fine powder of silica, a fine powder of ceria and / or a fine powder of alumina may be formed into a predetermined shape and then fired. The fixed abrasive grain size is 0.1
Is about 3.0 μm . The type and material of the polishing cloth spread on the polishing platen are not limited. For example, a hard urethane foam pad and a soft non-woven fabric pad obtained by impregnating and curing a non-woven fabric with a urethane resin can be used. In addition, a pad made by foaming urethane resin on a non-woven fabric may be used.

The invention according to claim 2 is the method of polishing a semiconductor wafer using the double-sided polishing apparatus according to claim 1, wherein the polishing agent is an alkaline solution. This alkaline liquid does not contain loose abrasive grains. The type of alkaline solution is not limited. Examples thereof include NaOH, KOH, piperazine and the like. The pH of this alkaline solution is not limited. However, the pH is usually 9 to 11.

According to a third aspect of the present invention, the fixed abrasive grain is a polishing grindstone, and the polishing cloth is a soft non-woven fabric pad obtained by impregnating and curing a non-woven fabric with urethane resin. It is a method of polishing a semiconductor wafer using the double-sided polishing apparatus described.

According to a fourth aspect of the present invention, the movement of the carrier plate is a circular movement that does not accompany the rotation of the carrier plate. The double-side polishing apparatus according to any one of the first to third aspects. Is a method for polishing a semiconductor wafer. The circular motion without rotation referred to here is
This is a circular motion in which the carrier plate always keeps a state of being eccentric by a predetermined distance from the axes of the upper platen and the lower platen and rotates. By this circular motion without rotation, all points on the carrier plate draw a locus of a small circle of the same size.

[0019]

According to the present invention, the carrier plate is moved between the fixed abrasive and the polishing cloth in a plane parallel to the surface of the plate while supplying the polishing agent to the semiconductor wafer. As a result, both the front and back surfaces of the semiconductor wafer are polished by the fixed abrasive and the polishing cloth. At this time, either one of the fixed abrasive and the polishing cloth is used to selectively polish the one surface of the wafer, which increases the polishing amount of the one surface of the wafer. That is, there is a difference between the polishing amount of one surface of the wafer by the fixed abrasive and the polishing amount of the other surface of the wafer by the polishing cloth. As a result, it is possible to perform polishing with different glossinesses on the front and back surfaces of the wafer, using this non-sun gear type double-side polishing apparatus.

In particular, according to the second aspect of the invention, an alkaline liquid containing no abrasive grains is used as the polishing agent during double-side polishing. Thereby, the flatness of the mirror surface of the wafer can be increased.

According to the invention of claim 4, the semiconductor wafer is held between the fixed abrasive and the polishing platen, and the carrier plate is kept in this state and the carrier plate is not rotated around the circle. The wafer surface is polished by movement. With non-rotating circular motion, all points on the carrier plate have exactly the same motion. It can be said that this is a kind of rocking motion. That is, it can be considered that the locus of the swinging motion is a circle. Due to such movement of the carrier plate, the semiconductor wafer is polished while rotating in the wafer holding hole during polishing. Thereby, polishing can be performed uniformly over substantially the entire area of the wafer polishing surface. For example, polishing sag on the outer peripheral portion of the wafer can be reduced.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are for explaining one embodiment of the present invention. In one embodiment, polishing will be described by taking as an example the polishing in which the front surface of the silicon wafer that is arranged upward is a mirror surface and the back surface that is arranged downward is a matte surface during double-side polishing.

In FIGS. 1 and 2, reference numeral 10 denotes a double-side polishing apparatus (hereinafter referred to as a double-side polishing apparatus) to which the semiconductor wafer polishing method according to the embodiment is applied. This double-sided polishing apparatus 10 has a carrier plate 11 made of glass epoxy, which is disk-shaped in plan view, in which five wafer holding holes 11a are formed every 72 degrees around the plate axis (in the circumferential direction).
And a silicon wafer W having a diameter of 300 mm which is rotatably inserted and held in each wafer holding hole 11a,
The upper surface of the polishing roller (polishing stone) 12 polishes the wafer surface into a mirror surface by sandwiching it from above and below and moving it relative to the silicon wafer W, and slightly polishing the back surface of the silicon wafer W with a polishing cloth. It is provided with a polishing surface plate 13 arranged on the lower side to be a matte surface. As the silicon wafer W, one having one surface covered with a silicon oxide film may be adopted. Also, the carrier plate 1
The thickness of 1 is 600 μm, and the thickness of the silicon wafer W is 7
It is slightly thinner than 30 μm.

The polishing roller 12 is a fixed-abrasive body for mirror-polishing the surface of the wafer arranged upward. The fixed-abrasive grain is hardened into a disc shape through a bonding material. Specifically, the polishing roller 12 is mainly composed of a roller body made of epoxy resin and having a diameter of 300 mm and a thickness of 10 mm, and the entire exposed surface including the polishing surface is
It is a roller to which fine polishing abrasive particles (silica particles) having a particle diameter of 3 μm are fixed. The mixing amount of the abrasive grains with respect to the entire resin is set to 15 with respect to the synthetic resin 100 by volume ratio. To fix the abrasive grains on the polishing roller 12, a method of mixing the abrasive grains with a liquid room temperature curing epoxy resin and casting the mixture into a mold is adopted. On the other hand, on the upper surface of the polishing surface plate 13, a soft non-woven fabric pad 15 made by impregnating and curing urethane resin in a non-woven fabric for making the back surface of the wafer satin is spread. The hardness of the soft non-woven fabric pad 15 (“MH-15” manufactured by Rodel Co., Ltd.) is 80 ° (Asker) and the thickness is 1270 μm.

As shown in FIGS. 1 and 2, the polishing roller 12 is rotated in the horizontal plane by the upper rotation motor 16 via the rotating shaft 12a extending upward. Further, the polishing roller 12 is vertically moved up and down by an elevating device 18 which advances and retracts in the axial direction. The elevating device 18 is used when the silicon wafer W is supplied to and discharged from the carrier plate 11. The pressure applied to the front and back surfaces of the silicon wafer W by the polishing roller 12 and the polishing platen 13 is
It is carried out by a pressing means such as an air bag system (not shown) incorporated in the polishing roller 12 and the polishing platen 13.
The polishing platen 13 is rotated in the horizontal plane by the lower rotation motor 17 via the output shaft 17a. This carrier plate 11 is provided with a circular carrier movement mechanism 19 so that the plate 11 itself does not rotate.
It makes a circular motion in a plane (horizontal plane) parallel to the plane of 1. Next, the carrier circular motion mechanism 19 will be described in detail with reference to FIGS. 1, 2, and 4 to 6.

As shown in these drawings, the carrier circular movement mechanism 19 has an annular carrier holder 20 for holding the carrier plate 11 from the outside. These members 11 and 20 are connected via a connecting structure 21. The connection structure 21 is a means for connecting the carrier plate 11 to the carrier holder 20 so that the carrier plate 11 does not rotate on its own axis and the expansion of the plate 11 during thermal expansion can be absorbed. That is, the connecting structure 21 includes a large number of pins 23 projecting from the inner peripheral flange 20a of the carrier holder 20 at predetermined angles in the holder circumferential direction and the carrier plate 11.
And a plurality of elongated pin-shaped pin holes 11b formed at the positions corresponding to the respective pins 23 on the outer peripheral portion of the.

These pin holes 11b are connected to the carrier holder 20 via the pins 23, and the carrier plate 1
The hole length direction is aligned with the plate radial direction so that 1 can move slightly in the radial direction. By loosely inserting the pins 23 into the respective pin holes 11b and mounting the carrier plate 11 on the carrier holder 20, the expansion due to the thermal expansion of the carrier plate 11 during double-side polishing is absorbed. The base portion of each pin 23 is connected to the inner peripheral flange 20a through an external screw engraved on the outer peripheral surface of this portion.
It is screwed into the screw hole formed in. Further, the carrier plate 1 is provided directly above the outer screw at the base of each pin 23.
A flange 23a on which 1 is placed is provided around. Therefore, the height position of the carrier plate 11 mounted on the flange 23a can be adjusted by adjusting the screwing amount of the pin 23.

On the outer peripheral portion of the carrier holder 20, 9
Four bearing portions 20b are provided that project outward every 0 degree. An eccentric shaft 24a protruding from an upper surface of an eccentric arm 24 having a small-diameter disk shape is attached to each bearing portion 20b. In addition, four eccentric arms 24
A rotating shaft 24b is provided at the center of the lower surface of the corner. These rotary shafts 24b are attached to the annular device base 25 by
A total of four bearing portions 25a are provided at every 0 degree, with the tip portions thereof protruding downward. Each sprocket 26 is fixed to the tip of each rotating shaft 24b protruding downward. Then, a timing chain 27 is horizontally laid across each sprocket 26 in a horizontal state. The timing chain 27 may be changed to a power transmission system having a gear structure. These four sprockets 26 and the timing chain 27 constitute a synchronizing means for simultaneously rotating the four rotary shafts 24b so that the four eccentric arms 24 synchronously move circularly.

Further, among these four rotary shafts 24b, one rotary shaft 24b is formed to have a longer length, and its tip portion is projected downward from the sprocket 26. A gear 28 for power transmission is fixed to this portion. The gear 28 is meshed with a large-diameter drive gear 30 fixed to an output shaft extending upward of a circular motion motor 29 such as a geared motor. Even if the timing chain 27 is not used for synchronization in this manner, for example, the four eccentric arms 24 each have a circular motion motor 2
9 may be provided and each eccentric arm 24 may be rotated individually. However, it is necessary to synchronize the rotation of each motor 29.

Therefore, when the output shaft of the circular motion motor 29 is rotated, its rotational force is transmitted to the timing chain 27 via the gears 30, 28 and the sprocket 26 fixed to the long rotary shaft 24b, By the rotation of the timing chain 27, the four eccentric arms 24 are synchronized with each other via the other three sprockets 26 to rotate in the horizontal plane about the rotation shaft 24b. This allows
The carrier holders 20 collectively connected to the respective eccentric shafts 24a, and by extension, the carrier plate 11 held by the holders 20 make a circular motion without rotation in a horizontal plane parallel to the plate 11. That is, the carrier plate 11 includes the polishing roller 12 and the polishing platen 1.
The vehicle turns while maintaining a state of being eccentric from the axis a of 3 by a distance L. This distance L is the same as the distance between the eccentric shaft 24a and the rotary shaft 24b. Due to this circular motion without rotation, all points on the carrier plate 11 draw a locus of small circles of the same size.

Further, FIG. 6 shows the positions of the abrasive supply holes in this apparatus. For example, the plurality of abrasive supply holes formed in the polishing roller 12 are arranged in the annular region X having a predetermined width in which the silicon wafer W always exists. Even if the wafer W oscillates, the polishing agent is constantly supplied to the surface of the wafer W that is mirror-finished. For abrasives, p
H is adjusted to 10.5, and an alkaline solution containing aminoethylethanolamine as a main component is used. As a result, a thin film of the backside of the wafer W is held by the polishing agent during polishing.

Next, a method of polishing the silicon wafer W using the double-side polishing apparatus 10 will be described. First, the silicon wafer W is rotatably inserted into each wafer holding hole 11a of the carrier plate 11. At this time, the surface of each wafer faces upward. Then, in this state, the polishing roller 12 is pressed against the front surface of each wafer at 200 g / cm ² , and the soft non-woven fabric pad 15 is applied to the back surface of each wafer.
Is pressed at 200 g / cm ² . After that, these two members 12 and 15 are pressed against the front and back surfaces of the wafer,
The timing chain 27 is rotated by the circular motion motor 29 while supplying the polishing agent from the polishing roller 12 side. As a result, the eccentric arms 24 rotate synchronously in the horizontal plane, and the carrier holder 20 and the carrier plate 11 collectively connected to the eccentric shafts 24a are rotated along the horizontal plane parallel to the surface of the plate 11. Perform no circular motion at 15 rpm. As a result, the front and back surfaces of each of the silicon wafers W are polished while rotating in the horizontal plane within the corresponding wafer holding holes 11a.

Here, at the time of double-side polishing, the carrier plate 11 is subjected to a circular motion without rotation of the plate 11 to polish both front and back surfaces of the wafer. The special movement of the carrier plate 11 causes the silicon wafer W
Since both surfaces of the wafer are polished, it is possible to uniformly polish the entire surface of the front and back surfaces of the wafer. Then, as a pair of polishing members for polishing the front and back surfaces of the wafer in this way, a polishing roller 12 (for the front surface) and a polishing surface plate 13 (for the back surface) on which a polishing cloth is spread are adopted, and this double-side polishing is performed. Since this is performed, the wafer surface can be selectively polished, and the polishing amounts on the front and back surfaces of the wafer can be made different. Therefore, it is possible to obtain a semiconductor wafer having different glossinesses on the front and back surfaces of the wafer. It should be noted that the front and back surfaces of the wafer having different glossinesses as described above have achieved a predetermined flatness according to the glossiness.

The double-side polishing machine 10 of this embodiment
Even if the carrier plate 11 is not moved circularly, the upper rotation motor 16 moves the polishing roller 12 to, for example, 25 rp.
Each silicon wafer W can be polished on both sides only by rotating the polishing platen 13 at, for example, 10 rpm by the lower rotation motor 17 while rotating at m. In this case, since each silicon wafer W is rotatably inserted and held in the wafer holding hole 11a, during the polishing, each silicon wafer W is rotated along the rotation direction of the surface plate on the faster rotation speed side ( To rotate). By rotating the silicon wafer W as described above, it is possible to eliminate the influence that the peripheral speed increases toward the outer periphery of the wafer in polishing by the polishing roller 12 and the polishing platen 13.
As a result, the entire front and back surfaces of the wafer can be uniformly polished. In this way, the polishing roller 12
Even if double-side polishing is performed by making a difference in rotational speed between the polishing surface plate 13 and the polishing surface plate 13, using a sun gear type double-side polishing device,
A silicon wafer having a mirror-finished wafer front surface and a satin-finished wafer back surface can be obtained. Further, the polishing roller 12 and the polishing platen 13 may be rotated at the same rotation speed to manufacture a silicon wafer W having a mirror surface on the front surface and a matte surface on the back surface.

Further, the silicon wafer W may be polished on both sides by rotating the polishing roller 12 and the polishing platen 13 while circularly moving the carrier plate 11. In this case, it is preferable that the rotation speeds of the polishing roller 12 and the polishing platen 13 are slow enough to prevent uneven polishing on both front and back surfaces of the wafer. By doing so, both front and back surfaces of the silicon wafer W can be uniformly polished over the entire area of each surface. It is preferable that the polishing roller 12 and the polishing platen 13 are rotated so that the surface plate contacting with the silicon wafer W can be constantly refreshed and the polishing agent can be uniformly supplied to the entire surface of the silicon wafer W.

Here, actually, based on the double-side polishing apparatus 10 of the embodiment and the double-side polishing conditions thereof, when the silicon wafer W is double-side polished, the glossiness of the mirror-finished surface of the silicon wafer and the matte surface are obtained. Each glossiness of the back surface of the wafer was measured. As a result, the glossiness of the mirror-finished wafer surface was 330% or more with a measuring instrument manufactured by Nippon Denshoku Co., Ltd. On the other hand, that on the backside of the wafer is 200 to 30
It was 0%.

[0037]

According to the present invention, as the pair of polishing members incorporated in the double-sided polishing device, the polishing roller and the polishing platen on which the polishing cloth is spread are adopted. One surface of the wafer can be selectively polished to make the polishing amounts on the front and back surfaces of the wafer different. This makes it possible to obtain semiconductor wafers having different glossinesses on the front and back surfaces.

In particular, according to the second aspect of the invention, since the alkaline liquid containing no abrasive grains is used as the polishing agent, the flatness of the mirror surface of the semiconductor wafer can be increased.

Further, according to the invention of claim 4, the semiconductor wafer is polished by circularly moving the carrier plate without rotation of the plate. Therefore, the semiconductor wafer is uniformly polished over substantially the entire front and back surfaces of the wafer. It can be performed.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a double-side polishing machine according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view during double-side polishing of a semiconductor wafer polishing method using a double-side polishing apparatus according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a state during polishing in the method for polishing a semiconductor wafer according to an embodiment of the present invention.

FIG. 4 is a schematic plan view of a double-side polishing machine according to an embodiment of the present invention.

FIG. 5 is an enlarged sectional view of an essential part of a kinetic force transmission system that transmits kinetic force to a carrier plate according to an embodiment of the present invention.

FIG. 6 is a plan view showing the positions of abrasive supply holes according to an embodiment of the present invention.

[Explanation of symbols]

10 Double side polishing machine, 11 carrier plate, 11a wafer holding hole, 12 polishing rollers, 12a rotation axis, 13 polishing surface plate, 15 soft non-woven pad, W Silicon wafer (semiconductor wafer).

Claims (4)

(57) [Claims] 1. A semiconductor wafer is inserted and held in a wafer holding hole formed in a carrier plate, and an abrasive is supplied to the semiconductor wafer, while a pair of polishing members opposed to each other are provided between the pair of polishing members opposed to each other. surface and the carrier plate exercised in a plane parallel to a polishing method of a semiconductor wafer using the double-side polishing apparatus capable of polishing both the front and back surfaces of the semiconductor wafer at the same time, one of the polishing member 0 Fixing particle size of 1 to 3.0 μm
A fixed abrasive having abrasive grains, that the other of the polishing pad the polishing member on a surface opposed to the fixed abrasive material and abrasive platen stretched, different polishing amount of the front and back surfaces of a semiconductor wafer Polishing method for semiconductor wafers using a double-sided polishing device. 2. The polishing agent is an alkaline solution.
A method for polishing a semiconductor wafer using the double-sided polishing apparatus according to item 1. 3. The double-sided polishing apparatus according to claim 1 or 2, wherein the fixed abrasive is a polishing grindstone, and the polishing cloth is a soft nonwoven fabric pad obtained by impregnating and curing a nonwoven fabric with urethane resin. Method for polishing semiconductor wafers. 4. The movement of the carrier plate is a circular movement without rotation of the carrier plate.
~ A method of polishing a semiconductor wafer using the double-sided polishing apparatus according to claim 3.