A method and system for monitoring a flying piece of a polishing machine and a polishing machine

Abstract

The application relates to the polishing technical field, in particular to a flying piece monitoring method of a polishing machine, which comprises the following steps: establishing a function model of a first distance value detected downward by a distance sensor before polishing starts, a second distance value detected downward by the distance sensor in a polishing process and a deviation value; confirming the deviation value based on the first distance value detected downward by the distance sensor before polishing starts, the second distance value detected downward by the distance sensor in the polishing process and the function model collected by each distance sensor; and judging a polishing state based on the deviation value. The polishing technical problem of frequent polishing shutdown is solved, and the technical effect of reducing the polishing shutdown frequency is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the polishing technical field, especially to a flying piece monitoring method and system of a polishing machine and the polishing machine. BACKGROUND

[0002] Polishing plays an important role in semiconductor processing technology. Polishing can realize mirrorization of the polishing piece and improve the flatness of the polishing piece. Polishing can also remove damage caused by the previous process step to the surface of the polishing piece to a certain extent.

[0003] In the prior art, during the polishing process of the polishing machine, due to unstable polishing head pressure, insufficient material and thickness of the silicon wafer, and other problems, the existing polishing head cannot know the completeness of the silicon wafer during the polishing process. The phenomenon of flying pieces caused by silicon wafer fragmentation often occurs. When multiple stations are polishing at the same time, if the silicon wafer flies out of the polishing head, the flying pieces will affect the polishing head that is being polished in other stations. The flying pieces of the silicon wafer are an important factor affecting the actual production efficiency. Therefore, when the polishing head flies, the polishing process can only be stopped by manual intervention, and the number of stoppages is large.

[0004] Therefore, the technical problem of the prior art is that the number of polishing stoppages is large. SUMMARY

[0005] The present application provides a flying piece monitoring method and system of a polishing machine and the polishing machine, which solves the technical problem of a large number of polishing stoppages and achieves the technical effect of reducing the number of polishing stoppages.

[0006] In a first aspect, the present application provides a flying piece monitoring method of a polishing machine, which adopts the following technical solution:

[0007] A flying piece monitoring method of a polishing machine is used for the polishing machine, the polishing machine has a polishing head, the bottom of the polishing head has a concave surface, a soft base pad is arranged on the concave surface to form an adjusting cavity between the concave surface and the soft base pad, the soft base pad is used for adsorbing a polishing piece, and the polishing pressure on the silicon wafer is adjusted by charging or applying pressure to the adjusting cavity. At least a plurality of distance sensors are arranged on the concave surface. The monitoring method comprises: establishing a function model of a first distance value detected downward by the distance sensor before polishing starts, a second distance value detected downward by the distance sensor during polishing, and a deviation value; confirming the deviation value based on the first distance value detected downward by the distance sensor before polishing starts, the second distance value detected downward by the distance sensor during polishing, and the function model of each distance sensor; and judging the polishing state based on the deviation value.

[0008] Preferably, the polishing state comprises normal polishing or abnormal polishing, and the abnormal polishing further comprises flying pieces or fragments.

[0009] As preferred, a function model of the deviation value C = |x-a| is established based on the first distance value detected by the distance sensor before polishing is started, the second distance value detected by the distance sensor during polishing, and the deviation value, wherein x is the first distance value detected by the distance sensor before polishing is started, and a is the second distance value detected by the distance sensor during polishing.

[0010] As preferred, n distance sensors are arranged on the concave surface, each of the distance sensors detects a distance downward and obtains a corresponding deviation value, and the "judging the polishing state based on the deviation value" comprises the following steps: defining a first preset value C max ; if Max{C1, C2, C3, …, C n}≤C max , it is judged that the polishing is normal; if at least one distance sensor has a deviation value C x satisfying: C x >C max , wherein C x ∈{C1, C2, C3, …, C n}, it is judged that the polishing is abnormal.

[0011] As preferred, the "judging the polishing abnormality" comprises the following steps: defining a second preset value Z, Z = |x-d|, wherein x is the first distance value detected by the distance sensor before polishing is started, and d is a third distance value detected by the distance sensor after the silicon wafer is taken away from the polishing head; if at least one distance sensor has a deviation value C x satisfying: C max <C x <Z, and the deviation values of the remaining distance sensors are all less than the second preset value Z, it is judged that the silicon wafer is broken and no flying pieces are generated; if at least one distance sensor has a deviation value C x satisfying: C x =Z, it is judged that the silicon wafer is broken and flying pieces are generated.

[0012] In the second aspect, the present application provides a flying piece monitoring system of a polishing machine, which adopts the following technical scheme:

[0013] A flying piece monitoring system of a polishing machine is used for a polishing machine, the polishing machine has a polishing head, the bottom of the polishing head has a concave surface, a soft base pad is arranged on the concave surface to form an adjusting cavity between the concave surface and the soft base pad, the soft base pad is used for adsorbing a polishing piece, and the polishing pressure on the silicon wafer is adjusted by charging or applying pressure to the adjusting cavity, wherein at least a plurality of distance sensors are arranged on the concave surface, the monitoring system comprises: a model establishing module, the model establishing module is used for establishing a function model of a first distance value detected downward by each distance sensor before polishing starts, a second distance value detected downward by the distance sensor during polishing, and a deviation value; a deviation confirming module, the deviation confirming module is used for confirming the deviation value based on the first distance value detected downward by each distance sensor before polishing starts, the second distance value detected downward by the distance sensor during polishing, and the function model; and a state judging module, the state judging module is used for judging the polishing state based on the deviation value.

[0014] As preferred, the state judging module comprises: a first judging module, the first judging module is used for judging whether the polishing is normal or abnormal; and a second judging module, the second judging module is used for judging whether the silicon wafer is flying or broken in the case of abnormal polishing machine.

[0015] As preferred, the function model of the first distance value detected downward by the distance sensor before polishing starts, the second distance value detected downward by the distance sensor during polishing, and the deviation value is: deviation value C = |x-a|; wherein x is the first distance value detected downward by the distance sensor before polishing starts; and a is the second distance value detected downward by the distance sensor during polishing.

[0016] As preferred, n distance sensors are arranged on the concave surface, each distance sensor downwardly detects a distance and correspondingly obtains a deviation value, and the "judging the polishing state based on the deviation value" comprises: defining a first preset value C max ; if Max{C1,C2,C3,…,C n}≤C max , it is judged that the polishing is normal; and if at least one distance sensor corresponds to a deviation value C x that satisfies: C x >C max , wherein C x ∈{C1,C2,C3,…,C n}, it is judged that the polishing is abnormal.

[0017] As preferred, the "judging the polishing abnormality" comprises: defining a second preset value Z, Z = |x-d|, wherein x is the first distance value detected downward by the distance sensor before polishing starts; and d is a third distance value detected by the distance sensor after the silicon wafer is taken away from the polishing head; and if at least one distance sensor corresponds to a deviation value Cx C max <C x <Z, and the deviation value corresponding to the rest of the distance sensor is less than the second preset value Z, then the silicon wafer fragments are judged, and there is no flying piece; if at least one distance sensor corresponds to a deviation value C x C x = Z, then the silicon wafer fragments are judged, and the flying piece occurs.

[0018] In a third aspect, the application provides a polishing machine, which adopts the following technical scheme:

[0019] A polishing machine comprises: a polishing head, the bottom of the polishing head has a concave surface, a soft base pad is arranged on the concave surface to form an adjusting cavity between the concave surface and the soft base pad, the soft base pad is used for adsorbing a polishing piece, the polishing pressure on a silicon wafer is adjusted by charging or applying pressure to the adjusting cavity, wherein at least a plurality of distance sensors are arranged on the concave surface; a monitoring system, the monitoring system is the monitoring system, the monitoring system is connected to the distance sensors, and is used for judging the polishing state according to the feedback of the distance sensors.

[0020] In summary, the application has at least one of the following beneficial technical effects:

[0021] 1. The distance sensors are arranged in the adjusting cavity in the polishing head, the distance sensors respectively monitor downward to obtain a first distance and a second distance before polishing is started and in the polishing process, and feedback is fed back, a first distance, a second distance and a deviation value function model are established, the first distance and the second distance monitored in real time in the polishing process are obtained, the deviation value is obtained through the function model, the polishing state is analyzed and judged based on the deviation value, the polishing state is fed back in time, the device is beneficial to take measures of stopping or not stopping, prevents the device from being damaged due to not stopping in time in the case of needing to stop, or reduces the polishing efficiency due to misjudgment of stopping in the case of not needing to stop; the technical problem of frequent polishing stoppage is solved, and the technical effect of reducing the polishing stoppage times is achieved.

[0022] 2. After normal and abnormal judgment, the distance sensors further monitor the distance value downward and feedback, the flying piece or fragment state is judged based on the first distance and the second distance monitored in real time and the deviation value function model, the device is beneficial to take measures of stopping in the flying piece state, prevents the flying piece from affecting other normal polishing heads, and improves the polishing efficiency in the case of not flying. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a monitoring method flowchart described in the application;

[0024] Figure 2 is a schematic view of a polishing head in the application;

[0025] Figure 3 is Figure 2 is an enlarged view of A in FIG. 1;

[0026] Figure 4 is a flow chart of establishing a function model in the monitoring method of the present application;

[0027] Figure 5 is a flow chart of confirming a deviation value in the monitoring method of the present application;

[0028] Figure 6 is a first flow chart of judging a polishing state in the monitoring method of the present application;

[0029] Figure 7 is a schematic view of a polishing head after taking out a silicon wafer according to the present application;

[0030] Figure 8 is a second flow chart of judging a polishing state in the monitoring method of the present application;

[0031] Figure 9 is Figure 7 is an enlarged view of B in FIG. 1;

[0032] Figure 10 is a schematic view of a polishing head in which a wafer is flying according to the present application;

[0033] Figure 11 is Figure 10 is an enlarged view of C in FIG. 1;

[0034] Figure 12 is a schematic view of another arrangement of distance sensors in a polishing head according to the present application.

[0035] BRIEF DESCRIPTION OF DRAWINGS 100, polishing head; 110, concave surface; 120, soft base pad; 130, adjusting cavity; 140, distance sensor; 141, first distance sensor; 142, second distance sensor; 143, third distance sensor; 144, fourth distance sensor; W, silicon wafer; M, polishing pad; 150, sliding cavity; 151, first cavity; 152, second cavity; 160, spring. DETAILED DESCRIPTION

[0036] The serial numbers of components used herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The "connection" and "coupling" in the present application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0037] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0038] The present application provides a flying piece monitoring method, system and polishing machine of a polishing machine, which solves the technical problem of silicon wafer W flying piece affecting polishing efficiency and achieves the technical effect of preventing silicon wafer W flying piece from affecting polishing efficiency.

[0039] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings and specific embodiments of the specification. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0040] The present application provides a monitoring method of a polishing machine, which is suitable for a polishing machine and is used for monitoring the polishing state of a silicon wafer W in the polishing machine. The polishing state of the silicon wafer W in the polishing process is fed back in time, and it is judged whether the machine needs to be stopped, which is beneficial to the equipment to take measures to stop or not to stop, prevents the equipment from being damaged due to the failure to stop in time when the silicon wafer W appears abnormal and needs to be stopped, or reduces the polishing efficiency due to the misjudgment of stopping in the case where the machine does not need to be stopped. As shown in the figure, the monitoring method comprises: Figure 1

[0041] S100: establishing a function model of the first distance value detected downward by the distance sensor 140 before polishing starts, the second distance value detected downward by the distance sensor 140 in the polishing process, and the deviation value; ​

[0042] S200: confirming a deviation value based on the first distance value detected downward by the distance sensor 140 before polishing starts, the second distance value detected downward by the distance sensor 140 during polishing, and the function model;

[0043] S300: judging the polishing state based on the deviation value.

[0044] Based on the above monitoring method, it is applied to a polishing machine, as shown in Figure 2 、 3 The polishing machine has a polishing head 100 for carrying a silicon wafer W, and the polishing of the silicon wafer W is completed by driving the polishing head 100 to rotate on a polishing pad M. It is worth noting that the bottom of the polishing head 100 has a uniform and arched concave surface 110, and a soft base pad 120 is connected to and covers the concave surface 110. In an embodiment, the soft base pad 120 can be in the form of an air bag, so that an adjusting cavity 130 is formed between the concave surface 110 and the soft base pad 120. The soft base pad 120 is bonded with the silicon wafer W. When the silicon wafer W is polished on the polishing pad M by the polishing head 100, the pressure on the silicon wafer W is adjusted by inflating the adjusting cavity 130. Inside the adjusting cavity 130, a plurality of distance sensors 140 are fixed on the concave surface 110 for downward monitoring and feedback.

[0045] Specifically, as shown in Figures 2-4 A function model of the first distance value detected downward by the distance sensor 140 before polishing starts, the second distance value detected downward by the distance sensor 140 during polishing, and the deviation value is established, including:

[0046] S110: obtaining the first distance value x detected downward by the distance sensor 140 before polishing starts;

[0047] S120: obtaining the second distance value a monitored downward by the distance sensor 140 during polishing;

[0048] S130: establishing a function model of the first distance value x, the second distance value a, and the deviation value C:

[0049] C = |x-a|

[0050] Wherein, x is the first distance value detected downward by the distance sensor 140 before polishing starts. It is worth noting that at this time, the silicon wafer W is pressed against the polishing pad M by the soft base pad 120, but the polishing head 100 and the polishing pad M have not started yet. At this time, the first distance value x monitored by the distance sensor 140 is the distance from the distance sensor 140 to the upper surface of the silicon wafer W;

[0051] a is the second distance value detected by the distance sensor 140 downward during the polishing process, and it is worth noting that at this time, the silicon wafer W is driven by the polishing head 100 to be in the polishing process, that is, the silicon wafer W rotates to perform polishing, and the second distance value a monitored by the distance sensor 140 at this time is the distance from the distance sensor 140 to the upper surface of the silicon wafer W rotating to perform polishing.

[0052] Specifically, as shown in Figure 5 Based on the first distance value detected by each distance sensor 140 downward before the polishing starts, the second distance value detected by the distance sensor 140 downward during the polishing process, and the function model, the deviation value is determined, including:

[0053] S210: Real-time acquisition of the second distance value a monitored by the distance sensor 140 downward during the polishing process x ;

[0054] S220: Through the function model of the above deviation value:

[0055] C x =|x-a x |

[0056] The real-time deviation value corresponding to the real-time second distance value ax is obtained.

[0057] For the polishing of the silicon wafer W, the silicon wafer W has a micro displacement in the vertical direction during the polishing process, that is, the second distance value a monitored by the distance sensor 140 is affected during the polishing process of the silicon wafer W. By monitoring the deviation C between the second distance value and the first distance value in real time, the current state of the silicon wafer W can be preliminarily judged. Generally, the conditions of the silicon wafer W during the polishing process include normal polishing, fragments, and flying pieces. In an embodiment, the polishing state of the silicon wafer W includes a normal state and an abnormal state, wherein the normal state means that the silicon wafer W does not have fragments and flying pieces, and the silicon wafer W is complete and located at the current position; the abnormal state means that fragments and / or flying pieces occur, that is, the abnormal state includes the fragment state and the flying piece state.

[0058] Specifically, as shown in Figure 6 Based on the first distance value detected by each distance sensor 140 downward before the polishing starts, the second distance value detected by the distance sensor 140 downward during the polishing process, and the function model, the deviation value is determined, including:

[0059] It is assumed that the concave surface 110 is provided with n distance sensors 140, which independently monitor the distance downward, and the deviation value is determined based on the monitored distance value:

[0060] S310: Define a first preset value C max , wherein C maxThis refers to the maximum allowable displacement fluctuation of the silicon wafer W in the vertical direction during the polishing process;

[0061] S320: Determine polishing status:

[0062] S321: If Max{C1,C2,C3,…,C…} n}≤C max If so, then the polishing is considered normal;

[0063] S322: If there exists at least one distance sensor 140 with a corresponding deviation value C x Satisfy: C x >C max , where C x ∈{C1,C2,C3,…,C n If the result is}, then the polishing is deemed abnormal.

[0064] Understandably, C max Used to determine the allowable fluctuations of silicon wafer W during normal polishing; if the obtained deviation value exceeds C... max This indicates that silicon wafer W has fragmented. When silicon wafer W fragments, because the soft base pad 120 still presses the silicon wafer W against the polishing pad M, and the polishing pad M is soft, the silicon wafer W cannot be pressed down as a whole. This results in uneven force on the silicon wafer W, causing the fragmented area to float up or fall down, thus causing the monitored and calculated deviation value C to be greater than C0. max .

[0065] like Figure 7 As shown, to improve the accuracy of judging the state of silicon wafer W, multiple distance sensors 140 are provided on the concave surface 110. Each distance sensor 140 monitors the distance vertically downwards and provides feedback. In one embodiment, the number of distance sensors 140 is four, and each distance sensor 140 is defined with a different C value. max That is, the allowable range of deviation value fluctuation at different positions in the radial direction is different; that is, each distance sensor 140 monitors independently, and each monitors the first distance value x, the second distance value a, and the third distance value d downwards.

[0066] like Figures 8-11 As shown, according to the above "S322: If there exists at least one distance sensor 140 corresponding to a deviation value C", x Satisfy: C x >C max , where C x ∈{C1,C2,C3,…,C n If the polishing is deemed abnormal, then the state of the silicon wafer W is assessed, specifically including:

[0067] S3221: defining a second preset value Z, Z = |x-d|, wherein x is the first distance value detected by the distance sensor 140 before polishing is started; d refers to the third distance value detected by the distance sensor 140 after the silicon wafer W is taken away from the polishing head 100;

[0068] It can be understood that before polishing is started or during polishing, the silicon wafer W is pressed against the polishing pad M by the soft base pad 120, at this time the silicon wafer W is taken away, and the third distance value is the distance from the distance sensor 140 to the upper surface of the polishing pad M;

[0069] S3222: determining how the polishing is abnormal:

[0070] S3223: if there is at least one distance sensor 140 corresponding to a deviation value C x satisfying: C max <C x <Z, and the deviation values corresponding to the remaining distance sensors 140 are all less than the second preset value Z, it is determined that the silicon wafer W has a fragment at x, but no flying piece occurs;

[0071] S3224: if there is at least one distance sensor 140 corresponding to a deviation value C x satisfying: C x = Z, it is determined that the silicon wafer W has a fragment and a flying piece occurs; and in the case of a flying piece, the polishing machine needs to be stopped.

[0072] It is worth noting that when the silicon wafer W is adsorbed on the soft base pad 120, it can be connected through the adsorption pad shown in FIG. 13 of the specification of application No. 202110964212.1. Through the setting of the adsorption pad, on the one hand, the possibility of the silicon wafer flying out is reduced, and on the other hand, the soft base pad 120 is prevented from being pushed out to the empty space when the silicon wafer W has a flying piece, thereby affecting the monitoring accuracy.

[0073] In one embodiment, as shown in FIG. 1, Figure 7 the number of distance sensors 140 is four, which are defined as the first distance sensor 141, the second distance sensor 142, the third distance sensor 143, and the fourth distance sensor 144. The deviation values C calculated after the corresponding monitoring and feedback are C1, C2, C3, and C4, respectively. At the same time, different deviation values have corresponding C max for comparison; each distance sensor 140 independently monitors and feeds back the distance value downward, specifically:

[0074] When the deviation values C calculated after the monitoring and feedback of the four distance sensors 140 are all less than or equal to the maximum allowable deviation C max under the current working condition, when Max{C1, C2, C3, C4} < C max, and the size relationship of the data does not change in a set time period, it is considered that the wafer W is in a normal working state and no chip or flying piece occurs;

[0075] When any one of the calculated deviations C of the four distance sensors 140 is greater than the maximum allowable deviation C under the current working condition max , it is determined that the wafer W is in an abnormal state, and the abnormal condition is further analyzed and compared:

[0076] When C max < C1 < Z; Max{C2, C3, C4} < C max , and the size relationship of the data does not change in a set time period, it is considered that the wafer W is in a normal working state and no chip or flying piece occurs;

[0077] When C1 < C max ; C2 < C max ; C3 < C max ; and C4 = Z, it is considered that the wafer W cannot be detected at the fourth distance sensor 144, that is, a flying piece occurs, and the rest of the positions are in a normal working state. At this time, the upper computer will send a stop signal to immediately stop the polishing process.

[0078] Further, the application also provides a flying piece monitoring system of a polishing machine, which is applied to the polishing machine. The polishing machine has a polishing head 100. The bottom of the polishing head 100 has a concave surface 110. A soft base pad 120 is arranged on the concave surface 110 to form an adjusting cavity 130 between the concave surface 110 and the soft base pad 120. The soft base pad 120 is used to adsorb a wafer. The polishing pressure on the wafer W is adjusted by charging or applying pressure to the adjusting cavity 130. The concave surface 110 is provided with at least a plurality of distance sensors 140. The monitoring system comprises a model establishing module, a deviation confirming module and a state judging module.

[0079] The model establishing module is used to establish a function model of a first distance value detected downward by the distance sensor 140 before polishing starts, a second distance value detected downward by the distance sensor 140 during polishing and a deviation value based on each distance sensor 140.

[0080] The deviation confirming module is used to confirm the deviation value based on the first distance value detected downward by the distance sensor 140 before polishing starts, the second distance value detected downward by the distance sensor 140 during polishing and the function model of each distance sensor 140. And

[0081] The state judgment module is configured to judge the polishing state based on the deviation value.

[0082] Further, the state judgment module comprises:

[0083] The first judgment module is configured to judge whether the polishing is normal or abnormal.

[0084] The second judgment module is configured to judge whether the wafer is a flying piece or a broken piece when the polishing machine is abnormal.

[0085] In one embodiment, the polishing state of the wafer W comprises a normal state and an abnormal state. The normal state means that the wafer W is not broken and flying, and the wafer W is complete and located at the current position. The abnormal state means that the wafer W is broken and / or flying.

[0086] Further, a function model of the deviation value is established based on a first distance value detected downward by the distance sensor 140 before polishing starts, a second distance value detected downward by the distance sensor 140 during polishing, and the deviation value.

[0087] The deviation value C = |x-a|.

[0088] Wherein, x is the first distance value detected downward by the distance sensor 140 before polishing starts. It is worth noting that at this time, the wafer W is pressed against the polishing pad M by the soft base pad 120, but the polishing head 100 and the polishing pad M have not started. At this time, the first distance value x monitored by the distance sensor 140 is the distance from the distance sensor 140 to the upper surface of the wafer W.

[0089] a is the second distance value detected downward by the distance sensor 140 during polishing. It is worth noting that at this time, the wafer W is driven by the polishing head 100 to be in the polishing process, that is, the wafer W rotates to perform polishing. At this time, the second distance value a monitored by the distance sensor 140 is the distance from the distance sensor 140 to the upper surface of the wafer W rotating to perform polishing.

[0090] Further, the concave surface 110 is provided with n distance sensors 140. Each distance sensor 140 downwardly detects a distance and obtains a corresponding deviation value. The first judgment module is configured to judge whether the polishing is normal or abnormal, comprising:

[0091] Define a first preset value C max ;

[0092] If Max{C1,C2,C3,…,C n}≤C max , it is judged that the polishing is normal, that is, C1,C2,C3,…,C n respectively correspond to C maxIn comparison, all are smaller than their respective C. max If so, then the polishing is considered normal;

[0093] If there exists at least one distance sensor 140 with a corresponding deviation value C x Satisfy: C x >C max , where C x ∈{C1,C2,C3,…,C n If the result is}, then the polishing is deemed abnormal.

[0094] Furthermore, the second judgment module is used to determine whether silicon wafer W is flyaway or fragmented in the event of a polishing machine malfunction, including:

[0095] Define a second preset value Z, Z = |xd|, where x is the first distance value detected downward by the distance sensor 140 before polishing starts; d is the third distance value detected by the distance sensor 140 after the silicon wafer W is removed during the polishing process.

[0096] If there exists at least one distance sensor 140 with a corresponding deviation value C x Satisfy: C max <C x If the deviation value of the silicon wafer W is less than Z, and the deviation value of the other distance sensors 140 is less than the second preset value Z, then it is determined that the silicon wafer W is fragmented and there are no flying wafers.

[0097] If there exists at least one distance sensor 140 with a corresponding deviation value C x Satisfy: C x =Z, then it is determined that the silicon wafer W is fragmented and a wafer fly has occurred.

[0098] Furthermore, the control module is used to stop the polishing machine when the silicon wafer W experiences a flyaway state.

[0099] Furthermore, this application also provides a polishing machine, including: a polishing head 100 and a monitoring system. The bottom of the polishing head 100 has a concave surface 110, and a soft base pad 120 is provided on the concave surface 110 so that an adjustment cavity 130 is formed between the concave surface 110 and the soft base pad 120. The soft base pad 120 is used to adsorb the wafer for polishing. The polishing pressure on the silicon wafer W is adjusted by pressurizing or applying pressure to the adjustment cavity 130. At least a plurality of distance sensors 140 are provided on the concave surface 110. The monitoring system is the aforementioned monitoring system. The monitoring system is connected to the distance sensors 140 and is used to determine the polishing status based on the feedback from the distance sensors 140. Based on the polishing status, i.e., when the silicon wafer W exhibits flyaway, the control module controls the polishing machine to stop.

[0100] In other embodiments, such as Figure 12As shown, the setting mode of the distance sensor 140 in the throwing head 100 can also be in a movable form: a sliding cavity 150 conforming to the arc of the concave surface 110 is opened in the inside of the concave surface 110, the distance sensor 140 is contained in the inside of the sliding cavity 150, and by the setting of the distance sensor 140, the long strip-shaped sliding cavity 150 is divided into a first cavity 151 and a second cavity 152, and it is worth noting that the distance sensor 140 is in contact with the inner wall of the sliding cavity 150 and is provided with a sealing structure, such as a sealing ring, etc., so that the first cavity 151 and the second cavity 152 are independent of each other, and when the distance sensor 140 slides in the sliding cavity 150 to change the position, the first cavity 151 and the second cavity 152 can still remain independent of each other due to the setting of the sealing structure.

[0101] A spring 160 is arranged in the first cavity 151, the spring 160 is contained in the inside of the first cavity 151, and the spring 160 is always in a compressed state, one end of the spring 160 is fixedly connected to the end of the first cavity 151, and the other end of the spring 160 is fixedly connected to the distance sensor 140; a pressurizing port (not shown) is opened on the second cavity 152, by pressurizing or depressurizing in the second cavity 152, the air pressure in the second cavity 152 changes, in this way, there is an air pressure difference between the first cavity 151 and the second cavity 152, so as to realize the driving of the movement of the distance sensor 140, more specifically, driving the distance sensor 140 to slide on the entire sliding cavity 150; in an embodiment, the pressurizing port can also be arranged on the first cavity 151; in this way, the sliding of the distance sensor 140 is driven by the air pressure difference, so that the distance sensor 140 can monitor the distance downward at different positions on the sliding cavity 150, that is, there is a mapping relationship between the air pressure and the position:

[0102] PL=f(p);

[0103] Wherein, p refers to the pressure added in the second cavity 152; PL refers to the position of the distance sensor 140 on the sliding cavity 150.

[0104] In this way, by driving a group of distance sensors 140, the distance values at different positions on the concave surface 110 are realized, only one distance sensor 140 can monitor the distance values downward at each point on the sliding cavity 150, and at the same time, corresponding to the above monitoring method, there is a corresponding deviation value of the distance sensor 140 at each point on the sliding cavity 150. It is worth noting that in order to realize that the distance sensor 140 can normally monitor the distance downward, the materials of the concave surface 110 and the sliding cavity 150 should be transparent, so that the distance sensor 140 monitors the distance downward through the transparent material.

[0105] In other embodiments, the implementation of the distance sensor 140 can also be other structures, such as a linear motor or a screw rod arranged inside the polishing head 100.

[0106] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0107] Working principle / steps:

[0108] A function model of the first distance value detected downward by the distance sensor 140 before polishing starts, the second distance value detected downward by the distance sensor 140 during polishing, and the deviation value is established; the deviation value is confirmed based on the first distance value detected downward by the distance sensor 140 before polishing starts, the second distance value detected downward by the distance sensor 140 during polishing, and the function model collected by each distance sensor 140; and the polishing state is judged based on the deviation value.

[0109] Technical effects:

[0110] 1. The distance sensor 140 is arranged in the adjusting cavity 130 in the polishing head 100. The distance sensor 140 respectively monitors the first distance and the second distance downward before polishing starts and during polishing, and feeds back the first distance and the second distance. A function model of the first distance, the second distance and the deviation value is established. The first distance and the second distance monitored in real time during polishing are obtained. The deviation value is obtained through the function model. The polishing state is analyzed and judged based on the deviation value. The polishing state is fed back in time. It is beneficial for the equipment to take measures of stopping or not stopping, preventing the equipment from being damaged due to not stopping in time in the case of needing to stop, or reducing the polishing efficiency due to misjudging stopping in the case of not needing to stop. The technical problem of the influence of the silicon wafer W flying on the polishing efficiency is solved, and the technical effect of preventing the silicon wafer W flying from affecting the polishing efficiency is achieved.

[0111] 2、The application is judged normally and abnormally, the distance sensor 140 further monitors the distance value and feeds back downward, based on the first distance and the second distance and the deviation value function model monitored in real time, the state of the flying piece or the fragment is judged, in the flying piece state, the device is beneficial to make the shutdown measure, prevents the flying piece from affecting other normal throwing heads 100, and in the case of no flying piece, it is not stopped, and the polishing efficiency is improved.

[0112] Although the preferred embodiments of the application have been described, those skilled in the art who understand the basic inventive concept can make further changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the application.

[0113] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application fall within the scope of the claims of the application and their equivalent technologies, the application also intends to include these modifications and variations.

Claims

1. A method of flying patch monitoring for a polishing machine, the method comprising: The application relates to a polishing machine, wherein the polishing head (100) has a concave surface (110) on the bottom, a soft base pad (120) is arranged on the concave surface (110) so that an adjusting cavity (130) is formed between the concave surface (110) and the soft base pad (120), the soft base pad (120) is used for adsorbing a polishing piece, the polishing pressure on a silicon wafer (W) is adjusted by charging or applying pressure to the adjusting cavity (130), and at least a plurality of distance sensors (140) are arranged on the concave surface (110), the monitoring method comprises the following steps: a function model of a first distance value detected downward by the distance sensor (140) before polishing starts, a second distance value detected downward by the distance sensor (140) during polishing and a deviation value is established; a deviation value is confirmed based on the first distance value detected downward by the distance sensor (140) before polishing starts, the second distance value detected downward by the distance sensor (140) during polishing and the function model of each distance sensor (140); a polishing state is judged based on the deviation value.

2. The method for monitoring fly blades in a polishing machine according to claim 1, characterized in that, The polishing state comprises: normal or abnormal polishing; the abnormal polishing further comprises a flying piece or a broken piece.

3. The method for monitoring fly blades in a polishing machine according to claim 2, characterized in that, The function model of the first distance value detected downward by the distance sensor (140) before polishing starts, the second distance value detected downward by the distance sensor (140) during polishing and the deviation value is: the deviation value C=|x-a|; wherein x is the first distance value detected downward by the distance sensor (140) before polishing starts, and a is the second distance value detected downward by the distance sensor (140) during polishing.

4. The method for monitoring fly blades in a polishing machine according to claim 3, characterized in that, The concave surface (110) is provided with n distance sensors (140), each distance sensor (140) downwardly detects a distance and correspondingly obtains a deviation value, and the "judging a polishing state based on the deviation value" comprises the following steps: defining a first preset value C max ; If Max{C1, C2, C3, …, Cn}≤C n}≤C max , it is determined that the polishing is normal; If there is at least one distance sensor (140) corresponding to the deviation value C x satisfies: C x > C max , wherein C x ∈ {C1, C2, C3, …, C n}, the polishing abnormality is determined.

5. The method for monitoring fly blades in a polishing machine according to claim 4, characterized in that, The "judging abnormal polishing" comprises the following steps: a second preset value Z is defined, Z=|x-d|, wherein x is the first distance value detected downward by the distance sensor (140) before polishing starts, and d is a third distance value detected by the distance sensor (140) after the silicon wafer (W) is taken away from the polishing head (100). If there is at least one distance sensor (140) corresponding to a deviation value C x Satisfies: C max <C x Z, and the deviation value corresponding to the remaining distance sensors (140) is less than the second preset value Z, it is determined that the silicon wafer (W) is broken and there is no flying piece. If there is at least one distance sensor (140) corresponding deviation value C x Satisfy: C x = Z, then determine the silicon wafer (W) fragments, and the flying pieces occur.

6. A flying piece monitoring system of a polishing machine, characterized by, The application relates to a polishing machine, wherein the polishing head (100) has a concave surface (110) on the bottom, a soft base pad (120) is arranged on the concave surface (110) so that an adjusting cavity (130) is formed between the concave surface (110) and the soft base pad (120), the soft base pad (120) is used for adsorbing a polishing piece, the polishing pressure on a silicon wafer (W) is adjusted by charging or applying pressure to the adjusting cavity (130), and at least a plurality of distance sensors (140) are arranged on the concave surface (110), the monitoring system comprises the following: a model establishing module, which is used for establishing, based on each distance sensor (140), a function model of a first distance value detected downward by the distance sensor (140) before polishing starts, a second distance value detected downward by the distance sensor (140) during polishing and a deviation value; a deviation confirmation module for confirming a deviation value based on a first distance value detected downward by the distance sensor (140) before polishing starts, a second distance value detected downward by the distance sensor (140) during polishing, and the function model; and a state judgment module for judging a polishing state based on the deviation value.

7. The flying height monitoring system of claim 6, wherein The state judgment module comprises: a first judgment module for normal or abnormal polishing; a second judgment module for judging a wafer (W) flying or fragment in the case of abnormal polishing machine.

8. The flying height monitoring system of claim 7, wherein the flying height monitoring system is configured to determine the flying height of the polishing pad based on the detected light intensity. A function model of the first distance value detected downward by the distance sensor (140) before polishing starts, the second distance value detected downward by the distance sensor (140) during polishing, and the deviation value is established as follows: Deviation value C = |x-a|; Wherein, x is the first distance value detected downward by the distance sensor (140) before polishing starts; a is the second distance value detected downward by the distance sensor (140) during polishing.

9. The flying height monitoring system of a polisher according to claim 8, wherein The concave surface (110) is provided with n distance sensors (140), each of which detects the distance downward and obtains a corresponding deviation value, and the "judging the polishing state based on the deviation value" comprises: defining a first preset value C max ; If Max{C1, C2, C3, …, Cn}≤C n}≤C max , then it is determined that the polishing is normal; If there is at least one distance sensor (140) corresponding to a deviation value C x satisfies: C x > C max wherein C x ∈ {C1, C2, C3, …, C n}, the polishing abnormality is determined.

10. The flying height monitoring system of a polisher according to claim 9, wherein The "judging the abnormal polishing" comprises: Defining a second preset value Z, Z = |x-d|, wherein x is the first distance value detected downward by the distance sensor (140) before polishing starts; d refers to the third distance value detected by the distance sensor (140) after the wafer (W) is taken away from the polishing head (100); If there is at least one distance sensor (140) corresponding to a deviation value C x satisfies: C max <C x <Z, and the deviation value corresponding to the rest of the distance sensors (140) is less than the second preset value Z, it is determined that the silicon wafer (W) is broken and there is no flying piece. If there is at least one distance sensor (140) corresponding deviation value C x satisfies: C x = Z, it is judged that the silicon wafer (W) is broken, and the flying piece occurs.

11. A polishing machine characterized by, Comprise: A monitoring system, the monitoring system is the monitoring system in any one of claims 6-10, the monitoring system is connected with the distance sensor (140), and is used for judging the polishing state according to the feedback of the distance sensor (140).

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