Patent Application
20240269797
This application claims the priority to Chinese Patent Application No. 202310113530.6, filed on Feb. 14, 2023, the disclosure of which is incorporated herein by reference in entirety.
The present application relates to the field of manufacturing semiconductor integrated circuits, in particular to a wafer temperature control system and control method, a computer device, and a storage medium.
Chemical mechanical polishing (CMP), also referred to as chemical mechanical planarization, is a processing technology that combines a chemical corrosion action and a mechanical removal action. Depending on different objects to be polished, CMP may be classified into: metal polishing and non-metal polishing, such as silicon polishing (Poly CMP), silicon oxide polishing (silicon oxide CMP), silicon carbide polishing (silicon carbide CMP), tungsten polishing (W CMP), and copper polishing (Cu CMP), etc. A polishing apparatus includes: a slurry, a pad, a platen, a brush, and chemicals such as a cleaning agent and a protective agent, etc.
During the chemical mechanical polishing, the pad is in contact with a wafer, and relative rotation friction is performed by means of the slurry, so as to remove a thin film with a certain thickness from the surface of the wafer. However, in the case of long polishing time, heat generated by the polishing cannot be dissipated, thus affecting the removal rate and the wafer state, which is unfavourable to accurate control of the process. Accordingly, polishing table cooling is required during the polishing. An existing method for polishing table cooling includes: 1) cooling the platen physically by means of cooling water circulation, using the principle of heat conduction resulting from a contact between a cooling water pipe and the platen; 2) when no slurry flows during the polishing or when the polishing ends, cooling the pad at the same time when flushing the pad under high pressure with deionized water; and 3) removing ambient heat within the polishing apparatus by means of a water curtain present on the sidewall of the table. However, cooling the platen merely reducing impacts of the metal platen on the heat of the pad; deionized water (DIW) cooling is just auxiliary cooling performed during cleaning, which has poor cooling effect; in addition, cooling realized by removing heat using the water curtain on the sidewall of the table likewise cannot achieve a desired effect.
In view of the above defects in the prior art, the objective of the present application is to provide a wafer temperature control system and control method, a computer device, and a storage medium, so as to solve the problem that the existing wafer cooling method cannot achieve a good cooling effect and thus leads to an impact on wafer polishing accuracy.
In order to achieve the above objective and other related objectives, the present application provides a wafer temperature control system, including: a wafer polishing apparatus, a control module, an adjustment module, and a monitoring module, wherein:
Optionally, the polishing head includes five independent gas passages, and during the chemical mechanical polishing, the cooling gas is introduced into all the five gas passages.
Optionally, the cooling gas includes nitrogen or an inert gas.
Optionally, the monitoring module includes at least one temperature sensor.
Optionally, the control module includes a receiving unit, a processing unit, and a sending unit, and the receiving unit is configured to receive the temperature signal and send the temperature signal to the processing unit; the processing unit performs analysis calculation according to the received temperature signal to obtain the adjustment signal, and sends the adjustment signal to the adjustment module by means of the sending unit.
Optionally, the adjustment module includes a gas flow adjuster.
The present application further provides a wafer temperature control method using the above wafer temperature control system, including:
The present application further provides a computer device, including a processor and a memory, wherein the processor is adapted to implement various instructions, and the memory is adapted to store a plurality of instructions, the instructions being adapted to be loaded by the processor and to perform the above wafer temperature control method.
The present application further provides a computer-readable storage medium, storing computer executable instructions which, when executed, implement the above wafer temperature control method.
As stated above, the wafer temperature control system and control method, the computer device, and the storage medium of the present application reduce the temperature of the wafer by introducing the cooling gas into the gas passages of the polishing head, and use the temperature sensor to monitor the temperature of the wafer in real time, so as to adjust the flow rate and the introduction duration of the cooling gas in real time, thereby adjusting the temperature of the wafer. Through the above ways, the impacts of the wafer temperature on the polishing during a polishing process may be reduced, thereby improving the accuracy of the chemical mechanical polishing.
The embodiments of the present application are described below using specific examples, and those skilled in the art could readily understand other advantages and effects of the present application from the contents disclosed in the description. The present application can also be implemented or applied using other different specific implementations, and various details in the description can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application.
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In particular, the polishing head includes five independent gas passages, and during the chemical mechanical polishing, the cooling gas is introduced into all the five gas passages.
In this embodiment, the five independent gas passages included in the polishing head control pressures on different areas of the surface of the wafer respectively, so as to control a removal rate.
As an example, the cooling gas includes nitrogen or an inert gas. In this embodiment, the inert gas includes argon.
In particular, the monitoring module includes at least one temperature sensor.
In this embodiment, the number of the temperature sensors may be selected as needed. In order to ensure the accuracy of the obtained temperature signal, a plurality of temperature sensors may be provided. The plurality of temperature sensors are used to acquire temperature data of different areas of the wafer, and then the acquired multiple pieces of temperature data are processed to obtain the temperature signal. Optionally, in this embodiment, there are three temperature sensors.
Particularly, the control module includes a receiving unit, a processing unit, and a sending unit, wherein the receiving unit is configured to receive the temperature signal and send same to the processing unit. The processing unit performs analysis calculation according to the received temperature signal to obtain the adjustment signal, and sends the adjustment signal to the adjustment module by means of the sending unit.
In this embodiment, the processing unit stores therein a correspondence between the temperature signal and the introduction duration and the flow rate of the cooling gas, adjusts the introduction duration and the flow rate of the cooling gas in real time according to the correspondence after receiving the temperature signal, and sends an adjusted introduction duration and flow rate to the adjustment module as the adjustment signal.
Particularly, the adjustment module includes a gas flow adjuster.
In this embodiment, the gas flow adjuster adjusts the introduction duration and the flow rate of the cooling gas when receiving the adjustment signal.
This embodiment further provides a wafer temperature control method using the above wafer temperature control system, including:
This embodiment further provides a computer device, including a processor and a memory, wherein the processor is adapted to implement various instructions, and the memory is adapted to store a plurality of instructions, the instructions being adapted to be loaded by the processor and to perform steps of the above wafer temperature control method. The steps of the wafer temperature control method are described in detail above, which are no longer repeated here.
This embodiment further provides a computer-readable storage medium for storing instructions which, when executed, implement the steps of the above wafer temperature control method. The steps of the wafer temperature control method are described in detail above, which are no longer repeated here.
To sum up, the wafer temperature control system and control method, the computer device, and the storage medium of the present application reduce the temperature of the wafer by introducing the cooling gas into the gas passages of the polishing head, and use the temperature sensor to monitor the temperature of the wafer in real time, so as to adjust the flow rate and the introduction duration of the cooling gas in real time, thereby adjusting the temperature of the wafer. Through the above ways, the impacts of the wafer temperature on the polishing during a polishing process may be reduced, thereby improving the accuracy of the chemical mechanical polishing. Therefore, the present application effectively overcomes various defects in the prior art and thus has high industrial utilization.
The above embodiments merely illustrate the principle and effect of the present application, rather than for limiting the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the art without departing from the spirit and technical idea disclosed in the present application shall still be covered by the claims of the present application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202310113530.6 | Feb 2023 | CN | national |
