METHOD OF USING SOLID CARBON DIOXIDE TO ROUGH SURFACE

Description

BACKGROUND

Field of Invention

The present disclosure relates to methods of using solid carbon dioxide to rough a surface.

Description of Related Art

Roughening the surface of the component in the semiconductor device may sometimes lead to advantages. For example, in the capacitor of a memory device, e.g., dynamic random-access memory (DRAM), when the surface of the electrode is rough, it may lead to a higher capacitance. However, the method to roughen the surface usually may need additional processing tools and steps, thereby significantly increasing the manufacturing cost. Therefore, a method compatible to the existing semiconductor processes and easy to implement is essential for roughening the surface.

SUMMARY

The present disclosure provides a method of using solid carbon dioxide to roughen a surface. The method includes the following operations. Solid carbon dioxide is generated. Generating the solid carbon dioxide includes directing carbon dioxide from a gas cylinder to pass through a cooled nozzle to enter a vacuum chamber, in which the solid carbon dioxide is formed after the carbon dioxide passes through the cooled nozzle, and a velocity of the solid carbon dioxide exiting from the cooled nozzle is from 1000 m/s to 3000 m/s. The cooled nozzle is moved continuously and substantially horizontally above a surface of a substrate in the vacuum chamber to bump the surface of the substrate with the solid carbon dioxide to form a rough surface of the substrate.

In some embodiments, the substrate includes silicon oxide, silicon nitride, metal, or combinations thereof.

In some embodiments, an average particle size of the solid carbon dioxide is from 3 nm to 300 nm.

In some embodiments, an average depth of holes on the rough surface of the substrate is from 5 nm to 2000 nm.

In some embodiments, when generating the solid carbon dioxide, a gas carbon dioxide is exited from the cooled nozzle along with the solid carbon dioxide, and a molar ratio of the solid carbon dioxide in a mixture of the gas carbon dioxide and the solid the carbon dioxide is at least 80%.

In some embodiments, a temperature of the cooled nozzle is from -50 °C to -100 °C.

In some embodiments, continuously and substantially horizontally moving the cooled nozzle above the surface of the substrate includes tilting the cooled nozzle at an angle relative to the surface of the substrate, and the angle is from 20° to 70°.

In some embodiments, a flow rate of the carbon dioxide from the gas cylinder is from 500 SCCM to 1000 SCCM.

In some embodiments, a diameter of an exit hole of the cooled nozzle is from 0.5 mm to 10 mm.

In some embodiments, a pressure in the vacuum chamber is from 0.1 Torr to 10 Torr.

In some embodiments, when continuously and substantially horizontally moving the cooled nozzle above the surface of the substrate, a distance between the cooled nozzle and the substrate is from 8 cm to 15 cm.

The present disclosure also provides a method of using solid carbon dioxide to roughen a surface. The method includes the following operations. Solid carbon dioxide is generated. Generating the solid carbon dioxide includes directing carbon dioxide from a gas cylinder to pass through cooled nozzles to enter a vacuum chamber, in which the solid carbon dioxide is formed after the carbon dioxide passes through the cooled nozzles, and a velocity of the solid carbon dioxide exiting from the cooled nozzles is from 1000 m/s to 3000 m/s. A surface of a substrate in the vacuum chamber is bumped with the solid carbon dioxide generated from the cooled nozzles to form a rough surface of the substrate.

In some embodiments, the cooled nozzles form an array extending above the surface of the substrate.

In some embodiments, the substrate includes silicon oxide, silicon nitride, metal, or combinations thereof.

In some embodiments, temperatures of the cooled nozzles are from -50 °C to -100 °C.

In some embodiments, bumping the surface of the substrate in the vacuum chamber with the solid carbon dioxide generated from the cooled nozzles includes tilting each one of the cooled nozzles at an angle relative to the surface of the substrate, and the angle is from 20° to 70°.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be more fully understood by reading the following detailed description of the embodiments, with reference made to the accompanying figures as follows.

FIG. 1 is a flowchart of a method of using solid carbon dioxide to rough a surface, according to some embodiments of the present disclosure.

FIG. 2 is a flowchart of a method of using solid carbon dioxide to rough a surface, according to some embodiments of the present disclosure.

FIG. 3 is a schematic diagram illustrating using the method of using solid carbon dioxide to rough a surface, according to some embodiments of the present disclosure.

FIG. 4 is a schematic diagram illustrating using the method of using solid carbon dioxide to rough a surface, according to some embodiments of the present disclosure.

FIG. 5 is a schematic diagram of the surface after using the method of using solid carbon dioxide to rough a surface, according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

To make the description of the present disclosure detailed and complete, the following is an illustrative description of the aspects of the embodiments. This is not to limit the embodiments of the present disclosure to only one form. The embodiments of the present disclosure may be combined or substituted with each other when it is beneficial, and other embodiments may be added without further explanation.

In addition, spatially relative terms, such as below and above, etc., may be used in the present disclosure to describe the relationship between one element (or feature) to another element (or feature) in the figures. In addition to the orientation depicted in the figures, spatially relative terms are intended to encompass different orientations of the device in use or in operation. For example, the device may be oriented otherwise (e.g., rotated at 90 degrees), and the spatially relative terms can be interpreted accordingly. In the present disclosure, unless otherwise indicated, the same element numbers in different figures refer to the same or similar elements formed from the same or similar materials by the same or similar methods.

The terms “around”, “approximately”, “nearly”, “basically”, "substantially", etc., used in the present disclosure include the stated values (or characteristics) and a deviation of the stated values (or characteristics) understood by one skilled in the art. For example, considering the errors of the values (or characteristics), these terms may indicate the values within one or more standard deviations (e.g., the values within ±30%, ±20%, ±15%, ±10%, or ±5%), or may indicate the characteristics including the deviation from the practical operation (e.g., the “substantially parallel” may indicate close to parallel in practical, rather than a perfect ideally parallelism). Furthermore, it is possible to select an acceptable range of the deviation according to the nature of the measurement or other properties, instead of applying only one single deviation range to all the values ​​(or characteristics).

The present disclosure provides a method 100 of using solid carbon dioxide to roughen a surface and a method 200 of using solid carbon dioxide to roughen a surface, as shown in FIGS. 1 and 2, respectively. The schematic diagrams of using the method 100 and the method 200 are provided in FIGS. 3 and 4, respectively. When reading FIGS. 1 and 2, please refer to FIGS. 3 and 4 for a more detailed explanation of the present disclosure. Next, the method 100 and the method 200 of the present disclosure are described in detail below.

In FIGS. 1 and 2 and referring to FIGS. 3 and 4, an operation 101 of the method 100 and an operation 201 of the method 200 include generating solid carbon dioxide. In the operation 101, generating the solid carbon dioxide includes directing carbon dioxide from a gas cylinder 1001 to pass through a cooled nozzle 1002 to enter a vacuum chamber 1003, in which the solid carbon dioxide is formed after the carbon dioxide passes through the cooled nozzle 1002. In the operation 201, generating the solid carbon dioxide includes directing carbon dioxide from a gas cylinder 2001 to pass through cooled nozzles 2002 to enter a vacuum chamber 2003, in which the solid carbon dioxide is formed after the carbon dioxide passes through the cooled nozzles 2002. After performing the operation 101 or the operation 102, the solid carbon dioxide is generated and exits from the cooled nozzle 1002 or the cooled nozzles 2002 with a velocity from 1000 m/s to 3000 m/s, for example, 1000 m/s, 1500 m/s, 2000 m/s, 2500 m/s, or 3000 m/s. If the velocity is too small, the energy of the solid carbon dioxide may not be strong enough to roughen a surface in the following operations, and/or the roughness on the surface may be too small to provide beneficial effects. If the velocity is too large, the energy of the solid carbon dioxide may be too strong and cause adverse effects, for example, damaging the surface.

Next, in FIGS. 1 and 2 and referring to FIGS. 3 and 4, in the operation 102 of the method 100 or the operation 202 of the method 200, the solid carbon dioxide is bumped to the surface 3000S of the substrate 3000 to form a rough surface 3000RS of the substrate 3000, as shown in FIG. 5. In the operation 102, the cooled nozzle 1002 is moved continuously and substantially horizontally above the surface 3000S of the substrate 3000 disposed in the vacuum chamber 1003 in order to bump the surface 3000S of the substrate 3000 with the solid carbon dioxide. In the operation 202, the cooled nozzles 2002 are not continuously and substantially horizontally moved above the surface 3000S of the substrate 3000 when bumping the surface 3000S of the substrate 3000 disposed in the vacuum chamber 2003 with the solid carbon dioxide. Instead, the geometrical center of the cooled nozzles 2002 is fixed in a horizontal direction parallel to the surface 3000S of the substrate 3000 when bumping the surface 3000S of the substrate 3000 with the solid carbon dioxide.

The method 100 and the method 200 of the present disclosure bump the surface 3000S of the substrate 3000 with the solid carbon dioxide to form the rough surface 3000RS of the substrate 3000 for the subsequent applications, for example, the applications used in various semiconductor processes. The rough surface 3000RS of the substrate 3000 may also improve the performance of the semiconductor structure, for example, increasing the capacitance of the capacitor in the semiconductor memory device when the substrate 3000 is the electrode of the capacitor and when the surface of the electrode is rough. The materials used in the method 100 and the method 200 are also easy to obtain and the whole processes are easy and compatible with the existing semiconductor processes. Next, the method 100 and the method 200 of the present disclosure are described in detail from the embodiments provided below.

In the operation 101 or the operation 201, the precursor (e.g., the gas carbon dioxide provided when carbon dioxide stored in the gas cylinder 1001 or the gas cylinder 2001 exiting from the gas cylinder 1001 or the gas cylinder 2001) of the solid carbon dioxide is provided by the gas cylinder 1001 or the gas cylinder 2001. In some embodiments, the gas cylinder 1001 or the gas cylinder 2001 includes carbon dioxide stored at a pressure above atmospheric pressure, for example, the pressure preferably from 5000 kPa to 8000 kPa, e.g., 5000 kPa, 6000 kPa, 7000 kPa, or 8000 kPa, to efficiently store a large amount of the carbon dioxide in the state of compressed gas, liquid, or a combination thereof. The high pressure of the carbon dioxide in the gas cylinder 1001 or the gas cylinder 2001 is also beneficial for being transformed into the solid carbon dioxide when temperature and pressure are reduced.

In the operation 101 or the operation 201, the pressure of the carbon dioxide is reduced after exiting from the gas cylinder 1001 or the gas cylinder 2001, and the temperature of the carbon dioxide is further reduced by passing through the cooled nozzle 1002 or the cooled nozzles 2002, such that the solid carbon dioxide is formed after exiting the cooled nozzle 1002 or the cooled nozzles 2002. In some embodiments, only the solid carbon dioxide is exited from the cooled nozzle 1002 or the cooled nozzles 2002. In some embodiments, a gas and solid mixture including the gas carbon dioxide and the solid carbon dioxide is exited from the cooled nozzle 1002 or the cooled nozzles 2002. In some embodiments, in the gas and solid mixture, a molar ratio of the solid carbon dioxide is preferably at least 80%, for example, at least 85%, at least 90%, or at least 95%, in order to increase the amount of the solid carbon dioxide for efficiently using the solid carbon dioxide to bump the surface 3000S of the substrate 3000 to become the rough surface 3000RS of the substrate 3000. In some embodiments, an average particle size or diameter of the solid carbon dioxide is preferably from 3 nm to 300 nm, for example, 3 nm, 5 nm, 15 nm, 75 nm, 150 nm, 175 nm, 200 nm, 250 nm, or 300 nm. If the average particle size or diameter is too small, the efficiency of bumping the surface 3000S of the substrate 3000 may be poor, and/or the roughness on the rough surface 3000RS of the substrate 3000 may not be desirable to provide beneficial effects. If the average particle size or diameter is too large, bumping the solid carbon dioxide to the surface 3000S of the substrate 3000 may cause adverse effects, for example, damaging the surface 3000S of the substrate 3000.

In addition, since the carbon dioxide is released from the pressurized gas cylinder 1001 or the gas cylinder 2001 and enters a small size of the cooled nozzle 1002 or the cooled nozzles 2002, the carbon dioxide may be accelerated in the cooled nozzle 1002 or the cooled nozzles 2002 to make the solid carbon dioxide exit from the cooled nozzle 1002 or the cooled nozzles 2002 as an explosion having the desirable velocity, solid composition, and/or solid size. In some embodiments, a preferable flow rate of the carbon dioxide from the gas cylinder 1001 of the gas cylinder 2001 to enter the cooled nozzle 1002 or the cooled nozzles 2002 is preferably from 500 SCCM to 1000 SCCM, for example, 500 SCCM, 600 SCCM, 700 SCCM, 800 SCCM, 900 SCCM, or 1000 SCCM, in order to provide a suitable amount of the carbon dioxide entering the cooled nozzle 1002 or the cooled nozzles 2002 and to cause a suitable pressure difference from the pressurized gas cylinder 1001 or the gas cylinder 2001 entering the small size of the cooled nozzle 1002 or the cooled nozzles 2002, thereby obtaining the solid carbon dioxide having the desirable velocity, solid composition, and/or solid size.

In some embodiments, the cooled nozzle 1002 or each one of the cooled nozzles 2002 is preferably having a smaller diameter D1 between the diameters of the two ends in order to perform a better explosion or acceleration of the carbon dioxide to obtain the solid carbon dioxide having the desirable velocity, solid composition, and/or solid size. In some embodiments, the diameter D2 on the end of the exit hole of the cooled nozzle 1002 or each one of the cooled nozzles 2002 is preferably from 0.5 mm to 10 mm, for example, 0.5 mm, 1 mm, 2 mm, 5 mm, 8 mm, or 10 mm, in order to perform a better explosion or acceleration of the carbon dioxide to obtain the solid carbon dioxide having the desirable velocity, solid composition, and/or solid size.

In some embodiments, a temperature of the cooled nozzle 1002 or a temperature of each one of the cooled nozzles 2002 is preferably from -50 °C to -100 °C, for example, -50 °C, -60 °C, -70 °C, -80 °C, -90 °C, or -100 °C, in order to decrease the temperature of the carbon dioxide passing through the cooled nozzle 1002 or the cooled nozzles 2002 to form the solid carbon dioxide in the desirable velocity, solid composition, and/or solid size.

In the operation 102 or the operation 202, the solid carbon dioxide exited from the cooled nozzle 1002 or the cooled nozzles 2002 is bumped to the surface 3000S of the substrate 3000 in the vacuum chamber 1003 or the vacuum chamber 2003 to form the rough surface 3000RS of the substrate 3000. In some embodiments, the exit hole of the cooled nozzle 1002 or each one of the cooled nozzles 2002 faces the surface 3000S of the substrate 3000, so the solid carbon dioxide can bump to the surface 3000S of the substrate 3000 directly through its high velocity. In the operation 102, the cooled nozzle 1002 is moved continually and substantially horizontally above the surface 3000S of the substrate 3000 along a direction DIR1 parallel to the surface 3000S of the substrate 3000, in order to evenly roughen the surface 3000S of the substrate 3000, and in some embodiments, the cooled nozzle 1002 is moved continually and substantially horizontally on an entirety of the surface 3000S of the substrate 3000. In the operation 102, in some embodiments, the cooled nozzle 1002 is connected to an actuator (not drawn). In the operation 102, in some embodiments, the cooled nozzle 1002 moves with a fixed rate above the surface 3000S of the substrate 3000. In the operation 202, the cooled nozzles 2002 are not continually and substantially horizontally moved on the surface 3000S of the substrate 3000, the geometrical center of the cooled nozzles 2002 is fixed in a horizontal position, and in some embodiments, the cooled nozzles 2002 form a two-dimensional array extending on an entirety of the surface 3000S of the substrate 3000 in order to evenly roughen the surface 3000S of the substrate 3000. In the operation 202, in some embodiments, the numbers of the cooled nozzles 2002 are more than one and not limited. In the operation 202, in some embodiments, the cooled nozzles 2002 are disposed equally above the surface 3000S of the substrate 3000.

In some embodiments, a long axis AXIS of the cooled nozzle 1002 or each one of the cooled nozzles 2002 is tilled at an angle θ relative to the surface 3000S of the substrate 3000, and the angle θ is preferably from 20° to 70°, for example, 20°, 30°, 40°, 50°, 60°, or 70°, such that the primary bumping direction DIR2 parallel to the long axis AXIS of the cooled nozzle 1002 or each one of the cooled nozzles 2002 has the angle θ relative to the surface 3000S of the substrate 3000, in order to efficiently obtain the desirable roughness on the rough surface 3000RS of the substrate 3000.

In some embodiments, a distance D3 between the cooled nozzle 1002 or the cooled nozzles 2002 and the surface 3000S of the substrate 3000 is preferably from 8 cm to 15 cm, for example, 8 cm, 10 cm, 12 cm, or 15 cm, in order to efficiently bump the surface 3000S of the substrate 3000 with the solid carbon dioxide and obtain the desirable roughness of the rough surface 3000RS of the substrate 3000. In some embodiments, a pressure in the vacuum chamber 1003 or the vacuum chamber 2003 is preferably from 0.1 Torr to 10 Torr, for example, 0.1 Torr, 1 Torr, 2.5 Torr, 5 Torr, 7.5 Torr, or 10 Torr, in order to remain a sufficient amount of the solid carbon dioxide in the vacuum chamber 1003 or the vacuum chamber 2003 to perform the bumping and to remove the impurity in the vacuum chamber 1003 or the vacuum chamber 2003 by vaporizing the impurity at low pressure.

In some embodiments, the substrate 3000 is disposed on a holder 1004 or a holder 2004 in the vacuum chamber 1003 or the vacuum chamber 2003. In some embodiments, the substrate 3000 is disposed above the cooled nozzle 1002 or the cooled nozzles 2002 relative to the gravity pointing down, so the impurity may not easily form on the surface 3000S of the substrate 3000 when the solid carbon dioxide is bumped to the surface 3000S of the substrate 3000 from bottom to top. In some embodiments, a vacuum pump 1005 or a vacuum pump 2005 is connected to the vacuum chamber 1003 or the vacuum chamber 2003 to maintain the desirable pressure of the vacuum chamber 1003 or the vacuum chamber 2003. In some embodiments, a vacuum tube 1006 or a vacuum tube 2006 is used to connect the gas cylinder 1001 and the cooled nozzle 1002 or the gas cylinder 2001 and the cooled nozzles 2002.

After performing the operation 102 or the operation 202, the rough surface 3000RS of the substrate 3000 is formed. In some embodiments, the substrate 3000 includes silicon oxide, silicon nitride, metal, or combinations thereof. In some embodiments, an average depth D4 of holes on the rough surface 3000RS of the substrate 3000 is preferably from 5 nm to 2000 nm, for example, 5 nm, 15 nm, 20 nm, 75 nm, 150 nm, 200 nm, 250 nm, 500 nm, 1000 nm, 1500 nm, or 2000 nm, in order to have a desirable roughness of the rough surface 3000RS of the substrate 3000 to improve the performance of the substrate 3000 for the subsequent applications, for example, increasing the capacitance of the capacitor when the substrate 3000 including the metal is used as the electrode of the capacitor in the memory device.

The methods of the present disclosure can form a rough surface of a substrate for the subsequent applications, for example, the applications used in various semiconductor processes or structures. In some embodiments, the rough surface of the substrate may improve the performance of the semiconductor structure and/or simplify the subsequent semiconductor processes. In addition, the materials used in the methods are easy to obtain and the whole processes are easy and compatible with the existing semiconductor processes.

The present disclosure is described in considerable detail in some embodiments, but other embodiments may also be feasible, so the description of the embodiments in the present disclosure is not intended to limit the scope and spirit of the claims attached. For one skilled in the art, the present disclosure may be modified and changed without deviating from the scope and spirit of the present disclosure. Such modifications and changes are intended to be covered by the present disclosure when they belong to the scope and spirit of the attached claims.