Effects of disk edge profile on scattering characteristics of liquid droplets splashed from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and purified water...Effects of disk edge profile on scattering characteristics of liquid droplets splashed from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and purified water is employed for liquid. Scattering phenomena of the droplets are captured by the high-speed digital camera. Distribution of the droplet diameter is evaluated from these images and distributions of horizontal flying velocity component and angle of the droplets are measured by human visual observation of images. Liquid filaments are stretched outward from the stagnant liquid layer on lateral surface of disk edge by centrifugal force. Two main peaks appear in the distribution of the scattered droplet diameter and they are originated from large terminal droplets and small droplets generated from filamentwise breakup. Most of the scattered droplets fly slightly inside of the tangential direction of the disk edge. The water droplets splashed from the disk scatters with regularity compared with ethanol droplets.展开更多
Scattering characteristics of liquid droplets spun off from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and ethanol is employed for liquid. Scattering phe...Scattering characteristics of liquid droplets spun off from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and ethanol is employed for liquid. Scattering phenomena of the droplets are captured by the high-speed digital camera. Frequency distribution of the droplet diameter is evaluated from these images and distributions of horizontal flying velocity and angle of the droplets were measured by PTV. Liquid filaments are stretched outward from the stagnant liquid layer by centrifugal force and skew complicatedly by aerodynamic force. Some peaks appear in the distribution of the scattered droplet diameter and they are origi- nated from large terminal droplets and small droplets generated from filamentwise breakup. Most of the scattered droplets fly slightly inside in the tangential direction of the disk edge. The droplets spun off from the thin disk scatter widely compared with that from the thick one.展开更多
Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor become more sophisticated. Spin coating is usually use...Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped resist scatters outward and reattaches to the film surface. So, the scattered resist is removed by the exhaust flow generated at the gap between the wafer edge and the catch cup. It is seriously concerned that the stripes called Ekman spiral vortices appears on the disk in the case of high rotating speed and the film thickness increases near the wafer edge in the case of low rotating speed, because it prevent the formation of uniform film. The purpose of this study is to make clear the generation mechanism of Ekman spiral vortices and the influence of exhaust flow on it Moreover the influence of the catch cup geometry on the wafer surface boundary layer flow is investigated.展开更多
Recently,development of high technology has been required for the formation of uniform thin film in manufacturing processes of semiconductor as the precision instruments become more sophisticated.A method called spin ...Recently,development of high technology has been required for the formation of uniform thin film in manufacturing processes of semiconductor as the precision instruments become more sophisticated.A method called spin coating is often used for spreading photoresist on a wafer surface and drying photoresist film.In spin coating process,photoresist is uniformly spread on the wafer surface by centrifugal force caused by rotating wafer.However,it is a serious concern that streaky lines,which are caused by spiral vortices,appear on the wafer surface and prevent the formation of uniform film in the case of high rotating speed.On the other hand,in the case of low rotating speed,a small hump of the film is formed near the wafer edge.The main purpose of this study is to make clear the drying characteristics of the flowing liquid film on the rotating wafer.Temperature distribution of the flowing liquid film is captured by an infrared thermal video camera and radial gradient of the film temperature is introduced in order to evaluate the drying characteristic of the flowing film under steady state condition.Effects of the flow rate of the liquid film on the film temperature are investigated.The film temperature gradually decreases in the radial direction in all cases.At low rotating speed,the radial gradient of the film temperature is almost constant widely.On the other hand,at high rotating speed,the radial gradient of the film temperature takes a certain maximum value.It is found that the location of the gradient peak corresponds with the transition region of the air boundary layer,in which spiral vortices swirl,and shifts to the inner side of the disk with an increase of the liquid flow rate.展开更多
Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is...Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film.展开更多
文摘Effects of disk edge profile on scattering characteristics of liquid droplets splashed from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and purified water is employed for liquid. Scattering phenomena of the droplets are captured by the high-speed digital camera. Distribution of the droplet diameter is evaluated from these images and distributions of horizontal flying velocity component and angle of the droplets are measured by human visual observation of images. Liquid filaments are stretched outward from the stagnant liquid layer on lateral surface of disk edge by centrifugal force. Two main peaks appear in the distribution of the scattered droplet diameter and they are originated from large terminal droplets and small droplets generated from filamentwise breakup. Most of the scattered droplets fly slightly inside of the tangential direction of the disk edge. The water droplets splashed from the disk scatters with regularity compared with ethanol droplets.
文摘Scattering characteristics of liquid droplets spun off from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and ethanol is employed for liquid. Scattering phenomena of the droplets are captured by the high-speed digital camera. Frequency distribution of the droplet diameter is evaluated from these images and distributions of horizontal flying velocity and angle of the droplets were measured by PTV. Liquid filaments are stretched outward from the stagnant liquid layer by centrifugal force and skew complicatedly by aerodynamic force. Some peaks appear in the distribution of the scattered droplet diameter and they are origi- nated from large terminal droplets and small droplets generated from filamentwise breakup. Most of the scattered droplets fly slightly inside in the tangential direction of the disk edge. The droplets spun off from the thin disk scatter widely compared with that from the thick one.
文摘Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped resist scatters outward and reattaches to the film surface. So, the scattered resist is removed by the exhaust flow generated at the gap between the wafer edge and the catch cup. It is seriously concerned that the stripes called Ekman spiral vortices appears on the disk in the case of high rotating speed and the film thickness increases near the wafer edge in the case of low rotating speed, because it prevent the formation of uniform film. The purpose of this study is to make clear the generation mechanism of Ekman spiral vortices and the influence of exhaust flow on it Moreover the influence of the catch cup geometry on the wafer surface boundary layer flow is investigated.
文摘Recently,development of high technology has been required for the formation of uniform thin film in manufacturing processes of semiconductor as the precision instruments become more sophisticated.A method called spin coating is often used for spreading photoresist on a wafer surface and drying photoresist film.In spin coating process,photoresist is uniformly spread on the wafer surface by centrifugal force caused by rotating wafer.However,it is a serious concern that streaky lines,which are caused by spiral vortices,appear on the wafer surface and prevent the formation of uniform film in the case of high rotating speed.On the other hand,in the case of low rotating speed,a small hump of the film is formed near the wafer edge.The main purpose of this study is to make clear the drying characteristics of the flowing liquid film on the rotating wafer.Temperature distribution of the flowing liquid film is captured by an infrared thermal video camera and radial gradient of the film temperature is introduced in order to evaluate the drying characteristic of the flowing film under steady state condition.Effects of the flow rate of the liquid film on the film temperature are investigated.The film temperature gradually decreases in the radial direction in all cases.At low rotating speed,the radial gradient of the film temperature is almost constant widely.On the other hand,at high rotating speed,the radial gradient of the film temperature takes a certain maximum value.It is found that the location of the gradient peak corresponds with the transition region of the air boundary layer,in which spiral vortices swirl,and shifts to the inner side of the disk with an increase of the liquid flow rate.
基金the 21~(st)Century COE program of Pulse Power Science of Kumamoto University
文摘Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film.
