CN-121973071-A - Wafer regeneration chemical mechanical polishing system and process

CN121973071ACN 121973071 ACN121973071 ACN 121973071ACN-121973071-A

Abstract

The invention provides a wafer regeneration chemical mechanical polishing system and a process, which belong to the technical field of semiconductor manufacturing, wherein the wafer regeneration chemical mechanical polishing system comprises a buffer unit, a conveying unit, a polishing unit, a cleaning unit and a control unit, the conveying unit, the polishing unit and the cleaning unit are positioned on the same side of the buffer unit and are sequentially arranged along a first straight line path, the conveying unit is positioned between the polishing unit and the cleaning unit, the buffer unit comprises a plurality of wafer boxes, optical detection stations positioned on one sides of the wafer boxes, and a conveying mechanism positioned on one side of the wafer boxes close to the conveying unit, the conveying unit comprises a transfer disc moving along a second straight line path, and the polishing unit comprises a first polishing assembly and a second polishing assembly which are arranged along the second straight line path, and the polishing assembly comprises at least two polishing discs and polishing heads corresponding to the polishing discs.

Inventors

WANG YAN
HE YANHONG
Zeng fen
ZHAO GUANGYUAN

Assignees

北京晶亦精微科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260109

Claims (10)

1. The wafer regeneration chemical mechanical polishing system is characterized by comprising a buffer unit, a conveying unit, a polishing unit, a cleaning unit and a control unit, wherein the buffer unit extends along a first linear path, the conveying unit, the polishing unit and the cleaning unit are positioned on the same side of the buffer unit and are sequentially arranged along the first linear path, the conveying unit is positioned between the polishing unit and the cleaning unit and extends along a second linear path, and the second linear path is perpendicular to the first linear path; The buffer unit comprises a plurality of wafer boxes arranged along the first linear path, optical detection stations positioned at one sides of the plurality of wafer boxes, and a transmission mechanism positioned at one side of the wafer boxes close to the transmission unit; The transfer unit comprises a transfer tray moving along the second linear path; The polishing unit comprises a first polishing component and a second polishing component which are arranged along the second linear path, the polishing components comprise at least two polishing discs and polishing heads corresponding to the polishing discs, and a plurality of the polishing discs are used for respectively performing the pre-polishing, rough polishing, fine polishing and buffer cleaning procedures; the cleaning unit is used for cleaning the polished wafer; The control unit is configured to receive the wafer damage degree acquired by the optical detection station, and set polishing procedures and cleaning parameters according to the damage degree.
2. The wafer recycling chemical mechanical polishing system of claim 1, wherein said buffer unit further comprises: the guide rail extends along the first straight path and is positioned at one side of the plurality of wafer cassettes close to the conveying unit; the transmission mechanism is connected to the guide rail in a sliding way and is used for transferring the wafer in the wafer box to the optical detection station and moving the wafer of the optical detection station to the transmission unit.
3. The wafer recycling chemical mechanical polishing system of claim 1, wherein said transfer unit further comprises: a first storage area comprising a plurality of stations, the first storage area corresponding to the first polishing assembly; A second storage area comprising a plurality of stations, the second storage area corresponding to the second polishing assembly; And the clamping mechanism is used for clamping the transfer disc and is placed on the station.
4. The wafer recycling chemical mechanical polishing system of claim 3 wherein said transfer unit further comprises a transfer mechanism positioned between said first storage area and said second storage area for transferring a transfer tray of said first storage area to said second storage area.
5. The wafer recycling chemical mechanical polishing system of claim 1, wherein the first polishing assembly and the second polishing assembly each comprise: The rotating mechanism is arranged at the center positions of the polishing discs; The polishing arm is fixedly arranged on the rotating mechanism; the polishing heads are fixedly connected to the polishing arms in a one-to-one correspondence manner.
6. The wafer recycling chemical mechanical polishing system of claim 1, wherein the first polishing assembly and the second polishing assembly each comprise: a polishing pad conditioner having a swingable conditioning head having a first state of contact with a polishing pad on the polishing disk and a second state of being located at an outer periphery of the polishing disk; and the liquid supply pipeline is provided with a liquid outlet positioned above the polishing disk.
7. The wafer recycling chemical mechanical polishing system of claim 1 wherein said cleaning unit comprises brush cleaning mechanisms, pen spray cleaning mechanisms, and single-piece cleaning mechanisms arranged at intervals along said second linear path, and a transfer mechanism is disposed between adjacent two of said cleaning mechanisms.
8. A wafer recycling chemical mechanical polishing process employing the wafer recycling chemical mechanical polishing system according to any one of claims 1 to 7, comprising: s10, presetting a polishing program in a control unit according to the damage degree; s20, moving the wafer in the wafer box to an optical detection station through a transmission mechanism for damage identification; s30, the control unit ranks the wafers according to the damage degree, and sequentially processes the wafers from high to low according to the damage degree; S40, placing the wafer on a transfer disc by the transmission mechanism, and sending the transfer disc to a corresponding polishing unit according to a polishing program corresponding to the wafer; And S50, polishing the wafer by the polishing unit according to a polishing procedure corresponding to the wafer, and then cleaning the wafer by the cleaning unit.
9. The wafer recycling chemical mechanical polishing process of claim 8, wherein said step S20 comprises: collecting the fluctuation value of the reflected light intensity of the wafer by adopting infrared light irradiation; if the fluctuation value is less than or equal to 5%, judging that the wafer is low in damage; If the fluctuation value is 5% -10%, judging that the wafer is damaged; If the fluctuation value is more than or equal to 10%, judging that the wafer is high damaged, and triggering a film type judging process; If the reflectivity of the infrared light is more than or equal to 80 percent and the reflected light waveform is uniform and has no impurity peak, the wafer is considered to be a wafer containing a metal layer; If the reflectivity of the infrared light is 10% -80%, the reflected light waveform has a hybrid peak, and the wafer is considered to be a nonmetallic film layer wafer.
10. The wafer recycling chemical mechanical polishing process of claim 9, wherein the low damage wafers correspond to a rough polishing and a fine polishing; the polishing procedure corresponding to the middle damaged wafer is rough polishing and fine polishing and buffer cleaning; The polishing degree corresponding to the high-damage wafer is pre-polishing, rough polishing, fine polishing and buffer cleaning.

Description

Wafer regeneration chemical mechanical polishing system and process Technical Field The invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a wafer regeneration chemical mechanical polishing system and a wafer regeneration chemical mechanical polishing process. Background The semiconductor manufacturing industry continues to develop and mass produce finer process nodes, breaking through from the relatively mature 28nm, 22nm step by step to 19nm and more advanced processes, and the demand for wafers as core substrates is high. The control baffle and the test piece for equipment debugging and process monitoring are scrapped due to surface residual film layers, scratches, particle defects and the like after single use, so that serious waste of silicon material resources is caused, and the overall manufacturing cost is increased. Particularly, in the prior process modularization application background, the regenerated wafer needs to meet the multiple requirements of high-precision surface, high-efficiency and low-cost regeneration. The chemical mechanical polishing process can realize global planarization of the surface of the wafer through the synergistic effect of chemical corrosion and mechanical polishing, and the surfaces of the control baffle and the test piece are treated through the chemical mechanical polishing process, so that the method is beneficial to recycling and reduces the cost. The degree of matching between the equipment structure and the process parameters in the chemical mechanical polishing process directly determines the regeneration effect of the wafer. There are several disadvantages to the current state: (1) The chemical mechanical polishing device is mainly divided into a single-disk single-head type and a multi-disk single-head type. The single-disk single-head polishing device only can realize single-machine polishing, has low efficiency, and the multi-disk single-head polishing device supports multi-step polishing, but is mostly of a serial fixed structure, cannot independently operate and cannot meet the flexible switching requirement of the series. (2) The existing multistage polishing process is mostly based on the parameter design of fixed equipment, the process redundancy of low-damage wafers is caused by not considering the damage difference of the wafers, the high-damage wafers are not thoroughly processed, the process suitability is poor, if parameters need to be adjusted, the wafer damage needs to be judged by relying on manual experience and the process parameters need to be manually matched, the efficiency is low, and the regeneration quality is easily influenced due to parameter mismatch. (3) The process and equipment have insufficient synergy, the polishing head pressure lacks independent regulation capability, and is difficult to adapt to different film layers (oxide films and metal films) and different damage areas, and the problems of uneven polishing, film layer residue and the like are easily caused. (4) The risk of transferring across working procedures is high, when wafers are transferred between different polishing units or polishing-cleaning equipment, the pollution prevention and high-precision positioning structure is lacking, environmental particles and edge damage are easy to introduce, the yield and stability are insufficient, and the high-efficiency and stability requirements of large-scale wafer regeneration are difficult to meet. Disclosure of Invention The embodiment of the invention provides a wafer regeneration chemical mechanical polishing system and a wafer regeneration chemical mechanical polishing process, and aims to solve the technical problems that parameters cannot be flexibly adjusted, process suitability is poor, different film layers are difficult to adapt and the risk of cross-process transfer pollution is high in the existing chemical mechanical polishing composition. In a first aspect, an embodiment of the present invention provides a wafer regeneration chemical mechanical polishing system, including a buffer unit, a transmission unit, a polishing unit, a cleaning unit, and a control unit, where the buffer unit extends along a first straight path, the transmission unit, the polishing unit, and the cleaning unit are located on the same side of the buffer unit and are sequentially arranged along the first straight path, and the transmission unit is located between the polishing unit and the cleaning unit and extends along a second straight path, and the second straight path is perpendicular to the first straight path; The buffer unit comprises a plurality of wafer boxes arranged along the first linear path, optical detection stations positioned at one sides of the plurality of wafer boxes, and a transmission mechanism positioned at one side of the wafer boxes close to the transmission unit; The transfer unit comprises a transfer tray moving along the second linear path; The polishing unit