Chemical Mechanical Polishing Device and Method

This application claims the benefit of Korean Patent Application No. 10-2024-0047394, filed on Apr. 8, 2024, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated by reference herein for all purposes.

The following embodiments relate to a chemical mechanical polishing device and method.

Manufacturing substrates requires chemical mechanical planarization (CMP) tasks including polishing, buffing, and cleaning. A CMP task includes a polishing process in which a substrate to be polished is physically worn by contacting a polishing pad, and through the polishing process, the surface state of the substrate reaches a target profile.

During the process of polishing the substrate, slurry may be supplied to the surface of the substrate. The slurry may be supplied between the substrate and the polishing pad to perform physical polishing through mechanical friction against the surface of the substrate, and at the same time, the surface of the substrate may be chemically polished through a chemical reaction of the composition that makes up the slurry.

During the process of polishing the substrate, the temperature of the surface of the polishing pad may increase due to the friction with the substrate. When the temperature of the polishing pad increases, the surface of the polishing pad may become vulnerable to damage and may cause defects in the substrate polished through the polishing pad. For example, foreign substances such as slurry used in the CMP process and particles from substrate polishing may chemically corrode the polishing pad and physically cause unevenness in the surface of the polishing pad. The corrosion and unevenness of the polishing pad may prevent the substrate from being polished smoothly, thereby lowering the yield of the substrate. Additionally, polishing the substrate using the polishing pad with an increased temperature may cause defects in the substrate such as dishing and erosion.

The above description is information the inventor(s) acquired during the course of conceiving the present disclosure, or already possessed at the time, and is not necessarily art publicly known before the present application was filed.

An embodiment provides a chemical mechanical polishing device and method of spraying a low-temperature gas on a polishing pad during substrate polishing.

An embodiment provides a chemical mechanical polishing device and method of reducing the temperature of a polishing pad through adiabatic expansion by spraying a gas compressed with high pressure.

An embodiment provides a chemical mechanical polishing device and method of preventing freezing around an outlet port of a nozzle when a low-temperature gas is sprayed through the outlet port of the nozzle.

An embodiment provides a chemical mechanical polishing device and method of detecting the temperature of a polishing pad and regulating the temperature of a gas to be sprayed based on the detected temperature.

According to an aspect, there is provided a chemical mechanical polishing device for spraying a gas on a polishing pad for poshing a substrate, the chemical mechanical poshing device including a first gas supplier configured to supply a first gas of a high pressure for cooling a polishing pad, a second gas supplier configured to supply a second gas for preventing water vapor from condensing, a spraying nozzle including a first outlet port connected to the first gas supplier and configured to spray the first gas on the polishing pad and a second outlet port connected to the second gas supplier and configured to spray the second gas on the polishing pad, an automatic regulating valve connected to each of the first gas supplier and the second gas supplier and configured to regulate supply of the first gas and the second gas to the spraying nozzle, and a controller configured to control the automatic regulating valve.

In an embodiment, the controller may be configured to control the automatic regulating valve such that the spraying nozzle sprays the first gas of high pressure to cool the polishing pad and sprays the second gas to prevent water vapor from condensing around the outlet port.

In an embodiment, based on cross-sections of the first outlet port and the second outlet port, the first outlet port may be positioned at a center, and the second outlet port may be formed to enclose a circumference of the first outlet port.

In an embodiment, based on the cross-sections of the first outlet port and the second outlet port, the first outlet port may be formed in a circular shape, and the second outlet port may be formed in an annular shape to enclose the circumference of the first outlet port.

In an embodiment, a sum of cross-sectional areas of the first gas supplier may be greater than a sum of total cross-sectional areas of the first outlet port.

According to an embodiment, the chemical mechanical polishing device may further include a temperature sensor configured to detect a temperature of the polishing pad. In an embodiment, the controller may be configured to feedback-control, based on the temperature of the polishing pad detected by the temperature sensor, the automatic regulating valve.

In an embodiment, the automatic regulating valve may include a pressure regulating value configured to regulate spraying pressure of the first gas and the second gas and a pressure sensor configured to detect pressure of the first gas and the second gas.

In an embodiment, the automatic regulating valve may include a flow rate regulating valve configured to regulate a flow rate of the first gas and a flow rate of the second gas and a flow rate sensor configured to detect the flow rate of the first gas and the flow rate of the second gas.

In an embodiment, the controller may be configured to control the automatic regulating valve to supply the first gas through the spraying nozzle and then additionally supply the second gas for a predetermined time.

In an embodiment, the controller may be configured to control the automatic regulating valve to supply the first gas and the second gas simultaneously through the spraying nozzle.

In an embodiment, the controller may be configured to control the automatic regulating valve such that the first gas and the second gas sprayed through the spraying nozzle are sprayed in a way that pressure of the first gas is different from pressure of the second gas.

In an embodiment, the spraying nozzle may include a mixing flow path and an outlet port fluidly connected to the mixing flow path and configured to spray, to outside, the first gas and the second gas mixed in the mixing flow path.

In an embodiment, the first gas may include at least one of carbon dioxide, ammonia, and butane. In an embodiment, the second gas may include an inert gas.

According to an aspect, there is provided a substrate polishing system including a polishing pad configured to polish a substrate, a carrier head configured to grip the substrate and cause the substrate to contact the polishing pad, and a chemical mechanical polishing device disposed on the polishing pad and configured to spray a gas on the polishing pad. In an embodiment, the chemical mechanical polishing device may include a first gas supplier configured to supply a first gas of high pressure, a second gas supplier configured to supply a second gas, a spraying nozzle fluidly connected to the first gas supplier and the second gas supplier and including an outlet port to spray the first gas and the second gas on the polishing pad, an automatic regulating valve connected to each of the first gas supplier and the second gas supplier and configured to regulate supply of the first gas and the second gas to the spraying nozzle, a controller configured to control the automatic regulating valve, and a temperature sensor configured to detect a temperature of the polishing pad. In an embodiment, the controller may be configured to control the automatic regulating valve such that the spraying nozzle sprays the first gas of high pressure to cool the polishing pad and sprays the second gas to prevent water vapor from condensing around the outlet port and feedback-control, based on the temperature of the polishing pad detected by the temperature sensor, the automatic regulating valve.

Additional aspects of embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure.

According to an embodiment, a chemical mechanical polishing device may decrease the temperature of a polishing pad by spraying a gas on the polishing pad during substrate polishing.

According to embodiment, the chemical mechanical polishing device may reduce and/or prevent defects that may occur on a substrate due to a poor state of a polishing pad by decreasing the temperature of the polishing pad during substrate polishing.

According to embodiment, the chemical mechanical polishing device may reduce or prevent a nozzle from being frozen by spraying a low-temperature gas through the nozzle by supplying different gases to the nozzle.

The effects of a low-temperature gas spraying device according to the disclosure are not limited to the above-mentioned effects, and other unmentioned effects can be clearly understood from the following description by one of ordinary skill in the art.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Regarding the reference numerals assigned to the components in the drawings, it should be noted that the same components will be designated by the same reference numerals, wherever possible, even though they are shown in different drawings. Also, in the description of the embodiments, detailed description of well-known related structures or functions will be omitted when it is deemed that such description will cause ambiguous interpretation of the present disclosure.

Also, in the description of the components, terms such as first, second, A, B, (a), (b) or the like may be used herein when describing components of the embodiments. These terms are used only for the purpose of discriminating one component from another component, and the nature, the sequences, or the orders of the components are not limited by the terms. When one component is described as being “connected”, “coupled”, or “attached” to another component, it should be understood that one component may be connected or attached directly to another component, and an intervening component may also be “connected”, “coupled”, or “attached” to the components.

Components included in one embodiment and components having a common function will be described using the same names in other embodiments. Unless otherwise mentioned, the descriptions of an embodiment may be applicable to other embodiments and thus, repeated descriptions are omitted for conciseness.

is a perspective view schematically illustrating a substrate polishing system according to an embodiment.

Referring to, a substrate polishing systemaccording to an embodiment may be used for a chemical mechanical planarization (CMP) process of a substrate. The substrate polishing systemmay physically and chemically polish a surface of a substrate W such that the smoothness of the surface of the substrate W reaches a target profile.

The substrate W, which is polished by the substrate polishing system, may be a silicon wafer for a semiconductor. However, the type of the substrate is not limited thereto, and the substrate may be glass for a flat panel display (FPD) device such as a liquid crystal display (LCD) and a plasma display panel (PDP).

In an embodiment, the substrate polishing systemmay include a polishing pad, a carrier head C, and a chemical mechanical polishing device.

In an embodiment, the carrier head C may grip the substrate W. The carrier head C may chuck and grip the substrate W to be polished and may move the gripped substrate W to the upper portion of the polishing pad. The carrier head C may polish the substrate W by causing the substrate W, which is moved to the upper portion of the polishing pad, to contact the polishing pad. The carrier head C may regulate the frictional force between the substrate W and the polishing padto regulate the degree of polishing by pressing the substrate W contacting the polishing pad. In an embodiment, the carrier head C may receive power from the outside and rotate on an axis perpendicular to a surface of the polishing pad. As the carrier head C rotates, the gripped substrate W may be polished while contacting the polishing padand rotating.

In an embodiment, the polishing padmay polish the substrate W by contacting the substrate W gripped by the carrier head C and relatively rotating. For example, the polishing padmay rotate while contacting the substrate W gripped by the carrier head C. For example, the polishing padmay stay still while the carrier head C gripping the substrate W rotates. In this case, the polishing padand the substrate W may cause friction by relatively rotating while in contact with each other, thereby polishing the substrate W. In this case, the temperature of the polishing padmay increase.

In an embodiment, the chemical mechanical polishing devicemay spray a gas G on the polishing padand regulate the temperature of the polishing pad. For example, the chemical mechanical polishing devicemay cool the polishing padof which the temperature increases due to the friction with the substrate W. In an embodiment, the chemical mechanical polishing devicemay cool the polishing padby spraying the gas G on the polishing padwhile polishing the substrate W. In an embodiment, the chemical mechanical polishing devicemay spray the gas G of high pressure on the polishing pad. In this case, the sprayed gas G may contact and cool the polishing pad. For example, the chemical mechanical polishing devicemay spray the gas G of high pressure on the polishing padthrough a spraying nozzle. In this case, the gas G of high pressure, sprayed by the chemical mechanical polishing device, may undergo a temperature drop through adiabatic expansion, and the gas G at low temperature may contact and cool the polishing pad. However, the gas G is not necessarily sprayed at high pressure, and various modifications may apply to the spraying of the gas G to cool the polishing pad. For example, the chemical mechanical polishing devicemay spray the gas G at low temperature and high pressure. For example, the chemical mechanical polishing devicemay spray the gas G in a liquefied state on the polishing pad. For example, the chemical mechanical polishing devicemay spray, on the polishing pad, the gas G in a solidified state through sublimation.

is a schematic view illustrating a chemical mechanical polishing device according to an embodiment.is a schematic view illustrating the chemical mechanical polishing device according to an embodiment.

In an embodiment, the chemical mechanical polishing devicemay include a first gas supplier, a second gas supplier, the spraying nozzle, an automatic regulating valve, a temperature sensor (not shown), and a controller (not shown). In an embodiment, the chemical mechanical polishing devicemay spray a first gas and a second gas on the polishing padthrough the spraying nozzle.

In an embodiment, the first gas suppliermay supply the first gas to the spraying nozzlesuch that the spraying nozzlesprays the first gas. In an embodiment, the first gas suppliermay be fluidly connected to the spraying nozzle. In an embodiment, the first gas suppliermay include a gas tank (not shown) in which the first gas is stored and a tube (not shown) forming a flow path. In this case, one end of the tube may be connected to the gas tank in which the first gas is stored, and the other end of the tube may be fluidly connected to the spraying nozzle. In this case, the first gas suppliermay supply the first gas from the gas tank to the spraying nozzlethrough the flow path. In an embodiment, the first gas suppliermay supply the first gas at high pressure. For example, the pressure of the first gas supplied from the first gas suppliermay be greater than or equal tobars. For example, the first gas suppliermay supply the first gas that is liquefied at high pressure. For example, the first gas suppliermay supply the first gas in a solidified state with sublimation at high pressure. In an embodiment, the first gas may include at least one of carbon dioxide, ammonia, and butane. However, the pressure, temperature and type of the first gas supplied by the first gas supplierare only examples and not limited thereto. For example, the first gas suppliermay supply the first gas at low temperature and high pressure.

In an embodiment, the second gas suppliermay supply the second gas to the spraying nozzlesuch that the spraying nozzlesprays the second gas. In an embodiment, the second gas suppliermay be fluidly connected to the spraying nozzle. In an embodiment, the second gas suppliermay include a gas tank (not shown) in which the second gas is stored and a tube (not shown) forming a flow path. In this case, one end of the tube may be connected to the gas tank in which the second gas is stored, and the other end of the tube may be fluidly connected to the spraying nozzle. In this case, the second gas suppliermay supply the second gas from the gas tank to the spraying nozzlethrough the flow path. In an embodiment, the second gas suppliermay supply the second gas at high temperature at high pressure. In an embodiment, the second gas may include an inert gas. For example, the second gas may include clean dry air (CDA). For example, the second gas may include nitrogen.

In an embodiment, the spraying nozzlemay cool the polishing padby spraying the first gas and the second gas on the polishing pad. In an embodiment, the spraying nozzlemay receive the first gas and the second gas from the first gas supplierand the second gas supplier. For example, the upper end of the spraying nozzlemay be fluidly connected to the first gas supplierand the second gas supplier. In an embodiment, the spraying nozzlemay spray the first gas and the second gas through an outlet port. For example, the outlet port spraying the first gas and the second gas may be formed at the bottom of the spraying nozzle. In this case, a plurality of outlet ports may be provided.

In an embodiment, the spraying nozzlemay mix the first gas with the second gas and spray the mixed gas. For example, the spraying nozzlemay reduce or prevent the water vapor in the air from condensing around an outlet port of the spraying nozzleand blocking the outlet port by mixing the first gas with the second gas and spraying the mixed gas. For example, the spraying nozzlemay spray the mixture of the first gas and the second gas, thereby regulating the temperature of the mixture of the first gas and the second gas. For example, the spraying nozzlemay form a mixing flow path (not shown). In this case, the mixing flow path may be fluidly connected to the first gas supplierand the second gas supplier. In this case, the gas mixed in the mixing flow path may be sprayed on the polishing padthrough an outlet port formed at the bottom of the spraying nozzle.

In an embodiment, the automatic regulating valvemay regulate the supply of the first gas and the second gas to the spraying nozzle. For example, the automatic regulating valvemay regulate the pressure and/or flow rate of the first gas and the second gas supplied to the spraying nozzle. In an embodiment, the automatic regulating valvemay be connected to each of the first gas supplierand the second gas supplier. For example, the automatic regulating valvemay be connected to a tube forming the flow path of the first gas supplierand a tube forming the flow path of the second gas supplier.

In an embodiment, the automatic regulating valvemay regulate the pressure of the first gas and the second gas. In an embodiment, the automatic regulating valvemay include a pressure regulating valve (not shown) for regulating the spraying pressure of the first gas and the second gas. For example, the automatic regulating valvemay individually regulate the spraying pressure of the first gas and the second gas supplied to the spraying nozzlethrough the pressure regulating valve. In an embodiment, the automatic regulating valvemay regulate the spraying pressure of the first gas and the second gas in real time while the first gas and the second gas are supplied to the spraying nozzle. In an embodiment, the automatic regulating valvemay include a pressure sensor (not shown) for detecting the pressure of the first gas and the second gas. For example, the automatic regulating valvemay individually detect the pressure of the first gas and the pressure of the second gas through the pressure sensor. For example, the automatic regulating valvemay individually detect the pressure of the first gas and the pressure of the second gas in real time while the first gas and the second gas are supplied to the spraying nozzlethrough the pressure sensor.

In an embodiment, the automatic regulating valvemay regulate the flow rate of the first gas and the second gas. In an embodiment, the automatic regulating valvemay include a flow rate regulating valve (not shown) for regulating the flow rate of the first gas and the second gas. For example, the automatic regulating valvemay individually regulate the flow rate of the first gas and the flow rate of the second gas, wherein the first gas and the second gas are supplied to the spraying nozzlethrough the flow rate regulating valve. In an embodiment, the automatic regulating valvemay regulate the flow rate of the first gas and the flow rate of the second gas in real time while the first gas and the second gas are supplied to the spraying nozzle. In an embodiment, the automatic regulating valvemay include a flow rate sensor (not shown) for detecting the flow rate of the first gas and the flow rate of the second gas. For example, the automatic regulating valvemay individually detect the flow rate of the first gas and the flow rate of the second gas through the flow rate sensor. For example, the automatic regulating valvemay individually detect the flow rate of the first gas and the flow rate of the second gas through the flow rate sensor while the first gas and the second gas are supplied to the spraying nozzle.

In an embodiment, the automatic regulating valvemay include a first automatic regulating valve-and a second automatic regulating valve-respectively connected to the first gas supplierand the second gas suppliersuch that the spraying pressure and/or flow rate of the first gas and the spraying pressure and/or flow rate of the second gas are individually regulated. For example, the first automatic regulating valve-and the second automatic regulating valve-may regulate the spraying pressure and/or flow rate of the first gas and the spraying pressure and/or flow rate of the second gas, respectively. The first automatic regulating valve-and the second automatic regulating valve-may be components that are substantially the same as the automatic regulating valve.

In an embodiment, the temperature sensor (not shown) may detect the temperature of the polishing pad. For example, the temperature sensor may measure the temperature of a surface of the polishing pad. For example, the temperature sensor may include an infrared sensor. For example, the temperature sensor may include a measuring sensor embedded in the polishing pad. However, the type and installation technique of the temperature sensor described in the present disclosure are only examples and not limited thereto.