CN-122003311-A - Cold liquid polishing control

Abstract

A chemical mechanical polishing apparatus includes a polishing platen for holding a polishing pad, a carrier for holding a substrate against a polishing surface of the polishing pad during a polishing process, a polishing liquid dispenser having a polishing liquid port positioned above the polishing platen to deliver polishing liquid onto the polishing pad, a temperature control system including a coolant fluid reservoir for containing a coolant fluid, a thermal controller configured to control a temperature of the coolant fluid within the coolant fluid reservoir, and a first dispenser having an opening in fluid connection with the coolant fluid reservoir, the opening being positioned to spray atomized coolant liquid directly onto the polishing pad, and a second dispenser having a coolant port in fluid connection with the coolant fluid reservoir, the coolant port being positioned above the polishing platen and configured to flow a coolant fluid directly onto the polishing pad.

Inventors

• P. D. La Rosa
• ZHUO ZHIZHONG
• WU HAOCHENG
• Sekine healthy people
• ZHANG ZHENWEI
• E.Zhong
• TANG JIANSHE
• S.Shen

Assignees

• 应用材料公司

Dates

Publication Date

20260508

Application Date

20241001

Priority Date

20231005

Claims (20)

1. 1.A chemical mechanical polishing apparatus comprising: a polishing platen for holding a polishing pad; A carrier for holding a substrate against a polishing surface of the polishing pad during a polishing process; A polishing liquid dispenser having a polishing liquid port positioned above the polishing platen to deliver a polishing liquid onto the polishing pad; A temperature control system, comprising: One or more coolant fluid reservoirs for containing one or more coolant fluids, A thermal controller configured to control a temperature of the one or more coolant fluids within the one or more coolant fluid reservoirs, and A first distributor having a plurality of openings in fluid connection with the one or more coolant fluid reservoirs, the plurality of openings positioned above the polishing platen and configured to spray atomized coolant directly onto the polishing pad, A second dispenser having a coolant port in fluid connection with the one or more coolant fluid reservoirs, the coolant port positioned above the polishing platen and configured to flow a flow of coolant directly onto the polishing pad.
2. 2. The apparatus of claim 1, further comprising a temperature control arm extending above the polishing platen, and wherein the one or more openings are formed in a nozzle secured to the temperature control arm.
3. 3. The apparatus of claim 2, wherein the coolant port is secured to the temperature control arm.
4. 4. The apparatus of claim 2, wherein the coolant port is secured to a separate temperature control arm.
5. 5. The apparatus of claim 4, comprising a slurry arm extending above the polishing platen, wherein the coolant port and the slurry port are on the slurry arm.
6. 6. The apparatus of claim 1, wherein the thermal controller comprises a temperature sensor and a temperature control element, and is configured to receive a temperature value from the temperature sensor indicative of a temperature of the coolant fluid, and to control the temperature control element to cool the coolant fluid to less than 5 ℃ based on the received temperature value.
7. 7. The apparatus of claim 1, wherein the one or more coolant fluid reservoirs comprise a first coolant fluid reservoir connected to the plurality of openings of the first dispenser and a second coolant fluid reservoir connected to the port of the second dispenser.
8. 8. The apparatus of claim 7, wherein the second coolant fluid reservoir is configured to hold less coolant fluid than the first coolant fluid reservoir.
9. 9. The apparatus of claim 7, wherein the first coolant fluid reservoir and the second coolant fluid reservoir hold the same composition of cooling fluid.
10. 10. The apparatus of claim 9, wherein the cooling fluid is deionized water.
11. 11. The apparatus of claim 7, wherein the temperature control system is configured to control both the first coolant fluid reservoir and the second coolant fluid reservoir to different temperature values, the temperature value of the second coolant fluid reservoir being lower than the temperature value of the first coolant fluid reservoir.
12. 12. The apparatus of claim 1, wherein the one or more coolant fluid reservoirs comprise a common coolant fluid reservoir connected to the plurality of openings of the first dispenser and to the ports of the second dispenser.
13. 13. The apparatus of claim 1, wherein the temperature control system is configured to dispense less than 1L of fluid through the second dispenser to reduce the temperature of the polishing pad by at least 10 ℃.
14. 14. The apparatus of claim 1, further comprising a controller configured to cause the first dispenser to spray the atomized coolant onto the polishing pad during a polishing step of polishing the substrate on the polishing pad, and to cause the second dispenser to flow the coolant fluid stream onto the polishing pad upon a transition from a first polishing step to a second polishing step.
15. 15. The apparatus of claim 14, wherein the controller is configured to receive a temperature measurement from a sensor during the polishing step and to control the first dispenser to spray the atomized coolant so as to bring the measured temperature to a desired temperature.
16. 16. The apparatus of claim 14, wherein the controller is configured to receive a signal indicative of less than a threshold amount of material remaining to be polished and to control the second dispenser to flow the coolant fluid stream onto the polishing pad in response to the signal.
17. 17. The apparatus of claim 1, further comprising a pad flushing system including nozzles to direct a flushing medium onto the polishing pad.
18. 18. A chemical mechanical polishing system comprising: two polishing stations, each station comprising A polishing platen for holding a polishing pad; A carrier for holding a substrate against a polishing surface of the polishing pad during a polishing process; a polishing liquid dispenser having a polishing liquid port positioned above the polishing disk to deliver a polishing liquid onto the polishing pad, and A coolant dispenser having a coolant port positioned above the polishing platen to deliver a coolant to the polishing pad, and A temperature control system, comprising: A coolant fluid reservoir for containing a coolant fluid and configured to deliver the coolant fluid to a respective coolant port of a respective polishing station, and A thermal controller configured to control the temperature of the coolant fluid within the coolant fluid reservoir.
19. 19. A method for controlling a chemical mechanical polishing process, comprising: In a polishing process, polishing a substrate on a surface of a polishing pad, comprising at least a bulk removal step and a cleaning step; Determining a desired temperature for the bulk removal step; During the bulk removal step, ejecting the polishing pad with a cooling liquid to bring the polishing pad to the desired temperature; detecting a transition from the bulk removal step to the purge step, and In response to detecting the transition from the bulk removal step to the purge step, the coolant is dispensed, flowed onto the surface to reduce the temperature of the polishing pad.
20. 20. The method of claim 19, further comprising controlling the temperature of the coolant to be less than 5 ℃ during the polishing process.

Description

Cold liquid polishing control Technical Field The present disclosure relates to chemical mechanical polishing, and more particularly to control of polishing rate during a polishing process. Background Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconductive or insulative layers on a silicon wafer. One fabrication step involves depositing a filler layer on a non-planar surface and planarizing the filler layer. For some applications, the conductive filler layer is planarized until the top surface of the patterned layer is exposed. For other applications, such as oxide polishing, the filler layer is planarized until a predetermined thickness is left on the non-planar surface. Furthermore, lithography generally requires planarization of the substrate surface. Chemical Mechanical Polishing (CMP) is a well-known planarization method. Such planarization methods typically require the substrate to be mounted on a carrier or polishing head. The exposed surface of the substrate is typically placed against a rotating polishing pad. The carrier head provides a controllable load on the substrate to urge the substrate against the polishing pad. A polishing liquid (e.g., an abrasive slurry) is typically supplied to the surface of the polishing pad. During some chemical mechanical polishing processes, it is desirable to perform different steps of the overall polishing process at different polishing rates. For example, it may be desirable to perform a batch polishing step at a higher polishing rate than the purge step. Conventional methods are to perform different steps, such as batch polishing and cleaning steps, at separate polishing discs (flats), for example with different slurries or with different applied loads. Disclosure of Invention In general, one aspect disclosed herein is a chemical mechanical polishing apparatus comprising a polishing platen for holding a polishing pad, a carrier for holding a substrate against a polishing surface of the polishing pad during a polishing process, a polishing liquid dispenser having a polishing liquid port positioned above the polishing platen for delivering polishing liquid onto the polishing pad, a temperature control system comprising one or more coolant fluid reservoirs for containing one or more coolant fluids, a thermal controller configured to control the temperature of the one or more coolant fluids within the one or more coolant fluid reservoirs, and a first dispenser having a plurality of openings positioned above the polishing platen and configured to spray atomized liquid directly onto the polishing pad, the second dispenser having a plurality of coolant ports positioned directly above the polishing platen and configured to flow coolant fluid onto the polishing pad, the first dispenser having the plurality of coolant ports positioned directly above the coolant fluid ports. Generally, one aspect disclosed herein is a chemical mechanical polishing system comprising two polishing stations, each polishing station comprising a polishing platen for holding a polishing pad, a carrier for holding a substrate against a polishing surface of the polishing pad during a polishing process, a polishing liquid dispenser having a polishing liquid port positioned above the polishing platen for delivering polishing liquid onto the polishing pad, and a coolant dispenser having a coolant port positioned above the polishing platen for delivering coolant onto the polishing pad, and a temperature control system comprising a coolant fluid reservoir for containing coolant fluid and configured to deliver the coolant fluid to the respective coolant ports of the respective polishing stations, and a thermal controller configured to control the temperature of the coolant fluid within the coolant fluid reservoir. Generally, one aspect disclosed herein is a method of controlling a chemical mechanical polishing process that includes polishing a substrate on a surface of a polishing pad during a polishing process, which may include at least a bulk removal step and a purge step, determining a desired temperature for the bulk removal step, spraying the polishing pad with a coolant during the bulk removal step to bring the polishing pad to the desired temperature, detecting a transition from the bulk removal step to the purge step, and, in response to detecting the transition from the bulk removal step to the purge step, distributing and flowing the coolant onto the surface to reduce the temperature of the polishing pad. Examples may include one or more of the following features. The cooling fluid in the process is deionized water. The method may include controlling the temperature of the cooling fluid to be less than 5 ℃ during the polishing process. Advantages may optionally include one or more of the following. The polishing rate can be suddenly and drastically reduced without removing the substrate from the polishing platen. Multiple sequential polis