CN115707558A - Wafer polishing apparatus and wafer polishing method - Google Patents

Abstract

The invention provides a wafer polishing apparatus and a wafer polishing method suitable for polishing a wafer. The wafer polishing device comprises a polishing carrier disc, a rotary table, a database, an input unit and a control unit. The polishing carrier disk is adapted to hold a wafer. The turntable is disposed corresponding to the polishing carrier. The turntable is adapted to have a polishing pad placed thereon such that the polishing pad is adapted to face the wafer. The control unit is connected with the polishing carrier disc, the rotary table, the database and the input unit. The database stores an array of polishing parameters. The polishing parameter array includes a first rotational speed corresponding to the polishing carrier, a second rotational speed corresponding to the turntable, and wafer polishing data. The first rotation speed is N1 rpm. The second rotational speed is N2 revolutions per minute, wherein: 30 ≦ N1 ≦ 75 or 10 ≦ N2 ≦ 60; and N1/N2= Q1, N2/N1= Q2, neither Q1 nor Q2 being a natural number.

Description

Wafer polishing apparatus and wafer polishing method

Technical Field

The present disclosure relates to polishing apparatuses and methods, and particularly to a polishing apparatus and a polishing method for a wafer having a corresponding relationship between rotational speeds.

Background

Generally, the scratches that may be encountered in wafer polishing (wafer polishing) are mostly optimally adjusted by the formulation of the polishing solution, the removal amount of the polishing solution, the selection of the abrasive particles and/or the polishing pad. However, the above approaches are mostly biased toward hardware adjustment. Therefore, whether there are other ways to improve the quality of wafer polishing has become a challenge to be studied.

Disclosure of Invention

The invention is directed to a wafer polishing apparatus or a wafer polishing method, which can make a polished wafer have a better quality.

According to an embodiment of the present invention, a wafer polishing apparatus is adapted to polish a wafer (wafer). The wafer polishing device comprises a polishing carrier disc, a rotary table, a database, an input unit and a control unit. The polishing carrier disk is adapted to hold a wafer. The turntable is arranged corresponding to the polishing carrier disc. The turntable is adapted to have a polishing pad placed thereon such that a disk surface of the polishing pad is adapted to face the wafer. The control unit is connected with the polishing carrier disc, the rotary table, the database and the input unit through signals. The database stores at least one array of polishing parameters. The polishing parameter array comprises a first rotating speed corresponding to the polishing carrier disc, a second rotating speed corresponding to the rotary table and chip polishing data corresponding to the first rotating speed and the second rotating speed. The first rotation speed is N1 rpm. The second speed is N2 rpm. The first rotational speed or the second rotational speed has the following relationship: 30 ≦ (less than or equal to) N1 ≦ (less than or equal to) 75 or 10 ≦ (less than or equal to) N2 ≦ (less than or equal to) 60; and N1/N2= Q1, N2/N1= Q2, neither Q1 nor Q2 being a natural number.

According to an embodiment of the present invention, the chip polishing data includes one or a combination of the following: the polishing carrier disc is arranged on the polishing pad, and the first rotating speed of the polishing carrier disc corresponds to the second rotating speed of the polishing pad; the estimated processing time corresponding to the first rotating speed of the polishing carrier disc and the second rotating speed of the polishing pad; or the area repetition rate corresponding to the first rotating speed of the polishing carrier disc and the second rotating speed of the polishing pad is as follows: the ratio of the area of the trace where the individual wafer contacts the polishing pad to the area of the path of the individual wafer during the polishing cycle time.

According to an embodiment of the present invention, the input unit is adapted to be inputted with at least one set of input parameters, and the input parameters include: the diameter of the wafer; the size of the face of the polishing pad; the thickness of the wafer; and an expected polishing amount by which the wafer is polished.

According to an embodiment of the present invention, the database stores a plurality of sets of polishing parameter arrays, and the control unit is adapted to compare the input parameters with the plurality of sets of polishing parameter arrays in the database to polish the wafer.

According to an embodiment of the invention, the first rotational speed or the second rotational speed further has the following relationship: at least one of Q1 or Q2 is a finite or infinite decimal number of 3 or more bits.

According to an embodiment of the invention, the first rotational speed or the second rotational speed further has the following relationship: the greatest common factor of N1 and N2 is greater than or equal to 5.

According to one embodiment of the present invention, the wafer polishing data comprises an area repetition rate corresponding to a first rotational speed of the polishing carrier and a second rotational speed of the polishing pad, and the area repetition rate is less than or equal to 40%, wherein the area repetition rate is: the ratio of the area of the trace where the individual wafer contacts the polishing pad to the area of the path of the individual wafer during the polishing cycle time.

According to an embodiment of the present invention, a wafer polishing method includes the steps of: providing a wafer polishing apparatus comprising: the polishing carrier disc and the rotary table are arranged corresponding to the polishing carrier disc; placing the wafer on a polishing carrier disc, placing a polishing pad on a turntable with the disc surface of the polishing pad facing the wafer; and rotating the polishing carrier disc in a first direction and the turntable in a second direction to polish the wafer held on the polishing carrier disc with the polishing pad, wherein: the polishing carrier disc has a first rotating speed, and the first rotating speed is N1 r/min; the rotary table has a second rotating speed which is N2 revolutions per minute; and the first rotational speed or the second rotational speed has the following relationship: 30 ≦ (less than or equal to) N1 ≦ (less than or equal to) 75 or 10 ≦ (less than or equal to) N2 ≦ (less than or equal to) 60; and N1/N2= Q1, N2/N1= Q2, neither Q1 nor Q2 being a natural number.

According to an embodiment of the present invention, the chip polishing apparatus further includes an input unit and a database, wherein the database stores wafer polishing data corresponding to a first rotational speed of the polishing carrier and a second rotational speed of the turntable, and the wafer polishing method further includes the steps of: inputting the polishing specification of the wafer by the input unit; and comparing the polishing specification with the wafer polishing data in the database to estimate a first rotating speed of the polishing carrier plate and a second rotating speed of the polishing pad.

According to an embodiment of the invention, the first rotational speed or the second rotational speed further has the following relationship: at least one of Q1 or Q2 is a finite decimal or an infinite decimal of 3 or more bits; the first rotational speed or the second rotational speed further has the following relationship: the greatest common factor of N1 and N2 is less than or equal to 5; and/or the wafer polishing data comprises an area repetition rate corresponding to the first rotating speed of the polishing carrier disc and the second rotating speed of the polishing pad, and the area repetition rate is less than or equal to 40 percent, wherein the area repetition rate is as follows: the ratio of the area of the trace where the individual wafer contacts the polishing pad to the area of the path of the individual wafer during the polishing cycle time.

Based on the above, the present invention can make the wafer polishing apparatus or the wafer polishing method have a better quality of the polished wafer by at least the relationship between the first rotation speed and the second rotation speed.

Drawings

FIG. 1A is a partial perspective view of a wafer being polished by a wafer polishing apparatus according to an embodiment of the present invention;

FIG. 1B is a table of values according to an embodiment of the present invention;

FIG. 1C is a table of values according to an embodiment of the present invention;

fig. 2A to 2D are diagrams of relative movement trajectories of the respective test examples.

Description of the reference numerals

100: a wafer polishing device;

110: polishing the carrier disc;

100a: a bearing surface;

111: an actuator;

d1: a first direction;

910: a wafer;

120: a turntable;

920: a polishing pad;

920a: a dish surface;

121: an actuator;

d2: a second direction;

130: a control unit;

140: a database;

150: an input unit;

160: a polishing liquid supply unit;

162: a liquid valve;

169: polishing solution;

171. 172, 174, 175, 176: and a signal line.

Detailed Description

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Referring to fig. 1A, the wafer polishing apparatus 100 includes a polishing carrier 110, a turntable 120, a database 140, an input unit 150, and a control unit 130. The wafer polishing apparatus 100 is adapted to polish the wafer 910 (i.e., polish the wafer 910). The polishing carrier plate 110 is adapted to hold a wafer 910. The turntable 120 is disposed corresponding to the polishing carrier plate 110. The turntable 120 is adapted to have a polishing pad 920 placed thereon (here: the turntable 120). At least when wafer 910 is polished, disk surface 920a of polishing pad 920 is adapted to face wafer 910.

In the present embodiment, the wafer polishing apparatus 100 may further include a polishing liquid supply unit 160. The polishing liquid supply unit 160 may include a corresponding liquid valve 162. The liquid valve 162 may control the supply amount and/or flow rate of the polishing liquid 169.

In the present embodiment, the control unit 130 may be signal-connected to at least one of the polishing carrier 110, the turntable 120, the database 140, the input unit 150, and/or the polishing solution supply unit 160 by wired signal transmission (wired signal transmission) via the signal lines 171, 172, 174, 175, 176, but the present invention is not limited thereto. In one embodiment, the control unit 130 may be in signal communication with at least one of the polishing carrier plate 110, the turntable 120, the database 140, the input unit 150 and/or the polishing liquid supply unit 160 by wireless signal transmission. In other words, the signal connection mentioned in the present invention can be generally referred to as a connection manner of wired signal transmission or wireless signal transmission. In addition, the present invention does not limit all signal connection modes to be the same or different.

In one embodiment, the polishing platen 110 may include an actuator (activator) 111. The control unit 130 may be signally connected to the actuator 111 of the polishing carrier disk 110 to cause the entire or a portion of the polishing carrier disk 110 to move and/or rotate in a corresponding direction. In an embodiment, the actuator 111 may include a power supply, a motor, a belt, a gear, and other related components, and the invention is not limited thereto. The related components include, for example, a communication component, a power component, a damping component, a positioning component or a sensing component, etc., but the invention is not limited thereto.

In one embodiment, the polishing pad 920 may be placed on or secured to the turntable 120. The turntable 120 may include an actuator 121. The control unit 130 may be in signal connection with the actuator 121 of the turntable 120 to drive the turntable 120 or the polishing pad 920 on the turntable 120 to rotate in a corresponding direction. In one embodiment, the actuator 121 of the turntable 120 may be the same as or similar to the actuator 111 of the polishing blade 110, but the invention is not limited thereto.

In the present embodiment, the control unit 130 may include corresponding hardware or software. For example, the Control unit 130 includes a computer, a calculator, a corresponding calculation program, a corresponding logic judgment program, or a platform (platform) suitable for performing Advanced Process Control (APC), but the invention is not limited thereto.

In the embodiment, the input unit 150 is, for example, a mouse, a keyboard or a touch panel, but the invention is not limited thereto. In an embodiment, the input unit 150 may include a virtual entity of the input unit 150. For example, the input unit 150 may include a signal receiving component (e.g., a communication chip, a communication antenna and/or a communication port), and the parameter or command may be transmitted to the control unit 130 via the input unit 150 via a remote control (remote control).

In this embodiment, the database 140 includes, for example, a memory capable of storing related data, a hard disk, a disk array, yun Duanji, and/or other electronic components or devices capable of temporarily or permanently storing data. The aforementioned related data may include at least one set of polishing parameter arrays (parameter arrays). The polishing parameter array will be described in detail later.

In the present embodiment, a method of polishing the wafer 910 by the wafer polishing apparatus 100 is exemplified as follows. The following steps are carried out in an unlimited order: placing or securing the polishing pad 920 on the turntable 120; and the wafer 910 is placed on the supporting surface 100a of the polishing platen 110, and the wafer 910 is fixed by the polishing platen 110. Then, the following steps are performed in an unlimited order: bringing the disk surface 920a of the polishing pad 920 into face-to-face relation with the wafer 910 on the polishing carrier 110, so that the wafer 910 on the polishing carrier 110 is in contact with the polishing pad 920; rotating the polishing platen 110 and/or the wafer 910 positioned thereon in a first direction D1; and the turntable 120 or the polishing pad 920 corresponding thereto is rotated in the second direction D2.

In this embodiment, the first direction D1 of rotation of the polishing carrier plate 110/wafer 910 may be opposite to the second direction D2 of rotation of the turntable 120/polishing pad 920. For example, one of the first direction D1 and the second direction D2 may be a clockwise direction, and the other of the first direction D1 and the second direction D2 may be a counterclockwise direction.

In this embodiment, the control unit 130 can make the polishing carrier plate 110 and/or the wafer 910 on the polishing carrier plate 110 have a corresponding first rotation speed and make the turntable 120 or the polishing pad 920 corresponding to the turntable 120 have a corresponding second rotation speed according to the polishing parameter array in the database 140.

Referring to fig. 1A and 1B, the polishing parameter array includes a first rotation speed corresponding to the polishing carrier 110/wafer 910, a second rotation speed corresponding to the turntable 120/polishing pad 920, and wafer polishing data corresponding to the first rotation speed and the second rotation speed. The first rotation speed is N1 rpm, the second rotation speed is N2 rpm, and the first rotation speed or the second rotation speed has the following relationship: (1) 30 ≦ N1 ≦ 75 or 10 ≦ N2 ≦ 60; and (2) N1/N2= Q1, N2/N1= Q2, wherein Q1 and Q2 are both not natural numbers (natural numbers).

A set of polishing parameter arrays may include a corresponding first rotational speed, a corresponding second rotational speed, and corresponding wafer polishing data. Taking FIG. 1B as an example, the database may store multiple sets (e.g., i sets) of polishing parameter arrays. By analogy, in fig. 1B, the numerical value corresponding to the 1 st group is represented by (1), (2) and (i) respectively.

In one embodiment, 30 ≦ N1 ≦ 75 and/or 10 ≦ N2 ≦ 60 is better for the tool setup range of the wafer polishing apparatus 100 and/or is easier to implement.

In one embodiment, the polishing quality of the wafer 910 (e.g., but not limited to, reducing the polishing scratch) can be improved by the relationship between the first rotation speed and the second rotation speed.

In an embodiment, the first rotational speed or the second rotational speed may further have the following relationship: at least one of Q1 or Q2 is a finite decimal (decimal) with a fractional digits (fractional places) of at least 3 bits; or, may be referred to as: a finite decimal number of 3 or more. That is, in Q1 or Q2, at least after the decimal point (after the decimal point), the value of the mth digit is not 0 (i.e., can be any natural number between 1 and 9), where the value of M is a natural number greater than or equal to 3.

In an embodiment, the first rotational speed or the second rotational speed may further have the following relationship: q1 or Q2 is an infinite decimal (infinite decimal).

In an embodiment, the first rotational speed or the second rotational speed may further have the following relationship: if N1 and N2 are integers, the maximum common factor (grease common factor/highest common factor) of N1 and N2 is less than or equal to 5.

In this embodiment, the wafer polishing data may include a polishing fluid flow corresponding to the first rotation speed and/or the second rotation speed.

In this embodiment, the wafer polishing data may include a predicted processing time corresponding to the first rotational speed and/or the second rotational speed.

In this embodiment, the wafer polishing data may include an area repetition rate corresponding to the first rotation speed and/or the second rotation speed.

In one embodiment, the wafer polishing data may include at least one of the slurry flow rate, the estimated process time, and the area repetition rate, or a combination thereof.

In an embodiment, the wafer polishing data may further include a polishing amount. In one embodiment, the polishing amount may be related to the first rotation speed, the second rotation speed, and the expected processing time and polishing liquid flow rate corresponding to the first rotation speed and the second rotation speed. Thus, wafer polishing data may be obtained or derived from prior actual experimental or process data (e.g., by interpolation or extrapolation from existing data).

In one embodiment, the ratio of the track area of the single wafer 910 in contact with the polishing pad 920 to the travel area of the single wafer 910 during the polishing cycle time may be an area repetition rate, and the area repetition rate is less than or equal to 40%. The area repetition rate is described in detail later.

For example, since the single wafer 910 has a certain area, when the single wafer 910 and the polishing pad 920 have relative movement, the area where the single wafer 910 contacts the polishing pad 920 during the movement can be defined as a corresponding area. And the aforementioned area can be expressed as "contact trace area".

Illustratively, if (i.e., one of the assumed states) the movement path of the wafer 910 relative to the polishing pad 920 is a simple straight line, the "contact path area" is substantially: the path of a point on wafer 910 (e.g., a specific point on the center or edge) is multiplied by the area of the wafer. That is, under the above-mentioned assumed condition, the above-mentioned product is approximately the maximum value of the "contact track area". It can also be said that, under the aforementioned assumption state, it can be said that the polished area is not repeated at all.

As another example, if (i.e., one of the assumed states) the wafer 910 has a corresponding rotation speed in one direction (e.g., a first rotation speed in the first direction D1) and the polishing pad 920 has a corresponding rotation speed in another direction (e.g., a second rotation speed in the second direction D2), so that there is a relative movement and/or rotation between the wafer 910 and the polishing pad 920, the movement track distribution of the wafer 910 relative to the polishing pad 920 may be dense or complex due to the difference between the first rotation speed and the second rotation speed. That is, a region of polishing pad 920 may be in contact with wafer 910 at a first time, then the region may not be in contact with wafer 910 at a second time after the first time, and then the region may be in contact with wafer 910 again at a third time after the second time. Briefly, the areas of wafer 910 in contact with polishing pad 920 may overlap (including partially overlapping or completely overlapping) between different times. Thus, after wafer 910 completes a cycle of orbital movement of polishing pad 920, the following calculations can be performed: "contact footprint area"/(circle center path x wafer area), the area repetition rate during polishing of wafer 910 can be estimated.

If (i.e., one of the hypothetical states) the area repetition rate is higher, it may indicate that the pad 920 is worn out more in a particular area. Thus, if (i.e., one of the hypothetical states) the "contact footprint area" is closer to the area of the polishing pad 920 (e.g., which can be expressed as a near 100% utilization of the polishing pad 920) and the area repetition rate is lower (e.g., which can be expressed as a non-repeating contact area), then the wear and/or usage of the polishing pad 920 can be considered to be more uniform.

In one embodiment, the first rotation speed, the second rotation speed and the corresponding rotation direction can simulate or estimate the corresponding track and/or "contact track area" of the wafer 910 in contact with the polishing pad 920. For example, the trajectory, "contact trajectory area" and/or the corresponding area repetition rate for wafer 910 in contact with polishing pad 920 may be simulated or estimated by coordinating, formulating, digitizing and/or other suitable means. It should be noted that the present invention is not limited to the simulation or estimation of the area repetition rate.

In the present embodiment, the input unit 150 is adapted to input at least one set of input parameters. As shown in fig. 1C, the input parameters may include a diameter of wafer 910, a size of a disk 920a of polishing pad 920, a thickness of wafer 910, an expected amount of polishing to be performed on wafer 910, and/or other polishing specifications to be performed on wafer 910.

In one embodiment, control unit 130 is adapted to compare the input parameters to one or more sets of polishing parameter arrays in database 140 to polish wafer 910.

For example, the polishing amount history data in the wafer polishing data may be used to output the polishing solution flow rate and/or the processing time corresponding to the first and second rotation speeds, and compare the output with the input parameters, so that the control unit 130 may determine or select the parameter range suitable for polishing.

It is to be noted that the numerical values mentioned above are reasonably well scaled up or down or slightly varied or adjusted according to actual machine conditions and still be within the equivalent scope of the reasonable explanation of the present invention, as understood by those skilled in the art. For example, if a rotation speed parameter is 3600 rpm or 1 rpm, an equivalent range of 60 rpm may still be used. For example, if a rotation speed parameter is 3601 rpm, 3605 rpm or 3610 rpm, but the rotation speed parameter is compared with the rotation speed parameter of 60 rpm, if the same function is achieved in the same manner to produce the same effect, the rotation speed parameter may still be in the equal range of 60 rpm.

The following description will be made by taking test examples of a relative movement locus diagram (simply referred to as a relative movement locus diagram) of a point on the edge of a wafer on the surface of a polishing pad under the condition that the rotation direction of a polishing carrier/wafer is opposite to the rotation direction of a turntable/polishing pad and under the condition of a corresponding first rotation speed and a corresponding second rotation speed. And, in the relative movement locus diagrams of fig. 2A to 2D, a thick solid black line (having a substantially circular profile) is a range of the disk surface of the polishing pad, one black point (substantially at the center of the circular thick solid black line) in the thick solid black line is the center of the disk surface of the polishing pad, a thin solid black line (having a substantially circular profile) in the thick solid black line is a range of the carrying surface of the polishing carrier disk in an initial state (i.e., at the start of polishing), one black point (substantially at the center of the circular thin solid black line) in the thin solid black line is the center of the carrying surface of the polishing carrier disk in the initial state, a thin solid black line (having a substantially circular profile) in the thin solid black line is a range of the wafer in the initial state, one thin solid black line (substantially at the center of the circular thin solid black line) in the initial state, and a dense point of the wafer edge is a relative movement locus of a point on the disk surface of the polishing pad in the initial state, wherein the aforementioned "one point of the wafer edge" is a point of the carrying surface closest to the edge of the wafer in the initial state. However, these test examples are not to be construed in any way as limiting the scope of the present invention.

In the description of the subsequent test examples, for clarity, the first rotation speed may be represented by N1, the second rotation speed may be represented by N2, the first rotation speed/the second rotation speed may be represented by Q1, and the second rotation speed/the first rotation speed may be represented by Q2. It should be understood that the values of N1, N2, Q1 and/or Q2 may be different for different test cases. In addition, when further calculating and/or comparing Q1 and Q2 (e.g., calculating a quotient, a maximum common factor, or other possible derivative value of each other), the first and second rotational speeds are first converted to the same unit for subsequent numerical calculation.

Fig. 2A is a diagram of the relative movement locus of [ test example 1A ]. Fig. 2B is a diagram of the relative movement locus of [ test example 1B ]. Fig. 2C is a diagram showing the relative movement locus of [ test example 1C ]. Fig. 2D is a diagram showing a relative movement locus of [ test example 1D ].

Test examples 1A to 1D were conducted in a state where the rotation direction of the polishing carrier/wafer was opposite to the rotation direction of the turntable/polishing pad, and the wafer was polished at different first and second rotation speeds. The first rotational speed and the second rotational speed corresponding to test examples 1A to 1D and the corresponding relationship are shown in table 1. And, the results of the single wafer of each test example after polishing the wafer under the conditions described by [ table 1] are shown in [ table 2 ].

[ Table 1]

[ Table 2]

Test example	Single chip area repetition rate	Period (seconds)	Defective rate of scratch
				1A	About 11%	Short (about 6.02)	About 9.5％
1B	About 38 percent	Middle (about 60.1)	About 1.3%
				1C	About 95%	Long (about 120)	About 13.2%
1D	About 72 percent	Partial length (about 80)	About 8.4%

As shown in [ table 1], [ table 2] and fig. 2A, in [ test example 1A ], the corresponding Q1 and Q2 are finite decimals of not more than 2 bits (inclusive). And, the greatest common factor of N1 and N2 is 10. Thus, although the area repetition rate may be low, the travel time of one cycle is short. As a result, polishing processes may be performed on the repeated paths within a unit time, which may cause uneven polishing pad usage and correspondingly increase the scratch rate of the polished wafer. That is, if the condition "at least one of Q1 or Q2 is a decimal with a decimal number of at least 3 bits" is not satisfied, the scratch ratio may be higher due to too short cycle.

As shown in [ table 1], [ table 2] and fig. 2B, in [ test example 1B ], Q1 and Q2 corresponding thereto are both infinite decimal numbers. And the greatest common factor of N1 and N2 is 5. Therefore, although the area repetition rate was higher than that of test example 1A, since the travel path per cycle was long, the number of times the same path was repeated per unit time was low, and the polishing pad could be used relatively uniformly. Therefore, the scratching rate of the polished wafer can be correspondingly reduced. That is, in [ test example 1B ], it satisfies that "at least one of Q1 or Q2 is a finite or infinite decimal whose decimal number is at least 3 bits; and, the condition that the greatest common factor of N1 and N2 is greater than or equal to 5", therefore, the cycle and/or the single-chip area repetition rate can be moderate, and the scratch ratio can be the lowest (compare in [ test example 1A ] - [ test example 1D ]).

As shown in [ table 1], [ table 2] and fig. 2C, in [ test example 1C ], both of Q1 and Q2 correspond to an infinite decimal number. And, the greatest common factor for N1 and N2 is 1 (i.e., N1 and N2 are relatively prime). In addition, the cycle time for which wafer polishing is performed is longest (comparison is made in [ test example 1A ] - [ test example 1D ]), and therefore, the number of times the same path is repeated per unit time may also be lowest (comparison is made in [ test example 1A ] - [ test example 1D ]). However, although the paths are not repeated or the repetition rate is low, the area repetition rate may be greatly increased due to the high density of the paths, which may result in polishing the wafer in the repeated region and increase the scratch rate (compare test 1A to test 1D). That is, in [ test example 1C ], it does not satisfy that "at least one of Q1 or Q2 is a finite or infinite decimal having a decimal number of at least 3 bits; and, a maximum common factor greater than or equal to 5 ". Under the condition that the condition is not met, the single-chip area repetition rate may be larger, and the scratch proportion may also be higher.

As shown in [ table 1], [ table 2] and fig. 2D, in [ test example 1D ], both of Q1 and Q2 correspond to infinite decimal numbers. And, the greatest common factor of N1 and N2 is 2. Therefore, the row path of [ test example 1D ] in one cycle may be longer than that of [ test example 1B ], so that the number of times of repeating the same path per unit time can be relatively reduced. However, the density of the paths may be increased, which may result in a high area repetition rate. As a result, the wafer may be polished in the overlapped region, and the scratch rate may be increased (as compared with test examples 1A, 1B, and 1D). That is, in [ test example 1D ], it is satisfied that "at least one of Q1 or Q2 is a finite fraction or a cyclic fraction of which the fractional number is at least 3 bits; and, a maximum common factor of less than 5 ". Under the condition that the condition is not met, the single-chip area repetition rate may be higher, and the scratching proportion may also be higher.

In summary, the present invention at least utilizes the relative relationship between the first rotation speed and the second rotation speed in the wafer polishing apparatus or the wafer polishing method to maximize the cycle time of the path as much as possible, and minimize the area repetition rate of the single wafer as much as possible, so that the polished wafer has better quality.

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.

Claims (10)

1. A wafer polishing apparatus, adapted to polish a wafer, comprising:

a polishing carrier disk adapted to hold the wafer;

a turntable disposed corresponding to the polishing carrier and adapted to have a polishing pad placed thereon such that a disk surface of the polishing pad is adapted to face the wafer;

a database;

an input unit; and

the control unit is in signal connection with the polishing carrier disc, the rotary table, the database and the input unit, wherein the database stores at least one group of polishing parameter arrays, and the polishing parameter arrays comprise:

a first rotational speed corresponding to the polishing carrier disc;

a second rotational speed corresponding to the turntable; and

wafer polishing data corresponding to the first rotation speed and the second rotation speed, wherein the first rotation speed is N1 rpm, the second rotation speed is N2 rpm, and the first rotation speed or the second rotation speed has the following relationship:

30 ≦ N1 ≦ 75 or 10 ≦ N2 ≦ 60; and is

N1/N2= Q1, N2/N1= Q2, and neither Q1 nor Q2 is a natural number.

2. The wafer polishing apparatus as set forth in claim 1 wherein the wafer polishing data comprises one or a combination of:

the polishing carrier disc is arranged between the polishing carrier disc and the polishing pad, and the first rotating speed of the polishing carrier disc and the second rotating speed of the polishing pad correspond to the flow of polishing liquid;

the estimated processing time corresponding to the first rotating speed of the polishing carrier disc and the second rotating speed of the polishing pad; or

An area repetition rate corresponding to the first rotational speed of the polishing platen and the second rotational speed of the polishing pad, wherein the area repetition rate is: a ratio of an area of a trace where a single wafer contacts the polishing pad to an area of a track where the single wafer travels during the polishing cycle time.

3. The wafer polishing apparatus as set forth in claim 1 wherein the input unit is adapted to be inputted with at least one set of input parameters, and the input parameters include:

a diameter of the wafer;

the dimensions of the disk face of the polishing pad;

a thickness of the wafer; and

an expected polishing amount by which the wafer is polished.

4. A wafer polishing apparatus as set forth in claim 3 wherein the database stores a plurality of sets of the polishing parameter arrays and the control unit is adapted to compare the input parameters with the plurality of sets of the polishing parameter arrays in the database to polish the wafer.

5. The wafer polishing apparatus as set forth in claim 1 wherein the first rotational speed or the second rotational speed further has the following relationship:

at least one of Q1 or Q2 is a finite or infinite decimal number of 3 or more bits.

6. The wafer polishing apparatus as set forth in claim 1 wherein the first rotational speed or the second rotational speed further has the following relationship:

the greatest common factor of N1 and N2 is greater than or equal to 5.

7. The wafer polishing apparatus as set forth in claim 1 wherein the wafer polishing data comprises an area repetition rate corresponding to the first rotational speed of the polishing carrier and the second rotational speed of the polishing pad, and the area repetition rate is less than or equal to 40%, wherein the area repetition rate is: a ratio of an area of a trace where a single wafer contacts the polishing pad to an area of a track where the single wafer travels during the polishing cycle time.

8. A method of polishing a wafer, comprising:

providing a wafer polishing apparatus comprising:

polishing the carrier disc; and

the rotary table is arranged corresponding to the polishing carrier disc;

placing a wafer on the polishing carrier disc, placing a polishing pad on the turntable with a disc surface of the polishing pad facing the wafer; and

rotating the polishing carrier disc in a first direction and the turntable in a second direction to polish the wafer held on the polishing carrier disc with the polishing pad, wherein:

the polishing carrier disc has a first rotational speed, the first rotational speed being N1 revolutions per minute (rpm);

the turntable has a second rotating speed which is N2 revolutions per minute; and is

The first rotational speed or the second rotational speed has the following relationship:

30 ≦ N1 ≦ 75 or 10 ≦ N2 ≦ 60; and is

N1/N2= Q1, N2/N1= Q2, neither Q1 nor Q2 being a natural number.

9. The wafer polishing method as set forth in claim 8 wherein the wafer polishing apparatus further comprises an input unit and a database, wherein the database stores wafer polishing data corresponding to the first rotational speed of the polishing carrier and the second rotational speed of the turntable, and the wafer polishing method further comprises:

inputting a polishing specification for the wafer by means of the input unit; and

and comparing the polishing specification with the wafer polishing data in the database to estimate the first rotating speed of the polishing carrier disc and the second rotating speed of the polishing pad.

10. The wafer polishing method as set forth in claim 8 wherein:

the first rotational speed or the second rotational speed further has the following relationship: at least one of Q1 or Q2 is a finite decimal or an infinite decimal of 3 or more bits;

the first rotational speed or the second rotational speed further has the following relationship: the greatest common factor of N1 and N2 is less than or equal to 5; and/or

The wafer polishing data comprises an area repetition rate corresponding to the first rotational speed of the polishing carrier and the second rotational speed of the polishing pad, and the area repetition rate is less than or equal to 40%, wherein the area repetition rate is: a ratio of an area of a trace where a single wafer contacts the polishing pad to an area of a track where the single wafer travels during the polishing cycle time.

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