A method for avoiding crystallization during high-temperature chemical etching reaction spraying

Abstract

The present invention discloses a method for avoiding crystallization during the spraying process of high-temperature chemical etching reaction, which relates to the field of semiconductor technology, including: S1, performing distributed staged control of the wafer, and performing differential optimization of three different positions: the center of the wafer, the outer edge of the wafer, and the interval between the wafer and the cleaning chamber; S2, performing differentiated heat flow distribution of the wafer, and delivering hot air to the upper surface of the wafer through a pure air blowing unit to increase the air flow speed, concentrate the flow and processing capacity of the liquid at the outer edge of the wafer and promote the flow in a stepped strong convection manner; S3, performing surface temperature control in the three-dimensional direction of the wafer. In the present invention, by optimizing the flow field of the wafer, hot air is sprayed onto the surface and edge area of ​​the wafer to control the temperature of the surface and edge area of ​​the wafer, destroying the basic conditions for crystallization, thereby avoiding crystallization on the surface and edge area of ​​the wafer and improving the cleaning effect.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for preventing crystallization from forming during a high-temperature chemical etching reaction spraying process. Background Art

[0002] In the existing technology, special acid solutions such as phosphoric acid, sulfuric acid, and nitric acid are used to clean wafers. These acid solutions are sprayed on the surface of the wafers. Since the acid solutions are released in an open environment, the temperature drops suddenly, and the relative concentration and viscosity increase rapidly, which can easily cause crystallization and affect the cleaning effect. Summary of the Invention

[0003] The object of the present invention is to provide a method for avoiding crystallization during the high-temperature chemical etching reaction spray process, so as to solve the above-mentioned technical problems.

[0004] The technical solution adopted in the present invention is as follows:

[0005] A method for preventing crystallization during a high-temperature chemical etching reaction spray process, comprising:

[0006] S1. Performing distributed phased control of the wafer, placing the wafer on a wafer carrying platform in a cleaning chamber, and performing differential optimization at three different positions: the center of the wafer, the outer edge of the wafer, and the distance between the wafer and the cleaning chamber, to generate exhaust distributions of different intensities to form a gradient intensity flow field;

[0007] S2. Performing differentiated heat flow distribution on the wafers, delivering hot air to the upper surface of the wafers through a pure air blowing unit to increase airflow speed, maintaining the center of the bottom of the wafer at room temperature, and increasing the temperature of the edge of the wafer to concentrate the flow and processing capacity of the liquid at the outer edge of the wafer and promote step-by-step strong convection flow;

[0008] S3. Control the surface temperature of the wafer in three dimensions, and heat the upper surface of the wafer, the lower surface of the wafer, and the edge area of ​​the wafer through comprehensive wafer contact with the heated air flow of the atmosphere.

[0009] Preferably, the edge region of the wafer is heated by a staggered non-contact aerodynamic component capable of outputting hot air flow, thereby ensuring the temperature range of the edge region of the wafer.

[0010] Preferably, a hot air flow jet is arranged at the center of the wafer supporting platform on the lower surface of the wafer, and a ring-shaped inclined angle jet hole is arranged at a relative position of the wafer supporting platform relative to the 3 / 4 inner diameter area of ​​the wafer.

[0011] Preferably, a wafer spray device capable of two-stage simple harmonic movement is arranged at the edge of the wafer, and a heating device is arranged on the wafer spray device to ensure that the outer edge of the wafer and the area adjacent to the outer edge of the wafer are heated and maintained, so that the edge line of the instantaneous contact area of ​​the outer edge of the wafer can concentrate and maintain the temperature.

[0012] As a further preference, the wafer spraying device is arranged at an angle.

[0013] Preferably, the cleaning chamber is divided into three independent layer chambers from top to bottom, each layer chamber is provided with an exhaust device, and the bottom of the wafer carrying platform is provided with a lifting mechanism.

[0014] The above technical solution has the following advantages or beneficial effects:

[0015] The present invention optimizes and controls the flow field of the wafer, utilizes hot air to spray toward the surface and edge areas of the wafer, controls the temperature of the surface and edge areas of the wafer, destroys the basic conditions for crystallization, thereby avoiding crystallization on the surface and edge areas of the wafer and improving the cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flow chart of a method for avoiding crystallization during a high-temperature chemical etching reaction spray process. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not intended to indicate or imply relative importance.

[0019] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0020] Figure 1 This is a flow chart of the method for avoiding crystallization during the high temperature chemical etching reaction spray process of the present invention. Figure 1 FIG. 1 shows a preferred embodiment of a method for avoiding crystallization during a high-temperature chemical etching reaction spray process, comprising:

[0021] S1. Perform distributed, staged control of the wafer. Place the wafer on a wafer support platform within the cleaning chamber and perform differential optimization at three different locations: the center of the wafer, the outer edge of the wafer, and the gap between the wafer and the cleaning chamber. This generates exhaust distributions of varying intensities to form a gradient intensity flow field. In this embodiment, the flow field intensity at the outer edge of the wafer is greater than the flow field intensity at the outer edge of the wafer and between the wafer and the cleaning chamber. The flow field intensity at the outer edge of the wafer and between the wafer and the cleaning chamber is also greater than the flow field intensity at the center of the wafer. This forms a gradient intensity flow field, promoting the concentrated flow field distribution and enhanced effect of the stepped process at the outer edge of the wafer, and preventing particles from remaining at the edge of the wafer.

[0022] S2. Perform differentiated heat flow distribution on the wafer. Use a pure air blowing unit to deliver hot air to the upper surface of the wafer to increase the airflow speed, and keep the center of the bottom of the wafer at room temperature. Increase the temperature at the edge of the wafer to concentrate the flow and processing capacity of the liquid at the outer edge of the wafer and promote stepped strong convection.

[0023] S3. Control the surface temperature of the wafer in three dimensions, and heat the upper surface of the wafer, the lower surface of the wafer, and the edge area of ​​the wafer through comprehensive wafer contact and heated air flow in the atmosphere. During the etching process of the wafer, the chemical liquid jet is concentrated on the surface of the wafer. Therefore, the particle control and flow field distribution during the spraying process of the wafer need to enhance the stage-by-stage control of the flow field in the center area of ​​the wafer. In this embodiment, the crystallization of the chemical liquid on the surface and edge area of ​​the wafer can be effectively avoided by performing distributed stage-by-stage control on the wafer surface, differential heat flow distribution control, and three-dimensional surface temperature control. The basic conditions for crystallization can be destroyed by hot air according to different stacking crystallization positions.

[0024] Furthermore, as a preferred embodiment, staggered, non-contact air dynamic components that output hot air flow heat the wafer edge region, ensuring a temperature range within the wafer edge region. In this embodiment, the non-contact air dynamic components are located on the upper and lower surfaces of the wafer edge region to control the temperature of the upper and lower surfaces of the wafer edge region, preventing crystallization at the edge and improving the cleaning effect at the edge.

[0025] Furthermore, as a preferred embodiment, a hot air flow jet is arranged at the center position of the wafer supporting platform on the lower surface of the wafer, and a ring-shaped inclined angle jet hole is arranged at a relative position of 3 / 4 relative to the inner diameter area of ​​the wafer on the corresponding wafer supporting platform. This can correspond to the overall heating of the lower surface of the wafer and enhance the accumulation and convection of hot air in the outer edge area.

[0026] Furthermore, as a preferred embodiment, a wafer spray device capable of two-stage simple harmonic movement is arranged at the edge of the wafer, and a heating device is arranged on the wafer spray device to ensure that the outer edge of the wafer and the area adjacent to the outer edge of the wafer are heated and maintained, so that the edge line of instantaneous contact with the outer edge area of ​​the wafer can concentrate and maintain the temperature.

[0027] Furthermore, as a preferred embodiment, the wafer spraying device is arranged at an angle.

[0028] Furthermore, as a preferred embodiment, the cleaning chamber is divided into three independent layers from top to bottom, each of which is equipped with an exhaust device, and a lifting mechanism is installed at the bottom of the wafer support platform. In this embodiment, the lifting mechanism can drive the wafer support platform to move the wafer up and down within the cleaning chamber, and in conjunction with the rotation of the wafer itself, different cleaning solutions are introduced into different layers. The staggered atmosphere isolation between the layers and the exhaust dispersion of the exhaust device maintain the separate diversion of different chemical solutions and atmospheres, which can effectively avoid the crystallization problems of some highly dangerous acids that are prone to crystallization due to temperature differences and viscosity properties, such as nitric acid, sulfuric acid, phosphoric acid, and other chemicals.

[0029] The above description is only a preferred embodiment of the present invention and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preventing crystallization during a high-temperature chemical etching reaction spray process, characterized in that: include: S1. Performing distributed phased control of the wafer, placing the wafer on a wafer carrying platform in a cleaning chamber, and performing differential optimization at three different positions: the center of the wafer, the outer edge of the wafer, and the distance between the wafer and the cleaning chamber, to generate exhaust distributions of different intensities to form a gradient intensity flow field; S2. Performing differentiated heat flow distribution on the wafers, delivering hot air to the upper surface of the wafers through a pure air blowing unit to increase airflow speed, maintaining the center of the bottom of the wafer at room temperature, and increasing the temperature of the edge of the wafer to concentrate the flow and processing capacity of the liquid at the outer edge of the wafer and promote step-by-step strong convection flow; S3, performing three-dimensional surface temperature control of the wafer, heating the upper surface of the wafer, the lower surface of the wafer, and the edge area of ​​the wafer through comprehensive wafer contact with the heated air flow of the atmosphere; A hot air flow jet is arranged at the center of the wafer carrying platform on the lower surface of the wafer, and a ring-shaped inclined angle jet hole is arranged at a relative position of the wafer carrying platform relative to the 3 / 4 inner diameter area of ​​the wafer.

2. The method for preventing crystallization during high temperature chemical etching reaction spraying according to claim 1, wherein: The edge area of ​​the wafer is heated by a staggered non-contact aerodynamic component capable of outputting hot air flow, thereby ensuring the temperature range of the edge area of ​​the wafer.

3. The method for preventing crystallization during high temperature chemical etching reaction spraying according to claim 1, wherein: A wafer spray device capable of two-stage simple harmonic movement is arranged at the edge of the wafer, and a heating device is arranged on the wafer spray device to ensure that the outer edge of the wafer and the area adjacent to the outer edge of the wafer are heated and maintained, so that the edge line of the instantaneous contact area of ​​the outer edge of the wafer can concentrate and maintain the temperature.

4. The method for preventing crystallization during high temperature chemical etching reaction spraying according to claim 3, wherein: The wafer spraying device is arranged tilted.

5. The method for preventing crystallization during high temperature chemical etching reaction spraying according to claim 1, wherein: The cleaning chamber is divided into three independent layer chambers from top to bottom, each layer chamber is provided with an exhaust device, and the bottom of the wafer carrying platform is provided with a lifting mechanism.

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