Vacuum deposition with a shadow mask has been widely used for preparing patterned organic films. We found that, during vacuum deposition of organic molecules with a shadow mask, a small amount of organic molecule was also deposited on the mask-shielded surface. This phenomenon was revealed by selective Mg-vapor deposition using photochromic diarylethenes (DAEs). With this selective Mg deposition, no Mg is deposited on the DAE surface in a colorless state with a low T_g near room temperature, even if the DAE film thickness is at a several-nm level. On the other hand, since Mg is deposited on the colored surface obtained by UV irradiation, the presence or absence of low-T_g organic film with a thickness of several-nm level can be determined by the Mg-deposition property. The Mg nondeposition areas of a mask-shielded region depended on the vacuum level, the space between a substrate and a shadow mask, and the DAE deposition quantity; a lower vacuum level (higher pressures), a thicker space, and a larger deposition quantity resulted in a larger Mg nondeposition area. Vacuum deposition in the high vacuum level (10⁻⁴–10⁻³ Pa) with a substrate-shadow-mask space distance of 60 μm led to an Mg nondeposition width over 100 μm from the mask-shielded edge. These results indicate that the origin is in molecular scattering by a residual gas in a vacuum chamber. When minute organic patterns are prepared using shadow masks, which are effective for obtaining satisfactory performances of organic electronics devices, the influence of small amount of deposition under mask-shielded areas should be taken into account.

中文翻译：

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通过选择性镁气相沉积揭示掩模屏蔽区域中的分子沉积

带阴影掩模的真空沉积已广泛用于制备图案化有机薄膜。我们发现，在用荫罩真空沉积有机分子的过程中，少量有机分子也沉积在荫罩屏蔽的表面上。这种现象是通过使用光致变色二芳基乙烯 (DAE) 的选择性 Mg 蒸气沉积来揭示的。与此选择性沉积的Mg，不含Mg沉积在DAE表面上无色状态具有低Ť_克室温附近，即使DAE膜厚处于几个纳米级别。另一方面，由于 Mg 沉积在通过紫外线照射获得的有色表面上，因此低T _g的存在与否几纳米级厚度的有机薄膜可以通过镁的沉积特性来确定。掩模遮蔽区域的Mg未沉积面积取决于真空度、基板与荫罩之间的空间以及DAE沉积量；较低的真空度（较高的压力）、较厚的空间和较大的沉积量导致较大的 Mg 非沉积区域。在高真空水平 (10 ^-4 –10 ^-3  Pa) 下真空沉积，基板-阴影-掩模空间距离为 60  μ m，导致 Mg 非沉积宽度超过 100  μm 从掩模屏蔽边缘。这些结果表明，起源于真空室中残留气体的分子散射。当使用荫罩制备微小的有机图案时，这对于获得令人满意的有机电子器件性能是有效的，应考虑掩膜屏蔽区域下少量沉积的影响。