The connection between hydrodynamic stability of gas flow in spin coating and coated film uniformity
The connection between hydrodynamic stability of gas flow in spin coating and coated film uniformity
复制标题
旋涂中气流的流体动力学稳定性与涂膜均匀性的关系
DOI：
10.1063/1.358751
复制
发表时间：
1995
影响因子：
3.2
通讯作者：
P. Seidel
中科院分区：
文献类型：
--
作者：
A. Oztekin;D. E. Bornside;Robert A. Brown;P. Seidel
旋涂薄膜的厚度均匀性取决于通过旋涂机的气流，特别是旋转晶片表面上方的边界层流，它控制着干膜中溶剂的蒸发。激光多普勒测速仪（LDV）和热线风速仪（HWA）被用来映射整个工业旋涂机的流场，并研究在边界层中的流动不稳定性的各种组合的晶片旋转速度和排气流量。通过LDV测量的流场与整个涂层碗的层流、轴对称和稳定气流的数值模拟进行了比较。然而，Ekman螺旋流动不稳定性的类型I（正螺旋角）和类型II（负螺旋角）被发现HWA在旋转晶片的表面附近的边界层。II型螺旋在2000-2500范围内的雷诺数下形成，I型螺旋在80 000-85 000范围内的雷诺数下形成。这是第二型螺旋是负责d.
The thickness uniformity of a spin‐cast film is governed by the air flow through the spin coater, particularly the boundary layer flow above the surface of the spinning wafer, which controls solvent evaporation from the dry film. Laser Doppler velocimetry (LDV) and hot wire anemometry (HWA) are used to map the flow field throughout an industrial spin coater and to study flow instabilities in the boundary layer for various combinations of wafer spin speed and exhaust flow rate. The flow field measured by LDV compares well with a numerical simulation of laminar, axisymmetric, and steady air flow throughout the coating bowl. However, Ekman spiral flow instabilities of both type I (positive spiral angle) and type II (negative spiral angle) were found by HWA in the boundary layer near the surface of the spinning wafer. The type‐II spirals form at Reynolds number in the range 2000–2500 and the type‐I spirals form at Reynolds number in the range 80 000–85 000. It is the type‐II spirals that are responsible for d...